Effect of localized strain deformation on SCC initiation of stainless steels in simulated PWR primary water

The effects of localized strain deformation induced by complex straining on stress corrosion cracking (SCC) initiation in stainless steels exposed to simulated pressurized water reactor (PWR) primary water environments at 360 °C were investigated using cruciform specimens. Complex straining was achieved by a combination of pre-straining in air, followed by straining in environment. Results showed that complex strains promoted intergranular stress corrosion cracking (IGSCC) initiation in stainless steels. High levels of straining were not required, neither in the initial (prior) or subsequent straining phase, when applied as a complex strain sequence to cause SCC initiation in stainless steels. There was a correlation between local strain concentrations and the ease of oxidation of the slip lines generated by the strains, which increased the susceptibility of the material to SCC.