Research Of Vehicle Axle Heat Rotary Forging Process And Forming Quality

Axle is a major component of automotive driveline, but also one of the highest failure frequency components in the automotive parts. There is important practical significance to improve the bending strength, shear strength, rigidity, toughness, fatigue limit and sensitivity of axle, so the axle has high demand for forging process. In this paper, a model car axle was taked as the research object, rotary forming process was used for the automobile axle forming. The finite element method was used to verify the reliability of the forming process, combined with physical experiments and numerical simulations, the relationships between the thermal rotary process and forming force, the average grain size, the maximum stress were studied. Based this, the rotary forming was optimized and the forming quality of axle was controled. The detail jobs are as follows:(1) Based on the theory of rotary forming and plastic forming, the forming process of rotary for axle was designed.(2) The finite element model of axle forging process was established and the correctness was verified. Based on metal flow, stress-strain field, temperature field and forming load, et al, the influence of processing parameters on the quality of forging and forming force was analyzed.(3) Based on experiments and dynamic recrystallization of42CrMo steel, the changes of axle average grain size after rotary forming was studyed. It shows good agreement between simulation and experimental data, grind grain has been significantly refined after upsetting and rotary forming.(4) Forming force, the average grain size and the maximum stress after forming were taked as the target, the parameters of rotary forming process were optimized using orthogonal experiment method. The influence of process parameters on the target value was analyzed, then the process parameters to get the optimal forming quality were obtained.