Effect of Cu on oxidation behaviour of FCC Fe-Ni-Cr-Al and Ni-Cr-Al based alloys

摘要

The high-temperature oxidation behaviour of Fe-Ni-Cr-Al and Ni-Cr-Al alloys with and without Cu addition was investigated at 1000 degrees C in air to determine the effect of Cu on the critical Al content necessary for forming an external Al2O3 scale. The oxidation mass gain of Fe-17Ni-17Cr-7.7Al-Cu and Ni-17Cr-10Al alloys was found to decrease with increased Cu content. An external Al2O3 scale developed when 5at%Cu and more and 10at%Cu and more was added to Fe-17Ni-17Cr-7.7Al and Ni-17Cr-10Al alloys, respectively. The beneficial effect of Cu is inferred to be due to decreased oxygen concentration at the alloy surface and enhanced Al outward diffusion.