High-Temperature Oxidation of an Fe-Mn-Al-C Alloy.

The behavior of an Fe-Mn-Al-C alloy during oxidation in air at 1000 e 1100 degree C was investigated. Metallographic analysis of the scale revealed a duplex oxide layer and the presence of precipitates in the underlying matrix. The oxides were identified by X-ray diffraction but the precipitates were not detected by the analysis. Microprobe analysis of the precipitates indicated a high Al-content. To investigate the influence of the oxidation atmosphere on the formation of the precipitates, new treatments were carried out under atmospheric pressure and 1000 degree C, first in pure O//2 and then in pure N//2. The results indicated an interesting effect of nitrogen on the oxidation behavior of the alloy.