This work presents a study of oxide-scale development on a B2 FeAl-based alloy (Fe40Al5Cr0.2TiB) during long-term isothermal oxidation at 700 °C in air, with particular emphasis on the effect of plastic processing. Oxidation tests were conducted for 300, 1000, and 2000 h. Surface morphology and chemical composition were examined using SEM/EDS, phase composition was identified by XRD, and local oxide thickness was measured by TEM. Surface topography was quantified by optical profilometry using Ra and Rz parameters. In both material states (as-cast and plastically processed), the alloy formed a continuous α-Al2O3-based scale. Plastic processing significantly affected oxidation kinetics, resulting in higher mass gain compared to the as-cast condition. Despite differences in mass gain, the average oxide-scale thickness after 2000 h remained in the submicrometric range (~340 nm) for both states. Surface topography analysis revealed differences in roughness and morphology associated with the material condition. The results demonstrate that plastic processing influences oxidation behavior primarily through microstructural modification, while the protective character of the alumina scale remains preserved. These findings provide data relevant to FeAl-based materials considered for high-temperature energy applications.
Pasek et al. (Wed,) studied this question.