Intergranular Stress Corrosion Cracking Susceptibility of Neutron-Irradiated, Thermally Sensitized Type 304 Stainless Steel

Abstract

Abstract Neutron-irradiated, thermally sensitized Type 304 (UNS S30400) stainless steels (SS) were examined by slow strain rate (SSR) stress corrosion cracking (SCC) tests in 290°C water of 0.2 ppm dissolved oxygen concentration (DO) and by SSR tensile tests in 290°C inert gas environment. Neutron fluences ranged from 4 × 1022 n/m2 to 3 × 1025 n/m2 (energy [E] > 1 MeV). Percent intergranular (%IG) cracking, which has been used as an intergranular (IG) cracking susceptibility indicator in the SSR SCC tests, changes anomalously with neutron fluence in spite of the strain-to-failure rate decreasing with an increase of neutron fluence. Apparently, %IG is a misleading indicator for the irradiated, thermally sensitized Type 304 SS and for the irradiated, nonsensitized SS when IG cracking susceptibility is compared at different neutron fluences, test temperatures, DO, and strain rates. These test parameters may affect deformation and fracture behaviors of the irradiated SS during the SSR SCC tests, resulting in ...