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青山 高士; Choudhary, S.*; Pandaleon, A.*; Burns, J. T.*; Kokaly, M.*; Restis, J.*; Ross, J.*; Kelly, R. G.*
Corrosion, 81(6), p.609 - 621, 2025/06
被引用回数：1 パーセンタイル：26.96(Materials Science, Multidisciplinary)This study presents a new test method for inducing controlled corrosion damage within simulated fastener holes of aluminum alloys, aimed at pretreating fatigue test specimens. The method involves insulating the outer surface while exposing the fastener hole surface to electrolytes containing 0.66 M NaCl + 0.1 M AlCl 
with varying concentrations of K 
S O 
. The evolution of corrosion damage within the fastener hole was examined as a function of exposure duration, electrolyte composition, and volume, as well as the effect of galvanic coupling with a SS316 cathode. Results indicate that fissure depth increases with an increase in K S O concentration but does not progress further after 24-48 hours of exposure in the chemical, or freely-corroding, exposure test. In contrast, galvanic coupling with a SS316 plate significantly accelerates corrosion, leading to much deeper fissures in a shorter time. The importance of electrolyte replenishment has been explored using electrochemical measurements, revealing the impact of evolving electrolyte chemistry. Beyond its application in fatigue specimen pretreatment, this method provides a simple yet effective approach for studying localized corrosion and evaluating mitigation strategies for fastener holes in aerospace structures.
木内 清; 井岡 郁夫; 橘 勝美; 鈴木 富男; 深谷 清*; 猪原 康人*; 神原 正三; 黒田 雄二*; 宮本 智司*; 小倉 一知*
JAERI-Research 2002-008, 63 Pages, 2002/03
JAERI-Research-2002-008.pdf:7.85MB
本研究は、平均燃焼度100GWd/tを目指したABWR用の超高燃焼度MOXを念頭にした「高性能燃料被覆管材質の研究」のフェーズ1である。フェーズ1は、平成10年度に実施した基礎調査結果を踏まえて、平成11年度と平成12年度の2年間にわたり実施した。フェーズ1では、現用Zr系合金の使用経験データを解析して、超高燃焼度化にかかわる長期耐久性の支配因子を摘出及び高性能被覆管の要求特性に照らして耐食合金間の相互比較,フェーズ2の中性子照射試験等の基礎評価試験用候補材の選定を行った。
鈴木 元衛
JAERI-Research 94-022, 36 Pages, 1994/10
JAERI-Research-94-022.pdf:1.28MB
ジルカロイ-4試料を、静止水型オートクレーブ中、300
Cの水中において酸化させ、ACインピーダンス法により酸化速度のin-situ測定を試みた。周波数応答解析法を適用して試料表面の酸化膜のインピーダンスデータを取得し、酸化速度を算出し、理論的な予測と比較した。その結果、本方法により酸化速度のin-situ測定は可能であるとの結論に至った。ただし、水質の劣化はデータに大きく影響すること、および、インピーダンスデータにより酸化膜の2層構造の性質変化を検知できることを見出した。
Li, Y.; 東 喜三郎*; 長谷川 邦夫
no journal, ,
Flaws due to stress corrosion cracking have been detected in stainless steel or nickel-based alloy dissimilar metal weld joints of piping systems in nuclear power plants. Generally, stainless steel and nickel-based alloy are ductile materials with high toughness, and the failure mode of flawed pipes made of ductile materials is expected to be net-section plastic collapse. Failure bending moment of a ductile pipe containing a circumferential flaw is predicted using the net-section stress approach according to ASME Code Section XI as a limit load criterion. However, in the current code, the failure bending moment can only be adopted for a pipe containing a single circumferential flaw with constant depth, although many flaws detected actually are multiple flaws, and the flaw shapes are generally complicated. In this study, a failure estimation method for pipes containing multiple circumferential flaws with complicated shapes was proposed. Furthermore, failure experiments were performed for 8-inch diameter Schedule 80 stainless steel pipes containing two circular circumferential flaws. The failure bending moments obtained from the experiments were compared with the estimated results. Based on the experimental results, it was concluded that the proposed failure estimation method satisfactorily represents the failure behavior of the pipes and can be applied in engineering application.
