The effect of low temperature heat treatment on stress corrosion crack initiation in machined 316L stainless steel in high-temperature hydrogenated water

Abstract

A notable reduction of the stress corrosion cracking (SCC) initiation susceptibility was identified for machined cold-rolled 316L stainless steel that received a 650°C/10 hours heat-treatment prior to slow strain rate tensile (SSRT) testing in high-temperature hydrogenated water. The cracks per unit area of the machined surface of heat-treated specimens decreased by ~50% compared to as-machined surfaces, and by >70% with respect to polished surfaces. The results were ascribed to recrystallization of the ultrafine-grains present in the outer deformation layer of the machined surface, which resulted in a reduction of the tensile residual stress and nano-indentation hardness.