The initiation of stress corrosion crack in Alloy 718 under pressurized water reactor primary water conditions
作者
单位
1CAS Key Laboratory of Nuclear Materials and Safety Assessment、Institute of Metal Research、Chinese Academy of Sciences、Shenyang、110016、P. R. China 2 School of Materials Science and Engineering、University of Science and Technology of China、Shenyang、110016、P. R. China 3 Institute of Corrosion Science and Technology、Guangzhou、510530、P. R. China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
Stress corrosion crack initiation behavior of alloy 718 was investigated through slow strain rate tensile (SSRT) test. Alloy 718 was subjected to two commercial heat treatments. Specimens solution -treated at 1080 °C exhibit precipitation of th e γ′ and γ′′ phase, ensuring the material possesses outstanding mechanical properties. This heat treatment method is characterized by a low sensitivity to stress corrosion. Conversely, specimens subjected to solid solution treatment at 970 °C demonstrate an increased propensity for stress corrosion cracking due to the additional precipitation of the δ phase. Grain boundaries, MX phases, and delta phases are susceptible to preferential oxidation, making them the prime sites for crack initiation.