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Yutaka Watanabe

Section

Graduate School of Engineering

Job title

Professor

Degree

工学博士（東北大学）

researchmap

https://researchmap.jp/read0180271

J-GLOBAL ID

200901014089929686

Research History 5

1997/04 - Present

東北大学助教授（工学研究科）大学院重点化による配置換
1996/06 - 1997/03

東北大学助教授（工学部）
1993/05 - 1996/05

東北大学講師（工学部）
1992/06 - 1994/03

Visiting Scientist & Postdoctoral Fellow, Massachusetts Institute of Technology
1991/04 - 1993/04

日本学術振興会特別研究員（PD）

Education 2

Tohoku University　Graduate School, Division of Engineering　機械工学第2専攻

- 1991/03/28
Tohoku University　Faculty of Engineering　機械工学第2

- 1985/03/26

Committee Memberships 54

腐食防食協会　理事

2010/02 - Present
腐食防食協会　理事

2010/02 - Present
日本原子力学会標準委員会発電炉専門委員会PLM分科会　委員

2007/07 - Present
日本原子力学会標準委員会発電炉専門委員会PLM分科会　委員

2007/07 - Present
腐食防食協会　評議員

2006/02 - Present
腐食防食協会　評議員

2006/02 - Present
CORROSION2006 Corrosion in Supercritical Systems Symposium　Vice Chair

2005/03 - Present
CORROSION2006 Corrosion in Supercritical Systems Symposium　Vice Chair

2005/03 - Present
2006 Asian Pacific Conference for Fracture and Strength　Scientific Committee Member

2005/01 - Present
2006 Asian Pacific Conference for Fracture and Strength　Session Developer

2005/01 - Present
2006 Asian Pacific Conference for Fracture and Strength　Scientific Committee Member

2005/01 - Present
2006 Asian Pacific Conference for Fracture and Strength　Session Developer

2005/01 - Present
溶接学会　論文レビュアーボード

2004/10 - Present
溶接学会　論文レビュアーボード

2004/10 - Present
日本学術振興会化学プラントのリスクベース保全技術に関する先導的研究開発委員会　幹事

2004/04 - Present
（独）原子力安全基盤機構革新的技術基盤調査研究検討会　委員

2004/04 - Present
日本学術振興会化学プラントのリスクベース保全技術に関する先導的研究開発委員会　幹事

2004/04 - Present
（独）原子力安全基盤機構革新的技術基盤調査研究検討会　委員

2004/04 - Present
Eighth International Symposium on Hydrothermal Reactions and Seventh International Conference on Solvothermal Reactions　Organizing Committee Member

2006/01 - 2006/08
Eighth International Symposium on Hydrothermal Reactions and Seventh International Conference on Solvothermal Reactions　Organizing Committee Member

2006/01 - 2006/08
International Symposium on High-temperature Oxidation and Corrosion 2005　Executive Committee Member

2005/03 - 2005/11
International Symposium on High-temperature Oxidation and Corrosion 2005　Executive Committee Member

2005/03 - 2005/11
日本学術会議第49回材料研究連合講演会　実行委員

2005/04 - 2005/09
日本学術会議第49回材料研究連合講演会　実行委員

2005/04 - 2005/09
日本材料学会第54期通常総会・学術講演会実行委員会　幹事

2004/10 - 2005/05
日本材料学会第54期通常総会・学術講演会実行委員会　幹事

2004/10 - 2005/05
日本材料学会第53期編集委員会　査読委員

2004/06 - 2005/04
日本材料学会第53期編集委員会　査読委員

2004/06 - 2005/04
(財)エンジニアリング振興協会「RBM汎用化開発委員会」　委員

2004/06 - 2005/03
(財)エンジニアリング振興協会「RBM汎用化開発委員会」　委員

2004/06 - 2005/03
日本機械学会論文集出版部会　校閲委員（第82期）

2004/04 - 2005/03
日本機械学会論文集出版部会　校閲委員（第82期）

2004/04 - 2005/03
（財）化学技術戦略推進機構超臨界流体利用環境負荷低減技術研究開発プロジェクト総合調査研究委員会　委員

2003/04 - 2005/03
（財）化学技術戦略推進機構超臨界流体利用環境負荷低減技術研究開発プロジェクト総合調査研究委員会　委員

2003/04 - 2005/03
Asian Pacific Conference for Fracture and Strength ’04　Steering Committee Member and Secretary

2004/01 - 2004/12
Asian Pacific Conference for Fracture and Strength ’04　Steering Committee Member and Secretary

2004/01 - 2004/12
(財)エンジニアリング振興協会「RBM汎用化開発委員会」　委員

2003/07 - 2004/03
(財)エンジニアリング振興協会「RBM汎用化開発委員会」　委員

2003/07 - 2004/03
日本機械学会材料力学部門第６技術委員会　委員

2003/04 - 2004/03
日本機械学会材料力学部門第６技術委員会　委員

2003/04 - 2004/03
2nd International Conference on Physics and Chemistry of Fracture　Executive Committee Chairmen

2003/01 - 2003/12
2nd International Conference on Physics and Chemistry of Fracture　Executive Committee Chairmen

2003/01 - 2003/12
日本材料学会第51期編集委員会　査読委員

2002/05 - 2003/04
日本材料学会第51期編集委員会　査読委員

2002/05 - 2003/04
日本機械学会論文集出版部会　校閲委員（第80期）

2002/04 - 2003/03
日本機械学会論文集出版部会　校閲委員（第80期）

2002/04 - 2003/03
日本材料学会第50期編集委員会　査読委員

2001/05 - 2002/04
日本材料学会第50期編集委員会　査読委員

2001/05 - 2002/04
Asian Pacific Conference on Fracture and Strength ‘01 & International Conference on Advanced Technology in Experimental Mechanics ‘01　Organizing Committee Member

2000/05 - 2001/12
Asian Pacific Conference on Fracture and Strength ‘01 & International Conference on Advanced Technology in Experimental Mechanics ‘01　Organizing Committee Member

2000/05 - 2001/12
欠陥評価に関わる破壊力学評価手法の向上に関する研究委員会（フェーズ２）　中立委員

1999/06 - 2001/03
欠陥評価に関わる破壊力学評価手法の向上に関する研究委員会（フェーズ２）　中立委員

1999/06 - 2001/03
日本機械学会材料力学部門講演会　セッションオーガナイザー

2003/09 -
日本機械学会材料力学部門講演会　セッションオーガナイザー

2003/09 -

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Professional Memberships 7

日本鉄鋼協会
日本保全学会
日本材料学会
腐食防食協会
Atomic Energy Society of Japan
NACE
日本機械学会

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Research Interests 2

Environmental strength
保全工学

Research Areas 3

Energy / Nuclear engineering / Plant Life Management
Nanotechnology/Materials / Material fabrication and microstructure control / Corrosion Science and Protection
Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Machine materials and mechanics / Environmentally Assisted Cracking

Awards 7

功労賞

2024/08　日本保全学会
岡本剛記念講演賞

2022/05　公益社団法人腐食防食学会
腐食防食学会技術賞

2016/05　公益社団法人腐食防食学会　高温水中における応力腐食割れ発生試験方法の規格化ならびに規格改正
トーキン科学技術振興財団研究奨励賞

2000/03/02　（財）トーキン科学技術振興財団　構造用合金の腐食および応力腐食割れの制御
日本材料学会学術奨励賞(JSMS Award for Promising Researchers)

1997/05/22　日本材料学会(The Society of Materials Science, Japan)　構造材料の経年損傷の監視および非破壊評価に関する研究 (Monitoring and nondestructive evaluation of in-service degradation ofstructural materials)
第３６回原田研究奨励賞(Harada Award)

1996/11/01　（財）金属研究助成会(Kinzoku Kenkyu Foundation)　構造用合金の経年損傷の非破壊計測・評価に関する研究(Nondestructive evaluation of materials degradation in structural alloys)
日本機械学会賞研究奨励賞(JSME Award for Young Engineers (Research))

1995/04/01　日本機械学会(The Japan Society of Mechanical Engineers)　電気化学的手法による経年的材質劣化の非破壊評価に関する研究 (Nondestructive evaluation of in-service materials degradation by means ofelectrochemical method)

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Papers 169

Stress corrosion cracking of steels in liquid ammonia: A comprehensive literature review Peer-reviewed

Yanagimoto Fuminori, Shiotani Kazuhiko, Sakakibara Yohei, Watanabe Yutaka, Tada Eiji

120　89-100　2025/04/17
Diffusible hydrogen facilitated stress corrosion cracking in 316 stainless steel using in-situ gaseous hydrogen charging in simulated PWR environment Peer-reviewed

Zihao Wang, Houzhi Liu, Yutaka Watanabe, Tetsuo Shoji, Xiangyu Zhong, Zhengcao Li, Sergio Lozano-Perez

Scripta Materialia　255　116390-116390　2025/01
Publisher: Elsevier BV
DOI： 10.1016/j.scriptamat.2024.116390 　

ISSN： 1359-6462
Influences of (Al, Ca, Si, Nb, Mn)-oxy-sulfide inclusions on corrosion degradation for newly designed 17–4 martensitic PH steel in simulated geothermal environments Peer-reviewed

Pan Liu, Yasuaki Watanabe, Xiangyu Zhong, Jun Chai, Fahe Cao, Mitsuo Yamashita, Sakae Izumi, Yutaka Watanabe, Tetsuo Shoji

Corrosion Science　237　112279-112279　2024/08
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2024.112279 　

ISSN： 0010-938X
Impact of diffusible hydrogen on corrosion of Alloy 600 at 288 °C: An in-situ electrochemical study Peer-reviewed

Zihao Wang, Sergio Lozano-Perez, Yutaka Watanabe, Yoichi Takeda, Xiangyu Zhong, Zhengcao Li, Tetsuo Shoji

Corrosion Science　234　112150-112150　2024/07
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2024.112150 　

ISSN： 0010-938X
New insights into stress corrosion cracking mechanism of Alloy 600 in boiling water reactor (BWR) environment Peer-reviewed

Pan Liu, Yunlong Wu, Xiangyu Zhong, Ken Oyama, Seiya Ogota, Jun Chai, Yutaka Watanabe, Tetsuo Shoji

Corrosion Science　232　112008-112008　2024/05
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2024.112008 　

ISSN： 0010-938X
Quantitatively evaluating the contribution of intergranular carbides, Cr-depleted zone, and grain boundary to intergranular stress corrosion cracking of Alloy 600 in a simulated boiling water reactors environment with high oxygen concentrations Peer-reviewed

Pan Liu, Yunlong Wu, Xiangyu Zhong, Zihao Wang, Ken Oyama, Seiya Ogota, Yutaka Watanabe, Tetsuo Shoji

Acta Materialia　269　119794-119794　2024/05
Publisher: Elsevier BV
DOI： 10.1016/j.actamat.2024.119794 　

ISSN： 1359-6454
Amount of hydrogen absorbed into 316L austenitic stainless steel and its correlation with properties of oxide film, dissolved oxygen concentration and low-cycle fatigue behaviors of this material in borated and lithiated high temperature water Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama, Nicolas Mary, Shaoyun Zhou

Corrosion Science　209　110793-110793　2022/12
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2022.110793 　

ISSN： 0010-938X
A critical review of the recent advances in inclusion-triggered localized corrosion in steel Peer-reviewed

Pan Liu, Qin-Hao Zhang, Yutaka Watanabe, Tetsuo Shoji, Fa-He Cao

npj Materials Degradation　6　(1)　2022/09/26
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41529-022-00294-6 　

eISSN： 2397-2106

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Abstract Localized corrosion triggered by inclusions is prone to metallic material failure. Except for chemical dissolution of some special inclusions, the principle of galvanic coupling is the most acceptable theory to explain the above corrosion damage mechanism over the past decades. Still, controversies continue to present, in particular, mounting recent evidence obtained by advanced technologies emphasizes the limitations of previous entrenched idea and discloses unexpected results. Here, we review relevant recent studies and carefully summarize their similarities and differences to reduce the knowledge gap between inclusion-triggered localized corrosion and material design, whilst the source of typical inclusions is treated and discussed.
Low-cycle fatigue behaviors of 316L austenitic stainless steel in high temperature water: Effects of pre-soaking, dissolved oxygen, and boric acid & lithium hydroxide Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama, Xiangyu Zhong, Nicolas Mary

Nuclear Engineering and Technology　54　(9)　3215-3224　2022/09
Publisher: Elsevier BV
DOI： 10.1016/j.net.2022.04.003 　

ISSN： 1738-5733
Contribution of Cathodic Reaction inside Crevice on Propagation of Crevice Corrosion of 304L SS in Chloride Solution Peer-reviewed

Kazuki Yakata, Yuichi Fukaya, Yutaka Watanabe

17321-17321　2022/07
Influence of mechanical surface treatments on oxide properties formed on 304L stainless steel in simulated BWR and PWR primary water Peer-reviewed

Kathleen Jaffré, Hiroshi Abe, Benoît Ter-Ovanessian, Nicolas Mary, Bernard Normand, Yutaka Watanabe

Journal of Nuclear Materials　556　153258-153258　2021/12
Publisher: Elsevier BV
DOI： 10.1016/j.jnucmat.2021.153258 　

ISSN： 0022-3115
Corrosion-resistant metallic coating on silicon carbide for use in high-temperature water Peer-reviewed

Ryo Ishibashi, Kazushige Ishida, Takao Kondo, Yutaka Watanabe

Journal of Nuclear Materials　557　153214-153214　2021/12
Publisher: Elsevier BV
DOI： 10.1016/j.jnucmat.2021.153214 　

ISSN： 0022-3115
Low-cycle fatigue behaviors of 316L austenitic stainless steels with different surface finishing in simulated pressurized water reactor primary water and an oxygenated, borated, lithiated high temperature water Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama, Xiangyu Zhong, Nicolas Mary

Corrosion Science　190　109709-109709　2021/09
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2021.109709 　

ISSN： 0010-938X
Role of the Jet Angle, Particle Size, and Particle Concentration in the Degradation Behavior of Carbon Steel under Slow Slurry Erosion-Corrosion Conditions Peer-reviewed

Charles Rasse, Nicolas Mary, Hiroshi Abe, Yutaka Watanabe, Bernard Normand

Metals　11　(8)　1152-1152　2021/07/21
Publisher: MDPI AG
DOI： 10.3390/met11081152 　

eISSN： 2075-4701

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Erosion-corrosion behavior of piping systems is a critical issue for their durability. This work concerns the erosion-corrosion behavior of carbon steel as a function of abradant characteristics as particle size and concentration. Degradation tests were performed in a jet erosion-corrosion cell with a maximum flow rate of 4.8 m/s, and jet angles comprised 30° and 90°. Abradant particles consisted of angular alumina powder with a mean diameter of 181, 219, and 359 µm. A critical threshold flow velocity of about 2.5 m/s was determined when experiments were performed with particles with diameters of 181 µm and jet angles of 45°. Even if erosion did not occur, the degradation rate increased compared with the stagnant condition because of dissolved dioxygen supply. A maximum of erosion-corrosion of 4 mg × cm−2 × h−1 was determined for the jet angle of 45°, irrespective of the particle sizes. The increase of abradant concentration led to a higher degradation rate regardless of the jet angle. However, the degradation rates tended to limit values of 7 mg × cm−2 × h−1 at 45° and 5 mg × cm−2 × h−1 at 90°. Above a critical concentration, a slowdown of the degradation was measured, suggesting that particle behavior in dense fluid acts on material degradation. This critical concentration can be understood from the interactions of the particles in concentrated media that modify trajectories in the flow and at the metal surface, reducing their kinetic energy consequently.
Effect of Mechanical Surface Treatments on the Surface State and Passive Behavior of 304L Stainless Steel Peer-reviewed

Kathleen Jaffré, Benoît Ter-Ovanessian, Hiroshi Abe, Nicolas Mary, Bernard Normand, Yutaka Watanabe

Metals　11　(1)　135-135　2021/01/12
Publisher: MDPI AG
DOI： 10.3390/met11010135 　

eISSN： 2075-4701

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The effect of dry grinding on 304L stainless steel’s passive behavior is compared to two other surface finishing (mechanical polishing down to 2400 with SiC emery paper and 1 µm with diamond paste, respectively). The characterization of the surface state was performed using scanning electron microscopy, transmission electron microscopy, 3D optical profilometer, and X-ray diffraction. Results indicate that each surface treatment leads to different surface states. The ground specimens present an ultrafine grain layer and a strong plastic deformation underneath the surface, while an ultrafine grain layer characterizes the subsurface of the polished specimens. Grinding induces high residual compressive stresses and high roughness compared to polishing. The characterization of the passive films was performed by electrochemical impedance spectroscopy and Mott–Schottky analysis. The study shows that the semiconductor properties and the thickness of the passive films are dependent on the surface state of the 304L stainless steel.
Low-cycle fatigue behaviors of 316LN austenitic stainless steel in borated and lithiated high temperature water with different levels of dissolved oxygen Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama, Nicolas Mary, Xiangyu Zhong

Corrosion Science　176　109048-109048　2020/11
Publisher: Elsevier BV
DOI： 10.1016/j.corsci.2020.109048 　

ISSN： 0010-938X
Effects of 100 ppb dissolved oxygen on low-cycle fatigue behaviors of 316LN austenitic stainless steel in borated and lithiated high temperature water and mechanism behind these effects Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama, Nicolas Mary

Corrosion Science　168　108567　2020/05
Effects of dissolved hydrogen on low-cycle fatigue behaviors and hydrogen uptake of 316LN austenitic stainless steel in simulated pressurized water reactor primary water Peer-reviewed

Yida Xiong, Yutaka Watanabe, Yuki Shibayama

International Journal of Fatigue　134　105457　2020/05
Effects of Gamma Ray Irradiation on Corrosion of Carbon Steels at Water Line Peer-reviewed

Tomomichi Ariga, Hiroshi Abe, Yutaka Watanabe

Proceedings of 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　960-966　2019/08
Characteristics of Work Hardened Surface Layer on Austenitic Stainless Steels and Its Relation to SCC Susceptibility in High Temperature Water Peer-reviewed

Hiroshi Abe, Yutaka Watanabe, Takamichi Miyazaki

Proceedings of 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　165-173　2019/08
Effect of molybdate anion addition on repassivation of corroding crevice in austenitic stainless steel Peer-reviewed

Shun Watanabe, Tomohiro Sekiguchi, Hiroshi Abe, Yutaka Watanabe

Minerals, Metals and Materials Series　9　1157-1168　2018
Publisher: Springer International Publishing
DOI： 10.1007/978-3-319-67244-1_73 　

ISSN： 2367-1696 2367-1181
Oxidation kinetics of austenitic stainless steels as SCWR fuel cladding candidate materials in supercritical water Peer-reviewed

Hiroshi Abe, Ryuichi Suzuki, Yutaka Watanabe

Minerals, Metals and Materials Series　9　1181-1194　2018
Publisher: Springer International Publishing
DOI： 10.1007/978-3-319-67244-1_75 　

ISSN： 2367-1696 2367-1181
Characterization and prediction of carbon steel corrosion in diluted seawater containing pentaborate Peer-reviewed

Yuichi Fukaya, Yutaka Watanabe

Journal of Nuclear Materials　498　159-168　2018/01/01
Publisher: Elsevier B.V.
DOI： 10.1016/j.jnucmat.2017.10.032 　

ISSN： 0022-3115
Influence of activated carbon on crevice corrosion in adsorption tower of advanced liquid processing system (ALPS) Peer-reviewed

Yoshikazu Maeda, Hiroshi Abe, Yutaka Watanabe

Corrosion Engineering, Science and Technology　53　39-43　2018
Application of Potentiostatic Etching for Nondestructive Testing of Accumulated Plastic Strain in Austenitic Stainless Steels Peer-reviewed

Shota Hokari, Akiyoshi Suzuki, Yutaka Watanabe

MATERIALS EVALUATION　75　(11)　1399-1405　2017/11

ISSN： 0025-5327
定電位エッチングを用いたオーステナイト系ステンレス鋼の塑性ひずみ検出手法の現場計測適用性 Peer-reviewed

帆加利翔太, 山本康平, 渡邉豊

保全学　16　(2)　75-81　2017

DOI： 10.18944/jsm.16.2_75 　
炭素鋼配管エルボ部における表面性状とFAC減肉速度に関する一考察 Peer-reviewed

阿部博志, 矢野拓磨, 渡邉豊, 中嶋誠, 田附匡

日本機械学会論文集　83　(847)　2017

DOI： 10.1299/transjsme.16-00453 　
Characterization of the Corroded Surface Morphology of a Carbon Steel Piping Elbow Affected by Flow-Accelerated Corrosion Peer-reviewed

Hiroshi ABE, Yutaka WATANABE, Makoto NAKASHIMA, Tadashi TATSUKI

E-Journal of Advanced Maintenance　9　(1)　26-32　2017
Nondestructive Potentiostatic Etching Technique for the Detection and Quantification of Preexisting Plastic Strain in Austenitic Stainless Steel Peer-reviewed

Shota Hokari, Akiyoshi Suzuki, Yutaka Watanabe

MATERIALS EVALUATION　74　(9)　1287-1295　2016/09

ISSN： 0025-5327
Critical Potentials for Re-Passivation of Corroding Crevice in Corrosion Resistant Alloys Peer-reviewed

Yutaka Watanabe, Hiroshi Abe, Tomohiro Sekiguchi

Proceedings of 20th International Conference on Water Chemistry of Nuclear Reactor Systems　Paper No.58　2016
Influence of Activated Carbon on Crevice Corrosion in Adsorption Tower of Advanced Liquid Processing System (ALPS)

Yoshikazu Maeda, Hiroshi Abe, Yutaka Watanabe

Proceedings of 17th Asian Pacific Corrosion Control Conference　2016/01
Corrosion kinetics of type 310 EHP stainless steel in nitric acid with Cr(VI) Peer-reviewed

Tetsunari Ebina, Shigeru Yamazaki, Yutaka Watanabe

Zairyo to Kankyo/ Corrosion Engineering　65　(7)　302-306　2016
Publisher: Japan Society of Corrosion Engineering
DOI： 10.3323/jcorr.65.302 　

ISSN： 1881-9664 0917-0480
Effect of Chromium Content on the Oxidation Behavior of Ni-Cr Model Alloys in Superheated Steam Peer-reviewed

Fethi Hamdani, Hiroshi Abe, Benoit Ter-Ovanessian, Bernard Normand, Yutaka Watanabe

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE　46A　(5)　2285-2293　2015/05

DOI： 10.1007/s11661-015-2786-7 　

ISSN： 1073-5623

eISSN： 1543-1940
Effects of phosphorus segregation on stress corrosion cracking in the heat-affected zone of a dissimilar weld joint between a Ni-base alloy and a low alloy steel Peer-reviewed

Ziqing Zhai, Hiroshi Abe, Yuichi Miyahara, Yutaka Watanabe

CORROSION SCIENCE　92　32-42　2015/03

DOI： 10.1016/j.corsci.2014.10.037 　

ISSN： 0010-938X

eISSN： 1879-0496
Determining the repassivation potential for crevice corrosion of 316L stainless steels and alloy 600 in chloride-containing environment Peer-reviewed

Hiroki Iwakane, Tomohiro Sekiguchi, Hiroshi Abe, Yutaka Watanabe

Proceedings of 17th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　in press　2015
Characterization of oxide film formed in flow accelerated corrosion of carbon steels and its relationship to thining rate Peer-reviewed

Hiroshi Abe, Takuma Yano, Takamichi Miyazaki, Yutaka Watanabe, Kazutoshi Fujiwara, Kimitoshi Yoneda, Fumio Inada

Proceedings of 17th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　in press　2015
Effects of Thermal History and Microstructure on Segregation of Phosphorus and Alloying Elements in the Heat-Affected Zone of a Low Alloy Steel Peer-reviewed

Ziqing Zhai, Yuichi Miyahara, Hiroshi Abe, Yutaka Watanabe

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE　45A　(13)　6163-6172　2014/12

DOI： 10.1007/s11661-014-2582-9 　

ISSN： 1073-5623

eISSN： 1543-1940
Oxidation behavior of austenitic stainless steels as fuel cladding candidate materials for SCWR in superheated steam Peer-reviewed

Hiroshi Abe, Seung Mo Hong, Yutaka Watanabe

NUCLEAR ENGINEERING AND DESIGN　280　652-660　2014/12

DOI： 10.1016/j.nucengdes.2014.08.020 　

ISSN： 0029-5493
Segregation behavior of phosphorus in the heat-affected zone of an A533B/A182 dissimilar weld joint before and after simulated thermal aging Peer-reviewed

Ziqing Zhai, Yuichi Miyahara, Hiroshi Abe, Yutaka Watanabe

JOURNAL OF NUCLEAR MATERIALS　452　(1-3)　133-140　2014/09

DOI： 10.1016/j.jnucmat.2014.05.005 　

ISSN： 0022-3115

eISSN： 1873-4820
Materials Peer-reviewed

Yutaka Watanabe, Hiroshi Abe, Yoshiaki Oka

Supercritical-Pressure Light Water Cooled Reactors　9784431550259　321-345　2014/05/01
Publisher: Springer Japan
DOI： 10.1007/978-4-431-55025-9_4 　
HIGH-TEMPERATURE STEAM OXIDATION KINETICS AND MECHANISM OF SCWR FUEL CLADDING CANDIDATE MATERIALS Peer-reviewed

Hiroshi Abe, Seung Mo Hong, Yutaka Watanabe

PROCEEDINGS OF THE 21ST INTERNATIONAL CONFERENCE ON NUCLEAR ENGINEERING - 2013, VOL 1　Paper No. 16432　2014

DOI： 10.1115/ICONE21-16432 　
STATE OF THE ART STUDY FOR THE BASIS OF PIPE WALL THINNING MANAGEMENT IN JAPAN Peer-reviewed

Fumio Nada, Yutaka Watanabe, Taku Ohira, Akira Nakamura

PROCEEDINGS OF THE 21ST INTERNATIONAL CONFERENCE ON NUCLEAR ENGINEERING - 2013, VOL 1　Paper No. 15184　2014

DOI： 10.1115/ICONE21-15184 　
DEVELOPMENT OF A RESIDUAL STRESS EVALUATION TECHNIQUE BY THE COMBINED USE OF SURFACE STRAIN MEASUREMENTS UNDER THE SPHERICAL INDENTATION METHOD Peer-reviewed

Norihiko Ozawa, Tomoaki Yoshizawa, Yutaka Watanabe, Tetsuo Shoji

PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE - 2013, VOL 5　Paper No. PVP2013-97818　2014
MECHANISTIC STUDY OF FAC PROCESSES FOCUSED ON THE OXIDE LAYER PROPERTIES Peer-reviewed

Hiroshi Abe, Yutaka Watanabe

PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE - 2013, VOL 6B: MATERIALS AND FABRICATION　Paper No. PVP2013-98066　2014
Development of a Suppression Method for Deposition of Radioactive Cobalt After Chemical Decontamination: Application of a Ferrite Film Formation Process to an Actual BWR Plant Peer-reviewed

Hideyuki Hosokawa, Makoto Nagase, Motomasa Fuse, Yutaka Watanabe

NUCLEAR SCIENCE AND ENGINEERING　175　(2)　135-148　2013/10

DOI： 10.13182/NSE12-80 　

ISSN： 0029-5639
Effects of Microstructure on Stress Corrosion Cracking in Heat Affected Zone of Alloy 182-A533B Dissimilar Weld Joint Under BWR Conditions Peer-reviewed

Ziqing Zhai, Hiroshi Abe, Yutaka Watanabe

Proceedings of 16th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　CD-ROM　2013
Oxidation Behavior of Austenitic Stainless Steels in Supercritical Water Peer-reviewed

Hiroshi Abe, Ryuichi Suzuki, SeungMo Hong, Yutaka Watanabe

Proceedings of 16th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors　CD-ROM　2013
Progress of Super Fast Reactor Phase 2 Project and Studies of Waseda University

Y. Oka, S. Morooka, M. Yamakawa, Y. Ishiwatari, Y. Katsumura, Hideo Mori, Yoshinori Hamamoto, T. Kugo, K. Takase, K. Ezato, T. Misawa, Y. Watanabe, H. Abe, K. Sue

Proceedings of the 6th International Symposium on Supercritical-Water-Cooled Reactors　ISSCWR6-13035　2013
Development of a residual stress evaluation technique based on surface strain measurements in indentation process of spherical indenter Peer-reviewed

Norihiko Ozawa, Tomoaki Yoshizawa, Yutaka Watanabe, Tetsuo Shoji

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　79　(807)　1571-1580　2013
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.79.1571 　

ISSN： 0387-5008
Establishing the evaluation technique of the biaxial residual stress determined with the surface strain measurement under the spherical indentation Peer-reviewed

Norihiko Ozawa, Tomoaki Yoshizawa, Tetsuo Shoji, Yutaka Watanabe

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　79　(801)　546-554　2013

DOI： 10.1299/kikaia.79.546 　

ISSN： 0387-5008
The influence of the substrate physical properties, determined with the technique for the residual stress evaluation based on the surface strain measurement induced by the spherical indentation Peer-reviewed

Norihiko Ozawa, Yoshihiro Toyama, Yutaka Watanabe, Tetsuo Shoji

Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A　79　(803)　1000-1008　2013

DOI： 10.1299/kikaia.79.1000 　

ISSN： 0387-5008
Electrochemical Evaluation of Radiation-Induced Segregation in Austenitic Stainless Steels with Oversize Solute Addition Peer-reviewed

Parag M. Ahmedabadi, V. Kain, M. Gupta, I. Samajdar, S. Sharma, P. Bhagwat, Y. Watanabe

JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE　21　(11)　2472-2479　2012/11

DOI： 10.1007/s11665-012-0201-8 　

ISSN： 1059-9495
Role of delta-ferrite in stress corrosion cracking retardation near fusion boundary of 316NG welds Peer-reviewed

Hiroshi Abe, Yutaka Watanabe

JOURNAL OF NUCLEAR MATERIALS　424　(1-3)　57-61　2012/05

DOI： 10.1016/j.jnucmat.2012.02.006 　

ISSN： 0022-3115
Iodine-Induced Stress Corrosion Cracking of Zircaloy-4: Identification of Critical Parameters Involved in Intergranular to Transgranular Crack Propagation Peer-reviewed

Virginie Francon, Marion Fregonese, Hiroshi Abe, Yutaka Watanabe

ENVIRONMENTAL DEGRADATION OF ENGINEERING & MATERIALS ENGINEERING AND TECHNOLOGIES　183　49-+　2012

DOI： 10.4028/www.scientific.net/SSP.183.49 　

ISSN： 1012-0394
製塩設備模擬環境におけるオーステナイト系耐食合金の応力腐食割れ感受性評価 Peer-reviewed

津川貴臣, 渡辺豊, 阿部博志

日本海水学会誌　65　(2)　88-96　2011/05
Publisher: The Society of Sea Water Science, Japan
DOI： 10.11457/swsj.65.88 　

ISSN： 0369-4550

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Constant strain SCC tests have been performed on five kinds of austenitic alloys, SUS316L, YUS270, NAS254N, NAS354N, and C-22, in simulated salt production environments. From the results of the SCC tests, susceptible conditions to SCC for each alloy. were clarified SUS316L and YUS270 were susceptible to SCC, but NAS254N, NAS354N, and C-22 were not susceptible in the salt production environments. Cold rolling increased SCC susceptibility for SUS316L and YUS270. And there was no potent influence on SCC resistance by a change in atmosphere, judging from the SCC test results under conditions of bubbling O₂ and N₂ gas only in bittern. The material selection guideline for salt production plants has been determined based on both the test results and reported SCC experiences in actual plants. The material selection guideline for the salt production environmentsis as follows; · It is possible to apply SUS316L to the condensation process. · It is reasonable to apply super stainless steel of over 40 in PRE to low density crystallization process. · If it is necessary to avoid all local corrosion in high density crystallization processes and later, super stainless steel of over 50 in PRE or Ni-base alloys should be applied. (Pitting Resistance Equivalent: PRE = Cr + 3.3Mo + 20N)
DEVELOPMENT OF μ-PIXE/RBS/SEM SYSTEM FOR CORROSION LAYER ANALYSIS OF STEEL Peer-reviewed

S. MATSUYAMA, K. ISHII, M. FUJIWARA, Y. KIKUCHI, H. SUGAI, K. FUJIKI, Y. HATORI, N. HAMADA, Y. ITO, S. HIRAISHI, Y. MIURA, A. FUKAYA, S. TANNO, H. ABE, Y. WATANABE, H. YAMAZAKI

International journal of PIXE　vol.21　(Nos.3&4)　87-93　2011
STRESS CORROSION CRACKING BEHAVIOR NEAR THE FUSION BOUNDARY OF DISSIMILAR WELD JOINT WITH ALLOY 182-A533B LOW ALLOY STEEL Peer-reviewed

Hiroshi Abe, Makoto Ishizawa, Yutaka Watanabe

15TH INTERNATIONAL CONFERENCE ON ENVIRONMENTAL DEGRADATION OF MATERIALS IN NUCLEAR POWER SYSTEMS-WATER REACTORS　CD-ROM　791-802　2011
Development of sulfuric acid transfer pump for thermochemical water-splitting IS process Peer-reviewed

Jin Iwatsuki, Yutaka Watanabe, Atsuhiko Terada, Kaoru Onuki

Kagaku Kogaku Ronbunshu　37　(5)　441-446　2011

DOI： 10.1252/kakoronbunshu.37.441 　

ISSN： 0386-216X 1349-9203
Effects of solidification mode and low-temperature aging on SCC behavior Peer-reviewed

Hiroshi Abe, Yutaka Watanabe, Takamichi Miyazaki

Proceedings of 19th International Conference on Nuclear Engineering　CD-ROM　2011
Understanding Key Parameters in Flow Accelerated Corrosion for Advanced Wall Thinning Prediction Peer-reviewed

Hiroshi Abe, Shinji Ebara, Nobuyuki Fujisawa, Hidetoshi Hashizume, Kiwamu Sue, Yutaka Watanabe, Takayuki Yamagata

Proceedings of International Symposium on the Ageing Management and Maintenance of Nuclear Power Plants (ISaG2010)　38-46　2010/05
Oxidation Behavior and Cracking Susceptibility of Ni-Cr Alloys in Dry Steam and Inert Gas under Extremely-Low Oxygen Partial Pressure Peer-reviewed

Hiroshi ABE, Yasuhiro KENMOKU, Takayuki ENDO, Takamichi MIYAZAKI, Yutaka WATANABE

Journal of Solid Mechanics and Materials Engineering　4　(7)　891-897　2010/04
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jmmp.4.891 　

ISSN： 1880-9871

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In order to investigate oxidation behavior and cracking susceptibility of the Ni-Cr alloys under extremely-low oxygen partial pressure, three Ni-Cr alloys (Ni-14Cr, Ni-22Cr and Ni-30Cr) were used as plate specimen and reverse U-bend specimen for oxidation experiments for 750 hours at 400 °C in two kinds of gas system (inert gas and dry steam) under various oxygen potential (Ni stable, Ni/NiO equilibrium and NiO stable). The Ni-Cr alloys cracked along grain boundary both in inert gas system (with trace O₂, without H₂O) and in hydrogenated steam. In the inert gas system, the cracking susceptibility was confirmed in near NiO stable condition. On the other hand, no crack was found in near Ni stable condition. In the dry steam system, the cracking susceptibility was confirmed in near Ni/NiO equilibrium. In contrast, no crack was found in near NiO stable condition. The cracking susceptibility was confirmed in near Ni/NiO equilibrium in hydrogenated steam as contrasted with higher oxygen potential in inert gas system. This result shows that potential range for the cracking susceptibility seemed to be different between the two kinds of gas system. Cracking severity was highest for Ni-14Cr and lowest for Ni-30Cr both in inert gas and steam; however, even Ni-30Cr was not immune to intergranular cracking in steam near Ni/NiO equilibrium.
Study of FAC rate of carbon steels based on characterization of oxide film Peer-reviewed

Yutaka Watanabe, Hiroshi Abe

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　76　(763)　433-435　2010
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.76.763_433 　

ISSN： 0387-5016
EFFECTS OF Cr CONTENT AND ENVIRONMENTAL FACTORS ON FAC RATE OF CARBON STEELS Peer-reviewed

Yutaka Watanabe, Kiwamu Sue, Hiroshi Abe

PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE, VOL 6, PTS A AND B　933-936　2010
Applicability Test of Glass Lining Material for High-Temperature Acidic Solutions of Sulfuric Acid in Thermochemical Water-Splitting IS Process Peer-reviewed

Jin Iwatsuki, Nobuyuki Tanaka, Yutaka Watanabe, Atsuhiko Terada, Kaoru Onuki

KAGAKU KOGAKU RONBUNSHU　36　(4)　413-419　2010

DOI： 10.1252/kakoronbunshu.36.413 　

ISSN： 0386-216X
EFFECT OF MATERIAL FACTORS ON FAC RATE AND CHARACTERISTICS OF OXIDE LAYER Peer-reviewed

Yutaka Watanabe, Hiroshi Abe, Takamichi Miyazaki

PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE 2010, VOL 6, PTS A AND B　1253-1256　2010

DOI： 10.1115/PVP2010-25584 　
高Ni 合金の高温水中SCC 機構解明と耐SCC 成分設計に関する基礎的研究(1)事業概要

渡辺豊, 竹田陽一, 阿部博志, 佐藤崇之, 宮崎孝道, 庄子哲雄

日本原子力学会「2009 年秋の大会」　2009/09
高Ni 合金の高温水中SCC 機構解明と耐SCC 成分設計に関する基礎的研究(2)高温水中SCC 感受性評価

佐藤崇之, 竹田陽一, 渡辺豊, 阿部博志, 宮崎孝道, 庄子哲雄

日本原子力学会「2009 年秋の大会」　2009/09
高Ni 合金の高温水中SCC 機構解明と耐SCC 成分設計に関する基礎的研究(3)気相中における応力下酸化挙動評価

阿部博志, 渡辺豊, 竹田陽一, 佐藤崇之, 宮崎孝道, 庄子哲雄

日本原子力学会「2009 年秋の大会」　2009/09
CHARACTERIZATION OF CORROSION LAYER OF CARBON STEEL BY MICRO-PIXE/RBS ANALYSIS Peer-reviewed

S. Matsuyama, K. Ishii, H. Yamazaki, M. Fujiwara, Y. Kikuchi, M. Nakhostin, Y. Kawamura, S. Tsuboi, K. Yamanaka M, Watanabe, S. Ohkura, Y. Hashimoto, M. Fujikawa, G. Catella, K. Fujiki, Y. Hatori, N. Hamada, S. Tanino, H. Abe, Y. Watanabe

International Journal of PIXE　19　61-66　2009/04
Metallurgical Study on Low-temperature Aging Characteristics and SCC Behavior of Type 316L Welds

H. Abe, Y. Watanabe

Proceedings of the 17th International Corrosion Congress (CD-ROM)　2008/08
Low-temperature aging characteristics of type 316L stainless steel welds: Dependence on solidification mode Peer-reviewed

Hiroshi Abe, Yutaka Watanabe

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE　39A　(6)　1392-1398　2008/06

DOI： 10.1007/s11661-008-9511-8 　

ISSN： 1073-5623
Low-Temperature Aging of Delta-Ferrite in 316L SS Welds; Changes in Mechanical Properties and Etching Properties Peer-reviewed

Hiroshi ABE, Keita SHIMIZU, Yutaka WATANABE

Journal of Power and Energy Systems　2　(1)　2-7　2008/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jpes.2.2 　

ISSN： 1881-3062

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Thermal aging embrittlement of LWR components made of stainless cast (e.g. CF-8 and CF-8M) is a potential degradation issue, and careful attention has been paid on it. Although welds of austenitic stainless steels (SSs) have γ-δ duplex microstructure, which is similar to that of the stainless cast, examination on thermal aging characteristics of the SS welds is very limited. In order to evaluate thermal aging behavior of weld metal of austenitic stainless steel, the 316L SS weld metal has been prepared and changes in mechanical properties and in etching properties at isothermal aging at 335°C have been investigated. The hardness of the ferrite phase has increased with aging, while the hardness of austenite phase has stayed same. It has been suggested that spinodal decomposition has occurred in δ-ferrite by the 335°C aging. The etching rates of δ-ferrite at immersion test in 5wt% hydrochloric acid solution have been also investigated using an AFM technique. The etching rate of ferrite phase has decreased consistently with the increase in hardness of ferrite phase. It has been thought that this characteristic is also caused by spinodal decomposition of ferrite into chromium-rich (α') and iron-rich (α).
Corrosion mitigation in supercritical water with chromium ion Peer-reviewed

Y. Daigo, Y. Watanabe, K. Sue

CORROSION　63　(12)　1085-1093　2007/12

ISSN： 0010-9312
Corrosion and Cracking of Alloys in Supercritical Water Invited

Yutaka Watanabe

Proceedings of the International Symposium on Energy related Materials　87-102　2007/11
Oxide Solubility-Based Prediction of Corrosion Rate of Ni Base Alloys in Supercritical and Sub-Critical Water

Yutaka Watanabe, Kiwamu Sue, Yuzo Daigo, Yoshiaki Kurata

Proceedings of 1st International Conference CORROSION AND MATERIAL PROTECTION　(CD-ROM)　1-6　2007/10
LOW-TEMPERATURE AGING CHARACTERISTICS AND SCC BEHAVIORS OF TYPE 316L WELDS Peer-reviewed

Hiroshi Abe, Yutaka Watanabe

Proceedings of 13th International Conference on Environmental Degradation of Materials in Nuclear Power Systems　(CD-ROM)　1-12　2007/08
Environmentally Assisted Cracking of Alloys at Temperatures near and above the Critical Temperature of Water Invited

Yutaka Watanabe

Proceedings of International Corrosion Engineering Conference 2007　CD-ROM　2007/05
Low-temperature aging of delta-ferrite in 316L SS welds; changes in mechanical properties and etching properties Peer-reviewed

Hiroshi Abe, Keita Shimizu, Yutaka Watanabe

Proceedings of The 15th International Conference on Nuclear Engineering　CD-ROM　(1)　2-7　2007/04
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jpes.2.2 　

ISSN： 1881-3062

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Thermal aging embrittlement of LWR components made of stainless cast (e.g. CF-8 and CF-8M) is a potential degradation issue, and careful attention has been paid on it. Although welds of austenitic stainless steels (SSs) have γ-δ duplex microstructure, which is similar to that of the stainless cast, examination on thermal aging characteristics of the SS welds is very limited. In order to evaluate thermal aging behavior of weld metal of austenitic stainless steel, the 316L SS weld metal has been prepared and changes in mechanical properties and in etching properties at isothermal aging at 335°C have been investigated. The hardness of the ferrite phase has increased with aging, while the hardness of austenite phase has stayed same. It has been suggested that spinodal decomposition has occurred in δ-ferrite by the 335°C aging. The etching rates of δ-ferrite at immersion test in 5wt% hydrochloric acid solution have been also investigated using an AFM technique. The etching rate of ferrite phase has decreased consistently with the increase in hardness of ferrite phase. It has been thought that this characteristic is also caused by spinodal decomposition of ferrite into chromium-rich (α') and iron-rich (α).
Corrosion Resistance of Ni Base Alloys in Supercritical Water Containing Sulfuric Acid : Dependencies on Alloying Elements Peer-reviewed

Yuzo Daigo, Yutaka Watanabe, Katsuo Sugahara, Takeshi Isobe

CORROSION2007 (CD-ROM)　Paper No.413　1-13　2007/03
Effect of chromium ion from autoclave material on corrosion behavior of nickel-based alloys in supercritical water Peer-reviewed

Y. Daigo, Y. Watanabe, K. Sue

CORROSION　63　(3)　277-284　2007/03

ISSN： 0010-9312
Corrosion mitigation in supercritical water with chromium ion Peer-reviewed

Y. Daigo, Y. Watanabe, K. Sue

Corrosion　63　(12)　1085-1093　2007
Publisher: National Assoc. of Corrosion Engineers International
DOI： 10.5006/1.3278326 　

ISSN： 0010-9312
Effect of precipitation on cryogenic toughness in N-containing austenitic stainless steels Peer-reviewed

M. L. Saucedo-Munoz, T. Hashida, Y. Watanabe, T. Shoji, V. M. Lopez-Hirata

THERMEC 2006, PTS 1-5　539-543　4914-+　2007

ISSN： 0255-5476
Effect of physical property of water on SCC growth rate of 316L stainless steels in high-temperature water Peer-reviewed

Hiroshi Abe, Yutaka Watanabe

PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4　353-358　270-274　2007

ISSN： 1013-9826
Understanding and detecting early stages of SCC initiation in sensitized stainless steel by means of electrochemical potential transients Peer-reviewed

S. K. Bidhar, Y. Watanabe, H. Tsukui, T. Uchimoto

PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4　353-358　2387-+　2007

ISSN： 1013-9826
Direct measurement of local surface temperature of eutectic solder for determining electromigration pattern Peer-reviewed

T Hasegawa, M Saka, Y Watanabe

JOURNAL OF ELECTRONIC MATERIALS　35　(5)　1074-1081　2006/05

DOI： 10.1007/BF02692569 　

ISSN： 0361-5235
Corrosion behavior of nickel-based alloys and type 316 stainless steel in slightly oxidizing or reducing supercritical water Peer-reviewed

R Fujisawa, K Nishimura, T Nishida, M Sakaihara, Y Kurata, Y Watanabe

CORROSION　62　(3)　270-274　2006/03

ISSN： 0010-9312
Compatibility of nickel-based alloys with Supercritical water applications: Aging effects on corrosion resistance and mechanical properties Peer-reviewed

Y Daigo, Y Watanabe, K Sugahara, T Isobe

CORROSION　62　(2)　174-181　2006/02

ISSN： 0010-9312
Corrosion mitigation in supercritical water with chromium ion

Yuzo Daigo, Yutaka Watanabe, Kiwamu Sue

NACE - International Corrosion Conference Series　064521-0645212　2006

ISSN： 0361-4409
P58 Effect of solidification mode on susceptibility of aging and corrosion behavior of 316L SS welds in high-temperature water

ABE Hiroshi, SHIMIZU Keita, WATANABE Yutaka

Proceedings of the 1992 Annual Meeting of JSME/MMD　2006　635-636　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2006.0_635 　
Corrosion rate and oxide scale characteristics of austenitic alloys in supercritical water Peer-reviewed

Yutaka Watanabe, Yuzo Daigo

HIGH-TEMPERATURE OXIDATION AND CORROSION 2005　522-523　213-219　2006

ISSN： 0255-5476
Corrosion behavior of nickel-based alloys and type 316 stainless steel in slightly oxidizing or reducing supercritical water Peer-reviewed

R. Fujisawa, K. Nishimura, T. Nishida, M. Sakaihara, Y. Kurata, Y. Watanabe

Corrosion　62　(3)　270-274　2006
Publisher: National Assoc. of Corrosion Engineers International
DOI： 10.5006/1.3278273 　

ISSN： 0010-9312
CORROSION OF ALLOYS IN AGGRESSIVE ENVIRONMENTS NEAR AND ABOVE THE CRITICAL TEMPERATURE OF WATER Invited

Y. Watanabe, K. Sue, Y. Kurata

16th International Corrosion Congress　2005/09/19
Corrosion behaviour of nickel base alloys and 316 stainless steel in supercritical water under alkaline conditions Peer-reviewed

R Fujisawa, M Sakaihara, Y Kurata, Y Watanabe

CORROSION ENGINEERING SCIENCE AND TECHNOLOGY　40　(3)　244-248　2005/09

DOI： 10.1179/174327805X66308 　

ISSN： 1478-422X
Compatibility of Ni Base Alloys with Supercritical Water Applications: Aging Effects on Corrosion Resistance and Mechanical Properties

Yuzo Daigo, Yutaka Watanabe, Katsuo Sugahara, Takeshi Isobe

Stainless Steel World　17　44-49　2005/05
CORROSION BEHAVIOR OF Ni BASE ALLOYS AND 316 STAINLESS STEEL IN LESS OXIDIZING OR REDUCING SCW CONTAINING HCl Peer-reviewed

Ryutaro Fujisawa, Kenji Nishimura, Takashi Nishida, Motohiro Sakaihara, Yoshiaki Kurata, Yutaka Watanabe

CORROSION2005　Paper No.392　1-10　2005/03
CRACKING SUSCEPTIBILITY OF Ni BASE ALLOYS AND 316 STAINLESS STEEL IN LESS OXIDIZING OR REDUCING SCW Peer-reviewed

Ryutaro Fujisawa, Kenji Nishimura, Takashi Nishida, Motohiro Sakaihara, Yoshiaki Kurata, Yutaka Watanabe

CORROSION2005　Paper No.395　1-13　2005/03
EFFECT OF CHROMIUM ION FROM AUTOCLAVE MATERIAL ON CORROSION BEHAVIOR OF NI BASE ALLOYS IN SUPERCRITICAL WATER Invited Peer-reviewed

Yuzo Daigo, Yutaka Watanabe, Kiwamu Sue

CORROSION2005　Paper No.393　1-10　2005/03
429 Importance of Physical Properties of Water in Stress Corrosion Cracking in High-Temperature Water and its Implication to the Cracking Mechanisms

WATANABE Yutaka, ABE Hiroshi

Proceedings of the 1992 Annual Meeting of JSME/MMD　2005　313-314　2005
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2005.0_313 　
408 Developing monitoring method of initiation processes of localized corrosion and stress corrosion cracking by means of electrochemical transients

WATANABE Yutaka, UCHIMOTO Tetsuya, SATO Keisuke, TSUKUI Hajime

Proceedings of the 1992 Annual Meeting of JSME/MMD　2005　269-270　2005
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2005.0_269 　
Estimation method of SCC initiation site based on electrochemical transients Peer-reviewed

Y Watanabe, K Sato, T Uchimoto, T Takagi

ADVANCES IN FRACTURE AND STRENGTH, PTS 1- 4　297-300　999-1004　2005

ISSN： 1013-9826
Stress Corrosion Cracking Mechanisms of 316 Stainless Steels in Sub-Critical Liquid Water and Supercritical Water from a “Dielectric Constant of Water” Point of View Peer-reviewed

Hiroshi Abe, Yutaka Watanabe, Kiwamu Sue

Proceedings of 2004 International Congress on Advances in Nuclear Power Plants　Paper No.4226　1942-1949　2004/06
低酸化性および還元性超臨界水環境におけるNi基およびFe基合金の腐食評価 Peer-reviewed

西田隆志, 境原基浩, 藤澤龍太郎, 渡辺豊, 倉田良明

材料と環境　53　(6)　322-328　2004/06
Publisher:
DOI： 10.3323/jcorr1991.53.322 　

ISSN： 0917-0480
CORROSION RESISTANCE AND CRACKING SUSCEPTIBILITY OF 316L STAINLESS STEEL IN SULFURIC ACID-CONTAINING SUPERCRITICAL WATER Peer-reviewed

Yutaka Watanabe, Hiroshi Abe, Yuzo Daigo, Takashi Nishida

CORROSION2004　Paper No.493　1-7　2004/03
Compatibility of Ni Base Alloys with Supercritical Water Applications: Aging Effects on Corrosion Resistance and Mechanical Properties Peer-reviewed

Yuzo Daigo, Yutaka Watanabe, Katsuo Sugahara, Takeshi Isobe

CORROSION2004　Paper No.487　1-8　2004/03
Improved Compatibility of a New Ni Base Alloy with Supercritical Water Applications: Beneficial Effects of Ta Addition on Corrosion Resistance and Aging Susceptibility Peer-reviewed

Katsuo Sugahara, Takeshi Isobe, Yuzo Daigo, Yutaka Watanabe

CORROSION2004　Paper No.489　1-7　2004/03
Steam oxidation of creep-strength enhanced 9CR ferritic steel: Void formation in oxide scale and its relation to scale exfoliation Peer-reviewed

Yutaka Watanabe, Hiroaki Kikkawa

American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP　476　93-96　2004

DOI： 10.1115/PVP2004-2575 　

ISSN： 0277-027X
Effect of physical property and chemistry of water on cracking of stainless steels in sub-critical and supercritical water Peer-reviewed

Y Watanabe, H Abe, Y Daigo, R Fujisawa, M Sakaihara

ADVANCES IN FRACTURE AND FAILURE PREVENTION, PTS 1 AND 2　261-263　1031-1036　2004

ISSN： 1013-9826
Electrochemical potentiodynamic reactivation: development and applications of the EPR test Peer-reviewed

Cihal, V, R Stefec, T Shoji, Y Watanabe, Kain, V

ADVANCES IN FRACTURE AND FAILURE PREVENTION, PTS 1 AND 2　261-263　855-864　2004

ISSN： 1013-9826
Environmentally Assisted Cracking of Sensitized Stainless Steel in Supercritical Water: Effects of Physical Property of Water Peer-reviewed

Yutaka Watanabe, Hiroshi Abe, Yuzo Daigo, Takashi Nishida

Proceedings of International Conference on Global Environment and Advanced Nuclear Power Plants　Paper No.1183　1-4　2003/09
Characteristics and a few key parameters of corrosion of alloys in supercritical water environments Invited Peer-reviewed

Y Watanabe, Y Daigo, K Sue, T Adschiri

TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS　56　(3)　297-304　2003/06

ISSN： 0019-493X
Cracking of Stainless Steels in Supercritical Water : A Mechanistic Insight

ABE Hiroshi, DAIGO Yuzo, WATANABE Yutaka, NISHIDA Takashi

Proceedings of the 1992 Annual Meeting of JSME/MMD　2003　745-746　2003
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2003.0_745 　
Characteristic and a few key parameters of corrosion of alloys in supercritical water environments Peer-reviewed

Yutaka Watanabe, Yuzo Daigo, Kiwamu Sue, Tadafumi Adschiri

International Symposium on Metals and Alloys for Chemical Industries　85-96　2002/11/15
Electrochemical transients observed during slow strain rate test of alloy 600 in borated and lithiated high temperature water Peer-reviewed

Yutaka Watanabe, Vivekanand Kain, Makoto Kobayashi

JSME International Journal, Series A: Solid Mechanics and Material Engineering　45　(4)　476-480　2002/10

DOI： 10.1299/jsmea.45.476 　

ISSN： 1344-7912
Electrochemical polarization reactivation - a comprehensive review Peer-reviewed

Vladimir Cihal, Tetsuo Shoji, Vivekanand Kain, Yutaka Watanabe, Rudolf Stefec

Proceedings of 15th International Corrosion Congress　2002/09
Development of a single loop EPR test method and its relation to grain boundary microchemistry for alloy 600 Peer-reviewed

Vivekanand Kain, Yutaka Watanabe

Journal of Nuclear Materials　302　(1)　49-59　2002/04

DOI： 10.1016/S0022-3115(02)00712-2 　

ISSN： 0022-3115
Relationship between Corrosion Rate and Metal Oxide Solubility in Supercritical Water Peer-reviewed

Kiwamu Sue, Noriko Tsujinaka, Tadafumi Adschiri, Kunio Arai, Yutaka Watanabe

CORROSION2002 (CD-ROM)　2002-April　(Paper No.354)　1-8　2002/04

ISSN： 0361-4409
EFFECTS OF OXYGEN CONCENTRATION ON CORROSION BEHAVIOR OF ALLOYS IN ACIDIC SUPERCRITICAL WATER Peer-reviewed

Yutaka Watanabe, Kazuhiro Shoji, Tadafumi Adschiri, Kiwamu Sue

CORROSION2002 (CD-ROM)　2002-April　(Paper No.355)　1-9　2002/03

ISSN： 0361-4409
Three Dimensional Computer Simulation of Electrochemical Transients for Detecting SCC Initiation

Watanabe Yutaka, Daigo Yuzo, Tamura Hiroto, Uchimoto Tetsuya

Proceedings of the 1992 Annual Meeting of JSME/MMD　2002　525-526　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2002.0_525 　
The In-Situ Measurement of a Local Chemical Reaction by Raman Spectroscopy -Time dependent Enrichment of Chloride Ions on the Surface of 304L Stainless Steel- Peer-reviewed

Masao TAKEGOSHI, Yutaka WATANABE, Tetsuo SHOJI

Proceedings of APCFS&ATEM'01　1　76-81　2001/10
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeatemapcfs.1.01.203.0_76 　

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In this research, in situ microscopic Raman spectroscopy was used to measured and to analyze the local enrichment of chloride ions on the surface of 304L stainless steel in a sodium chloride solution where the potential of the sample was controlled by a potentiostat. The Raman Spectroscopy measurement was performed on the specimen under the potential control with an area of φ10μm. The local concentration of chloride ions was measured by the variation of the water Raman spectrum since the O-H stretching mode of water Raman scattering (at 3250 - 3400cm^<-1>) is very sensitive to changes in the electrolyte concentration. The parameter for a measurement of small bands fits by Raman difference spectroscopy (RDS) proposed in the recent literature, which can clearly indicates a small change in the Raman spectrum, was utilized in this investigation. Corrosion pits occurred on the specimen surface after 60 minutes under the condition of +200 mV(SCE) in 0.5 mol/l NaCl solution and, in this case, the parameter was monotonically increased with the exposure time. On the contrary, in the case where no corrosion pits occurred, no increase in the parameter was observed. These results demonstrate that the enrichment of chloride ion was observed only on the specimens where the corrosion pits were formed.
Oxidation rate of advanced heat-resistant steels for ultra-supercritical boilers in pressurized superheated steam Peer-reviewed

YS Yi, Y Watanabe, T Kondo, H Kimura, M Sato

JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME　123　(3)　391-397　2001/08

DOI： 10.1115/1.1373656 　

ISSN： 0094-9930
Radiation-Induced Grain Boundary Segregation and its Corrosion Behavior in Hydrogen-Ion Irradiated Type 304 Austenitic Stainless Steel Peer-reviewed

K.Kondou, A.Hasegawa, K.Abe, V.Kain, Y.Watanabe

Proceedings of Tenth International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (CD-ROM)　1-9　2001/08
Effect of Ce doping on passive film electrical resistance of 316 stainless steel exposed to oxygenated pure water at 288 degrees C and its relation to stress corrosion cracking Peer-reviewed

KS Raja, Y Watanabe, T Shoji

JOURNAL OF MATERIALS SCIENCE LETTERS　20　(10)　965-968　2001/05

DOI： 10.1023/A:1010909723426 　

ISSN： 0261-8028
SIGNIFICANCE OF WATER DENSITY ON CORROSION BEHAVIOR OF ALLOYS IN SUPERCRITICAL WATER Peer-reviewed

Yutaka Watanabe, Teruo Kobayashi, Tadafumi Adschiri

CORROSION2001　Paper#369　1-8　2001/03

ISSN： 0361-4409
ELECTROCHEMICAL NOISE DURING EXPOSURE OF ALLOY 600 TO BORATED AND LITHIATED HIGH TEMPERATURE WATER Peer-reviewed

Vivekanand Kain, Yutaka Watanabe, Makoto Kobayashi

CORROSION2001　Paper#118　1-16　2001/03
ESTIMATION OF METAL OXIDE SOLUBILITY AND UNDERSTANDING CORROSION IN SUPERCRITICAL WATER Peer-reviewed

Tadafumi Adschiri, Kiwamu Sue, Kunio Arai, Yutaka Watanabe

CORROSION2001　Paper#354　1-8　2001/03

ISSN： 0361-4409
Steam oxidation of ferritic heat-resistant steels for ultra supercritical boilers Peer-reviewed

Y. Watanabe, Y. Yi, T. Kondo, K. Suzuki, K. Kano

Zairyo to Kankyo/ Corrosion Engineering　50　(2)　50-56　2001
Publisher: Japan Society of Corrosion Engineering
DOI： 10.3323/jcorr1991.50.50 　

ISSN： 0917-0480
Crack growth behavior of ferritic steel for USC boilers in pressurized superheated steam Peer-reviewed

M Inuil, Y Watanabe, T Kondo, K Suzuki, K Kano

MATERIALS AT HIGH TEMPERATURES　18　(2)　119-124　2001

ISSN： 0960-3409
Current and potential fluctuation characteristics in intergranular stress corrosion cracking processes of stainless steels Peer-reviewed

Y Watanabe, T Kondo

CORROSION　56　(12)　1250-1255　2000/12

ISSN： 0010-9312
Importance of pressure in corrosion and oxidation of alloys in supercritical water and superheated steam Invited

Yutaka Watanabe, Tadafumi Adschiri, Tatsuo Kondo

Proceedings of The First International Symposium on Supercritical Water-cooled Reactors, Design and Technology　232-239　2000/11
Oxidation of heat-resistant ferritic steels for USC boilers in pressurized superheated steam Peer-reviewed

Yutaka Watanabe, Yong-Sun Yi, Tatsuo Kond, Kazuhiro Inui, Tomoyuki Kishinami, Hiroshi Kimura, Minoru Sato

Proceedings of Ninth International Conference on Pressure Vessel Technology　1　545-552　2000/04
Effect of Ce addition on the sensitization properties of stainless steels Peer-reviewed

Y. Watanabe, V. Kain, T. Tonozuka, T. Shoji, T. Kondo, F. Masuyama

Scripta Materialia　42　(3)　307-312　2000/01/17
Publisher: Elsevier Science Ltd
DOI： 10.1016/S1359-6462(99)00352-8 　

ISSN： 1359-6462
Effect of microstructure evolution on fracture toughness in isothermally aged austenitic stainless steels for cryogenic applications Peer-reviewed

Maribel L. Saucedo-Muñoz, Yutaka Watanabe, Tetsuo Shoji, Hideaki Takahashi

Cryogenics　40　(11)　693-700　2000
Publisher: Elsevier Ltd
DOI： 10.1016/S0011-2275(01)00004-2 　

ISSN： 0011-2275
SENSITIZATION PROPERTIES & IGSCC SUSCEPTIBILITY OF CERIUM-MODIFIED STAINLESS STEELS Peer-reviewed

Y. Watanabe, T. Tonozuka, T. Shoji, T. Kondo, F. Masuyama

CORROSION/99　Paper No.453　1-10　1999/04
Oxidation Rate of Heat Resistant Ferritic Steels in Superheated Steam - Relation to the Film Structures

Y.Watanabe, T.Kondo, T.Kishinami, M.Inui, Y.S.Yi

Report of the 123rd Committee on Heat-Resisting Metals and Alloys, Japan Society for the Promotion of Science　39　(3)　389-395　1998/11
Electrochemical Noise Characteristics of IGSCC in Stainless Steels in Pressurized High-Temperature Water Peer-reviewed

Yutaka Watanabe, Tetsuo Shoji, Tatsuo Kondo

Corrosion/98　Paper No.129　1-7　1998/03
Current and Potential Fluctuation Characteristics in IGSCC Processes of Stainless Steels Peer-reviewed

Yutaka Watanabe, Tatsuo Kondo

Corrosion/98　Paper No.376　1-7　1998/03
Corrosion of New Type TiAl Alloys in Pressurized Superheated Steam - Exploration of Potential Material/Coolant Syatem in Application to Advanced Fusion Reactors

T.Kondo, Y.Watanabe, A.Hishinuma, Y.S.Yi

Report of the 123rd Committee on Heat-Resisting Metals and Alloys, Japan Society for the Promotion of Science　39　(1)　45-51　1998/03
Corrosion Behaviors of Advanced Boiler Tubing Steels in Pressurized Superheated Steam

Y.S.Yi, Y.Watanabe, T.Kondo, M.Sato

Report of the 123rd Committee on Heat-Resisting Metals and Alloys, Japan Society for the Promotion of Science　39　(1)　53-59　1998/03
An evaluation of potential material-coolant compatibility for applications in advanced fusion reactors Peer-reviewed

T. Kondo, Y. Watanabe, Y. S. Yi, A. Hishinuma

Journal of Nuclear Materials　258-263　2083-2087　1998
Publisher: Elsevier
DOI： 10.1016/S0022-3115(98)00344-4 　

ISSN： 0022-3115
Changes in Slip Band Etching Characteristics of INCONEL718 due to High-Temperature Low-Cycle Fatigue Peer-reviewed

Shin-ichi Komazaki, Yutaka Watanabe, Tetsuo Shoji

Transactions of the Japan Society of Mechanical Engineers　63　(611)　1481-1488　1997/07
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.63.1481 　

ISSN： 0387-5008

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Etching properties of INCONEL718 with various degrees of fatigue damage have been investigated. The etching properties have been found to be sensitive to low-cycle fatigue damage given to the meterial. Low-cycle fatigue damage was simulated using load-controlled uniaxial fatigue tests at 600°C and also at room temperature, and samples with various degrees of fatigue damage were prepared. A chemical etching technique was utilized to detect fatigue damage, and it was found that the etching method preferentially etches persistent slip bands (PSBs) in the fatigue-damaged materials. The density of slip bands increased with increased fatigue life fraction and showed an unique correlation with a usage factor N/Nf. In conclusion, an applicability of the etching technique to fatigue damage evaluation has been suggested.
Nondestructive Evaluation of Fatigue Damage by Induced Current Focusing Potential Drop Peer-reviewed

Minoru Murayama, Tetsuo Shoji, Yutaka Watanabe, Yasumoto Sato

Transactions of the Japan Society of Mechanical Engineers　63　(609)　1119-1125　1997/05
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.63.1119 　

ISSN： 0387-5008

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Quantitative evaluation of fatigue damage accumulation and resultant crack initiation and propagation is one of the greatest concerns for plant life time management and license renewal in various industries. To develop a novel nondestructive evaluation method for fatigue damage evaluation, we applied Induced Current Focusing Potential Drop (ICFPD), which was developed for an inspection of defects, to processes of fatigue damage accumulation, small crack initiation and coalescence, and macroscopic crack growth. Measurements were performed on specimens fatigued under an axial strain controlled tension/compression load with various degrees of fatigue damage defined as a cycle ratio, N/Nc where Nc is a cycle giving a maximum crack size of 3 mm at surface. ICFPD can be used to clearly detect and differentiate all of these fatigue processes of damage accumalution without crack initiation and subsequent small crack initiation and macroscopic crack propagation.
Electochemival Noise in Slow Strain Rate Tests of a Type 316 Stainless Steel in High-Temperature High- Pressure Water Peer-reviewed

Y.Watanabe, F.Kimura, T.Shoji

Zairyo-to-Kankyo (Corrosion Engineering)　45　(11)　667-673　1996/11
Publisher:
DOI： 10.3323/jcorr1991.45.667 　

ISSN： 0917-0480
An Electrochemical Study of Thermal Degradation in Austenitic Stainless Steels

Maribel L. Saucedo-Munoz, Yutaka Watanabe, Tetsuo Shoji, Hideaki Takahashi

Proc.Asian Pacific Conference for Fracture and Strength'96　837-842　1996/07
Nondestructive evaluation of high temperature low-cycle fatigue damage accumulation in Inconel 718 by chemical method

S Komazaki, Y Watanabe, T Shoji

SUPERALLOYS 718, 625, 706 AND VARIOUS DERIVATIVES　617-628　1996
Lead Induced Stress Corrosion Cracking of Alloy 690 in High Temperature Water Peer-reviewed

Koo-Kab Chung, Shin-ichi Moriya, Yutaka Watanabe, Tetsuo Shoji, Jae-Kyu Lim

Proc.7th Int.Symp.Environmental Degradation of Materials in Nuclear Power System　233-244　1995/08
Creep Life Evaluation of 2.25Cr-1Mo Steel Components and In-Situ NDE by Electrochemical Technique Peer-reviewed

Yutaka Watanabe, Tetsuo Shoji

Proceedings of 1995 ASME Pressure Vessels and Piping Conference　Vol.315　397-405　1995/07
Effects of Loading Modes on Environmentally Assisted Cracking of Pressure Vessel Steels in High Temperature Water Peer-reviewed

Tetsuo Shoji, Yutaka Watanabe, Shin-ichi Moriya, Shigeharu Takata

Proceedings of 1995 ASME Pressure Vessels and Piping Conference　Vol.306　29-33　1995/07
The effect of transection of pyloric branch of vagal nerve on gastropyloric motility measured by a novel method

Chikashi Shibata, Iwao Sasaki, Hiroo Naito, Seiki Matsuno, Yutaka Watanabe, Tetsuo Shoji

Geka-Chiryo　72　(6)　1121-1122　1995/06
A Novel NDI and Monitoring Technique for Plant Life Management -Induced Current Focusing Potential Drop Technique Peer-reviewed

T. Shoji, H. Kim, T. Maeda, Y. Sato, Y. Watanabe

Proc. Int. Symp. Plant Aging and Life Prediction of Corrodible Structure　371　371-376　1995/05
Effects of neutron irradiation on transpassive corrosion behavior of austenitic stainless steels Peer-reviewed

Y. Watanabe, R. G. Ballinger, O. K. Harling, G. E. Kohse

Corrosion　51　(9)　651-659　1995
Publisher: Natl Assoc of Corrosion Engineers
DOI： 10.5006/1.3293626 　

ISSN： 0010-9312
Fundamental Research for Evaluation of IASCC Susceptibility Peer-reviewed

Yoshimasa Iwabuchi, Takahiro Fujimoto, Yutaka Watanabe, Tetsuo Shoji

Zairyo-to-Kankyo　42　(1)　2-8　1993

DOI： 10.3323/jcorr1991.42.2 　

ISSN： 1881-9664 0917-0480
NONDESTRUCTIVE EVALUATION OF THERMAL AGING EMBRITTLEMENT OF DUPLEX STAINLESS-STEELS Peer-reviewed

YS YI, T TOMOBE, Y WATANABE, T SHOJI

PROCEEDINGS OF THE SIXTH INTERNATIONAL SYMPOSIUM ON ENVIRONMENTAL DEGRADATION OF MATERIALS IN NUCLEAR POWER SYSTEMS - WATER REACTORS　409-417　1993
NONDESTRUCTIVE DETECTION OF FATIGUE DAMAGE ACCUMULATION OF RPV STEEL Peer-reviewed

T SHOJI, Y KAWAMORI, Y WATANABE

PROCEEDINGS OF THE SIXTH INTERNATIONAL SYMPOSIUM ON ENVIRONMENTAL DEGRADATION OF MATERIALS IN NUCLEAR POWER SYSTEMS - WATER REACTORS　433-441　1993
In-Service Degradation of Structural Materials and Its Nondestructive Evaluation

Tetsuo Shoji, Yutaka Watanabe, Yoshimasa Iwabuchi, Yoshihisa Saito

Journal of Society of Plant Engineers Japan　3　(3)　61-70　1992/02
THE EVALUATION OF FATIGUE DAMAGE OF RPV STEELS BY ELECTROCHEMICAL METHOD

T SHOJI, Y KAWAMORI, Y WATANABE

PROCEEDINGS OF THE VII INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS, VOLS 1 AND 2　1148-1153　1992
Fatigue Properties of Reactor Pressure Vessel Steel and Damage Evaluation Peer-reviewed

Tetsuo Shoji, Yuji Kawamori, Yutaka Watanabe, Juichi Fukakura

Journal of the Society of Materials Science, Japan　41　(469)　1558-1564　1992

DOI： 10.2472/jsms.41.1558 　

ISSN： 1880-7488 0514-5163
THE EVALUATION OF IN-SERVICE MATERIALS DEGRADATION OF LOW-ALLOY STEELS BY THE ELECTROCHEMICAL METHOD Peer-reviewed

Y WATANABE, T SHOJI

METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE　22　(9)　2097-2106　1991/09

DOI： 10.1007/BF02669877 　

ISSN： 0360-2133
Development of Nondestructive On-Site Measurement Techniques by Means, of an Electrochemical Method for Material Degradation of S/H SUS Steel Tubes of Fossil Boilers Peer-reviewed

Yoshihisa SAITO, Tetsuo SHOJI, Yutaka WATANABE

Transaction of the Japan Society of Mechanical Engineers　57　(588)　1442-1448　1991/06

DOI： 10.1299/kikaia.57.1442 　
Newly Developed Electrochemical Evaluation Method of Temper Embrittlement of Cr-Mo-V Steel and 2.25 Cr-1 Mo Steel Peer-reviewed

Yutaka WATANABE, Tetsuo SHOJI

Transactions of the Japan Society Mechanical Engineers　57　(537)　1233-1239　1991/05
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.57.1233 　

ISSN： 0387-5008

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A nondestructive electrochemical method is developed for detection and evaluation of temper embrittlement of Cr-Mo-V Steel and 2.25 Cr-1 Mo steel. In this method, temper embrittlement can be detected and evaluated by the second peak of current density "I_P2" which appears in the anodic polarization curves measured in a calcium nitrate solution. In contrast to nonembrittled materials (couplings and de-embrittling heat-treated materials) which exhibited the dull and low second peak, the sharp and high second peak current appeared in the anodic polarization curves measured on embrittled materials. This increase in I_P2 is caused by selective dissolution of embrittled (impurity-enriched) grain boundaries and that increase in I_P2 has a good correlation with the shifts in FATT. Temper embrittlement can be nondestructively evaluated by I_P2 measurements with high accuracy.
Nondestructive Evaluation of Temper Embrittlement of Cr-Mo-V Cast Steels by Electrochmical Method Using Calcium Nitrate Solution Peer-reviewed

Yutaka Watanabe, Tetsuo Shoji

Journal of the Iron and Steel Institute of Japan　77　(4)　566-573　1991/04
Publisher: The Iron and Steel Institute of Japan (ISIJ)
DOI： 10.2355/tetsutohagane1955.77.4_566 　

ISSN： 0021-1575

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Quantitative evaluation of temper embrittlement of turbine casing material, Cr-Mo-V cast steel, by means of anodic polarization behavior in calcium nitrate solution was investigated. Furthermore, based upon these results, nondestructive electrochemical method for detection and evaluation of temper embrittlement of Cr-Mo-V cast steel is newly developed with high sensitivity. Intergranular Corrosion (IGC) occurs only on temper embrittled samples during anodic polarization process in calcium nitrate solution. In polarization curves measured at 60℃, the characteristic changes such as increases in current density at passive potential range and in passivation potential attributable to IGC have a excellent correlation with shifts in FATT caused by temper embrittlement. On the other hand, in polarization curves measured at 30℃, increases in the current density of the second peak current attributable to IGC have a good correlation with shifts in FATT. By use of these electrochemical characteristic values, the degree of temper embrittlement can be quantitatively estimated.
Nondestructive Evaluation of Material Degradation in 2.25Cr-1Mo Steel by Electrochemical Technique Peer-reviewed

Yutaka Watanabe, Tetsuo Shoji

Journal of the Society of Materials Science, Japan　40　(448)　89-95　1991

DOI： 10.2472/jsms.40.89 　

ISSN： 1880-7488 0514-5163
Nondestructive Detection and Evaluation of Materials Degradation of 2.25Cr-1Mo Steel by Electrochemical Method

Yutaka Watanabe, Tetsuo Shoji

Proc. KSME/JSME Joint Conf. FRACTURE AND STRENGTH '90　702-707　1990/07
The Mechanism and the Condition of Occurence in the Erosion-Corrosion Damage of Carbon Steel by Gas-Liquid Two-Phase Flow Peer-reviewed

Y. Watanabe, T. Shoji, H. Takahashi

Transactions of the Japan Society of Mechanical Engineers (A)　55　(519)　2294-2298　1989/11
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.55.2294 　

ISSN： 0387-5008

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The erosion-corrosion characteristics of carbon steel commonly used as piping material subjected to an impinging gas-liquid two-phase flow under various pH. chloride ion concentration and flow rate combinations were investigated. Environmental condition saffected not only the damage rate but also the type of damage. One of these was the enhanced general corrosion observed mainly under high chlorine ion concentration (1220ppm) and another was flow-induced pitting corrosin observed under the pH7-[C1^-] 140ppm condition. Each condition of the chemical solution had its own flow effect. For example, in the case of high chlorine ion concentration, high flow rate accelerated corrosion damage by decreasing diffusion control. On the other hand, under low chlorine ion concentration, high-speed flow decreased the corrosion rate by the action of removing nonprotective oxide layer. To indicate the condition of occurrence for enhanced corrosion damage, a two-dimensional chart which had axes of [C1^-] concentration and flow rate was constructed for each pH value.
A NEW HIGH-T_C SUPERCONDUCTOR YBa₂Ca₂Cu₃O_X Peer-reviewed

A.SHIMA, T.SHOJI, M.UKAKU, Y.WATANABE, Y.TAZAWA, H.SAKAI

Modern Physics Letters B　3　(16)　1233-1236　1989/09

DOI： 10.1142/S0217984989001886 　
A Novel NDE Method for Creep Damage Evaluation by Means of Electrode Impedance Method(EIM) Peer-reviewed

T.Matsushita, T.Shoji, Y.Watanabe, Y.Saito

Proc. 1989 ASME Pressure Vessel and Piping Conference, NDE-Vol.5　213-220　1989/07
Tensile Strength and Fracture Toughness of YBCO Superconductor and Resistivity during Fracture Test Peer-reviewed

Y.Watanabe, T.Shoji

Trans. JSME (A)　55　(512)　843-846　1989/04
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.55.843 　

ISSN： 0387-5008

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Tensile strength of sintered YBCO superconductor at 77K was evaluated by Brazilian test and fracture toughness at 85K was measured by use of round compact tention specimen. Superconductivity of specimens during Brazilian tests were examined by the four-point terminal method. Density of a specimen was the principal factor of tensile strength and the fracture surface exhibited the cleavage-intergranular mixed pattern. No change in superconductivity of specimens was observed until mechanical fracture occurred. Namely, no stress dependence on superconductivity was observed for these material tested. Fracture toughness K_Q of sintered YBCO was also measured by use of a round compact specimen. The K_Q value of sintered YBCO with a density of 4, 84g/cm³ was 1.1Mpa·m^l/2. The obtained K_Q shows the value of one third or quarter compared with that of ordinary ceramics (ZrO₂, Al₂O₃).
The Electrochemical Mechanism in the Erosion-corrosion Damage of Carbon Steel by Gas-Liquid Two-Phase Flow Peer-reviewed

Y. Watanabe, T. Shoji, H. Takahashi, S. Moriya

Trans. JSME (A)　54　(505)　1807-1813　1988/09
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/kikaia.54.1807 　

ISSN： 0387-5008

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The erosion-corrosion characteristics of a carbon steel commonly used as a piping material subjected to an impinging gas-liquid two-phase jet were investigated. The localized damage was observed, and the range of the erosion rate under the experimental conditions was beteen 45 mm/year and 87 mm/year. It became clear that the principal mechanism of this damage was the occurrence of pitting corrosion caused by the corrosion potential distribution on a specimen and the rapid growth of pits. The significance of flow-induced potential distribution on a specimen was demonstrated by use of an array of test pieces insulated electrically from each other. This potential distribution induced by the flow distribution on a specimen also gave crucial effects on the location where the erosion-corosion damage occurred. Namely, erosion-corrosion damage took place locally, just at the part of the specimen where the corrosion potential was shifted to more nobler than the pitting potential of the condition of interest. This corrosion potential distribution was caused by the distribution of the oxygen supply rate and deposition and/or removal of oxydizer corrosion product (γ-FeOOH). These were originally caused by the flow distribution. This erosion-corrosion damage was completely inhibited by keeping the pitting potential nobler than the corrosion potential ; for example, by the addition of NaNO₂ to the system.
Electrochemical Aspect in Erosion-Corrosion Damage of Carbon Steel by Gas-Liquid Two Phase Flow Peer-reviewed

Y. Watanabe, T. Shoji, H. Takahashi

Boshoku Gijutsu　37　(2)　69-74　1988/02
Publisher: Japan Society of Corrosion Engineering
DOI： 10.3323/jcorr1974.37.2_69 　

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Erosion-corrosion characteristics of a carbon steel commonly used as a piping material subjected to impinging gas-liquid two phase jet was investigated. Effects of impingement angle and atmospheric gas on erosion-corrosion behavior were examined in terms of time dependence of weight loss, depth of pits and corrosion potential. Significance of flow-induced potential distribution on a specimen was demonstrated by use of array of small test piece insulated electrically, and also this potential distribution caused by flow distribution on a specimen gave crucial effects on the location where erosion-corrosion damage occurred. Hence, based upon above experimental evidences, corrosion potential distribution on a surface can be concluded as a primary factor of damage mechanisms through both electrochemical processes and mechanical processes such as removal of corrosion product on a surface.
Corrosion Fatigue of High Strength Steel in Sea Flowing Water Peer-reviewed

S. Jang, T. Shoji, H. Takahashi, Y. Watanabe

Boshoku Gijutsu　35　(9)　503-508　1986/09
Publisher: Japan Society of Corrosion Engineering
DOI： 10.3323/jcorr1974.35.9_503 　

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Corrosion fatigue tests were conducted in synthetic sea water to investigate the influence of flow rate on crack growth behavior in various corrosion potentials for HT80 steel. The effect of increasing flow rate under free corrosion potential was to increase the cathodic reaction rate of dissolved oxygen reduction and results in increase of crack propagation rate. When the potential was controlled electrochemically by a potentiostatt at -450mV (vs. Ag/AgCl), it showed different mechanisms with respect to flow rates. At low flow rate, two mechanisms can operate in series with testing time. The first one is hydrogen embrittlement mechanism, which become possible to occur at the crack tip with low pH. After this process, the crack propagation rate decreases with the decrease of effective stress intensity range caused by cumulated corrosion products in crevice after long test period. On the other hand, at high flow rate, the same mechanism as free corrosion potential test governed the crack propagation rate high. In the case of -523mV (vs. Ag/AgCl) test, both low and high flow rates made no difference in crack propagation rate. This result was considered that the impressed current density at low flow rate was high enough to maintain the high crack propagation rate.

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Misc. 58

カーボンフリーエネルギーキャリア利用における科学と技術

小林秀昭, 橋本望, 小原拓, 内一哲哉, 高木敏行, 丸田薫, 中村寿, 早川晃弘, 渡邉豊

東北大学流体科学研究所共同利用・共同研究拠点流体科学国際研究教育拠点活動報告書　2017　199-200　2019/02
OS0915-416 Wastage mechanism of heating tubes made of austenitic stainless steels in a melamine production plant

YAMAMOTO Kohei, ABE Hiroshi, WATANABE Yutaka, ONO Masashi, ARIOKA Shinpei

2015　"OS0915-416-1"-"OS0915-416-3"　2015/11/21
Publisher: The Japan Society of Mechanical Engineers

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It was reported by the authors that a nitrided layer formed on SUS310S heating tubes in the reactor of melamine production plant showed a severe spalling susceptibility. After replacement to SUS304 heating tubes, spalling and thinning was suppressed. According to the previous studies, phases of the nitrided layers of the SUS310S and SUS304 heating tubes consist mainly of γ' and α', respectively. The reason why the SUS310S heating tube showed the high spalling susceptibility was considered to be a higher expansion rate of γ' compared with α'. The purpose of this study is to investigate the relation between the spalling susceptibility and nitrided layer characteristics (crystal structure, nitrogen concentration). EDX analysis showed a higher nitrogen concentration of SUS310S than that of SUS304. This results are consistent with the solid solubility of nitrogen shown in the phase diagram of Fe-N systems. XRD analysis indicated that the nitrided layer of SUS310S consists of both γ' and α'. The nitrogen concentration and expansion rate of γ' estimated by XRD analysis was higher than that of α'. Those results infer that the high expansion rate of γ' causes severe spalling susceptibility of the SUS310S heating tubes.
B124 Oxidation rate of candidate materials for fuel cladding of supercritical water-cooled reactor

Suzuki Ryuichi, Abe Hiroshi, Watanabe Yutaka

National Symposium on Power and Energy Systems　2015　(20)　43-46　2015/06/07
Publisher: The Japan Society of Mechanical Engineers

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Supercritical water-cooled reactor (SCWR) is one of the advanced reactor concepts for generation IV nuclear reactors. Material of fuel cladding for SCWR is required long term integrity and durability at metal temperature of 700℃. Then, 15Cr-20Ni austenitic stainless steel (1520S) which has sufficient creep strength at 700℃ was proposed for the candidate materials for fuel cladding of SCWR. In this study, oxidation behavior of 1520S as candidate materials, SUS316L and SUSS 1 OS as comparison materials in supercritical water at 700℃ and 650℃ under 24MPa for 1500h were discussed in terms of: temperature, cold work (CW) and surface finish. The main objective of this work is to predict the oxide behavior of candidate materials after 50,000h which is the estimated maximum operating time of fuel cladding.
A233 Relationship between thinning rate of carbon steels due to flow-accelerated corrosion and characteristics of oxide films formed

YANO Takuma, ABE Hiroshi, Miyazaki TAKAMICHI, WATANABE Yutaka, FUJIWARA Kazutoshi, YONEDA Kimitoshi

National Symposium on Power and Energy Systems　2015　(20)　205-208　2015/06/07
Publisher: The Japan Society of Mechanical Engineers

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Major mechanism of the pipe wall thinning taking place in the nuclear power plant is flow-accelerated corrosion (FAC). Mechanism of FAC is not yet fully understood, especially, role of oxide film in determining thinning rate. The main objective of this work is finding characteristics of oxide film and examining a relationship between film characteristics and thinning rate. Furthermore, role of film characteristics on FAC model was discussed. Transmission Electron Microscope (TEM) observation using Fresnel contrast was used to investigate the microscopic defect structure of the oxide film. As a result of observation, the oxide layer formed on the specimens was consisted of porous and compact oxides in nanometer-scale and the thinning rate increased with decreasing compact oxide thickness. However, it have been suggested that compact oxide thickness doesn't affect thinning rate and rate determining step is diffusion of ferrous ion in diffusion layer.
OS1407 Microstructure and ageing properties of stainless steel weld

ABE Hiroshi, TERAO Toshihiko, WATANABE Yutaka

2013　"OS1407-1"-"OS1407-3"　2013/10/12
Publisher: The Japan Society of Mechanical Engineers

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To evaluate the rate of thermal embrittlement of type 316 low-carbon stainless steel weld metal at BWR operating temperature, aging test at 310℃, 335℃, and400℃ was carried out. Hardness of each ferrite and austenite phase of specimens was measured selectively by microhardness tester. Hardness of ferrite was increased apparently with all three aging temperatures, whereas hardness of austenite was not changed. Changes in the microstructure of ferrite aged at 310℃ for 11,000h and 18,000h were analyzed by TEM. It has been revealed that hardening of ferrite with aging at 310℃ was result of spinodal decomposition. Arrhenius plot for hardening rate of ferrite at each three aging temperature was plotted, and apparent activation energy was estimated. Using the apparent activation energy, hardening rate at 288℃ was discussed.
D113 A study of FAC mechanism based on detailed observation of oxide film

ABE Hiroshi, WATANABE Yutaka

National Symposium on Power and Energy Systems　2013　(18)　109-110　2013/06/19
Publisher: The Japan Society of Mechanical Engineers

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Effects of Cr content on flow accelerated corrosion (FAC) of carbon steels have been evaluated and their relation to oxide scale characteristics based on detailed oxide layer characterizations using transmission electron microscope with X-ray analyzer have been discussed There is no "threshold" concentration of chromium below which there is no effect of Cr content on the corrosion rate Time dependency to chromium effect has also been not observed Thickness of oxide layer does not affect the FAC rate in this experiments
球状圧子の圧入に伴う表面ひずみ計測に基づく残留応力評価手法における基材物性値の影響

小澤則彦, 吉澤智明, 庄子哲雄, 渡辺豊

機械・構造物の強度設計,安全性評価に関するシンポジウム前刷集　13th　27-30　2013
D113 Evaluation of aging embrittlement of low-carbon austenitic stainless steel weld metal near the BWR operating temperature

TERAO Toshihiko, ABE Hiroshi, WATANABE Yutaka

National Symposium on Power and Energy Systems　2012　(17)　121-124　2012/06/20
Publisher: The Japan Society of Mechanical Engineers

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Austenitic stainless steel weld metal used in boiling water reactor (BWR) is mainly austenitic, but contains up to around 15 % of ferrite. Abe et al. examined aging properties of type 316 low-carbon stainless steel weld metal at 335℃ and suggested that thermal hardening due to spinodal decomposition potentially occur even at lower temperature such as BWR operating temperature (288 ℃). To evaluate the rate of thermal embrittlement of type 316 low-carbon stainless steel weld metal at BWR operating temperature, aging test at 310℃, 335℃, and 400℃ was carried out. It is revealed that hardening with aging at 310℃ was result of spinodal decomposition. Comparing thermal hardening behavior, hardening rate at 288℃ was discussed.
ひずみ計測を併用した圧痕法による金属材料表面の残留応力評価

小澤則彦, 池田泰造, 庄子哲雄, 渡辺豊

日本非破壊検査協会講演大会講演概要集　2012　159-160　2012/05/22
炭素鋼配管の流れ加速型腐食ならびに酸化皮膜構造に及ぼす材料・環境因子の影響評価

阿部博志, 渡辺豊

一般社団法人表面技術協会　63　(5)　290-295　2012
Publisher: The Surface Finishing Society of Japan
DOI： 10.4139/sfj.63.290 　
高Ni合金の環境助長割れ感受性条件の検討(3)高温気相環境での割れ条件と皮膜特性

阿部博志, 渡辺豊, 竹田陽一, 佐藤崇之, 山内大輔, 宮崎孝道, 庄子哲雄

日本原子力学会秋の大会予稿集(CD-ROM)　2011　ROMBUNNO.E49　2011/09/02
高Ni合金の環境助長割れ感受性条件の検討(2)高温水環境での応力下酸化挙動と割れ感受性評価

竹田陽一, 山内大輔, 渡辺豊, 阿部博志, 佐藤崇之, 宮崎孝道, 庄子哲雄

日本原子力学会秋の大会予稿集(CD-ROM)　2011　ROMBUNNO.E48　2011/09/02
高Ni合金の環境助長割れ感受性条件の検討(1)研究内容と成果の概要

渡辺豊, 竹田陽一, 阿部博志, 佐藤崇之, 山内大輔, 宮崎孝道, 庄子哲雄

日本原子力学会秋の大会予稿集(CD-ROM)　2011　ROMBUNNO.E47　2011/09/02
OS2507 Microstructural characteristics and SCC susceptibility near the fusion boundary of dissimilar weld joint with Ni-base weld metal and low alloy steel

ABE Hiroshi, WATANABE Yutaka

2011　"OS2507-1"-"OS2507-2"　2011/07/16
Publisher: The Japan Society of Mechanical Engineers

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Stress corrosion cracking (SCC) behavior near the fusion boundary of dissimilar weld joint with Alloy 182-A533B low alloy steel (LAS) in high temperature water have been investigated focused on the relationship between the crack pass and characteristics of microstructure. It has been observed that spherical and crack-like oxides were formed in LAS. From the results of metallographic observation of the SCC specimens, cracks in Alloy 182 propagated along the dendrite grain boundary, and crack-like oxides in LAS propagated along the prior austenite grain boundary in coarse-grained heat-affected zone. It has been suggested that the continuousness between dendrite and prior austenite grain boundary across the fusion boundary, namely the continuousness of crack pass, affects the SCC behavior in LAS. Possible effect of multiple heat cycle of welding process on the formation of the continuous grain boundary has also been suggested.
C202 Mechanistic study of Cr effect on FAC rate of carbon steel

ABE Hiroshi, WATANABE Yutaka

National Symposium on Power and Energy Systems　2011　(16)　291-292　2011/06/22
Publisher: The Japan Society of Mechanical Engineers

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Combined effects of Cr content and pH on flow accelerated corrosion (FAC) of carbon steels have been formulated and their relation to oxide scale characteristics based on detailed oxide layer characterizations using transmission electron microscope with X-ray analyzer have been discussed. It has been possible that the solubility of Fe_3O_4 was enhanced locally by the high H_2 partial pressure which results from the high corrosion rate. Cr concentration is highest at top surface of oxide layer, and that decrease from surface to oxide / metal interface gradually. It has been suggested that Cr enrichment stabilize oxide layer (decrease solubility of oxide layer), as a result, FAC suppressed.
C211 Effect of material and environmental factors on FAC rate and on characteristics of oxide film of carbon steels

WATANABE Yutaka, ABE Hiroshi

National Symposium on Power and Energy Systems　2010　(15)　345-346　2010/06/20
Publisher: The Japan Society of Mechanical Engineers

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Combined effects of Cr content and pH on corrosion rate of carbon steels due to flow accelerated corrosion have been examined by experiments and their relation to oxide scale characteristics based on detailed oxide layer characterizations using transmission electron microscope with X-ray analyzer have been discussed. Effect of Cr content on FAC mitigation decrease continuously as pH is increased from neutral to 10.4 and effect of pH on that increase significantly from pH 9.1 to 9.4. Obvious Cr enrichment has been observed in the oxide layer of 1.01 wt % Cr content steel regardless pH condition. Cr concentration is highest at top surface of oxide layer, and that decrease from surface to oxide / metal interface gradually. It has been suggested that Cr enrichment stabilize oxide layer (decrease solubility and defect density of oxide layer), as a result, FAC suppressed.
製塩設備模擬環境におけるオーステナイト系合金の応力腐食割れ感受性

津川貴臣, 渡辺豊, 阿部博志

日本海水学会誌　64　(3)　166-167　2010/05/20

ISSN： 0369-4550
B105 Study of FAC rate of carbon steels based on characterization of oxide film

WATANABE Yutaka, ABE Hiroshi

National Symposium on Power and Energy Systems　2009　(14)　59-60　2009/06/28
Publisher: The Japan Society of Mechanical Engineers

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Effects of Cr content and environmental factors, pH and dissolved oxygen concentration, on removal rate of carbon steels due to flow accelerated corrosion have been examined by experiments. Cr content holds a strong impact on the FAC rate regardless of pH values from 6.84 to 10.4. Addition of 1% Cr to carbon steel reduces the FAC rate by one order of magnitude under the environmental conditions, where magnetite forms. Detailed characterizations of oxide film formed on the specimen have been carried out by using SEM and TEM. Preferential corrosion of pearlite phase has been observed at specimen surface of low Cr content steel in early stage of FAC. It has been suggested that oxide structure and porosity were obviously different between low and high Cr content steels.
131 Metallurgical Study on Stress Corrosion Cracking of Type 316L Welds

ABE Hiroshi, WATANABE Yutaka

2008　(43)　63-64　2008/03/15
Publisher: The Japan Society of Mechanical Engineers
応力腐食割れの発生条件と対策＜力学因子を中心に＞

Yutaka Watanabe

The Piping Engineering　49　(2)　13-18　2007/02
Publisher: 日本工業出版
ISSN： 0385-9894
Observation of Electromigration Pattern in Sn-Pb Eutectic Solder by Measuring Micro-Area Temperature under Current Flow

Takashi HASEGAWA, Yutaka WATANABE, Masumi SAKA

Proceedings of the 1992 Annual Meeting of JSME/MMD　2005　601-602　2005/11/04
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/jsmezairiki.2005.0_601 　

eISSN： 2433-1287
応力腐食割れの発生・進展メカニズム

渡辺豊

メインテナンス　245　(245)　22-26　2005/07
Publisher: 科学図書出版
ISSN： 0388-7529
超臨界水環境における金属腐食対策研究の動向

渡辺豊

高圧ガス　40　(7)　585-589　2003/07
Publisher: 高圧ガス保安協会
ISSN： 0452-2311
204 Corrosion Rate and Scale of Ni-base alloys and 316SS in Super Critical Water

SHOJI Kazuhiro, WATANABE Yutaka, ADSCHIRI Tadafumi

2001　(36)　54-55　2001/03/10
Publisher: The Japan Society of Mechanical Engineers

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Supercritical water oxidation (SCWO) is expected as a potential solution decomposition of organic waste, such as PCB and Dioxin. Corrosion control of structural materials is key issue in the applications of supercritical water to such chemical processes. In this study, corrosion rate s of Ni-base alloys and 316SS in 400℃/60MPa with various pH and dissolved oxygen content were investigated. The corrosion behaviors and scales formed were also discussed with thermodynamic stable phase for the experiment conditions.
Cerium-Modification Effects on Grain Boundary Sensitization Characteristics of Stainless Steels.

渡辺豊, 戸野塚哲也, KAIN V, 庄子哲雄, 増山不二光

日本機械学会年次大会講演論文集　1999　(Vol.1)　285-286　1999/07/26
Analysis of stress corrosion cracking of alloys in pressurized high-temperature water

Y Watanabe

DENKI KAGAKU　66　(11)　1083-1088　1998/11

ISSN： 0366-9297
Effect of cerium addition to sensitized stainless steel on grain boundary stress corrosion cracking sensitivity.

戸野塚哲也, 渡辺豊, 近藤達男, 庄子哲雄, 増山不二光

材料と環境討論会講演集　45th　261-262　1998/08
Evaluation of controlling factor for corrosion life of heat exchanger by genetic algorithm. (2)

佐藤武司, 渡辺豊, 加藤靖, 中里俊晴, 東正樹, 中原正大, 庄子哲雄

材料と環境討論会講演集　44th　187-190　1997/09
Effect of addition of rare earth element on thermal sensitization characteristic of stainless steel.

渡辺豊, 戸野塚哲也, 近藤達男, 庄子哲雄

材料と環境討論会講演集　44th　317-320　1997/09
Evaluation of current and potential noise observed in IGSCC process of stainless steel.

渡辺豊, 近藤達男, 庄子哲雄

材料と環境討論会講演集　44th　465-468　1997/09
Evaluation of heat exchanger corrosion life controlling factor by genetic algorithm.

佐藤武司, 渡辺豊, 加藤靖, 中里俊晴, 東正樹, 中原正大, 庄子哲雄

材料と環境講演集　1997　213-216　1997/04
Evaluation of Fatigue Damage by Induced Current Focusing Potential Drop Technique.

村山稔, 庄子哲雄, 渡辺豊

日本機械学会東北支部総会・講演会講演論文集　32nd　41-42　1997/02
Trial of local corrosion prediction by noise analysis. Evaluation on stress corrosion cracking by current noises in high-temperature high-pressure water.

渡辺豊, 庄子哲雄

腐食防食シンポジウム資料　113th　49-57　1997
Publisher: 腐食防食協会
Stress corrosion crack and electro-chemical noise of sensitized stainless steel in high-temperature and high-pressure water.

渡辺豊, 木村史貴, 庄子哲雄

腐食防食討論会講演集　43rd　551-552　1996/10
A study of defects inspection in boiler dram by an Induced Current Focusing Potential Drop technique.

佐藤康元, 清野雅彦, 庄子哲雄, 渡辺豊

日本機械学会材料力学部門講演会講演論文集　1996-A　443-444　1996/09
Evaluation of SCC Behaviors of SUS316 Steels in High-Temperature High-Pressure Water by means of Electrochemical Noise.

渡辺豊, 木村史貴, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1996-A　615-616　1996/09
Creep Behavior and Damage Evaluation of Directionally Solidified Ni-base Superalloy.

駒崎慎一, 渡辺豊, 庄子哲雄, 岸繁雄

日本機械学会材料力学部門講演会講演論文集　1996-B　151-152　1996/09
A study of nondestructive inspection of surface defects of a Type 304 stainless steel weld by use of discrete induction sensor for ICFPD.

庄子哲雄, 佐藤康元, 渡辺豊

日本機械学会東北支部地方講演会講演論文集　1996　(Hachinohe)　25-27　1996/08
Electrochemical noise in a slow strain-rate test of SUS316 steel in high-temperature and high-pressure water.

渡辺豊, 木村史貴, 庄子哲雄

腐食防食講演集　1996　57-60　1996/05
A Nondestructive Evaluation Technique of High Temperature Degradation in Directionally Solidified Nickel-base Superalloy.

武市徹也, 渡辺豊, 駒崎慎一, 庄子哲雄

日本機械学会通常総会講演会講演論文集　73rd　(Pt 2)　270-271　1996/04
Evaluation of Defect and Fatigue Properties of Sintered Iron. Detection of Defect and Fatigue Damage in Sintered Iron by Induced Current Focusing Potential Drop.

小沢則彦, 渡辺豊, 庄子哲雄, 高橋和彦

日本機械学会通常総会講演会講演論文集　73rd　(Pt 2)　330-331　1996/04
A Measurement of Fatigue Damage by Induced Current Focusing Potential Drop Technique

村山稔, 渡辺豊, 佐藤康元, 庄子哲雄

大会講演概要集　1996　(1)　183-186　1996/03/25
Parameter for suitable design of a sensor of Induced Current Focusing Potential Drop method and sensor sensitivity

佐藤康元, 庄子哲雄, 渡辺豊

大会講演概要集　1996　(1)　187-190　1996/03/25
Characteristics of lead induced stress corrosion cracking of alloy 690 in high temperature Peer-reviewed

Koo Kab Chung, Jae Kyoo Lim, Yutaka Watanabe, Tetsuo Shoji

NACE - International Corrosion Conference Series　1996-March　1996/01/01

ISSN： 0361-4409
47. 迷走神経幽門枝切離の幽門輪運動に対する影響(<特集>第24回胃外科研究会)

柴田近, 佐々木巌, 内藤広郎, 土屋誉, 舟山裕士, 宣偉民, 増子毅, 高橋賢一, 松野正紀, 渡辺豊, 庄子哲雄

日本消化器外科学会雑誌　28　(12)　2334-2334　1995/12/01
Publisher: 一般社団法人日本消化器外科学会
ISSN： 0386-9768
Detection of SCC Initiation by means of Impedance Monitoring.

渡辺豊, 山口賢太郎, 森谷信一, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1995-B　169-170　1995/08
A Measurement of Low-Cycle Fatigue Damage by Induced Current Focusing Potential Drop.

村山稔, 庄子哲雄, 渡辺豊, 佐藤康元

日本機械学会材料力学部門講演会講演論文集　1995-B　443-444　1995/08
Evaluation of High Temperature Fatigue Damage Accumulation in INCO718 by Chemical Etching Methods.

駒崎慎一, 渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1995-B　414-415　1995/08
Nondestructive damage evaluation of low-alloy steels for high temperture components.

久保達也, 渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1994-B　401-402　1994/10
Evaluation of High Temperature Fatigue Damage in INCO718 by Electrochemical Method.

駒崎慎一, 渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1994-B　29-30　1994/10
The flexible strain-impedance transducer for the measurement of gastrointestinal motility.

柴垣光隆, 渡辺豊, 庄子哲雄, 柴田近, 内藤広郎, 佐々木巌

日本機械学会全国大会講演論文集　70th　(Pt A)　270-272　1992/09
Nondestructive Evaluation of Fatigue Damage of A508 Steels by the Electrochemical Method.

河守裕二, 渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1992　415-416　1992/08
NONDESTRUCTIVE DETECTION AND EVALUATION OF MATERIALS DEGRADATION OF 2.25CR-1MO STEEL BY MEANS OF ELECTROCHEMICAL METHOD Peer-reviewed

Y WATANABE, T SHOJI

FRACTURE AND STRENGTH 90　51-2　542-548　1991

ISSN： 0252-1059
Development of non-destructive in situ measurement techniques by means of electrochemical method for material degradation of S/H tubes of fossil boilers.

斎藤喜久, 庄子哲雄, 渡辺豊

日本機械学会全国大会講演論文集　68th　(Pt A)　422-424　1990/09
Electrochemical evaluation of IGSCC susceptibility of non-sensitized type 304 stainless steel in high temperature water.

岩淵義昌, 渡辺豊, 八巻健一, 林慎一郎, 庄子哲雄

日本機械学会全国大会講演論文集　68th　(Pt A)　398-400　1990/09
Nondestructive detection and assessment of aged degradation of 2.25 Cr-1 Mo steel by the electrochemical polarization method.

渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　1989　130-131　1989/10/26
Superconducting characteristics of fiber composite YBCA and evaluation of its strength and toughness.

渡辺豊, 庄子哲雄

日本機械学会材料力学部門講演会講演論文集　954th　115-116　1988/10
Electrochemical damage mechanism erosion corrosion of carbon steels.

渡辺豊, 庄子哲雄, 高橋秀明

腐食防食討論会講演集　33rd　376-379　1986/10

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Books and Other Publications 5

原子力保全ハンドブック

日本保全学会

ERC出版　2020/02

ISBN: 9784900622654
Supercritical-Pressure Light Water Cooled Reactors

Hiroshi Abe, Koichiro Ezato, Yoshinori Hamamoto, Yosuke Katsumura, Takeharu Misawa, Hideo Mori, Shunichi Morooka, Yusa Muroya, Yoshiaki Oka, Kazuyuki Takase, Yutaka Watanabe

Springer　2014

ISBN: 9784431550242
機械工学便覧基礎編α３材料力学

日本機械学会編

日本機械学会　2005/06

ISBN: 4888981248
超臨界流体とナノテクノロジー

阿尻雅文

シーエムシー出版　2004/08

ISBN: 4882314614
EPR -A Comprehensive Review-

Vladimir Cihal, Tetsuo Shoji, Vivekanand Kain, Yutaka Watanabe, Rudolf Stefec

2004/03

ISBN: 4990195302

Presentations 33

Corrosion Control Strategy and Required Research International-presentation Invited

WATANABE Yutaka

Fukushima Research Conference on Corrosion Prediction and Mitigation for Key Components of Fukushima Daiichi NPS　2017/11/27
Nondestructive and quantitative detection of pre-existing plastic strain in stainless steels by means of potentiostatic etching International-presentation Invited

Yutaka WATANABE, Shota HOKARI

5th International Symposium on Materials and Reliability in Nuclear Power Plants　2017/09/26
Potential Thermal Ageing Issues in Weld Components of Light Water Reactors after Long Term Service International-presentation Invited

WATANABE Yutaka

4th International Symposium on Materials and Reliability in Nuclear Power Plants　2015/09/20
Evaluation of Crevice Forming Materials for Creviced Stress Corrosion Cracking Tests in Oxygenated High-Temperature Water International-presentation

19th International Corrosion Congress　2014/11/02
Potential Corrosion Issues and Anti-Corrosion Measures Concerning Spent Fuel Pools of Fukushima Daiichi Nuclear Power Plant International-presentation

223rd ECS Meeting　2013/05/12
Anti-Corrosion Measures Concerning Spent Fuel Pools of Fukushima Daiichi Nuclear Power Plant after the Accident International-presentation

Yutaka WATANABE

Corrosion Conference & Expo 2012 (CORCON 2012)　2012/09/26
Effects of Materials and Water Chemistry Factors on FAC Rate of Carbon Steels International-presentation

Yutaka WATANABE, Hiroshi ABE

Second International Conference on Advances in Nuclear Materials (ANM-2011)　2011/02/09
Potential Importance of Microstructural Aspects for Deeper Understanding of SCC Behaviors in Stainless Steels International-presentation

Yutaka WATANABE, Hiroshi ABE

International Seminar on Maintenance Science and Technology for Nuclear Power Plants　2010/11/02
Visualizing Initiation Processes of Stress Corrosion Cracking International-presentation

Yutaka Watanabe, Ryo Ohtake, Kenta Sugimori

The Asian Workshop on maintenance Technology for Nuclear Power Plant　2009/01/20
Corrosion and cracking of alloys in supercritical water International-presentation

International Symposium on Energy Related Materials　2007/11/13
Environmentally Assisted Cracking of Alloys at Temperatures near and above the Critical Temperature of Water International-presentation

International Corrosion Engineering Conference 2007　2007/05/20
Oxide Solubility-Based Approach for Predicting Corrosion Rate of Alloys in Aggressive Environments near and above the Critical Temperature of Water International-presentation

8th International Symposium on Hydrothermal Reactions (ISHR-8) and 7th International Conference on Solvothermal Reactions (ICSTR-7)　2006/08/05
CORROSION OF ALLOYS IN AGGRESSIVE ENVIRONMENTS NEAR AND ABOVE THE CRITICAL TEMPERATURE OF WATER International-presentation

16th International Corrosion Congress　2005/09/19
高圧過熱水蒸気中でのフェライト系耐熱鋼の酸化速度とスケール構造

日本鉄鋼協会安全率・許容応力設定調査委員会　2005/03/10
超臨界水環境での腐食速度と酸化皮膜

日本金属学会2004年秋期講演大会　2004/09/30
超臨界水環境での腐食と割れ：解ったことと解らないこと

第11回SIC研修セミナー特別講演　2004/02/25
Corrosion and cracking of alloys in supercritical water environments: from a “physical property of water” point of view International-presentation

SCR-2003 “Radiation Effects on Water Chemistry of Supercritical Water-cooled Reactor”　2003/09/18
超臨界水中および高温液相中での腐食と割れ：水の基本物性の視点から

水化学標準研究専門委員会（日本原子力学会）　2003/07/11
超臨界水反応容器材料の腐食および応力腐食割れ−環境因子と材料因子−

第33回Continuing Educationシリーズ講習会「超臨界応用技術の新展開−反応・環境・エネルギー分野において」　2002/12/05
Characteristics and a few key parameters of corrosion of alloys in supercritical water environments International-presentation

Yutaka Watanabe, Yuzo Daigo, Kiwamu Sue, Tadafumi Adschiri

International Symposium on Metals and Alloys in Chemical Industries　2002/11/15
超臨界水腐食における支配因子の考え方と課題

第137回腐食防食シンポジウム（腐食防食協会）− 超臨界水利用技術の開発と装置材料の腐食防食研究の現状　2002/10/04
電気化学ノイズから割れの発生位置は判るか？

第135回腐食防食シンポジウム－電気化学ノイズ解析の現状と腐食モニタリングへの展開　2001/11/16
Characteristics and A Few Key Parameters of Corrosion and Cracking of Alloys in Supercritical Water International-presentation Invited

Yutaka WATANABE, Tadafumi ADSCHIRI, Kiwamu SUE

Supercritical Water Oxidation - Achievements and Challenges in Commercial Applications, Sponsored by U.S. Army and U.S. Navy　2001/08/14
超臨界水の特徴とその金属腐食への影響

特別講演会「高温高圧流体中における装置材料の腐食防食技術」　2001/06/29
超臨界水の特徴と合金の腐食挙動

腐食防食協会材料のパフォーマンス研究会　2001/04/13
超臨界水・亜臨界水環境での耐食合金の腐食と応力腐食割れ

日本原子力学会水化学最適化研究専門委員会構造材－水環境相互作用部会　2000/12/04
Importance of Pressure in Corrosion and Oxydation of Alloys in Supercritical Water and Superheated Steam International-presentation

The First International Symposium on Supercritical Water-Cooled Reactors, Design and Technology　2000/11/06
Crack Growth Behavior of Ferritic Steel for USC Boilers in Pressurized Superheated Steam International-presentation

International Symposium on High-Temperature Corrosion and Protection 2000　2000/09/17

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(プロシーディング) Proceedings of the International Symposium on High-Temperature Corrosion and Protection 2000 Science Reviews 2000 423 428
材料工学の観点からの水利用－腐食・防食技術

東北サマーシンポジウム（（社）日本化学工学会東北支部主催）　2000/08/24
高温高圧水中応力腐食割れ試験における電気化学ノイズ計測および評価の現状

第124回腐食防食シンポジウム電気化学ノイズ解析による腐食モニタリング　1999/10/29
フェライト系耐熱鋼の高圧過熱水蒸気酸化 − 酸化速度の鋼種・温度・圧力依存性

耐熱鋼の水蒸気酸化に関する研究会　1999/02/19
電流ノイズによる高温高圧水中応力腐食割れの評価

第113回腐食防食シンポジウムノイズアナリシスによる局部腐食予測の試み　1997/05/29
高温高圧水中環境助長割れ評価と局所情報計測

第83回日本材料学会破壊力学部門委員会講演会　1996/07/02

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Industrial Property Rights 4

ステンレス鋼の塑性ひずみの検出方法

渡邉豊, 鈴木明好

特許5495033

Property Type: Patent
応力腐食割れおよび孔食等の発生検知方法

渡辺豊

特許第4872087号

Property Type: Patent
超臨界水環境での金属防食方法

渡辺豊, 太期雄三

Property Type: Patent
超臨界水反応容器

渡辺豊, 梶ヶ谷哲史

Property Type: Patent

Research Projects 34

過酷事故原子炉の廃止措置におけるリスク管理 Competitive

2014/10 - Present
燃料デブリ研究とSEEM学構築を基軸とした研究人材育成

Offer Organization: 国立研究開発法人日本原子力研究開発機構

System: 英知を結集した原子力科学技術・人材育成推進事業研究人材育成型廃炉研究プログラム

Institution: 国立大学法人東北大学

2024/09 - 2029/03
Mechanistic study on unique corrosion phenomena in specific environments and challenges to extend the service life of accelerators and irradiation facilities

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2023/04/01 - 2026/03/31
古代の出土文化財が教えてくれる1000年超の腐食寿命予測モデル

渡辺豊, 宮崎孝道, 阿部博志, 柳田明進, 山本正弘

Offer Organization: 日本学術振興会

System: 科学研究費助成事業基盤研究(B)

Category: 基盤研究(B)

Institution: 東北大学

2022/04/01 - 2025/03/31
軽水炉１次系隙間腐食抑止と隙間水質迅速浄化技術の開発：化学的ポンピング手法の創案

渡辺豊, 宮崎孝道, 阿部博志, 竹田陽一, 青木聡

Offer Organization: 日本学術振興会

System: 科学研究費助成事業基盤研究(B)

Category: 基盤研究(B)

Institution: 東北大学

2019/04/01 - 2022/03/31

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（１）バルク水環境の高純度水による置換のみを用いた通常の浄化手段と比較して、バルク水へのNa2MoO4あるいはK2MoO4の添加と高純度化を交互に行うことによる『化学的ポンピング操作』により隙間内浄化(Cl-の排出)が加速される効果を評価・実証した。すなわち、一定時間後の隙間内溶液のCl-濃度を、隙間内環境にモリブデン酸塩が共存している場合としていない場合で比較し、後者を基準としてモリブデン酸塩添加によるCl-排出促進効果を定量的に調査した。当該実験において、当初は、狭隘液絡部と液溜まり部を有するチタン製ブロックの試験体を使用していたが、同一条件下においてもCl-濃度のバラツキが大きいことが問題であった。そこで、ステンレス鋼製の針を有する注射器を改造して、狭隘液絡部と液溜まり部を有する試験体を作製することにより、試験後にイオン分析に持ち込むまでの操作を減らした。これによって、実験の再現性が格段に向上した。（２）多様な条件下での予測技術への展開を図るため、COMSOLをベースとして、隙間内環境浄化のプロセスを再現可能な数値シミュレーションを実現した。（３）NaCl水溶液中での隙間腐食試験へのトレーサー技術の適用方法を確立することを目標に予備試験を実施した。試験片にはSUS304ステンレス鋼製M4六角ボルトおよびナットを、試験溶液は0.6 mol/L NaCl水溶液(室温、放射能量8 kBq / 20.4mL (Cl- 20853 ppm))を用いた。30日間自然浸漬したがすきま腐食の発生は認められなかった。また、イメージングプレートを用いて36Cl-トレーサーを分析したが、今回の試験条件では検出できなかった。
Development of a visualization method of hidden damage for integrity evaluation of components exposed to a massive earthquake

Watanabe Yutaka

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2016/04/01 - 2019/03/31

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A potentiostatic etching method to visualize plastic strain introduced in stainless steels has been newly developed, where difference in dissolution rate of metal due to local mis-orientation caused by deformation twin or accumulation of dislocation at slip planes is utilized. This method can detect and quantify pre-existing plastic strain introduced in stainless steels at ambient temperature or at operating temperature of a nuclear reactor. The potentiostatic etching method has been first developed for Type 316 stainless steels and then a methodology has been developed in order to apply the etching method to evaluate other types of austenitic stainless steels. A procedure to apply the etching method to actual components has also been proposed.
Hydrogen Embrittlement Suppression Based on Protective Film-Oriented Compositional Design

WATANABE Yutaka, ABE Hiroshi, MIYAZAKI Takamichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2012/04/01 - 2014/03/31

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Oxide species of which solubility of hydrogen is extremely low has been investigated based on literature survey. It has been considered that Cr2O3 shows excellent performance from the suppression of hydrogen permeation point of view. Hydrogen permeability of the oxide layer which formed on type 430 stainless steel with different condition of surface finish and oxidation treatment has been evaluated by electrochemical hydrogen permeation technique. Even a nanometer-scaled Cr rich oxide decrease the hydrogen permission current significantly. Different hydrogen permission current behaviors have been found for different type of surface finish and it may be due to the difference in protectiveness of oxide layer.
Understanding initiation processes of stress corrosion cracking by means of real time imaging and development of anti-SCC materials

WATANABE Yutaka, TAKEDA Yoichi, OIKAWA Katsunari, ABE Hiroshi, MIYAZAKI Takamichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2010 - 2012

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A visualization method has been developed, where local and transient anodic events occurring in initiation processes of stress corrosion cracking can be observed in a wide window and in real time. The initiation process was found to be intermittent and very small-scale anodic events and their repassivation. Cracks tend to initiate at the location where a few anodic events occur in proximity to each other. In most cases, oxide inclusions containing Si, Mg, or Al, provided initiation sites. Stress corrosion cracks tend to retard when they reach δ-ferrite located on grain boundaries (especially on triple points). We may be able to effectively improve SCC initiation life of steels by locatingδ-ferrite on grain boundaries as much as up to a few % of volume fraction.
Study on Environmentally Assisted Degradation of Structural Components in Supercritical Water Oxidizing Environment Competitive

1999/04 - 2008/03
Study on Oxidation and Environmentally Assisted Cracking of Advanced Heat - Resistant Alloys in Superheated Steam Competitive

1996/04 - 2008/03
A new concept for predicting corrosion resistance of alloys in high-temperature water environments based on oxide solubility

WATANABE Yutaka, SUE Kiwamu, HARA Nobuyoshi, OGAWA Kazuhiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2006 - 2008
Nano-Crystallization by Using Cavitation Shotless Peening

SOYAMA Hitoshi, WATANABE Yutaka, YAMANAKA Masashi, KAI Akira

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2005 - 2006

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The main results obtained are as follows: 1. Cavitation impact was increased by increases of injection pressure of cavitating jet and an ambient pressure at cavitation bubble collapsing region. Novel cavitation shotless peening, which use a cavitating jet in water with associated water jet, was proposed and it was revealed that the ability of the jet was increased. 2. In order to make clear a mechanism of improvement of fatigue strength by cavitation shotless peening, residual stress was precisely measured by using an X-ray diffraction method. It was revealed that residual stress was closely related to the improvement of fatigue strength by cavitation shotless peening. 3. A fundamental parameter approach was tried to evaluate grain size and micro strain. It was revealed that the fundamental parameter approach can evaluate them. It was found that cavitation shotless peening relieved micro strain with introducing macro strain, i.e., compressive residual stress. 4. It was revealed that plastic deformation depth, elastic deformation depth and maximum deformation depth could evaluate the characteristics of the surface treated by cavitation shotless peening using indentation test. 5. In order to make clear the mechanism of gettering using cavitation shotless peening, the gettering site of silicon wafer was observed by using a transmitting electron microscope, the gettering site was consist of the dislocations whose size was about 100 nm. 6. Cavitation impact was increased by changing nozzle outlet geometry, the peening effect was increased, and then the improvement of fatigue strength was also increased. It was revealed at treatment of gear teeth that the consideration of flow pattern at mechanical parts of cavitation shotless peening was very important.
軽水炉の高経年化対応研究 Competitive

System: Funded Research

2005/04 -
Study of Next Cavitation Shotless Peening

SOYAMA Hitoshi, WATANABE Yutaka, YAMANAKA Masashi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2002 - 2004

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The main results obtained are as follows : 1.The cavitating jet in air was observed and it was revealed that the periodical cavitation-cloud-shedding around the high-speed water jet and the fluctuation of the low-speed water jet were interfered each other. 2.Pure aluminum specimen was treated by the cavitation shotless peening. It was revealed by means of recrystallization-etch technique that the plastic deformation was induced by the cavitation shotless peening. 3.The cavitation impacts energy was measured by the cavitation impact counter. It was revealed that the cavitation impacts induced by the cavitating jet in air were more intense compared with that of the cavitating jet in water. 4.The stress distribution of cavitation impacts was estimated by the shape of plastic deformation pits. In order to apply the cavitation shotless peening to tribology area, the introduction of compressive residual stress into titanium alloy was revealed. 5.In order to establish monitoring method of cavitation shotless peening, the relation between the impact energy measured by the PVDF sensor and the vibration measured by the laser doppler velocity meter were revealed. 6.The proposed shotless peening and the conventional shot peening were compared. The difference of the peening methods in view point of introduction of compressive residual and the improvement of fatigue strength was revealed. 7.In order to control the cavitation impact intensity, the plastic deformation pits produced by cavitation shotless peening were measured precisely. The pressure distribution of cavitation impact was successfully controlled by the injection pressure of the low-speed water jet and the standoff distance. 8.The injection pressure of the low-speed water jet and the standoff distance, which were the main parameters of the cavitation shotless peening, were optimized.
活性酸素の高耐食性不動態被膜生成への有効利用

祖山均, 渡辺豊

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽研究

Category: 萌芽研究

Institution: 東北大学

2002 - 2003

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本研究は,一般には流体機械に振動や騒音、致命的損傷を生じる害悪であるキャビテーション気泡の崩壊時に生じる局所的高圧かつ高温環境下を用いて,キャビテーション噴流が活性酸素を生成することを実証し,この活性酸素の高耐食性不動態被膜生成への有効利用を目的とする。本年度は,昨年度の成果を踏まえて以下の研究を実施した。 1.活性酸素生成を目的としたキャビテーション噴流の最適化キャビテーション気泡の崩壊衝撃力の計測等により,キャビテーション噴流の最適噴射条件を明らかにした。キャビテーション噴流をシリコンウェーハ裏面に噴射して生成させた酸化積層欠陥により,ゲッタリング効果があることを実証した。さらにキャビテーション噴流により加工して酸化積層欠陥を生じる場合には,X線回折によりシリコンの結晶構造が乱れていること,ならびにWrightエッチングによりエッチピットを生じる、ことを明らかにした。 2.活性酸素による耐食性不動態被膜生成の最適化生成した金属酸化物の酸化被膜が生じる光電効果において,ある一定のひずみを付与することにより,短絡電流が増大して,光起電力が増大する事実を明らかにした。なおこのときには開放電圧はほとんどひずみの影響を受けなかった。しかしながら,この一定値以上のひずみを負荷すると,短絡電流ならびに開放電圧ともに低下して,光起電力が著しく低下することが判明した。すなわち,ひずみによる金属酸化物半導体の光起電力向上においては最適値が存在することが判明した。
Understanding and Mitigatin of Stress Corrosion Cracking of Reactor Vassel Materials in Oxidizing Supercritical Water Environments

WATANABE Yutaka, IKUSHIMA Yutaka, YUGAMI Hiroo, AJIRI Tadafumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2001 - 2003

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Corrosion morphology and rates of various corrosion resistant alloys have been examined in simulated environments of supercritical water oxidation processes. Importance of physical property of water, in particular dielectric constant, to corrosion of metals in supercritical water have been demonstrated. It has been demonstrated that corrosion rate of metals in supercritical water is strongly dependent on applied pressure and can he uniquely arranged by dielectric constant of water including both supercritical state and sub-critical liquid phase. Scale oxides formed in supercritical water environments were in good agreement with thermodynamically predicted oxide. Corrosion rate was able to be correlated with types of the scale oxides. Slow strain rate tests have been performed in neutral to acidic supercritical water up to 550℃/6OMPa to evaluate stress corrosion cracking (SCC) behavior of alloys in supercritical water environments. Effects of applied pressure (water density or dielectric constant effect) and sulfuric acid have been demonstrated. For sensitized stainless steel -pure water system, effects of phase state of water and applied pressure, more essentially, physical property of water, were clearly observed. SCC did not occur in the oxygenated "gas-like" supercritical water at 400℃/25MPa. Cracking occurred at 400℃/30MPa and the cracking severity was more pronounced as applied pressure was increased up to 60MPa at the same temperature. The results gave a strong evidence of the "dissolution mechanism". In contrast, for non-sensitized stainless steel -sulfuric acid water system, severe cracking with IG occurred even in a "gas-like" supercritical water and dielectric constant did not affect cracking severity. The results would indicate "dissolution mechanism" is not very likely and might suggest "oxidation cracking". Importance of aging degradation in both mechanical properties and corrosion resistance in supercritical water environments has been pointed out. A new corrosion-inhibition method for supercritical water environments has been developed, where dependence of solubility of Cr oxides on temperature and dielectric constant of water is utilized.
Development of Shotless Peening System and Manufacturing Considering Preservation of Environment

SOYAMA Hitoshi, KOBAYASHI Yuji, YAMANAKA Masashi, WATANABE Yutaka

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2001 - 2003

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1.The cavitating jet in air was successfully realized using cavitation shotless peening system without a water-filled chamber. It was revealed that the cavitating jet in air was most powerful compared with a cavitating jet in water and a normal water jet in air. 2.The erosion test and measurement of cavitation intensity were carried out at various conditions to measure the ability of cavitating jet in air, then the optimum condition of the cavitating jet was obtained. 3.Several steel were peened by the cavitating jet in air, the residual stress was measured by an X-ray diffraction method. The introduction of compressive residual stress was demonstrated. It shows the possibility of the surface modification by using the cavitating jet in air. 4.The optimum peening time was obtained from the relation of the peening time and the residual stress or the fatigue test at constant load changing with the peening time. 5.In order to compare the proposed shotless peening considering the prevention of environment and the conventional shot peening, a rotating bending fatigue test was carried out, and it was shown that the improvement of fatigue strength by shotless peening was better than that of shot peening. 6.In order to establish non-destructive testing method to evaluate the surface modification layer peened by the shotless peening, the residual stress and austenitic ratio were measured by using an X-ray diffraction method. 7.The improvement of fatigue strength of gear was demonstrated by a bending fatigue test of gear tooth comparing the result of shot peening. 8.In order to apply the shotless peening to various materials, the relation between the cavitation intensity and the materials properties was investigated, and the fundamental threshold level of materials for the cavitation impact was revealed.
Physics and Chemistry of Fracture and Failure Prevention

SHOJI Tetsuo, WATANABE Yutaka, SAKA Masumi, YOKOBORI Toshimitsu, KOKAWA Hiriyuki, KITAMURA Masaharu

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for COE Research

Category: Grant-in-Aid for COE Research

Institution: Tohoku University

1999 - 2003

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Assurance of reliability of materials and structures with synergistic effects of combined environments by mechanical, chemical, radiation and high temperature conditions is extremely important for prevention of failure and accidents. In general, failure accidents are initiated by local damage and its extension by aging. Therefore, in order to prevent these failures, detection and evaluation of the degradation at an early stage is essential. Especially, technology for 21^<st> century will go towards more precise, higher speed, higher efficiency and higher temperature and pressure and consequently, surrounding environments which materials and structures will face to can be severer than before more. The objective of this research program is to conduct a comprehensive research on mechanics and mechanisms of fracture and to construct a failure prevention system. It has been well recognized that the macroscopic approach such as Fracture Mechanics has been successfully used for structural integrity and safety assessment in purely mechanical loading condition but not in environmental condition where physical and chemical reactions at crack tip plays a crucial role in fracture. Therefore, a local approach is mandatory for mechanistic understanding of this complicated fracture from a viewpoint of physics and chemistry of fracture. Measurements of local information such as local characteristics of materials, local environment such as local water chemistry at crack tip, for examples, are essential for the local approach. In the same way, local crack tip strain and tiny defects are also of importance for the local approach. These local measurements are in the order of a few nanometer to several hundreds micrometer and several tens nano-liter to a few micro-liter. Especially, an emphasis has been placed to carry out the research on crack initiation and early stage of propagation based upon local parameters obtained by a fusion of various local information, which govern the most of the life time of the components. In this program, following research areas have been covered as, (I)mechanistic understanding of physics and chemistry of fracture, (II)-1 methodology development for local measurements of materials chemistry, (II)-2 methodology development for local measurements of crack tip water chemistry, (II)-3 methodology development for local measurements of crack tip mechanics, (II)-4 methodology development for local measurements of defects (III) construction of a prediction system of failure based upon a fusion these local information. The program has been carried out by the research group shown below who have been made a significant contribution internationally on the research areas of physic and chemistry of fracture, grain boundary engineering, raser ultrasonic microscope, intelligent instrumentations, fracture in complex systems, damage evaluation and so on. After this program, this activity has been reinforced by initiating a new research institute, Fracture and Reliability Research Institute as a new extension of former Fracture Research Institute. The Institute maintains the facilities, spaces and international research network
Research on Hybrid Surface Modification by Cavitating Jet

SOYAMA Hitoshi, WATANABE Yutaka, SAKA Masumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

1999 - 2001

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1. Injecting a cavitating jet to metallic materials such as stainless steel, silicon manganese steel, tool alloy and carbon steel, it was revealed that the cavitating jet can introduce compressive residual stress on the metallic materials by means of X-ray diffraction method. It was also revealed to evaluate the surface modification with depth from the surface by using Micro-Vickers hardness testing changing with the load. 2. It was revealed that the corrosion resistance and the mechanical strength of carbon steel were improved at same time, i.e., hybrid surface modification, by using a cavitating jet. 3. The flow rate of various type of nozzle was measured. The cylindrical nozzle was suitable for the cavitating jet for the hybrid surface modification in view point of repeatability. 4. Cavitation impacts were measured by a PVDF transducer, which is developed by the investigators, for various cavitating conditions. The intensity of cavitation impact can be controlled by the upstream and downstream pressure of the nozzle. 5. It was shown that the cavitating jet could improve the fatigue strength of aluminum alloy casting, silicon manganese steel and carbonized steel. 6. Cavitating flow was affected by the shape of impinging surface. In order to treat gear, the optimum peening condition was investigated. It was revealed that the peened surface by a cavitating jet was very smooth comparing with that of the shot peening. 7. It was shown that the roughness of the surface and the residual stress were main factor of optimum processing time. It will be possible to evaluate the surface modification by means of the residual stress using X-ray diffraction method.
Monitoring and Understanding Initiation of Stress Corrosion Crocking Competitive

2000/04 -
ナノスケール・アプローチによるニッケル基600合金および690合金の応力腐食割れ機構の解明

渡辺豊, KAIN V.

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

1999 - 2000
Research on Surface Modification System by Using a Cavitating Jet

SOYAMA Hitoshi, URANISHI Kazuo, WATANABE Yutaka, ITO Takatoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B).

Category: Grant-in-Aid for Scientific Research (B).

Institution: Tohoku University

1998 - 2000

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1.Surface modification system has been developed considering scale effects of nozzle diameter. Diameter of nozzle is from 0.4mm to 1.9mm. 2.Cavitation impacts were measured by a PVDF transducer for various cavitating conditions. When the nozzle diameter was increased, the frequencies of the cavitation impacts were not only increased but also the intensity of the cavitation impacts increased. Reducing air contents ration in the test water also increased the cavitation impacts. 3.Optimum peening time or optimum scanning speed was demonstrated by measuring hardness or residual stress. The cavitating jet can introduced compressive residual stress in the surface of the materials. The value of the compression was saturated at certain processing time or speed. In case of the improvement of the corrosion resistance by using a cavitating jet, optimum processing time was obtained by the relation between the potential by means of an electrochemical method and the processing time. 4.Regarding test liquid of the cavitating jet, several liquids ware tested changing with pH.Suitable test liquids for iron were clarified referring Pourbaix diagram of iron. 5.Peening for gears and specimens with a notch was carried out. It was revealed that the peened surface by a cavitating jet was very smooth comparing with that of the shot peening. The cavitating jet can also introduce the compressive residual stress into hard materials such as tool alloy SKD61. 6.In order to demonstrate improvement of fatigue strength by suing a cavitating jet, a rotating bending fatigue test was carried out. It was shown that the cavitating jet could improve the fatigue strength. It was also revealed that the cavitating jet could improve the corrosion resistance about 30% by means of an electrochemical method.
Development of monitoring method for SCC initiotion in LWR components by means of electrochemical noise analysis

WATANABE Yutaka, SUZUKI Shunichi, HARA Nobuyoshi, SHOJI Testuro, KAWAMURA Hirotaka, OONAKA Noriyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B).

Category: Grant-in-Aid for Scientific Research (B).

Institution: TOHOKU UNIVERSITY

1998 - 2000

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1. Testing facilities were developed to monitor electrochemical noise generating during stress corrosion cracking(SCC)processes of alloys in simulated LWR coolant environments. In particular, ground loop problems and fluctuation in pressure, which can cause electrochemical noise, were solved and successful monitoring of electrochemical noise with high sensitivity was achieved. 2. The three electrodes method, which consists of a working electrode(specimen), a counter electrode made of the identical material to the specimen, and a reference electrode, was adopted to simultaneously monitor fluctuations of coupling current and of corrosion potential. It was successfully demonstrated that SCC initiation in pressurized high-temperature water can be detected with high sensitivity by this method. 3. Based on current noise analysis, the slip dissolution mechanism was supported for SCC of sensitized stainless steels in a simulated boiling water reactor(BWR)environment. 4. As for SCC of Ni-base Alloy 600 in primary water of pressurized water reactor(PWR), cathodic current spikes were superimposed on anodic current spikes, indicating that both anodic dissolution of metal and cathodic reaction(hydrogen generation)were enhanced on bare metal surface produced by mechanical film rupture. This fact supports either the slip dissolution mechanism or hydrogen cracking. 5. It was found that excess electrons produced by transient anodic dissolution of metal were temporarily accumulated at double layer capacitance of metal-water interface. This fact implies that relatively large anodic event can take place, if that is a transient event, even in the primary water environment, where concentration of oxidizer is very low. 6. A concept of multiple counter electrodes method was devised for monitoring of SCC initiation in plant components and validity of the concept was demonstrated by a model experiment.
応力腐食割れに免疫なステンレス鋼の開発

渡辺豊, 粕壁善隆

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽的研究

Category: 萌芽的研究

Institution: 東北大学

1998 - 1999

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本研究は、希土類元素セリウムを適量添加することによりステンレス鋼の応力腐食割れに対する耐性を飛躍的に向上させるとともに、微視構造の観点から割れ抑制機構を明らかにすることを目的とするものである。とくに鋭敏化熱履歴後の高温水中での応力腐食割れ感受性の改善効果に主として焦点を当て、本年度は、下記の成果を挙げた。 (1)セリウムの微量添加によりSUS316鋼において鋭敏化熱処理後の応力腐食割れ感受性が抑制される場合のあることを前年度に見いだした。本年度は、割れ抑制効果が発現する条件範囲をセリウム添加量、熱処理条件の双方の関数としてより詳細を明らかにした。600℃〜700℃の温度範囲で溶接熱影響を模擬した数種の熱処理を施した試料を用意し、高温高圧水中での応力腐食割れ感受性を割れ破面率および割れ発生個数に基づいて評価した結果、無添加材に対してEPRレシオ10%程度までの鋭敏化度を与える鋭敏化熱処理条件において、セリウム添加の効果が現れることが判った。添加量としては、0.01wt%において割れ感受性が最も改善されるが、0.04wt%以上の添加では改善効果は現れないことが判った。 (2)高温水中で形成される皮膜に及ぼすセリウム添加の効果をオージェ電子分光法、X線回折法などにより調べた結果、セリウム添加により皮膜厚さが30%程度小さくなる傾向が認められたが、その他顕著な特徴は見いだされなかった。 (3)セリウム添加による割れ感受性改善効果の発現機構の解明を目的として、鋭敏化特性をセリウム添加量、熱処理条件の双方の関数として詳細に調べた。セリウム添加は材料の鋭敏化およびその回復速度をともに減速する効果があることが判った。これは、原子半径の大きなセリウムが固溶することによってCrの拡散速度が低下することに依るものと理解された。この効果により鋭敏化初期において割れが抑制されることが判った。
A cooperative Study on Environmentally Assisted Cracking of structural materials of nuclear reactor

SHOJI Tetsuo, MINKOV DORIAN, WATANABE Yutaka, SAKA Masumi, NAKAJIMA Mikiko, RAJA KRISHNAN SELVA

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B).

Category: Grant-in-Aid for Scientific Research (B).

Institution: Tohoku University

1997 - 1999

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Assuring the safety of nuclear power plants is an important issue all over the world. Especially the quantitative evaluation of environmentally assisted cracking (EAC) of materials in high temperature water is critical. However, EAC is affected by so many factors that estimation is not accurate enough up to now. This is a cooperative research that combines the fundamental research achievements on EAC of the leader of this project with the research results of Russian researchers who possess rich data of practical nuclear reactors. Main achievements can be summarized as follows : (1) The relation between corrosion fatigue crack growth rate and the shape of MnS inclusions has been studied. It has been shown that the size distribution of the inclusions is more important than the total sulfur content in steel. Reactor pressure vessel steel made by Russian that has high sulfur content but well distributed small particles of MnS inclusions was evaluated in Tohoku University. Results showed that the higher crack growth rate expected only from the sulfur content was not observed. (2) Detection method for small defects have been studied. The validities of induced current focusing potential drop (ICFPD) technique and direct current potential drop (DCPD) technique using adjacent probes were confirmed. A cooperative research project on how to detect inside defects in stainless steel welds from the outer surface has been set up for the future. The materials will be prepared by Central Institute of Structural Materials in Russian. The evaluation will be done in Tohoku University. (3) The relation between aging degradation of surface film and EAC has been studied. The research results on contact electric resistance and other electric properties accompanying film growth were exchanged. According to the electric property change with film growth during irradiation, the relation to irradiation assisted stress corrosion cracking has been made clearer. (4) Investigation for improvement for EAC incidents of VVER type nuclear power plants and, strong methods of material test has been done. Defect detection and crack growth rate evaluation have been suggested. (5) EAC at condensation pail of low pressure seam turbine has been researched. A practical plan about experimental facilities and analysis has been suggested. It has been made clear that Kelvin probe is useful for evaluating corrosion in the thin water layer condition. The experiments have been carried out partly.
Experimental investigation for the theory of environment assisted cracking on local environmental conditions

SHOJI Tetsuo, NAKAJIMA Mikiko, WATANABE Yutaka, MINKOV Dorian, TAMAKAWA Kinji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

1997 - 1999

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A theoretical formulation of crack growth rate based on the film rupture/slip dissolution mechanism was proposed by the head of investigators of this project. However, it is difficult to evaluate crack growth rate quantitatively because of diversities of mechanical, metallurgical, environmental and their interaction parameters. Measurements of local conditions around crack tip were required for the parameters included in the theoretical formulation, aiming which quantitative information of the local environmental condition was the most important. Accordingly, this project was started from 1997 and main achievements can be summarized as follows. (1) Although the sampled volume could be reduced from 50μL to 2μL by the improvement of the micro-sampling system, it was still needed to reduce the sampled volume. A novel sampling method was developed in this study and optimization was performed. Maximum resolution could be improved to about 5ppb of ClィイD1-ィエD1 and SOィイD32-(/)4ィエD3. The experiments mentioned above was performed on the specimens made of both low alloy and stainless steels in high temperature, high pressure water environments. (2) Local physical properties of surface film formed due to the local active environment were measured by atomic force microscope and magnetic force microscope, and it turned out that electrical and magnetic properties of films could be changed in different environment. In-situ contact electric resistance (CER) measurements were performed in high temperature, high pressure water as an in-situ local measurement of local physical properties of surface film. Results showed that CER of the film depends on corrosion potential, temperature and materials. (3) Results showed that the parameter "m" for dissolution characteristics of new bare surface was very important, which depends strongly on crack tip solution chemistry. The effect of crack tip strain rate on parameter "m" was taken into account in the theoretical formulation. Unknown parameters were obtained by inverse analysis. The results of theoretical analysis were in good agreement with experimental results.
Exploration of Potential Material - Coolant System in Application to A First Wall Structure of Fusion Reactors

WATANABE Yutaka, HISHINUMA Akimichi, RAJA Krishnan selva, SHOJI Testuo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: TOHOKU UNIVERSITY

1997 - 1999

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To develop a first wall structure of fusion reactors, which separates plasma and energy conversion system, solutions for material-related issues, such as irradiation induced degradation and compatibility with environments, are required. In this project, a new design concept was proposed to give a potential solution for this problem, where pressurized superheated steam is used as coolant. An experimental evaluation was carried out of the compatibility of several candidate fusion structural materials using pressurized superheated steam (up to 70℃, 100 bar) as test environment. The tested candidate materials include (1) low-activation ferritic-martensitic steel F82H, (2) vanadium alloys, and (3) TiAl-based intermetallic compounds. Based on the oxidation rates and results of oxide scale analysis, following conclusions were drawn; 1. TiAl-based alloys showed the highest oxidation resistance in superheated steam environment. Steam oxidation property of F82H was equivalent to that of advanced heat-resistant steels for USC boiler application. Both the TiAl-based alloys and F82H have sufficient compatibility with superheated steam environment from an oxidation rate point of view. 2. In particular, Ti-Al-V alloy, which has about 8% ductility at room temperature, showed excellent oxidation resistance in superheated steam. 3. AlィイD22ィエD2OィイD23ィエD2 did not form as a continuous layer both for TiAl and Ti-Al-V in superheated steam, where oxidation potential of the environment was not high, and hence, AlィイD22ィエD2OィイD23ィエD2 did not work as a diffusion barrier. However, the relatively low oxidation potential of the environment does not allow to form VィイD22ィエD2OィイD25ィエD2. Therefore, accelerated oxidation did not occur for Ti-Al-V. The excellent oxidation resistance of Ti-Al-V was explained that substitutional solid solution of V in the oxide scale TiOィイD22ィエD2 lowered concentration of oxygen vacancy in the oxide scale due to smaller atomic radius of V compared with Ti and, as a result, diffusion rate of oxygen decreased.
nondestructive measurement of degradation in aged plants and remaining life evaluation system

SHOJI Tetsuo, TAMAKAWA Kinji, NAKAJIMA Mikiko, WATANABE Yutaka, SAKA Masumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: TOHOKU UNIVERSITY

1995 - 1997

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Degradation mechanisms which can take place in aged energy plant components are widely varied depending on material of the component, service environment, and operating conditions. For plant life management and extension, prediction of remaining lives of the plants which is based on detection and quantitative evaluation of in-service degradation of the components. (1) development of nondestructive inspection methods for various types of degradation which are respectively based on the degradation mechanisms, and (2) development of a prototype system which can specify the dominant deterioration factors for a aged plant components under given operation conditions, have been in the scope of this research project. For defect-type degradation, Induced Current Focused Potential Drop method has been successfully applied to determine shape and size of three dimensionally shaped surface cracks. For material-type degradation, Electrochemical Materials Characterization methods have been developed for the following degradations which no nondestructive inspection methods have been available for ; creep damage in directionally solidified Ni-base super alloy for gas turbine applications, creep damage in W-modified heat-resistant ferritic steels, high-temperature low-cycle fatigue damage in Ni-base superalloys, thermally aging embrittlement of duplex stainless cast, and aging embrittlement of type 310S stainless steel. With respect to the life evaluation system, genetic algorithm has been introduced to develop the prototype system which supports identifying dominant factors for in-service degradation and helps to predict remaining lives of components. The system has been successfully applied to corrosion damage evaluation of heat-exchanger tubes of chemical plants.
RESEARCH ON NONDESTRUCTIVE MEASUREMENT OF FATIGUE DAMAGE

SHOJI Tetsuo, TAMAKAWA Kinji, NAKAJIMA Mikio, WATANABE Yutaka, SAKA Masumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: TOHOKU UNIVERSITY

1994 - 1996

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THE OBJECTIVE OF THIS PROJECT IS TO ESTABLISH A NONDESTRUCTIVE MEASUREMENT AND EVALUATION OF FATIGUE DAMAGE TO PREVENT FATIGUE FAILURES IN VARIOUS ENGINEERING STRUCTURES.FATIGUE DAMAGE PROCESSES CAN BE CATEGORIZED INTO THREE,ONE IS FATIGUE DAMAGE ACCUMULATION STAGE WHERE MICROSTRUCTURAL CHANGES WILL TAKE PROCESS WITHOUT ANY CRACK FORMATION,SECOND CRACK INITIATION AND SMALL CRACK GROWTH STAGE AND THIRD MACROSCOPIC CRACK GROWTH STAGE WHICH CAN BE INTERPRETED BY FRACTURE MECHANICS APPROACH.IN THIS PROJECTS,TWO NOVEL NONDESTRUCTIVE TECHNIQUES ARE PROPOSED FOR DETECTION OF DAMAGE ACCUMULATION AND CRACK INITIATION AND PROPAGATION ON NUCLEAR PRESSURE VESSEL STEELS,Ni-BASE SUPPER ALLOY AND SINTERED LOW ALLOY STEELS. FIRST PROPOSAL IS INDUCED CURRENT FOCUSING POTENTIAL DROP TECHNIQUE (HERE AFTER DENOTED AS ICFPD) AND SECOND IS ELECTROCHEMICAL METHOD. ICFPD HAS BEEN SUCCESSFULLY APPLIED FOR MONITORING OF FATIGUE DAMAGE PROCESSES AND CAN DETECT DAMAGE ACCUMULATION AS A DECREASE OF MEASURED POTENTIAL DUE TO REDUCTION OF MAGNETIC PERMEABILITY CORRESPONDING TO MICROSTRUCTURAL CHANGES BY FATIGUE.AFTER CRACK INITIATION,MEASURE POTENTIAL INCREASES AS EXPECTED FROM AN INCREASE IN CURRENT PATH DUE TO CRACKS.THIS KIND OF VARIATION OF MEASURED POTENTIAL CAN BE INTERPRETED BY A SIMPLE MODEL OF A COMBINATION OF DECREASE IN MAGNETIC PERMEABILITY OF MATERIALS AND INCREASE IN CURRENT PATH CAUSED BY CRACKS.SECOND ONE IS BY ELECTROCHEMICAL METHOD FOR A DETECTION OF FATIGUE DAMAGE ACCUMULATION.DAMAGE ACCUMULATION CAN BE CAUSED BY INCREASE IN DISLOCATION DENSITY AND RESULTANT FORMATION OF DISLOCATION CELL STRUCTURES.THIS METHOD IS BASED ON DETECTION OF THESE POSSIBLE ELECTROCHEMICALLY OR CHEMICALLY ACTIVE SITES BY A PROPER ELECTROLYTE AND POLARIZATION PROCEDURES.THE BEST ELECTROLYTES ARE SODIUM MOLYBDATE SOLUTION FOR PRESSURE VESSEL STEELS AND MIXTURE OF HCL,H2SO4, CUSO4 AND WATER FOR INCONEL 718, RESPECTIVELY. THESE RESULTS CAN PROVIDES A POTENTIAL PROCEDURE FOR NONDESTRUCTIVE EVALUATION OF FATIGUE DAMAGE IN THOSE OPERATING PLANTS SUCH AS NUCLEAR POWER PLANTS,CHEMICAL PLANTS AND AEROSPACE ENGINEERING COMPONENTS.
フラクタルノイズ解析を用いた応力腐食割れ初生現象の解明

渡辺豊

Offer Organization: 日本学術振興会

System: 科学研究費助成事業奨励研究(A)

Category: 奨励研究(A)

Institution: 東北大学

1995 - 1995

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本研究では、応力腐食割れ(SCC)の初期過程の現象を明らかにし、SCC初生機構を解明することを目的として、SCCの初期損傷過程の計測手法を開発し、それらの方法によりSCC発生過程での金属表面の電気化学的挙動の変化を詳細に調べた。まず、巨視き裂発生以前のSCC初期の現象をその場計測するために、下記の2種類の電気化学的手法を開発した。 (1)インピーダンスモニタリングによるSCC発生の検出種々の鋭敏化度を持つSUS304ステンレス鋼についてチオ硫酸ナトリウム水溶液中での低ひずみ速度試験を行い、その過程での電極インピーダンスの変化を連続監視した。その結果、SCCが発生する場合にのみ電極インピーダンスが急激に低下すること、また、電極インピーダンスの変化は顕微鏡観察によってき裂が発見され始める以前に現れることを見いだし、SCCの発生を極めて初期の段階で検知できることが示された。 (2)電気化学的ノイズ(短絡電流ノイズ)計測によるSCC発生の検出種々鋭敏化度を変えたSUS316ステンレス鋼を用いて高温高圧水中でのひずみ速度試験を行った。その過程で、試験片と対極との間に流れる短絡電流を連続モニタリングし、SCCとの対応関係を詳細に調べた結果、スパイク状の変動として観測される電流ノイズが割れの発生・進展と対応することが明らかとなり、割れ発生を極めて初期の段階で検知できることが示された。これらの電気化学的手法に加え、従来法に比べてより高感度な交流電位差法を開始し、き裂検出能力の向上を図った。これらの成果により、これまで捉えることが容易でなかったSCC初期プロセスにおける金属表面でのローカルな皮膜破壊・再生挙動ならびに皮膜特性の変化をリアルタイムで監視することが可能となった。その結果、皮膜の再生速度と皮膜破壊の局所への集中が割れ発生条件を決める要因となることが推察された。
Establishment of a novel method to measure gastrointestinal motility using magnetic fluid.

MATSUNO Seiki, NAKATSUKA Katsuto, WATANABE Yutaka, SHOJI Testuo, SHIBATA Chikashi, SASAKI Iwao

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Developmental Scientific Research (B)

Institution: Tohoku University

1993 - 1995

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It is one of very important factor to analyze the gastrointestinal motility for accurate understanding of pathophysiology in gastrointestinal disease. However, ideal method to measure the gastrointestinal motility clinically has not been established. Only a radioisotope technique has been available as a method to evaluate gastric emptying directly which will be significantly useful for the investigation of gastric disease. But, this method has not been so common in ordinary hospital, and not accepted as a clinical test covered by Japanese health insurance system, because, in radioisotope method, it is not so easy to deal with radioactive subject by legal and facility difficulties, and there is a medical problem of exposure to high level of radioisotope. Therefore, the destination of this project should be to develop a novel technique to measure the gastric emptying accurately without radiation exposure which will propagate world widely. Then, we have paid attention to magnetic fluid for performance of this aim. The principle of our method is to get the data about distributive information of magnetic fluid by measuring magnetic field grandient and magnetic field strength to reconstruct the figure or intensity of ingested magnetic fluid which will be located in the homogenous magnetic condition. Employing this principle, we have tried to establish the measuring system which can observe gastric figure and gastric emptying after evaluation of location and residual intensity of magnetic fluid in the stomach. For this purpose, we have investigated 1)the most suitable magnetic fluid for the clinical use 2)the measuring system and it' development in accuracy. The results were obtained as follows : Magnetic fluid which is consisted with central magnetites and superficial monopalmitic acid polyoxyethylenesorbitan was clarified as the most suitable for clinical use of ingestion, because it has no toxicity to human and is neither absorbable nor cohesive in the gastrointestinal lumen. The measuring system has been recently evolved both in the duration and accuracy by changing the Hall element to the new element conceived according to flux principle low. Then it has been possible to detect fine figure of gastric outline, and quantitative evaluation of gastric emptying was also able to be evaluated according to the evidence of good correlation between the calculated values and measured values of concentration of magnetic fluid and magnetic field density in model stomach. These results obtained in this project study showed the positive possibility of this novel method for clinical application.
航空機機体構造のリベット・カウンターシンクにおける経年損傷の評価とその機構解明

渡邉豊

Offer Organization: 日本学術振興会

System: 科学研究費助成事業奨励研究(A)

Category: 奨励研究(A)

Institution: 東北大学

1994 - 1994

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機体構造のリベット・カウンターシンクにおいては、疲労損傷と隙間部腐食環境による環境助長割れの双方が生じる可能性があり、しばしばそれらは重畳する。本研究では、アルミニウム合金をはじめとする合金材料を用いて、リベット・カウンターシンクに代表される繰り返し応力の集中を伴う隙間部でのき裂の発生・成長について、その評価方法を開発し、損傷機構について調べた。まず、孔食発生臨界条件におよぼす材料因子および応力因子の影響を動電位法ならびに定電位法による孔食臨界電位を用いて評価した。材料因子として冷間加工度および低温時効処理条件を変えた。本研究の範囲では、これらの影響は必ずしも顕著ではなく、実機経年劣化をより良く模擬したさらに長時間の低温時効材について引き続き検討を加えていく予定である。予疲労が腐食挙動におよぼす影響についても調査し、特定の電解溶液においては累積疲労損傷が材料の電気化学的挙動に顕著に影響することが見いだされた。このことを利用すれば電気化学的方法により累積疲労損傷を計測できることが明らかとなり、ロケットエンジン部材の疲労損傷評価等に応用された。また、孔食発生におよぼす応力の同時作用効果については、電位規制下の定荷重および定ひずみ速度試験を用いて溶解電流の急増を監視することにより明らかにし、同時に交流電位差法を併用して割れの発生を監視して割れ臨界電位と材料因子の関係が明らかにされた。これらに加え、経年部材の疲労損傷評価のためには累積損傷の非破壊評価および疲労き裂の探傷技術が重要であるとの観点から、それら評価技術の開発も行われた。上述のように累積疲労損傷の評価には電気化学的方法が有効であることが明らかにされ、き裂については電磁誘導を利用した新しい探傷法がアルミニウム合金等の常磁性体においても有効であることが示された。
産業設備の経年劣化機構と保全技術 Competitive

System: Cooperative Research

1991/04 -
Irradiation Assisted Stress Corrosion Cracking of Reactor Internals of Light Water Reactors

SHOJI Tetsuo, WATANABE Yutaka, SAKA Masumi, HWANG I. S., KOHSE G. E., HARLING O. K., BALLINGER R. G.

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for international Scientific Research

Category: Grant-in-Aid for international Scientific Research

Institution: Tohoku University

1990 - 1991

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The objective of this research is to develop a nondestructive evaluation method for detection of radiation induced segregation such as Cr-depletion with very narrow width and impurities segregation. These changes in grain boundary chemistries are possible causes of Irradiation Assisted Stress Corrosion Cracking. Several heats of Type 304 Stainless Steels including high purity, commercial purity, nuclear grade, low sulfur materials. In addition to grain boundary chemical analysis, slow strain rate tests were performed in oxygenated high temperature water at 288ﾟC. Results can be summarized as follows, 1. Modified EPR can detect irradiation induced narrow Cr depletion. 2. RIS was strongly affected by carbon content and nuclear grade material showed the highest resistance to IGSCC. 3. Impurity segregation can be quantitatively evaluated by total charge density measured at-1050mv for one hours in 5N-H_2SO_4 4. These NDE technique can be applied to TEM disc specimens by RIS detector. 5. IGSCC region can be mapped in terms of Cr-depletion and impurity segregation. 6. Further research is needed to evaluate the segregation of B and N which can transmute to form He and H and results in grain boundary weakening. Taking account of those grain boundary analysis and it relation to IGSCC, IASCC mechanisms can be made clear.

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Social Activities 39

International Strategies Operational Committee, NACE（米国腐食学会）, Committee Member

2001/03 - Present

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International Strategies Operational Committee, NACE（米国腐食学）, Committee Member
腐食防食協会コロージョンセミナー企画委員会委員長

2000/11 - Present

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腐食防食協会コロージョンセミナー企画委員会委員長
日本材料学会第49期編集委員会査読委員

2000/05 - Present

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日本材料学会第49期編集委員会査読委員
（財）豊田理化学研究所研究嘱託

2000/04 - Present

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（財）豊田理化学研究所研究嘱託
腐食防食協会超臨界水腐食研究会委員

2000/04 - Present

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腐食防食協会超臨界水腐食研究会委員
日本鉄鋼協会耐熱鋼の高強度・高耐食化フォーラム委員

2000/04 - Present

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日本鉄鋼協会耐熱鋼の高強度・高耐食化フォーラム委員
日本原子力学会「水化学最適化」研究専門委員会「構造材－水化学相互作用(SWIS)」ＷＧ委員

2000/04 - Present

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日本原子力学会「水化学最適化」研究専門委員会「構造材－水化学相互作用(SWIS)」ＷＧ委員
腐食防食協会会誌「材料と環境」編集委員

1999/04 - Present

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腐食防食協会会誌「材料と環境」編集委員
電気化学ノイズ解析分科会中立機関委員腐食防食協会

1999/01 - Present

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電気化学ノイズ解析分科会中立機関委員腐食防食協会
Indian Institute of Technology, Bombay 博士学位論文外部審査委員

1998/07 - Present

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Indian Institute of Technology, Bombay 博士学位論文外部審査委員
腐食防食協会「金属の腐食防食Q&A－応力腐食割れ110番」編集委員会委員

1998/05 - Present

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腐食防食協会「金属の腐食防食Q&A－応力腐食割れ110番」編集委員会委員
腐食防食協会腐食センター・パフォーマンス研究会委員

1998/01 - Present

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腐食防食協会腐食センター・パフォーマンス研究会委員
欠陥評価に関わる破壊力学評価手法の向上に関する研究委員会日本高圧力技術協会

1997/06 - Present

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破壊力学評価手法の向上に関する研究委員会日本高圧力技術協会
日本機械学会論文集出版部会校閲委員（第79期）

2001/04 - 2002/03

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日本機械学会論文集出版部会校閲委員（第79期）
日本材料学会第48期編集委員会査読委員

1999/05 - 2000/04

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日本材料学会第48期編集委員会査読委員
日本機械学会第二出版部会第77期校閲委員

1999/04 - 2000/03

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日本機械学会第二出版部会第77期校閲委員
腐食防食協会東北支部幹事

1998/04 - 2000/03

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腐食防食協会東北支部幹事
水蒸気酸化研究会委員

1998/12 - 1999/03

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水蒸気酸化研究会委員
日本機械学会誌トピックス委員

1998/04 - 1999/03

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日本機械学会誌トピックス委員
日本材料学会第47期編集委員会査読委員

1998/04 - 1999/03

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日本材料学会第47期編集委員会査読委員
日本機械学会第二出版部会第76期校閲委員

1998/04 - 1999/03

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日本機械学会第二出版部会第76期校閲委員
腐食防食協会電気化学ノイズ解析研究会Phase II 幹事

1997/01 - 1998/12

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腐食防食協会電気化学ノイズ解析研究会Phase II 幹事
電気化学ノイズ解析研究会中立機関委員腐食防食協会

1995/01 - 1998/12

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電気化学ノイズ解析研究会中立機関委員腐食防食協会
日本機械学会第75期通常総会講演会セッション・オーガナイザー

1997/10 - 1998/04

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日本機械学会第75期通常総会講演会セッション・オーガナイザー
日本機械学会第76期全国大会実行委員

1997/09 - 1998/04

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日本機械学会第76期全国大会実行委員
日本機械学会第75期材料力学部門第2技術委員会委員

1997/04 - 1998/03

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日本機械学会第75期材料力学部門第2技術委員会委員
定量評価電位差法研究会委員日本非破壊検査協会

1996/05 - 1998/03

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定量評価電位差法研究会委員日本非破壊検査協会
第44回材料と環境討論会実行委員腐食防食協会

1997/02 - 1997/09

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第44回材料と環境討論会実行委員腐食防食協会
日本機械学会第７４期メカライフ編集委員

1996/04 - 1997/03

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日本機械学会第７４期メカライフ編集委員
破壊制御設計の適用による原子力機器設計の高度化に関する委員会中立委員日本高圧力技術協会

1994/11 - 1997/03

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破壊制御設計の適用による原子力機器設計の高度化に関する委員会中立委員日本高圧力技術協会
日本機械学会第７３期メカライフ編集委員

1995/04 - 1996/03

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日本機械学会第７３期メカライフ編集委員
電位差法による欠陥及び材質評価に関する研究会委員日本非破壊検査協会

1994/12 - 1996/03

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電位差法による欠陥及び材質評価に関する研究会委員を行う
日本プラントメンテナンス協会疲労損傷計測・評価に関する調査研究委員会委員

1994/04 - 1996/03

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日本プラントメンテナンス協会疲労損傷計測・評価に関する調査研究委員会委員を行う
日本機械学会東北学生会顧問教官

1994/04 - 1995/03

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日本機械学会東北学生会顧問教官
日本機械学会第７２期メカライフ編集委員

1994/04 - 1995/03

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日本機械学会第７２期メカライフ編集委員
応力腐食割れ試験超臨界水中で実現

2001/07/05 -

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従来類を見ない高温高圧（最高550℃／65MPa）の超臨界水環境下での低ひずみ速度試験を可能とする装置を（株）東京衡機製造所と共同開発したことが報じられた。
超臨界水環境ニッケル基耐食合金の腐食水圧変化で速度が増減

2000/05/31 -

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超臨界水環境においては、従来の常識に反して、金属の腐食速度が水圧に強く依存することが渡辺らのグループにより発見されたことが報道された。
日本機械学会東北支部第35期総会・講演会実行委員（総務担当）

2000/03 -

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日本機械学会東北支部第35期総会・講演会実行委員（総務担当）
日本機械学会東北支部第31期総会・講演会実行委員

1996/03 -

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日本機械学会東北支部第31期総会・講演会実行委員

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Media Coverage 1

Oxidation of Ferritic Steels in Pressurized, Superheated Steam

Newsletter of the U.S. Department of Energy, Advanced Reserach and Technology Development Materials Program, and EPRI

2000/08/01

Type: Newspaper, magazine

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超々臨界圧ボイラ用フェライト系耐熱鋼の水蒸気酸化速度に関する研究が紹介された。

Other 48

局部腐食の進展停止条件に関する研究フェーズ３

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局部腐食の進展停止条件に関する研究
隙間内浄化促進効果に関する評価研究

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隙間内浄化促進効果に関する評価研究
石炭火力ボイラーの水冷壁管における酸化皮膜に関する研究（２）

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石炭火力ボイラーの水冷壁管における酸化皮膜に関する研究
石炭火力ボイラーの水冷壁管における酸化皮膜に関する研究

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石炭火力ボイラーの水冷壁管における酸化皮膜に関する研究
BWRコアシュラウド溶接継手部の応力腐食割れ感受性評価

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BWRコアシュラウド溶接継手部の応力腐食割れ感受性評価
局部腐食の進展停止条件に関する研究フェーズ２

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局部腐食の進展停止条件に関する研究
PWR一次系環境におけるSCC発生に及ぼす表面仕上げの影響

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PWR一次系環境におけるSCC発生に及ぼす表面仕上げの影響
CNRS工学・科学極限環境下における物質とシステムに関するLyon・東北によるジョイントラボラトリー

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工学・科学極限環境下における物質とシステムに関する共同研究
圧力バウンダリ構成部で使用されるステンレス溶接金属の熱時効脆化評価のための基盤技術開発

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圧力バウンダリ構成部で使用されるステンレス溶接金属の熱時効脆化評価のための基盤技術開発
非有害アニオンを利用したすき間腐食不活性化技術ならびにすき間内浄化技術の開発

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非有害アニオンを利用したすき間腐食不活性化技術ならびにすき間内浄化技術の開発
メラミンプラント加熱管の異常減肉機構の解明と対策技術に関する研究

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メラミンプラント加熱管の異常減肉機構の解明と対策技術に関する研究
PWR一次系環境におけるSCCメカニズムの検討（２）

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PWR一次系環境におけるSCCメカニズムの検討（２）
配管減肉現象に及ぼす材料、環境因子の解明

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配管減肉現象に及ぼす材料、環境因子の解明
含水飽和緩衝材共存条件における炭素鋼腐食のセンシング技術の検討（１）

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含水飽和緩衝材共存条件における炭素鋼腐食のセンシング技術の検討（１）
原子力発電設備への海水混入によるステンレス合金の局部腐食の発生と進展継続性評価に係る研究

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原子力発電設備への海水混入によるステンレス合金の局部腐食の発生と進展継続性評価に係る研究
ＰＷＲ一次系環境におけるＳＣＣメカニズムの検討（1）

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ＰＷＲ一次系環境におけるＳＣＣメカニズムの検討（1）
FAC損傷部材評価によるメカニズム解明に関する研究

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FAC損傷部材評価によるメカニズム解明に関する研究
平成25年度原子力設備への海水混入によるステンレス合金の局部腐食の発生と進展継続性評価に係る研究

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原子力設備への海水混入によるステンレス合金の局部腐食の発生と進展継続性評価に係る研究
地震荷重により構造物に蓄積された疲労損傷の可視化技術と健全性評価

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地震荷重により構造物に蓄積された疲労損傷の可視化技術と健全性評価
MLプラント加熱管の減肉評価

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MLプラント加熱管の減肉評価
配管減肉現象に及ぼす材料、環境因子の解明

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配管減肉現象に及ぼす材料、環境因子の解明
材料・冷却材相互作用に関する研究開発

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材料・冷却材相互作用に関する研究開発
Ni基合金/低合金鋼境界部における停留き裂の再進展条件とそのメカニズム解明

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環境条件を変数としたSCC試験と組織調査等により、Ni基合金/低合金境界部あるいは低合金鋼におけるき裂停留と再進展の条件を探求する。
材料・冷却材相互作用に関する研究開発

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材料・冷却材相互作用に関する研究開発
Ni基合金/低合金鋼境界部における停留き裂の再進展条件とそのメカニズム解明

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環境条件を変数としたSCC試験と組織調査等により、Ni基合金/低合金境界部あるいは低合金鋼におけるき裂停留と再進展の条件を探求する。
オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解

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オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解
ニッケル基合金溶接金属／低合金鋼境界部における微視組織のキャラクタリゼーション

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ニッケル基合金溶接金属／低合金鋼境界部における微視組織のキャラクタリゼーション
オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解

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オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解
PWR1次系環境におけるNi基合金溶接継手部のSCC感受性評価方法の検討

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PWR1次系環境におけるNi基合金溶接継手部のSCC感受性評価方法の検討
PWR1次系環境におけるNi基合金溶接継手部のSCC感受性評価方法の検討

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PWR1次系環境におけるNi基合金溶接継手部のSCC感受性評価方法の検討
微視組織に着目した低炭素ステンレス鋼溶融線近傍におけるSCC停留挙動のメカニズム解明

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微視組織に着目した低炭素ステンレス鋼溶融線近傍におけるSCC停留挙動のメカニズム解明
オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解

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オーステナイト系合金の応力腐食割れ感受性マップ構築とその機構的理解
応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究

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応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究
応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究

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応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究
316L鋼溶接部の凝固モードおよび低温時効と高温水中き裂進展特性ならびに酸化特性

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316L鋼溶接部の凝固モードおよび低温時効と高温水中き裂進展特性ならびに酸化特性
応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究

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応力腐食割れ発生の素過程と加工硬化表面の役割解明に関する研究
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