Grain-Boundary Segregation and IGSCC in Cold-Worked Type 304 SS Available to Purchase

Applied-potential constant extension rate tensile (CERT) tests were conducted on unirradiated, mill-annealed type 304 (UNS⁽¹⁾ S30400) stainless steel, in an attempt to reproduce irradiation-assisted intergranular stress corrosion cracking (IGSCC) in the laboratory. To simulate highly irradiated material, the test material was cold worked and given a low-temperature anneal. Significant (10%) IGSCC was obtained in samples that had been cold rolled 30%, aged at 500°C for 700 hours, and CERT tested under an anodic potential of 0 V_SHE. The results of Auger electron spectroscopy (AES) showed that the amount of intergranular phosphorus segregation could be correlated with the degree of IGSCC and elongation measured in the CERT tests. The depth of intergranular attack in the HNO₃/Cr⁺⁶ corrosion test could also be correlated with the amount of phosphorus segregation.