マルテンサイト系ステンレス鋼の応力腐食割れおよび腐食疲労き裂進展特性の評価

概要

論文の詳細を見る
This work aimed to characterize crack growth of stress corrosion cracking (SCC) and corrosion fatigue (CF) for two types of martensitic stainless steel, SUS410 and SUS410S, in air and hydrogen charging environment. The crack growth characteristics were evaluated by fracture mechanics tests which were conducted under stress intensity factor, K-control, and by acoustic emission (AE) monitoring. Crack growth acceleration was observed in the hydrogen charging environment. The SCC characteristics of SUS410S were slower than those of SUS410, while the CF characteristics of both materials were similar. The observations of the fracture surface suggested that the hydrogen embrittlement cracking occurred near the surface of the specimen, where hydrogen diffused more quickly. Based on the AE and electrochemical analyses, the difference in SCC characteristics of both materials was attributed to the penetration of the hydrogen through the passive film for each material. Since the crack growth characteristics of the both materials exhibit the same relation, the passive film is broken by cyclic loading in CF tests.
2010-12-25