Effects of neutron irradiation on the creep-rupture properties of type 316 stainless-steel tubes

The effects of irradiation in the Dounreay Fast Reactor and the Dounreay Materials Testing Reactor on the creep-rupture properties of Type 316 stainless-steel tubing have been investigated. DFR irradiation produced a loss of rupture ductility but, in general, no change in creep strength in 650 deg C biaxial tests of solution-treated material. Cold-worked tubes suffered a loss of 550 deg C creep strength. Irradiation of solution-treated tubes at 650 deg C in DMTR caused a severe loss of high-temperature ductility and a ten-fold reduction of creep rate both during and after irradiation; it is possible that an irradiation-induced carbide precipitation process is responsible for the increase of creep strength. (auth)