Simulation Study Of Electric Hot Machining For GCr15 Steel Based On Deform

With the development of modern industrial technology and the improvement of product parts performance requirements,so many new type of difficult machining materials have been discovered and produced by researchers.Because the new type of difficult machining materials have higher hardness,resulting in greater cutting force,higher temperature in the processing area.These problems lead to the increase of the cutting tool wear,the decrease tool life,the bad workpiece surface quality,and the lower cutting efficiency.Therefore,a new method and theory to reduce the wear of cutting tools and improve the quality of workpiece is proposed.It has very important academic value and engineering significance that revealing the effects of cutting parameters on cutting process,determining the key factor of the EHM-cutting current,putting forward the new empirical formula of main cutting force by simulation.Based on Deform 2D,the effects of cutting angle ?,cutting speed V,feed rate f and initial temperature T on the main cutting force,contact zone temperature and tool wear were studied.The empirical formula of the optimum current and the main cutting force of YT726 cutting GCr15 were determined.The principle of EHM reducing difficulty of workpiece machining was analyzed.Based on the analysis of the heating resistance and comparing with the existing heating resistance model,a better resistance model was chosen as the heating resistance model.In addition,this topic also introduced material constitutive model,wear model,and friction model in detail,According to the actual situation,the simulation model and parameters were selected.Through simulation test study,the paper got the following main conclusions:(1)The main cutting force decreased with the increase of tool rake angle,cutting speed and initial temperature of the workpiece.The main cutting force increased with the increase of feed rate.With the increase of tool rake angle,the plastic deformation of cutting layer of the workpiece decreased,and the friction of contact area decreased.With the increase of the cutting temperature,the strength of the machining area was reduced and the main cutting force decreased.(2)The temperature of cutting area increased with the increase of cutting speed,feed rate,and the initial temperature,and decreased with the rake angle increase.The main reason why the temperature of cutting area decreases was that chip deformation weakened and cutting heat decreased with tool orthogonal rake increase.With the increase of cutting speed,the heat produced in the cutting process could not be taken away by the chip in time,and the cutting heat was not enough to transfer to the cutting tool,thus the cutting temperature increased.(3)The tool wear increased with the increase of the rake angle,cutting speed,feed rate,and decreased with the increase of initial temperature of workpiece.The high temperature led to the loss of cobalt with high strength in the tool material,and the iron and carbon in the workpiece material diffused to the tool material.Its led to the weakening of the strength of the tool and the increase of tool wear.(4)Based on the analysis of the influence of heating current on the main cutting force,cutting temperature and tool wear,the optimal current range of YT726 cutting GCr15 was determined to be 110-130 A.(5)The empirical formula of the main cutting force of YT726 cutting GCr15 was determined with the multiple nonlinear regression analysis by the SPSS software.