According to the structural characteristics of sand casting mud pump body and the physicochemical properties of ZG35, two sets of gating system design schemes are put forward:
(1) Scheme I
In order to make the molten steel fill the mold layer by layer from bottom to top during pouring, so as to better realize sequential solidification and avoid defects such as shrinkage, the pump body of sand casting mud pump adopts an open double-layer stepped gating system. The bottom layer of the gating system adopts three internal sprues and the upper layer adopts one internal sprue. In order to simplify the structure of the gating system, all sprues adopt circular section. The process scheme of the gating system is shown in Figure 1.
(2) Scheme II
Considering the stability of liquid steel filling the mud pump body of sand casting and the oxidation of liquid steel, the mud pump body of sand casting adopts an open bottom injection gating system, the bottom layer adopts three internal sprues, and all sprues also adopt circular section. The process scheme II of gating system is shown in Figure 2.