Thermally activated deformation of irradiated reactor pressure vessel steel

Temperature and strain rate change tensile tests were performed at two VVER 1000-type reactor pressure vessel welds with different content of nickel in unirradiated and irradiated conditions in order to determine the activation parameter of the contribution of the thermally activated deformation. There are no differences in the activation parameters in the unirradiated and the irradiated condition as well as for the two different materials. This shows irradiation hardening preferentially results from a friction hardening mechanism by long-range obstacles.