Effect of Chloride and Oxygen on Stress Corrosion Cracking of 304N in High Temperature Water

The stress corrosion cracking (SCC) behavior and mechanism of solution-treated 304N stainless steel in high temperature water were studied by slow strain rate tensile test (SSRT) and fracture surface analysis. The results show that the SCC behavior of 304N in high temperature water reveals as transgranular cracking, and with the increasing of Cl^- content, the susceptibility of SCC increases. The specimen shows brittle fracture mode when it is exposed to high temperature aerated water containing 50 mg/L Cl^-. The present results also indicate that the susceptibility of chloride induced SCC decreases significantly with decreasing of dissolved oxygen (DO) content in water, which reveals that DO plays a significant role in promoting SCC of 304N in high temperature water.