Creation of the wear-resistant layer on narrow walls MNLZ crystallizers with use gas-thermal covering

To increase service life of CCM mold on their narrow sides from M1 copper before the last renovation created a heat-resistant wear-resistant layer plating chromium coating. Previously investigated the structure of the coating, phase composition, hardness and microhardness of the surface layers. As shown by experiments, heat treatment of the walls with an aluminum gas-thermal coating in a protective environment at a temperature of 900 о С and the exposure time 10 h necessary to create the desired thickness of the diffusion layer, leading to them warping as a result of this process, which is not eliminated by mechanical means. Therefore, it was necessary to adjust the modes of heat treatment or applied to the wall material, not inferior in properties of Cu-Al diffusion layer and which does not require heat treatment. The coating of Nickel alloy was deposited on the entire working surface of the two narrow walls. The required cleanliness class of the working surface of the walls was achieved through machining. Chromium-Nickel coating thickness of 0.5-0.6 mm were deposited on the surface of the pair of narrow walls of thick-walled mold. The coating on the samples with a Cr-Ni layer consists of three phases: dark, contains the largest amount of chromium and oxygen: (Cr) to 63.4%, (O) to 33.4%, (Ni) 3,2-9,1%; light, within which the detected maximum amount of Nickel to 89% and sulfur phases: (Ni)=63,9-73,5%, (Cr) to 12.4%, (O)=22-24,9%, (Fe) to 3.4%, (Si)=0,3-0,5% Thus, to obtain the desired cleanliness class of the surface of the walls required machining by grinding and will require work to increase the thickness of the Chromium-Nickel coating.