Oxidation of stainless steels (AISI 304 and 316) at high temperature. Influence on the metallic substratum

Stainless steels of type AISI 304 and 316 were heated in air (1-5-15 minutes at 900-1000-1100 °C) and the oxide layers formed on the surface were analyzed by XRD, CEMS, SIMS and FTIR. At these temperatures the main oxides are Cr2O3 and a spinel close to MnCr2O4 for polishing samples (with Fe2O3 for the chemically cleaned samples). The oxidation induces a Cr and Mn depletion from the metallic substratum and a phase transformation γ (f.c.c.) → α (b.c.c) in a thin layer of the steels near the oxides - metal interface