Long-term oxidation performance of ingot-produced Fe3Al alloys

The oxidation performance of ingot-produced Fe-28at.%Al-(2-5)%Cr alloys wit h minor oxygen-active element additions was examined in long-term exposures at 1,000-1,300 degrees C. As expected for alumina-forming alloys, addition s of Zr, Y and Hf improved the oxidation behavior of these alloys. At the l ower end of the temperature range, these alloys performed similarly to othe r iron-base alumina-formers. However, at higher temperatures, scale spallat ion was increased and significant deformation of the substrate was observed . This type of scale spallation was not observed on other alumina-formers. Oxidation data were used to predict times to breakaway for this temperature range.