Comprehensive Impact of Machined Surface Integrity on Stress Corrosion Cracking Initiation in 316 Austenitic Stainless Steel

The comprehensive impact of machined surface integrity on stress corrosion cracking (SCC) initiation in 316 austenitic stainless steel was investigated. The surface biaxial residual stress and surface roughness are measured for different milled and turned surfaces. The crack density was measured after SCC test in boiling magnesium chloride solution and used to evaluate the SCC susceptibility. The relationship between crack density and surface integrity properties is analyzed based on nonparametric statistical method. Additionally, the equivalent stress intensity factor related to the machining-induced residual stress and surface roughness is proposed which shows a strong correlation with the SCC crack density. Based on the relationship, a predictive model is established to predict the SCC crack density.