The mould is the most critical component in the continuous casting machine in steelmaking plant. The quality of the mould copper plate directly affects the surface quality of the continuous casting slab, the operating rate and cost of continuous casting production. In the production, the mould copper plate mainly has problems of edge wear, wide surface hot crack, narrow surface shrinkage, corrosion. At present, the focus of research on mould copper plates is to adopt a suitable surface treatment technique to electroplate one or more materials on the surface of the copper plate to obtain a special functional surface. When the thermal conductivity of the mould is required not to be affected by the coatings, various coa-tings with strong bonding with the substrate, good wear resistance and strong thermal corrosion resistance are obtained to improve the surface properties of the copper plate, prolong the service life and improve the quality of the continuous casting slab, which leads to achieving the purpose of reducing the cost of casting steel. The development of high-speed continuous casting imposes higher requirements on the surface properties of the mould. Surface modification techniques such as electroplating, electroless plating, thermal spraying and laser cladding can be used to solve the problems of corrosion resistance and wear resistance of mould copper plate. The coatings of the mould copper plate were developed by Cr plating, Ni plating, Ni-Fe plating and Ni-Co (Co-Ni) coating. Co-Ni alloy coatings have high temperature hardness, good thermal stability and strong electrochemical corrosion resistance, which are ideal copper plate coatings for the mould copper plate, but the cost of Co is high, the plating stress is high when the hardness is high, and the heat exchange resistance is poor. Therefore, researchers have continuously applied new processes and materials to develop different coatings for further improving the surface properties of the mould copper plate in recent years. Coating materials change from alloy coatings to composite coatings, and preparation techno-logy changes from thermal spray to laser cladding. The hardness and wear resistance of the coatings are further improved. The coatings mainly uses Ni and Co as the base phase, and Si, Cr, Zr, W, and P are common hard phases, and Al2O3, carbide, boride, etc. are used as the cera-mic phase to increase the wear resistance of the coatings. The nanomaterials can reduce the grain size of the coatings, and show unique advantages in increasing the bonding force of the coatings, improving the wear resistance and thermal conductivity of the coatings, which has become a research focus for the development of new mould surface coating materials. Using nano-scale ceramic particles with good wear resistance and thermal conductivity on the surface of the mould is an important measure to optimize the properties of the existing coatings. Using multi-layer structure is contribute to improve the bongding strength between the coatings and the substrate. In addition, it has been proved that apply different coatings on different parts of the mould can effectively prolong the life of the mould. The electroplating and thermal spraying coatings are mainly mechanical bonding with the substrate. Because of its low production cost and good wear-resistance and heat-conducting properties, they are widely used in industrial production. The laser cladding layers are metallurgical bonding with the surface of the substrate and they are mainly used for the surface repair of the mould. In this paper, the application status of electroplating, thermal spraying and laser cladding in the surface treatment on the mould is reviewed. The abrasion resistance and application characteristics of the coatings obtained under different preparation conditions are evaluated. Research directions of further improving the surface properties of copper plate in the continuous casting mould are proposed. © 2019, Materials Review Magazine. All right reserved.
