Stress Corrosion of Ferritic and Martensitic Stainless Steels in Saline Solutions

The influence of strength level and test temperature on SCC of 410 stainless steel in a NaCl solution poisoned with Na₂S has been determined and compared with the behavior of 430 stainless steel. The 430 steel is immune to SCC in this environment, and 410 exhibits SCC only when heat treated to strength levels above a critical value that depends on test temperature. The correspondence between the effects of strength level and test temperature of hydrogen embrittlement (HE) and stress corrosion cracking (SCC), once again provides support for the role of HE in mechanism of SCC and demonstrates that the immunity of 430 to SCC arises primarily from its low yield strength.