Role of Mechanical Factors in PWSCC of Stainless Steel

摘要

In this study, the role of the tensile stress ahead of the crack tip in the primary water stress corrosion cracking (PWSCC) of type 316 stainless steel (SS) was investigated. First, under a given set of loading conditions, the tensile stress distribution around a crack tip in a compact tension (CT) specimen of 316 SS was calculated using finite element analysis (FEA) as function of stress intensity factor (K_I) and yield strength (σ_(YS)). Then, the crack growth rates (CGR) of 316 SS in the PW condition were extracted from literature and their dependence on KI and σ_(YS) were evaluated. Finally, by converting the values of K_I and σ_(YS) to maximum tensile stress ahead of the crack tip, σ_(yy, max), the correlation between the CGRs and σ_(yy, max) was investigated. The analysis results show that the crack growth rates in 316 SS with different yield strengths and at different stress intensities could be correlated with the single parameter, σ_(yy, max), suggesting that the tensile stress ahead of a crack tip plays an important role in the PWSCC of 316 SS.