High temperature treatment of Cr₃C₂@SiC-NFA composites in water vapor environment

This work focuses on the oxidation resistance of a new class of composites, chromium carbide coated silicon carbide-nanostructured ferritic alloy (Cr₃C₂@SiC-NFA), in a water vapor containing atmosphere at 500–1000 °C. Oxidation temperature effects on surface morphologies, scale characteristics, and cross-sectional microstructures are investigated and analyzed. The Cr₃C₂@SiC content in the composites is strongly associated with the oxidation resistance by forming a dense Cr- and Si-rich inner-layer, which can be explained based on the Thermo-Calc simulation. The fundamental understandings offer important guidance for the applications of this class of composites in nuclear reactors and high temperature moist environments.