Radiation effects on environmental cracking of stainless steels

Stainless steels exposed to radiation and hot water may fail by irradiation -assisted stress corrosion cracking. Cracking is especially evident in aust enitic stainless steels exposed to light-water reactor irradiation and oxid izing water chemistry at temperatures near 288 degrees C. Neutron doses gre ater than one displacement per atom are typically required to induce observ ed cracking susceptibility. Thee evidence of a threshold dose suggests that radiation-induced material changes promote irradiation-assisted stress cor rosion cracking, not radiation effects on water chemistry. Radiation-induce d chromium depletion is considered the primary material change impacting th is cracking. Impurity influences on solute segregation are apparent and may influence specific alloy susceptibility. Synergistic chemical/mechanical c reep contributions to the intergranular failure mode are not important for light-water reactor conditions.