Stress Corrosion Cracking Behavior of Type 304 Stainless Steel Irradiated under Different Neutron Dose Rates at JMTR

摘要

In order to investigate the effect of neutron dose rate on tensile property and irradiation stress corrosion cracking (IASCC) behavior, crack growth rate (CGR) and, tensile tests and microstructure observation have been conducted with type 304 stainless steel specimens. The specimens were irradiated in high temperature water simulating boiling water reactor (BWR) environments up to about 1dpa with two different dose rates at the Japan Materials Testing Reactor (JMTR). While radiation hardening increased with the dose rate, CGR was not affected by the dose rate. Increase of the yield strength of the low dose rate specimens was caused by the increase of number density of Frank loops. Little difference of radiation-induced segregation at grain boundaries was observed in specimens irradiated by different dose rates. Furthermore, no dose rate effect on local plastic deformation behavior was found near crack tip in the crystal plasticity simulation