Corrosion behavior of eutectic high-entropy alloys in supercritical CO2 environments
Wanhuan Yang, Xueli Zhao, Jichun Zou, Wenqin Wang, Qi Liu, Wen Yang, Shen Li, Weihua Zhong
Abstract
This study explores the corrosion resistance of AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA) in supercritical CO2 (S–CO2). The corrosion behavior was meticulously examined under conditions of 500 °C and 25 MPa CO2 over a duration of 800 h. The formation of distinct passivation layers on the face-centered cubic (FCC) and body-centered cubic (BCC) B2 phases was observed, leading to a cooperative passivation effect of Al and Cr. The protective Al2O3 oxide layers, which were dense and continuous, played a crucial role in inhibiting carburization and further oxidation, thereby significantly enhancing the corrosion resistance. Interestingly, no carburization was observed in this study.