Comparative study on short time oxidation of un-irradiated and protons pre-irradiated 316l stainless steel in simulated pwr water

Abstract

Achieving a better understanding of the Irradiation Assisted Stress Corrosion Cracking resistance is one of the issues to improve the durability of Pressurized Water Reactors. To do so, assessing the interaction of irradiation defects with oxidation of internal vessel bolts, made of 316L alloy, is crucial. In this work we studied the effect of protons pre-irradiations at 1 dpa on the very first steps of oxidation (1 min < t < 24 h) in simulated PWR environment. The morphology of the oxide layer was investigated using optical microscopy and Scanning Electron Microscopy. The oxidation kinetics for short term oxidation is discussed based on the obtained results. It was observed that crystallographic orientation has an effect on the oxidation process. The level of cold-work and the presence of precipitates were taken into account and both seemed to accelerate the oxidation kinetic. Finally, irradiation also tended to speed-up the oxidation phenomenon.