Effects of neutron irradiation on the tensile properties of the stainless steel DIN 1.4948 (similar to AISI 304)

Tensile properties of DIN 1.4948 stainless steel irradiated at 723 K and 823 K in the HFR at Petten and of the parallel heat treated steel are compared for the temperature range 723 K - 923 K and strain rates ranging from 6.10-6 s-1 up to 6 s-1. This was done for base materials as well as welded joints. Two types of irradiations were carried out: the first one up to a fast fluence (E>0.1 MeV) of 1023 n.m-2 and a thermal fluence of 4.4x1022 n.m-2, the second one up to a fast fluence of 5.1024 n.m-2 and a thermal fluence of 1.6x1024 n.m-2. Results indicate only a minor influence of irradiation on the 0.2% yield stress and the ultimate tensile strength. A significant loss of ductility was observed at high temperature and low strain rates. After irradiation to a thermal fluence of 1.6x1024 the total elongation at 923 K remained unchanged at a strain rate of 6 s-1 but was reduced from 42% to 6% at a strain rate of 6.10-6 s-1. (Auth.)