Research On Heat Treatment Residual Stress In Train Axle After Cross Wedge Rolling

With the rapid development of railway construction,the requirements for axles are becoming more and more important,such as its performance and reliability.Plastic forming and heat treatment,as important processing technologies in the preparation of axles,play a vital role in the performance of axles.And the residual stress generated during the preparation of the axle will threaten the safety and reliability of the axle.It is necessary to carry out numerical simulation analysis on the forming process and the heat treatment process to obtain the distribution law of the stress field,temperature field and tissue field inside the axle,so as to optimize the process parameters so that the axle can obtain the best performance.In this paper,the cross wedge rolling process is used to thermoform the train axle.In the finite element software DEFORM-3D,a finite element model of cross wedge rolling is created and the process is numerically simulated.After the simulation is completed,the distribution of the internal stress of the axle is analyzed,and the influence of different rolling temperatures,different forming angles and different widening angles on the internal stress and residual stress of the axle is studied.The finite element model of train axle quenching process was established by using finite element software,and the distribution of temperature field,structure field and stress field of axle during heat treatment was studied.Taking the three heat treatment process parameters of quenching temperature,heating time and cooling method as factors,the axle heat treatment process scheme was designed through orthogonal experiments and the heat treatment process was completed in the finite element software,and its residual stress was obtained in the post-treatment.The effects of quenching temperature,heating time and cooling method on the residual stress of the axle surface and core were analyzed.Based on the simulation data,a BP neural network model is constructed,and the genetic algorithm is used to optimize the axle heat treatment process parameters.