Large Axle Cross Wedge Rolling Forming Process And Damage Theory Model Construction And Application

As the driving part and preform of heavy-duty forgings,large-scale shaft parts are the key basic parts of heavy-duty equipment,which are widely used in the fields of transportation,construction machinery,national defense and military industry.As an important load-bearing component of high-speed railway bogie,the performance of large axle has an absolute effect on the safety of train transportation.At present,the main methods used in our country are fast forging,precision forging,machining center forming,etc.,however,there are some defects in the forming process,such as low production efficiency,low material utilization ratio and unstable product quality,which restrict the efficient production of axle.Therefore,a new research method is put forward in this paper,which is called cross wedge rolling process for rolling large axles,and the crack damage caused by cross wedge rolling process is studied in depth.In this paper,by optimizing the structural design and process parameters of the mold,baffle and rolling parts involved in wedge transverse rolling,and combining with the working principle and basic theory of wedge transverse rolling axle,the basic parameter range of the process mold is determined.Secondly,Gleeble-3800 thermal simulator tests LZ50 axle steel,and analyzes the relationship between rheological stress and deformation temperature under different true strain conditions.The results show that the rheological stress of LZ50 axle steel decreases with the increase of temperature during thermal deformation The reduced sample observed the metallographic tissue and studied the changes of the specimen at different strain rates and different temperatures;using the dynamic material model（DMM）,the temperature is 1050-1150℃and the strain rate is in the range of 1-5s^-1for the best process area.Thirdly,through the application of ANSYS finite element simulation software,combined with previous research and literature,the rolling process is dynamically simulated,and the changes of stress,strain and temperature field during the forming process of axle steel are analyzed.The results show that the plastic deformation of the metal increases The more significant,when the finishing section,the temperature on the surface and interior of the mill reached a more uniform distribution.Finally,in view of the damage defects caused by the uneven force of the rolling parts in the rolling process,the damage model analyzes and predicts the results of the three process parameters of the process parameters,so as to realize the secondary development and application of the axle forming process.The research results in this paper provide a theoretical basis for solving the problems of forming difficulty,forming instability and the prediction of central crack damage after forming in cross wedge rolling of large axles,it provides reliable reliable model and data reference guidance for practical rolling forming.