A Cost-effective Fe-rich Compositionally Complicated Alloy with Superior High-Temperature Oxidation Resistance

Abstract The high-temperature oxidation resistance of a novel Fe45Ni25Cr25Mo5 compositionally complicated alloy (CCA) was investigated with comparison to 316L stainless steel and Inconel 625 superalloy. The Fe-rich CCA exhibited superior oxidation resistance at 1200 °C, including low oxidation rate and high spallation resistance. This was attributed to the formation of an exclusive and compact chromia scale with high hardness and elastic modulus, protecting the substrate from further oxidation and high resistance against cracking during the oxidation process. The superior mechanical properties of the chromia scale originated from its high compactness, fine-grains and solid-solution strengthening induced by diffused Fe atoms.