Irradiation effects on mechanical properties of an SMAW deposited Type 308 stainless steel

Pre- and post-irradiation tensile and creep-rupture tests have been conducted on a shielded metal-arc welding (SMAW)-deposited Type 308 stainless steel containing controlled residual elements (CRE) boron, phosphorus and titanium. Fast reactor (EBR-II) neutron irradiation produced changes in the mechanical properties which are broadly consistent with trends established in wrought austenitic stainless steels. However, some behavioral differences, both prior to and after irradiation, are noted: higher as-deposited yield strength, lower ductility, lower ability to strain harden and a lower irradiation damage accumulation rate in the CRE 308 weld metal. All of these differences can be associated with inherent differences in the microstructure and thermal-mechanical history between the weld deposited CRE 308 and the wrought Type 304 stainless steel. (U.S.)