An experimental characterization of the effects of thermal treatments and of fast-neutron irradiation on the elevated-temperature tensile and creep-rupture properties of a gas tungsten-arc-deposited Type 316 stainless steel has been completed. Intermediate-temperature (1472°F) stress relief and high-temperature (1950°F) solution an— nealing produce changes in the mechanical properties, some of which may be correlated with coincident changes in the microstructure. Irradiation-induced property changes observed in the weld metal are broadly consistent with trends established for wrought Type 316; however, the extent of property change clearly depends on the condition (heat treatment) of the material as well as fluence, irradiation temperature, and test temperature.