High temperature oxidation behavior of heat resistant steel with rare earth element Ce

Abstract

Abstract This study examined the oxidation properties of rare earth steel at high temperatures (600 °C–900 °C) in the air atmosphere by using Scanning Electronic Microscope (SEM) with an energy dispersive spectroscopy (EDS), x-ray diffraction analyzer (XRD) and atomic force microscopy (AFM) analysis method. High temperature oxidation experiment showed that rare earth element Ce played a very good antioxidant effect with the increasing oxidation temperature. After continuous oxidation at 600 °C, 700 °C, 800 °C and 900 °C for 150 h, the mass gain of the rare earth steel were 1.25 mg cm−2, 2.41 mg cm−2, 12.34 mg cm−2, and 13.37 mg cm−2, respectively. In comparison, the matrix steel under the same conditions were 1.31 mg cm−2, 2.94 mg cm−2, 13.98 mg cm−2, and 15.63 mg cm−2, respectively. AFM features of the oxidized surface confirmed that the rare earth element Ce could inhibit the growth rate of the oxide in the early stage of oxidation, and preferentially promote the formation of the spinel oxide. The surface-dense spinel oxide (Fe, Cr, Ni, Mn)3O4, the enrichment of Cr-containing layer in the middle, and the formation of the Si-rich oxide in the inner layer all affected the high-temperature oxidation resistance of the rare earth steel.