Effects of dissolved oxygen and cold work on the stress corrosion crack growth behavior of 316L stainless steel in high-temperature high-pressure water

This study investigates the effects of cold work (with deformation levels of 10%, 16%, and 20%) and dissolved oxygen (DO) concentration on the stress corrosion cracking (SCC) growth behavior of 316L stainless steel in high-temperature, high-pressure water. It is found that sustained intergranular crack growth requires a minimum cold-work deformation of 16% or a DO concentration of 50 ppb. Under conditions of 10% cold work and low DO, only short, predominantly transgranular cracks were observed, with a growth rate (≈1.6 × 10 -12 m/s) more than an order of magnitude lower than that under any other tested condition. Once intergranular cracks are initiated, the average crack growth rates across all conditions fall within a relatively narrow range (6 × 10 -11 to 3 × 10 -10 m/s); further increases in cold-work deformation or DO concentration result in, at most, a roughly fivefold increase in the crack growth rate. Consequently, for 316L stainless steel, limiting cold-work deformation is an effective mitigation strategy—provided that the DO concentration is maintained at a low level. However, fluctuations in DO concentration on the order of tens of ppb are sufficient to trigger intergranular cracking, even in materials with only slight deformation. This paper discusses the synergistic effects of cold work and DO on the SCC growth behavior of 316L stainless steel, as well as the underlying micro-mechanisms.