Stress corrosion cracking of Ru doped 304 stainless steel in high temperature water

In pressurised water reactor primary water, there is generally growing concern that stress corrosion cracking (SCC) may occur in occluded locations where residual oxygen and other impurities may be trapped. For these critical components, the deployment of more SCC resistant materials is desirable. In this paper, the effect of 1 wt-%Ru additions on the SCC susceptibility of 304 austenitic stainless steels was investigated in high temperature water. Slow strain rate tensile tests were performed on standard and 1 wt-%Ru modified 304 stainless steels in both sensitised and cold worked conditions. Preliminary results showed that, although both ruthenium doped and standard 304 stainless steels exhibited intergranular SCC, the former was less susceptible as indicated by a greater strain to failure. The results obtained suggest an improved performance of the Ru doped 304 stainless steel towards SCC susceptibility in these environments.