Evaluation of SCC Crack Growth Behavior of Non-Sensitized Stainless Steels in High Temperature Water by SSRT

Abstract

Slow strain rate test (SSRT) method was applied to evaluate the SCC behavior of non-sensitized stainless steels in high temperature water. Crack growth rate (CGR) was evaluated by investigating the time dependence of the maximum crack depth in SSRT. The effects of materials and test conditions on the CGRs were studied. As the result, the CGR of non-sensitized 18Cr-8Ni stainless steels (SUS316, SUS304, SUS347) was in the range of (3−6)×10⁻¹⁰ m/s. In 316NG (nuclear grade), the CGR showed the highest at 561 K, and increased with the concentration of dissolved oxygen and conductivity. The CGR in SSRT was higher by 10 times than that obtained in the crack extension test using CT specimens.