Effect of rare earth elements on high temperature oxidation behaviour of austenitic steel

The oxidation behaviour of K-52 austenitic steel with rare earth elements investigated at 1000 degrees C for up to 150 h. The oxidation kinetics indicated that the addition of the rare earth elements Y or Ce improved the oxidation resistance of steel. However, the simultaneous addition of Y and Ce decreased the oxidation resistance. The oxidation films forming at different stages were evaluated in detail using surface analysis methods. The improved oxidation resistance primarily resulted from the formation of a complete spinel structure, the inner oxidation of silicon and the existence of MnO2 in the Mn-rich zone.