The advantage of casting technology is that it can produce castings of any size and shape at low cost, but the service performance of castings is greatly affected by the technical characteristics of casting technology itself; The mechanical properties of forgings produced by forging process are excellent, but if the shape of parts is complex, the process is cumbersome. The driven spiral bevel gear of automobile rear axle studied not only has complex geometry, but also has strict requirements for service performance. Casting forging compound forming process combines the advantages of casting process and forging process. It is very suitable for processing parts with high performance and precision requirements and complex structure. In recent years, the research on compound forging process in various countries has achieved fruitful results.
When Lee K and others studied the forming process of aluminum alloy parts, they found that the tensile strength and elongation of the products produced by the casting forging composite forming process were greatly improved compared with the traditional casting process; Kim HR and others used the casting forging compound forming process to produce the connecting rod joint of automobile steering gear. The process test shows that the hardness of the parts produced by this process after heat treatment is more than 20% higher than that produced by casting process; Li Weidong and others compared and analyzed the casting forging compound forming process with other processes, and emphatically expounded the technical problems involved in the casting forging compound forming process and the matters needing attention in designing the die; Li Zhiguang and others successfully applied the casting forging compound forming process to the actual production of 1340 coal scraper of a certain type of coal mining conveyor. The actually produced parts not only meet the design requirements, but also have low production cost, high efficiency and good economic benefits; When Li Yaning and others applied the compound forming process to process magnesium alloy parts, they found that after the casting workpiece went through the plastic deformation process, the internal structure formed uniform fine grains. After heat treatment, the mechanical properties such as yield strength and elongation of the parts were significantly improved; Li Jia introduced the casting forging compound forming process into the production of automobile steering control arm. The optimal process parameters were obtained through simulation, and the mechanical properties of the workpiece obtained from production trial production were significantly improved; Ruan Falin tried to process the wheel hub of ad91 magnesium alloy motorcycle by using the composite process of die forging and die casting. The forming process was simulated by orthogonal experiment, and the process parameters were optimized. By observing the process prototype under the microscope, it was found that the microstructure was basically fine equiaxed crystal, and the average size reached 25 μ Below m; Gao Lin applied sand mold casting technology and swing ring rolling technology to the processing of low carbon steel flange parts. It is concluded that secondary heating can significantly improve the mechanical properties of the blank, and the swing ring rolling can close the shrinkage cavity defects in the blank; Cao Zhengzheng applied the casting and rolling process to the forming process of Q235B ring parts, and analyzed the solidification process of the ring parts by using the casting simulation software. The results show that reducing the pouring temperature within a certain temperature range is conducive to refining the grains; Wang Shuncheng and others designed and manufactured the casting forging integrated forming equipment, which greatly reduced the time of using the composite forming process to produce parts and saved the production cost.