Fatigue damage in 20% cold-worked type 316L stainless steel under deuteron irradiation

Type 316L stainless steel samples in 20% cold-worked conditions were exposed to fully reversed fatigue cycling in torsion at 400 C during an irradiation with 19 MeV deuterons. Fatigue tests were performed in the high cycle fatigue (HCF) range under continuous cycling and in the low cycle fatigue (LCF) range by imposing a hold-time at the minimum strain value. In comparison with tests under thermal conditions, an increase in the number of cycles to failure Nf by a factor of 6 is observed for the HCF tests and a decrease in Nf, by more than an order of magnitude, for the LCF tests. The data are analyzed using a fatigue damage model: a fatigue damage parameter is defined and the change in this parameter caused by the different irradiation or loading conditions shows directly the effect of changed experimental conditions on the fatigue life. ((orig.))