Short-term oxidation behavior of 304 stainless steel in N2-21 vol％O2 environment between 900 and 1200 °C

Oxidation behavior and microstructure evolution of 304 stainless steel at 900–1200 °C in N2-21 vol％O2 were investigated. At 900 °C, Cr2O3 protective oxide is formed on the surface of the steel. With the increase in temperature (1100 °C), an inner oxide layer is formed consisting of two phases (Fe, Cr)3O4 oxide and remaining Ni-Fe metallic. The oxide scale formed at 1200 °C has a unique morphology consisting of the inner Cr-rich oxidation region, middle gap region, outer porous Fe3O4 oxide region, and outermost dense Fe2O3 oxide scale. A discontinuous SiO2 layer appears in the oxide scale.