Oxidation properties of complex concentrated alloys FeAlCrV and FeAlCrMo

Abstract

Complex concentrated alloys (CCAs) are attracting considerable interest due to their potential applications under extreme conditions. This study focuses on two complex concentrated alloys, the FeAlCrV and the FeAlCrMo alloys, which already exhibited exceptional mechanical properties at high temperatures. In this regard, room temperature corrosion resistance and high-temperature oxidation were studied to investigate their potential applicability in harsh environments. It is shown that the corrosion resistance of both CCAs is much higher than that of AISI 304 and P91 steels in 0.5 M H2SO4 solution, while in 3.5% NaCl solution was comparable. On the contrary, high-temperature oxidation of CCAs was unsatisfactory, especially exceeding 700 °C. The intensive analysis of the formed oxide scales revealed that the protective oxide layer is not being formed at temperatures above 700 °C, primarily because of the occurrence of vanadium corrosion (FeAlCrV) and evaporation of Mo oxides (FeAlCrMo). The results of this study unambiguously showed the importance of studying oxidation properties at high temperatures parallel with the mechanical properties for the development of CCAs for cutting-edge technical applications.