A high-resolution characterization of irradiation-assisted stress corrosion cracking of proton-irradiated 316L stainless steel in simulated pressurized water reactor primary water

ABS T R A C T Irradiation-assisted stress corrosion cracks (IASCCs) from a proton-irradiated 316 L stainless steel (2.5 dpa) after constant load test in simulated PWR primary water were analyzed. The irradiation damages are consistent with those from neutron irradiations at similar dose. The IASCC cracks show microstructural and microchemical features similar to those reported from neutron-irradiated samples, confirming that proton is effective in emulating neutron for IASCC study. Si segregated at grain boundary gets oxidized preferentially beyond the crack tip and then dissolves into solution, resulting in enhanced porosity within the intergranular oxide. The Si effect is an important factor behind IASCC in reducing environment.

Automated summary

Analysis of irradiation-assisted stress corrosion cracks (IASCCs) in proton-irradiated 316 L stainless steel after constant load test in simulated PWR primary water showed consistent damage with neutron irradiations at similar dose. The microstructural and microchemical features of IASCC cracks were similar to neutron-irradiated samples, indicating the effectiveness of protons in emulating neutron for IASCC study. The preferential oxidation of Si at grain boundaries beyond the crack tip and its dissolution into solution leading to enhanced porosity within the intergranular oxide were identified as important factors behind IASCC in reducing environment.