Research On Precision Forming Of Plat Cold Cross Wedge Rolling

The cross wedge rolling process is an advanced precision forming technology for stepped shaft parts,which is mainly used for precision blank making and volume distribution for die forging.Under the background of the transformation and upgrading of global manufacturing industry and the transformation of domestic industry from "made in China" to "fine made in China",the cross wedge rolling industry should also develop to the direction of fine manufacturing.Using the Simufact finite element software as an auxiliary tool,this paper mainly studies the precision and internal quality of the stepped shaft parts formed by plate cross wedge rolling at room temperature.Firstly,the simulation accuracy of the finite element software is judged based on the metal elastic-plastic forming theory,which lays a theoretical foundation for the reliability of the simulation results of the finite element software.Secondly,based on the basic theory of cross wedge rolling process,the range of process parameters during stable rolling of plate cold cross wedge rolling is determined,a typical example is selected to establish the finite element model,and the whole process is simulated numerically.According to the simulation results,the state of stress and strain in the rolled piece was analyzed,the characteristics of metal flow in the rolling process were obtained,and the quality of the rolled piece was determined to be improved.By extracting the coordinate data of all nodes on the cross-section profile of the rolled piece at the end of simulation,the graphics are drawn in 2D CAD software,compared with the theory of graphics,explore the forming Angle ?,the stretching angle ?,section shrinkage rate ? of area bits of three the influence law of process parameters on the accuracy of rolled piece.Some force and energy data are also obtained in the simulation,which provide theoretical data for the design of plate cold cross wedge rolling equipment.Under the condition that the die is regarded as a rigid body,the main causes of the circular section diameter error and roundness error of the rolled piece are analyzed in this paper: the error caused by elastic springback and insufficient axial flow of metal lead to ovalization of rolled pieces.In order to improve the precision of the rolled piece,the die reduction compensation method is adopted to reduce the elastic rebound error,and the local structure optimization method is adopted to reduce the ovality of the rolled piece.The results show that under the ideal stiffness condition,the simulation results show that the precision of plate cold wedge rolling is up to 0.01 mm,which is very close to the requirement of 0.009 mm for grade 6 precision.In other words,there is no need for subsequent cutting.This paper improves the numerical simulation research on precision forming of plate cold cross wedge rolling,provides theoretical guidance for the reliability of numerical simulation of elastic-plastic forming in precision research,and provides reliable theoretical guidance for practical production.