Influence of the simultaneous processes of scale evaporation and reaction surface reduction on the oxidation kinetics of chromia-forming alloys doped with rare-earth elements

The high-temperature oxidation of FeCr(La) and Cr(Ce) alloys was studied by thermogravimetry. The kinetic dependence of the FeCr(La) mass change has a specific form due to the simultaneous occurrence of scale evaporation and reduction of the reaction surface. The latter is due to the formation of diffusion barriers from lanthanum chromite. The kinetic dependence of the mass change of Cr(Ce) has an identical form. Based on this identity, it was suggested that diffusion barriers can also exist in the Cr(Ce) alloy, as is the case for the FeCr(La) alloy.