Effects of Implanted Deuterium on <I>In-Situ</I> Irradiation Fatigue Behaviors of Cold-Worked 316 Stainless Steel at 60 and 300&deg;C

Abstract

Stress-controlled fatigue tests were performed for 20% cold-worked 316 stainless steel under in-situ 10 MeV deuteron irradiation with an energy degrader at 60 and 300 C. The irradiation dose rate and the deuterium implantation rate were arranged in response to beam intensity in three conditions as (A) 1:0 Â 10 À7 dpa/s and 1:1 Â 10 À3 appm/s, (B) 5:0 Â 10 À7 dpa/s and 5:5 Â 10 À3 appm/s and (C) 1:0 Â 10 À6 dpa/s and 1:1 Â 10 À2 appm/s, respectively. The number of fatigue cycles to fracture (N F ) increased with the dose rate in order of conditions (A), (B) and (C) at 300 C, while N F was lower in condition (C) than that in condition (B) irrespective of the higher dose rate at 60 C. Although transgranular cracking in the ductile fracture mode was indicated on fracture surface for all specimens, higher density of dimples was formed for the in-situ irradiation specimen in condition (C) at 60 C. Some evidence of effects of implanted deuterium on in-situ irradiation fatigue behavior were demonstrated in this paper.