Effect of post weld heat treatment on stress corrosion cracking of a low alloy steel to stainless steel transition weld

Abstract The susceptibility to stress corrosion cracking (SCC) of a low alloy to stainless steel transition weld, A508-309L/308L, in simulated pressurised water reactor (PWR) primary water, contaminated with low levels of sulphate, at 292°C was assessed via slow strain rate tests under controlled potentials and static load tests at free corrosion potentials. The minimum potential for SCC, Ec, and crack growth rate were used to evaluate the susceptibility of as-welded and post-weld heat treated material. U-bend specimens tested at open circuit potential showed no SCC. The results indicate that if exposed, the transition weld should be immune to SCC in PWR primary side coolant water.