When the molten metal is poured into the mold, the volume shrinkage will occur during cooling and solidification. This shrinkage may result in defects in the final solidified part of the axle housing – shrinkage cavity or porosity. Common casting alloys with large volume shrinkage, such as cast steel, malleable cast iron and some non-ferrous alloys, have such defects, so it is necessary to design a feeding system to solve this problem.
Shrinkage cavity and shrinkage porosity have a significant impact on the compactness of the axle housing, which will greatly reduce the effective bearing area of the axle housing, which can not meet the requirements of mechanical properties, and even directly scrap the products in serious cases. In engineering practice, the purpose of feeding the defect is usually achieved by setting risers. The riser can store liquid metal to make up the defects of the axle housing, and at the same time it can vent gas and collect slag.
Due to the chilling effect of the chill, the solidification rate of the cold part on the surface of the axle housing is faster than that of the adjacent section. In order to obtain compact axle housing, cold iron can be used as the end zone to reduce the number of risers and improve the process yield of the axle housing.
According to the results of the computer simulation of the axle housing, the riser and chill are added. Then the quality of the axle housing is observed and the influence of riser and chill on the solidification process is studied.