High-temperature oxidation behavior of iron-chromium-aluminum alloys

The detailed oxidation behavior of Fe-10Cr alloys, containing aluminum in t he range of 2-8% by weight, was studied in pure oxygen at I atm pressure. T he investigations were performed over the temperature range 950-1050 degree sC under cyclic conditions (3-hr cycles) in each case. The cyclic-oxidation resistance, as measured by the specific weight-gain values, was observed t o progressively improve with increasing aluminum content in the alloy. For a particular aluminum content, however, the oxidation resistance decreased with increasing temperature. Following the initial transient-oxidation peri od, a healing layer of chromia was established on the four alloys. The lowe r-aluminum alloys (24%Al) were observed to end up with I;e-rich oxide scale s under the experimental conditions at all temperatures, whereas those cont aining aluminum in the range of 6-8% formed alpha -Al2O3 scales.