Effect of residual stress gradients in austenitic stainless steels on stress corrosion cracking

Abstract

The effect of the residual stresses developed during simulated weld heat affected zone in austenitic stainless steel specimen on the stress corrosion cracking susceptibility was studied. Residual stresses was measured using X-ray diffraction technique. Boiling Magnesium Chloride was used as corrosive environment. Compressive stresses developed in the HAZ of the specimen and in regions away from the HAZ stress free values were obtained. The magnitude of the stress gradient decreased as the peak temperature attained during simulated welding decreased. Transgranular cracks were observed in the compressive stress gradient region and time to cracking decreased with increasing stress gradient. Higher nickel content alloys took longer to crack as opposed to lower nickel content alloys at approximately the same stress gradient.