Preparation and research of WC–Cr3C2–Ni coating with efficient resistance to molten steel erosion and high-temperature oxidation

This study focused on the threat of molten steel erosion in the failure of the WC–Cr₃C₂–Ni coating on the surface of the crystallization roller. An innovative experimental method for dipping low-melting-point metal surface coatings against high-temperature liquid metal erosion was proposed, filling the gap in experimental technology in this field. The WC–Cr₃C₂–Ni coating demonstrated excellent resistance to scouring erosion and high-temperature oxidation when exposed to long-term molten steel erosion during service. After 500 tons of steel throughput equivalent, the roller body performance did not decrease, and the hardness of the WC–Cr₃C₂–Ni coating was only reduced from 1298.75 Hv_0.5 to 1265.21 Hv_0.5 (by only 0.8 %). During the service process, the molten steel could not permeate into the WC–Cr₃C₂–Ni coating, and only micron-sized spherical steel slag particles (particle size 1–3 μm) were left on the coating surface. This study made it clear that the erosion of molten steel played a weak influencing factor in the failure of the production line. The experimental results provide a theoretical basis for the life evaluation of crystallization rollers and the prediction of production line maintenance time.