In-Beam Stress Corrosion Behavior of Welded 308 Stainless Steel at 473 K in Aerated and Hydrogenated Water Conditions

Abstract

Stress corrosion tests were performed for welded 308 stainless steel under proton irradiation at 473 K in aerated water (DO: 0.15–0.22 ppm, DH: <10 ppb) and hydrogenated water (DH: 1.0–1.4 ppm, DO: <5 ppb) conditions. The in-beam loading condition was 0 and 300 MPa in tension under an irradiation dose rate of 1.3 × 10⁻⁷ dpa/s. In situ measurement of electrochemical corrosion potential (ECP) and subsequent SEM analysis were also conducted for all the specimens. In the aerated water condition, the process of stress corrosion cracking (SCC) was significantly accelerated under irradiation, while the in-beam effect on SCC was suppressed in the hydrogenated water condition. The in-beam stress corrosion behavior is discussed in terms of both water radiolysis and radiation-induced microstructures.