Taking the sand mold casting of the mud pump body as the research object, firstly, the gating system, feeding system and chilling system of the sand mold casting of the mud pump body are designed by using the theoretical knowledge of casting technology, and then the temperature field and flow field in the filling process, the temperature field and stress field in the solidification process are analyzed by using the casting CAE software ProCAST, Verify the rationality of sand mold casting process scheme of mud pump body. The main work and conclusions are as follows:
(1) Firstly, according to the basic theory of casting technology, the casting process analysis of the structure of mud pump body in sand mold casting is carried out. Referring to the analysis results, two sets of pouring systems of bottom injection and step are proposed, the pouring time and speed of sand mold casting of mud pump body are calculated, and the size of each sprue in the two sets of process schemes is determined, The gating system design of sand mold casting of mud pump body is completed.
(2) Firstly, the modeling design of sand mold casting of mud pump body is completed by using the software Creo, and then the finite element mesh is divided by using the software geomesh and meshcast. Finally, the filling process of two pouring schemes of sand mold casting of mud pump body is simulated and calculated by using the software ProCAST. Comparing the simulation results of the two sets of process schemes, it is known that although the filling process of the bottom injection gating system is slow and stable, and the erosion to the mold wall is small, there is no good temperature gradient distribution in the pouring process, which is easy to cause shrinkage defects, and the large drop of liquid metal temperature is easy to cause oxidation on the surface of the casting; The stepped gating system can provide a better temperature gradient distribution, and the decrease of liquid metal temperature is small. Finally, the stepped scheme is adopted for the gating system of sand mold casting mud pump body.
(3) The design of feeding system and chilling system of sand mold casting mud pump body was completed, and the temperature field and stress field of sand mold casting solidification process of mud pump body were simulated by software ProCAST. The temperature field simulation results show that due to the insufficient feeding distance of the riser in the designed feeding system, the feeding efficiency is not high, the setting of cold iron in the chilling system is unreasonable, the temperature distribution of each part of the casting is disordered during solidification, forming many isolated liquid phase regions, resulting in shrinkage porosity and shrinkage cavity defects in the solidification process; The stress field simulation mainly analyzes the equivalent stress, deformation and hot crack distribution of the mud pump body of sand mold casting during solidification. It is found that due to the different wall thickness between the casting flange and the pump pipe, there is a temperature difference during solidification, there is large deformation at the flange, and the riser design needs to be improved.
(4) According to the simulation analysis results of the original process scheme, on the basis of the original scheme, the design of the inner runner is adjusted, cold iron and subsidies are added, the insulation riser is used, and the insulation agent is sprayed at the same time. The optimized process scheme is put forward again. The optimized process scheme is simulated and analyzed again by ProCAST. According to the simulation results, the optimized scheme can effectively eliminate the sand mold casting defects of the mud pump body and make it meet the technical requirements.