Mould copper-plated wear-resistant plate processing method
Crystallizer is the core component of continuous casting steel in steelmaking. The copper-coated wear-resistant plate of crystallizer is an important thermal conductivity component for continuous casting from liquid molten steel to solidified solid billet shell, and its quality directly affects the surface quality of the billet and the drawing speed of the continuous casting machine. In order to better protect the wear-resistant plate, avoid contact between the wear-resistant plate and molten steel, and extend the life of the mold, the surface layer of the wear-resistant plate must have excellent wear resistance. Current approaches are:
1, metal plating
According to the combination form of deposited metal elements, metal coatings can be divided into single metal coating, alloy metal coating and composite coating. By adding metals with different properties, the alloy coating is developed on the basis of a single metal coating. A composite coating with excellent properties can be obtained by adding the second phase particles into the metal or alloy. There are Ni coating, Ni-Cr layer, Co-Ni layer, Ni-Fe-W coating and so on.
2, spraying layer
The spray layer can be obtained on the surface of the workpiece by using thermal spraying technology. The specific method is to heat the spray material to a molten or semi-molten state, atomize and accelerate it with high-speed airflow, and spray it on the surface of the workpiece at high speed. The coating material includes powder, filamentary metal, cermet and other solids, which can form metal alloy layer, ceramic coating and cermet coating after processing. There are: Cr3C2p/NiCr coating, ZrO2/NiCr cermet coating, etc.
3, laser cladding layer
Laser cladding layer is the use of high-energy laser beam irradiation, the material quickly melted, expanded and solidified, after complex physical, chemical and metallurgical changes, on the surface of the substrate to form a layer of special chemical and mechanical properties of composite materials. The laser cladding layer applied to the surface modification of crystallizer is divided into pure metal cladding layer and composite layer with reinforcement phase introduced.
4. Infiltration layer
The infiltration layer is an alloy layer formed by placing the metal or alloy workpiece in the active medium at a certain temperature to hold heat, so that one or several elements penetrate into the surface of the workpiece. The infiltration layer is firmly combined with the matrix, and the hardness of the infiltration layer is higher. Maintain high hardness and wear resistance at the same time. However, the diffusion between the metal and the copper lattice of the infiltration layer is difficult to control, and the high cost limits its application.
At present, it seems that after years of development, the wear-resistant layer on the surface of the crystallizer based on electroplating production will still occupy the main position. Thermal spraying and laser cladding coatings will also be developed in the long run due to their own performance advantages. In the future, the wear-resistant layer prepared by electroplating technology will coexist with other surface technology wear-resistant layers and complement each other.
