APPLICABILITY OF FORMULA OF THE IRRADIATION ASSISTED STRESS CORROSION CRACKING RATES FOR NEUTRON-IRRADIATED TYPE 316L STAINLESS STEELS TO VARIOUS TYPES OF STAINLESS STEELS UNDER BOILING WATER REACTOR CONDITION

摘要

The Hashimoto-Koshiishi model is the predictive mechanistic model for crack growth rates (CGRs) of stress corrosion cracking (SCC). The simplified formula of the Hashimoto-Koshiishi model was developed for the calculation of CGRs of irradiated Type 316L stainless steels (SSs). This study evaluated the applicability of the developed formula to various types of stainless steels by analyzing experimental data of CGRs. The developed formula was determined to be applicable for Type 304L SSs and 316NG SSs as well as Type 316L SSs. On the other hand, the formula was unsuitable for irradiated Type 304 SSs because the mechanical properties and the Cr concentrations at the grain boundaries of Type 304 SSs were different from these quantities for Type 316L SSs.