Research On The Process Parameters And Tool Wear Of Concave And Curved Surface Hardened Steel Cr12MoV

Hardened steel Cr12 MoV mold is one of the most widely used in the manufacture of automotive parts mold,especially in the automotive parts cover mold.Its performance has great thermal stability,wear resistance.Due to its high hardness,the process results in greater milling force,serious tool wear.This paper for the study of the process parameters of the convex-concave surface milling of the hardened steel Cr12 MoV mold and tool wear prediction were studied to provide a reasonable reference for the milling process.In this paper,the process parameters and tool wear prediction of the concave-convex surface milling process of the Hardened steel Cr12 MoV mold is stidied,the main contents as follows:According to the analysis of the milling concave-convex surface of the ballend tool,the instantaneous milling area model of the tool and the influence of the milling parameters on the milling force fluctuation are established milling force model.The effective milling depth at any moment is calculated by feed rate,geometry of the surface,and the milling edge curve.After the integral calculation,the mathematical model of the milling area of the ball-end tool is established.The milling force model is established based on the change of the contact area between the milling edge and the machining area and the influence of milling parameters on the milling force fluctuation in the process of the convex-concave surface with ball end milling tool.Different milling parameters can cause the fluctuation of different milling forces,and the influence factors of milling parameters on the milling force can be obtained.The theoretical model of milling force is established by using the spindle speed and the contact area between the cutting edge and the machined area.By the finite element software analysis,a three-dimensional finite element simulation model of convex-concave surface milling process is established by using numerical simulation method,combined with finite element techniques such as material constitutive model,knife-chip contact friction model,and separation criterion.Firstly,the characteristics of milling force variation in milling process of convex-concave surface were studied.Secondly,according to the variation of milling parameters(milling speed,feed rate)and radius of curvature in the simulation process of convex-concave surface,the variation of milling force and the milling force parameters are studied by single factor analysis method.Based on the tool wear experiment of ball-end tool to mill convex-concave surfaces,an empirical formula for tool wear is established by means of different tooling methods Through orthogonal analysis of range analysis and variance analysis,the influence of milling parameters on tool wear is studied.Tool wear empirical formula is established by using linear regression method,and the residual error is used for the test and its experimental verification.Not only It improves tool life,but also processing efficiency.