Effects of Rare Earth Metal Ce Additions on the 1150°C Isothermal Oxidation Behavior of Ni-20Cr Alloy

Abstract

Isothermal oxidation behavior was investigated for Ni-20Cr alloy with addition of different Ce 0 (wt)%, 0.042(wt)% and 0.094(wt)% at 1150°C for 100h.The surface and cross-section microstructures of the oxide scales were analyzed by EPMA(Eelectron Probe Micro-Analysis). The addition of Ce in Ni-20Cr alloy may improved the cohesion between the matrix and the oxide scales significantly and increased the oxidation resistance of Ni-20Cr alloy. Compared with 0 (wt)%Ce and 0.042(wt)% Ce in Ni-20Cr alloys, the oxide scales on Ni-20Cr alloy with addition of 0.094(wt)% Ce showed compact, which limited the internal oxidation.The cross-section microstructure of oxide scales presented three complicated oxide layers, which were Cr2O3, SiO2and Al2O3from the oxide scales to the matrix.