Solidification simulation and process optimization of sand casting for large bearing pedestal

Through the analysis of the physical parameters of the sand mold casting, it is determined that the quality of the sand mold casting is better when the pouring temperature is 1 530 ~ 1 570 โ„ƒ and the pouring time is about 65 ~ 110 s.

The solidification process of sand castings is directly related to the shrinkage cavity, porosity and stress concentration of sand castings. The solidification process simulation of sand castings is to predict the location of shrinkage cavity and porosity. Similarly, shrinkage cavity and porosity can also be predicted according to experience from solidification time and solidification sequence. The solidification defect distribution diagram of sand casting in the original scheme is obtained by Huazhu CAE software, as shown in Figure 1. It can be seen that there are a lot of shrinkage cavity and porosity defects in sand castings, indicating that the feeding effect of riser is not good and needs to be improved.

According to the solidification diagram of the original process, the feeding effect of the riser is not good, and defects such as shrinkage cavity and porosity are formed in the sand casting. In order to eliminate the defects of shrinkage cavity and porosity, the riser design needs to be changed. The riser is calculated by modulus method, and the waist shaped open riser is used. The number is two, symmetrically arranged on the left and right, and the shape and volume are the same. Then conduct solidification simulation, and the results are shown in Figure 2. It can be seen that the shrinkage defects of waist open riser have been greatly improved, and almost all the shrinkage holes are concentrated in the riser, which optimizes the original process.