Effect of Fe content on corrosion behavior of heat-resistance alloys in high-temperature supercritical carbon dioxide

Abstract

The corrosion behavior of heat-resistant alloys with different Fe contents in high-temperature supercritical CO₂ was investigated by simulation and experiment. Results shown that CO₂ molecules preferentially reacted with Cr to form Cr₂O₃. Cr₂O₃ layers were formed on all heat-resistant alloys. A middle Fe₃O₄ layer was formed in the Cr₂O₃ layers and Cr₂₃C₆ carbides were generated in the sub-layer matrix of Fe-containing alloys. The weight gains of alloys gradually increased with Fe content. The formation of Fe₃O₄ in the middle of Cr₂O₃ layer led to greater weight gain compared to Fe-free alloy. Fe-free alloy exhibited higher resistance to oxidation and carburization.