1993 Volume 42 Issue 1 Pages 15-19
Effect of NaF concentration, temperature, strain rate and dissolved oxygen on intergranular stress corrosion cracking (IGSCC) of sensitized type 304 stainless steel has been examined by using a slow strain rate technique (SSRT). Comparing with polarization curves, electrochemical conditions of IGSCC in this system were discussed and an IGSCC susceptibility-temperature-NaF concentration diagram was made. It was found that oxygen dissolved in the solution was necessary for occurrence of IGSCC, and corrosion potential during IGSCC was in the active potential region at which the anodic current peak was observed. The highest IGSCC susceptibility was found at 103ppm, and the susceptibility increased with temperature. The critical concentration of NaF to cause IGSCC was more than 8.4×103ppm at 303K, 5-10ppm at 323K, and less than 1ppm at 353K, respectively.
