BEHAVIOR OF STRESS CORROSION CRACKING FOR TYPE 316LSTAINLESS STEEL WITH CONTROLLED DISTRIBUTION OF SURFACE WORK HARDENED LAYER IN SIMULATED BOILING WATER REACTORS ENVIRONMENT

摘要

Stress corrosion cracking (SCC) of Type 316L stainless steels with controlled surface hardnessdistribution was investigated under simulated boiling water reactor (BWR) condition by crevicedbent beam (CBB) tests. Intergranular microcracks having a depth of less than 50 μm areobserved in 50 hours. Until 250 hours, depths of the microcracks are not increased. After 500hours, cracks with depths of more than 50 μm are observed. SCC is initiated preferentially in asteep hardness gradient area.