Abnormal Oxidation Kinetics of Fe-Cr-Al Alloys at 1273 K Induced by Cr-rich Phases

摘要

The oxidations of Fe-10Cr-10Al, Fe-15Cr-10Al, and Fe-20Cr-10Al (all in at.) alloys were conducted in 0.1 MPa oxygen at 1273 K. After a transient oxidation stage, three alloys underwent a selective oxidation of Al incorporated with oxidation of Cr and then a steady state stage involving exclusive oxidation of Al. Compared with Fe-10Cr-10Al and Fe-20Cr-10Al, Fe-15Cr-10Al exhibited abnormal oxidation kinetics, i.e. the much higher oxidation rate during the selective oxidation of Al and the much lower oxidation rate during the exclusive oxidation of Al. The abnormal oxidation kinetics of Fe-15Cr-10Al was induced by the Cr-rich phases existing parallel to the surface of the specimens.