STUDY ON SCC BEHAVIOR OF AUSTENITIC STAINLESS STEELS IN H_ 2S SATURATED AQUEOUS SOLUTIONS CONTAINING Cl_

Stress corrosion cracking (SCC) sensibility of austentic stainless steels SUS 316 and SUS 316L in H 2S saturated aqueous solution containing Cl - or CO 3 2- was investigated by U bend samples. Addition of Cl - and reduction of solution pH intensified the SCC susceptibility of these two steels.But it was decreased obviously when adding 0.001mol/L Na2CO3 into the aqueous solution especially for SUS316. Intergranular corrosion sensibility of SUS 316 was increased after sensitization heat treatment, and its SCC resistance got worse.However,SUS 316L exhibited remarkable immunity to sensitization.The SCC cracking morphology and the mechanism were also discussed.