High-temperature oxidation behavior and mechanism of a new type of wroughtNi-Fe-Cr-Al superalloy up to 1300 degrees C

The oxidation behavior of a new type of wrought Ni-Fe-Cr-Al superalloy has been investigated systematically in the temperature range of 1100 to 1300 d egrees C. Results are compared with those of alloy 214, Inconel 600, and GH 3030. It is shown that the oxidation resistance of the new superalloy is e xcellent and much better than that of the comparison alloys. Scanning elect ron microscopy (SEM), electron probe microanalysis (EPMA), and X-ray diffra ctian (XRD) experiments reveal that the excellent oxidation resistance of t he new super-alloy is clue to the formation of a dense, stable and continuo us Al2O3 and Cr2O3 oxide layer at high temperatures Differential thermal an alysis (DTA) shows that the formation of Cr2O3 and Al2O3 oxide layers on th e new superalloy reaches a maximum at 1060 and 1356 degrees C, respectively . The Cr2O3 layer peels off easily, and the single dense Al2O3 layer remain s, giving good oxidation resistance at temperatures higher than 1150 degree s C. In addition, the new superalloy possesses high mechanical strength at high temperatures. On-site tests showed that the new superalloy has ideal o xidation resistance and can be used at high temperatures up to 1300 degrees C in various oxidizing and corrosion atmospheres, such as those containing SO2, CO2 etc., for long periods.