Creep Behavior of SMA Type 316 Weld Metal With Controlled Residual Elements

Abstract

Type 316 stainless steel filler metal is a candidate material for welds in piping and other components of Liquid Metal Fast Breeder Reactors. There are few elevated-temperature tensile and creep data for type 316 weld metal in the literature, and reported properties vary widely with material batches or welding process variables. A nuclear components fabricator has developed a type 316 SMA weld that contains controlled amounts of the residual elements (CRE) boron, phosphorus, and titanium, analogous to the chemical element content of an improved type 308 CRE weld that was reported recently. The type 316 CRE weld has good strength and ductility at 649°C in both short-term tensile tests and creep tests lasting up to about 6000 hr. No tendency for cracking along interphase boundaries or substructural boundaries was found in these limited tests.