Oxidation and Chromium Volatilisation of AISI 430 Stainless Steel in O<sub>2</sub>-H<sub>2</sub>O and Ar-CO<sub>2</sub>-H<sub>2</sub>O at 800°C

Abstract

To investigate the behaviour of oxidation and chromium volatilisation, AISI 430 stainless steel was oxidised in O2-H2O and Ar-CO2-H2O atmospheres for 96 h at 800°C with varying water vapour content. In the O2-H2O environment, the volatilisation rate of Cr and Mn increased as the water vapour content increased from 5% to 20%. In the case of Ar-CO2-H2O conditions, the presence of water vapour in the Ar-20%CO2 environment reduced the oxidation rates of the steel. However, increasing the H2O content in Ar-20%CO2 had an insignificant effect on the oxidation rate. Water vapour was found to accelerate the volatilisation rate of Cr and Mn. Breakaway oxidation occurred in Ar-20%CO2-40%H2O, resulting in the highest volatilisation rates of Cr and Mn.