Microchemistry characterization by Auger electron spectroscopy of a cold-worked AISI-304L stainless steel

Abstract

Auger electron spectroscopy (AES) has been performed on grain boundaries of an AISI-304L stainless steel. The aim of the work was to study microchemistry at grain boundaries by AES after simulating irradiation effects by cold work followed by heat treatments. The results show that phosphorus was present at interfaces in all material conditions. Sometimes, phosphorus was accompanied by molybdenum and by chromium enrichment. Those analyses were attributed to ferrite/austenite interfaces while those where phosphorus was found alone were thought to belong to austenite/austenite interfaces. Cold work when combined with heat treatment at low temperature was shown to affect phosphorus and chromium segregation in a similar way to radiation-induced segregation. In this respect, cold work enhanced non-equilibrium phosphorus segregation to interfaces, while it induced chromium diffusion away from grain boundaries. Finally, corrosion and stress corrosion tests were performed to study the influence of this particular microchemistry on 304L performance.