Research On Repairing Forging Die Technic And Numerical Simulation Based On Reverse Engineering And Fuse Surfacing Adding Manufacturing Technology

This study adopts the technology of combining reverse engineering with fuse surfacing to repair forging die based on the problems of low automation,low repair efficiency and waste of welding materials in traditional surfacing repair forging die.Compared with the traditional method of repairing forging dies,the digital acquisition technology of reverse engineering and the off-line programming of robots are added in the repairing process of forging dies in this study.The purpose of repairing forging die by robot automatic copying surfacing instead of manual surfacing is achieved.The dynamic process of surfacing repair is further simulated and analyzed by numerical simulation,which provides guidance for the actual production of enterprises.The main results and conclusions are as follows:(1)Acquisition of Defect Location Model of Forging Die.The original forging die and the forging die to be repaired are designed and processed.Three-dimensional digital models of two kinds of forging dies are obtained by scanning.By comparing the two digital models,the digital model of the defect part of forging die is obtained.Finally,the digital model of the defect part is materialized.Compared with the target defect model,it meets the requirements.(2)Definition of Technological Parameters for Surfacing Repair of Forging Die.5CrNiMo is the base material and ER50-6 is the welding wire material.Through several surfacing tests and comparative analysis,the preferable technological parameters for repairing the forging die are selected.The welding current is 160 A,and the welding voltage is 19 V,and the welding speed is 5 mm/s,and the width of the weld is 6 mm,and the distance between the welds is 4 mm,and the height of the weld is 3 mm.(3)Acquisition of Repair Path for Forging Die Surfacing.The obtained forging die defect model is sliced and path planning is carried out based on Powermill off-line programming software.Combining the simulation results of temperature field and stress field in the process of multi-layer and multi-pass surfacing for different paths with actual production,considering comprehensively,the one-way straight wire surfacing path is selected to repair forging die.(4)Experiments on Repair of Forging Die by Surfacing Welding.The forging die is repaired by robotic fuse surfacing based on the above surfacing process parameters and the obtained path.The microstructure of the surfacing layer and fusion zone of the repaired forging die is tested and analyzed.The results show that: the microstructure of the surfacing layer is fine and uniform pearlite + ferrite;the interlaminar fusion degree is high,and the distribution of the microstructures on both sides of the fusion zone is significantly different.(5)Simulation and Analysis of Temperature Field and Stress Field in Multilayer Multi-pass Single/Bidirectional Straight Wire Surfacing of Forging Die.Under the above conditions of surfacing process parameters,the temperature and stress fields in the process of multi-layer and multi-channel single/bidirectional linear wire surfacing are simulated by(6)MSC.Marc finite element analysis software.Comparing the simulation results of the two paths,the results show: both paths have the same peak temperature of 1500?;the temperature gradient of the node in the heat cycle process under the single straight path is less than that of the bidirectional straight path;the residual stress generated under the two paths mainly concentrates at the center of the weld zone,and the peak value of the residual stress is about 296 MPa;a stable stress platform has appeared and the steady state has been achieved.(7)Simulation and Analysis of Temperature Field and Stress Field in Multi-layer and Multi-channel Ring Fuse Surfacing of Forging Die.Under the same welding parameters,the temperature and stress fields in the process of multi-layer and multi-channel annular fuse surfacing are simulated.The simulation results show that: the temperature of weld zone is the highest during the heating process of fuse surfacing,and the peak value of temperature field is1500?;the temperature of weld zone tends to base metal temperature as cooling proceeds;the transverse and longitudinal stresses show uniform and symmetrical distribution,and the peak values are 400 MPa and 370 MPa,respectively.(8)Simulation and Analysis of Temperature Field and Stress Field in Single Layer Multi-pass Single/Bidirectional Linear Fuse Surfacing of Forging Die.Under the same surfacing process parameters,the dynamic changes of temperature field and stress field in the process of single-layer and multi-channel single/bidirectional straight wire surfacing are simulated by relevant software.The results show that: the distribution of temperature fields for the two kinds of path welding process is basically the same,and the peak temperature is1500?;the distribution of the residual stress for the two kinds of path welding process is almost the same,and the peak value is 250 MPa.