The 75 kW box type electric furnace is used for investment casting impeller blade investment baking equipment. The investment casting impeller blade shall be calcined at 850 ± 30 ℃ for 1.5 ~ 2H, and shall be cast immediately after being discharged from the furnace.
During the investment baking process of investment casting impeller blade, the investment mold shell of investment casting impeller blade shall be placed horizontally in a stainless steel disk filled with 20 / 40 mesh quartz sand to prevent the investment mold of investment casting impeller blade from deformation at high temperature. The surface of the well roasted shell is white, and there should be no black smoke when it is discharged from the furnace; When the mold shell is roasted repeatedly, the investment casting impeller blade mold shell expands and shrinks continuously during heating and cooling, which will produce microcracks, and even make the ethyl silicate surface layer of the mold shell layered with the water glass reinforcing layer. Therefore, the investment casting impeller blade mold shell is not allowed to be roasted twice.
The picture shows the effect of investment casting impeller blade after the investment mold shell is roasted. As can be seen from the figure, the surface coating of ethyl silicate is smooth and white after roasting. It meets the needs of molding and pouring of composite shell.