Effect of implantation defects on the corrosion of 316L stainless steels in primary medium of pressurized water reactors

Abstract : 316L samples were implanted with xenon ions in order to generate defects (characterised as cavities) in the alloy subsurface region. Their oxidation kinetics in pressurized water reactor primary water at 325 °C were determined using ion beam analyses. After a 24 h exposure, the internal oxide layer reaches a thickness equivalent to the implanted affected depth (90 nm) which does not change much for longer exposure duration. Two-stages corrosion experiments followed by secondary ion mass spectrometry analyses have revealed two oxygen diffusion regimes in the internal oxide layer, which seems to be linked with the distribution of implanted defects.