The evaluation for the initiation stage in stress corrosion cracking is important for estimating life time of Alloy 600 on Primary Water Stress Corrosion Cracking (PWSCC). In this study, a new evaluation technique for the short crack growth rate in the initiation stage of PWSCC has been developed by using constant-load test and SSRT. It was revealed that the PWSCC growth rate of MA600 in the initiation stage was lower than in the propagation stage by about one order of magnitude. The prediction curve of PWSCC growth was determined based on this study and it was verified by comparison with the investigation results obtained from an actual plant material. As a result, it is considered that this evaluation method enables prediction of PWSCC growth of actually used material fairly accurately.
Key Words : Stress corrosion craking, alloy600, primarywater, SCC, PWSCC life time prediction, short crack, crack growth rate