The Forming Simulation And Research On Cross Wedge Rolling Of High-speed Train Axle

Cross wedge rolling process is an advanced precision forming technology,and its operational principle is to use the shoe mold to carry out radial compression and axial extension of the workpiece at the same time,and forming different shapes eventually.In recent years,as an important component of high-speed train,the hollow axle has a great demand,considering that it belongs to the large long axis,so the technology of cross wedge rolling is the best choice for forming hollow axles.However,the research on the cross wedge rolling of hollow shaft is still at the initial stage,so it has important theoretical significance and economic value to study the multi wedge synchronous rolling hollow axle.With the hollow axle of high-speed railway is taken as the research object in this paper,The method of theoretical analysis and numerical simulation is used to study the mould design,the hot deformation behavior and microstructure evolution of the material used for the high speed hollow axle.Through the research on the design of the multi wedge rolling hollow axle die,the formula and the selection principle of the basic process parameters are obtained;the EA4 T steel which is used for high-speed axle was studied by the single and double pass hot deformation experiments in Gleeble-3800 thermal simulator,summarizes the different effects of rolling temperature,strain rate and other parameters on the average grain size.To provide theoretical basis for the optimization of the grain size?good mechanical properties and the optimization of process parameters;the finite element simulation of the multi wedge synchronous rolling hollow axle is carried out,and select several important variables(equivalent stress and strain field,velocity field and rolling force)for analysis.Summarizes the laws of the variation related to workpiece quality in the different process parameters(broadening angle,forming angle,section shrinkage).Finally,with the secondary development function of the finite element simulation software Deform-3D and the dynamic recrystallization model of EA4 T steel which was obtained based on the experimental data,the simulation of dynamic recrystallization of EA4 T steel during cross wedge rolling was carried out.The results show that the dynamic recrystallization percentage and average grain size distribution of EA4 T steel in the process of cross wedge rolling are obtained,which provides an important theoretical basis for the refinement and homogenization of the material.