Effect of cold work on the irradiation creep of SUS 316L

The network dislocation density in structural materials is one of the important factors of radiation-induced deformation. Hence creep deformation under 17 MeV proton irradiation was examined for SUS 316L with 5% and 25% cold work at ∼300 °C. At relatively low stresses, irradiation creep of 5%CW specimen was larger than that of the 25%CW specimen, and the measured creep rates of both specimens were close to the results of computer simulation. The stress dependencies of the two specimens are roughly similar, and their stress exponents appear to correspond well with the simulation results. At relatively high stresses, the dependence of creep rate on the applied stress was stronger for both cold-worked specimens. Acceleration of thermal creep mechanism due to irradiation might be one of the causes for the increase.