Numerical Analysis And Optimization Of Molding Forging Process About 60 AT Tip Rail

In recent years in our country, high speed railway mileage increases rapidly, and itsdedicated connected devices has been changed into high-speed turnout, in order to meet therequirements of the speed and safety. AT railway(short special-section rail), as the mostimportant part of switching point in the high-speed turnouts system, locates at the corner ofthe rails, where the curvature and centripetal force is very large and the train can not decreasespeed leading to risk of accidents such as prone to derailment. Therefore, the quality of AT railwhich is the throat of the rail restricts the safety, reliability and the speed of trains, and affectsthe speed directly.The section of AT rail is highly asymmetric, causing a complex process. The new processwas simulated in this paper by using DEFORM, whose operation of forming is automaticcompletely under high temperature.Design and draw the mold model of every forging process in the three-dimensiondrawing software (Pro/E) platform. Set the simulation parameters and simulate preliminarythe forging process, analyze metal flow of the workpiece in deforming process, observe theshape of formed AT rail, modify the mold cavity shape, in order to obtain reasonable cavitysize. Simultaneously, solve the key deformation issues such as heightening of the rail andlengthening of short-leg.Simulate the molding gorging process of AT rail again based on gaining the reasonablecavity. Analyze the metal flowing law in forming process, the distribution of effective stress,effective strain and temperature of workpiece, and temperature distribution of the dies as wellas its load changing trend. There is not fin appear in the whole deformation process, leaving asmall amount of forming margin on the top of the rail in the deformation part. The effectivestress and effective strain mainly distribute at the waist and the bottom of AT rail where thedeformation is large. Temperature uniform distribute after completely forging, thoughexchanging heat with mold in forming process and with surroundings in the process ofchanging mold between the forging step, and the final temperature meets the need of onlineresidual heat normalizing. High die temperature distribute at the section that contact withworkpiece directly, and the maximum temperature is 400℃.Optimize the parameters of the molding forming process of AT rail using MATLABneural network toolbox, the parameters include deformation rate, interval time for changingmold, preheating temperature of mold and friction coefficient. Forecast the optimization result,the final temperature of workpiece, and compare the temperature with simulation temperatureand actual production temperature. The compared result shows the optimized processparameters are more in line with the actual temperature and meet the actual requirement,which provide a theoretical basis and guide for actual producing process.