The effect of elastic and plastic strain on surface and intergranular oxidation of alloy 600 in simulated PWR primary water

Abstract

The effects of deformation and stress on the surface and grain boundary oxidation of Alloy 600, exposed to primary water of Pressurized Water Reactors (PWRs), were investigated by Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Scanning Electron Microscopy (SEM). It was found that tensile straining prior to oxidation does not modify the surface oxide thickness while the intergranular oxide depth increases when the strain reaches a critical value of 15%. The oxide growth rates at surface and grain boundaries are enhanced under stress. The effect of stress is more significant when the specimen is under elastic strain than plastically deformed.