Wear-resistant aluminum and chromonickel coatings at the narrow mold walls in continuous-casting machines

Abstract

To extend the working life of molds in continuous-casting machines, a heat- and wear-resistant layer is formed on the narrow M1 copper walls prior to final repair, by spraying on aluminum and chromonickel coatings. The first step is to determine the coating structure, phase composition, and the hardness and microhardness of the surface layers. A chromonickel coating (thickness 0.5–0.6 mm) is sprayed on the surface of the pair of narrow walls of the thick-walled mold. To obtain the required surface purity, the walls must be ground. Efforts are required to increase the thickness of the chromonickel coating. With a coating thickness greater than 0.8 mm, peeling is possible. Therefore, to increase the strength with which the chromonickel coating is bound to the copper base, we consider the possibility of using an aluminum substrate. Thus, to extend the life of the narrow mold walls in a continuous-casting machine, a chromonickel coating with an aluminum substrate may be applied if bonding of the porous layer with the α phase is ensured or the porosity of the layer is reduced.