Stress Corrosion Cracking of Annealed Type 316 Stainless Steel in High-Temperature Water

Slow strain rate tests have been performed on annealed type 316 (UNS(1) S31600) stainless steel in 5 ppm chloride content water at temperatures from 100 to 300°C under various applied potentials. Stress corrosion cracking was observed in two ranges of potential. At high potentials, large transgranular stress corrosion cracks occurred. However, a lower potential range for cracking also existed in which short transgranular cracks formed during the slow strain rate tests. Such cracks were initiated by the fracture of the oxide layer on the specimens, but the cracks then propagated into the matrix. The potential ranges for cracking were different at the different temperatures and separated by a noncracking range. The potentials at which cracking occurs are mapped as a function of temperature. The results are compared with data for sensitized austenitic stainless steels.