Oxidation behavior of high-strength FeCrAl alloys in a high-temperature supercritical carbon dioxide environment

Abstract

The oxidation behavior of three high-strength FeCrAl alloys was investigated in supercritical carbon dioxide environment at 650 °C. After exposure for 500 h, the weight gains of the FeCrAl alloys gradually decreased with increasing Al content. The oxide scales are primarily composed of α-Al2O3 and spinel oxides. With increasing Al content, the amount of α-Al2O3 increases and the C content decreased in the oxide scale and sub-scale matrix. Moreover, larger (Nb,Mo)C carbides formed in the sub-scale matrix and their number decreased with the increase of Al content.