Effect of CeO2 on Microstructure and Properties of Cr3C2/Fe-Based Composite Coatings

As a critical component of scraper conveyors, the middle trough operates under harsh conditions for extended periods, making it prone to failure and thus reducing the overall service life of the equipment. To address this issue and extend its service life, this study incorporated different amounts of CeO2 into Cr3C2/Fe-based composite coatings. It investigated the effects of CeO2 on the coating’s phase composition, microstructural evolution, wear resistance and corrosion resistance. Results show that CeO2 addition did not alter the coating’s phase composition. The composition remained α-Fe, M23C6 (M: Fe, Cr) and vanadium carbides. However, CeO2 promoted the transformation from columnar grains to equiaxed grains and refined the grains. With increasing CeO2 content, the composite coating’s mechanical properties gradually improved. The Ce2 coating exhibited the highest microhardness (923.08 HV0.5), the lowest friction coefficient (0.31) and the lowest wear rate (0.00217 mm3/N·m). Its dominant wear mechanisms were abrasive wear and mild adhesive wear. In 3.5% NaCl solution, the Ce2 coating showed the highest corrosion potential (−0.82 V) and the lowest corrosion current density (2.04 × 10−6 A/cm2), indicating excellent corrosion resistance. This study provides theoretical support for preparing high-performance Cr3C2/Fe-based composite coatings. It clarifies the key mechanism by which CeO2 regulates coating properties. The developed composite coating has broad application potential due to its excellent combined wear and corrosion resistance. It can be widely used for surface strengthening of vulnerable components in mining machinery such as scraper conveyors, offering important theoretical and technical support for improving the service life of scraper conveyor middle troughs.