SCC behavior of SUS316L in the high temperature pressurized water environment

The effects of dissolved oxygen (DO:8 ppm) and hydrogen (DH:0.4 ppm and 1.4 ppm) on stress corrosion cracking (scc) of SUS316L were tested by slow strain rate test (SSRT) and crevice bent beam test (CBB) in high-temperature (288 °C) pressurized (7.8 MPa) water environment. Sensitized and non-sensitized SUS316L were cold-worked up to the rolling ratio of four patterns (0, 25, 50, and 75%). The SSRT tensile elongation of non-sensitized SUS316L was significantly reduced in hydrogen dissolved water environment, indicating hydrogen enhanced SCC. The fractured surface was mainly TGSCC, and the TGSCC increased with increasing dissolved hydrogen in the water. Also the TGSCC in the fractured surface was reduced by cold-work because of the shortage of test period for the cold-worked specimens broken in a small elongation in a ductile manner. The CBB test results indicate that susceptibility of TGSCC was increased by cold work.