Simulation Analysis And Experimental Study Of Casting Performance For Large Engineering Truck Axle Housing

This type of axle housing is large-sized steel castings which is rarely involved in the domestic, for supporting the main reducer, differential and axle of the heavy truck. Because the quality of the axle housing has an important influence for safe operation of engineering vehicle, the process of product design and manufacturing requirements are particularly high. Until recently, axle housing has been exposed many problems. The result showed that there are casting defects, such as porosity defects and hot tears of the axle housing. Among them, porosity defects of axle housing's abdomen has been particularly severe, and it had reached above 80%. However, the occurrence rate of hot tears of axle housing reached 100%. This not only affected the quality of the product, but also extended the production cycles and increased the manufacturing cost of the product.In this paper, the first to simulate the original gating process of axle housing based on numerical simulation software MAGMA. By analyzing the distribution like temperature field, flow field and porosity in the filling and solidification process, the scheme of optimization design for gating system was proposed. Using bottom gating process to replace the original gating process can keep alloy liquid steady during mold filling, and prevented the splattering and oxidation of alloy liquid and realized simultaneous solidification of axle housing's abdomen, so as to achieve the goal which the incidence of porosity defects was reduced. In addition, based on simulating the filling and solidification. By coupling stress, strain and temperature field to get the distribution of hot tears in semi-solid range, and to analyze the potential location of hot tears. According to the causes for hot tears, original gating process optimization problem was solved. By increasing the cracking strip and cold iron, improving the surface strength of the location where the hot tears happen, speeding the rate of axle housing and enhancing compactness in structure. so as to achieve the goal which the incidence of hot tears was reduced.The production validation was taken to examine the improved technical scheme of axle housing, and the result showed that in the same case, using bottom gating system to replace the original gating system was benefit to eliminating the porosity defects. The incidence of defects from the original 80% to 15%, and the quality of axle housing has been significantly increased. After increasing the cracking strip and cold iron, the crack circumstance of the edge of bowl, neck, bottom platform and flange position of axle housing were improved to some extent. The overall incidence of defects from the original 100% to 20%, and the width of the crack was less than 1mm which was easy to be weld. The scrap rate was reduced, and the manufacturing efficiency of axle housing was obviously enhanced.