Development of short crack nucleation and growth model for stainless steel based on experimental data

Environmentally assisted cracking (EAC), which is represented by stress corrosion cracking or corrosion fatigue, is one of the most important subjects in the study of material degradation of light water reactors. A significant proportion of the lifetime of a component subject to EAC may be spent in crack initiation and subsequent growth and/or coalescence to produce cracks which can be evaluated by conventional linear elastic fracture mechanics approaches. In this study, the state of nucleation and growth of a short crack was investigated experimentally in the EAC of austenitic stainless steel(SUS304) at high-temperature primary water in PWR, and the number of cracks as a function of time and short crack growth rates was obtained. Based on the experimental data, a Monte Carlo model for crack nucleation, short crack interaction, coalescence and crack growth was formulated. (author)