Mechanistic understanding of the temperature dependence of crack growth rate in alloy 600 and 316 stainless steel through high-resolution characterization

This is the authors' abstract. We don't add key points for this paper.

Stress corrosion cracking of Alloy 600 (A600) and 316 stainless steel (316SS) exposed to simulated pressurized water reactor primary water at temperatures of 320–360 °C has been investigated and compared. Intergranular oxidation developed ahead of all crack tips prepared from these two alloys. High-resolution characterization reveals that there are two main rate-controlling mechanisms contributing to crack propagation: a diffusion-based and a mechanical deformation-based. The different temperature dependence of crack growth rate (CGR) in A600 and 316SS can be explained after confirming that the two rate-controlling mechanisms exhibit different “weights” in the two alloys. The diffusion-based mechanism plays a dominant role in accelerating the CGR of A600, while the mechanical deformation-based mechanism is responsible for the observed CGR decrease of 316SS at higher temperatures.