Study On Surface Roughness And White Thickness Of High Speed Milling 3Cr2Mo Steel

Surface roughness is one of the important indicators to measure the surface quality of highspeed cutting hardened steel.At present,it is mainly based on milling experiments and empirical values to select appropriate milling process parameters and tools to control the roughness of the processed surface,which has certain uncertainties and limitations.In the process of high-speed milling,the workpiece hardness and milling parameters have a certain influence on the surface quality of the workpiece;therefore,the study of the influence of the workpiece hardness and milling parameters on the roughness has theoretical and practical application.Single-factor milling tests were conducted using 3Cr2 Mo steel specimens with hardness 31 HRC and 41 HRC,respectively,and the effects of milling speed V,feed per tooth fz and milling width Rd on different workpiece hardness surface roughness were studied.Three-factor orthogonal milling experiments of three factors(milling speed V,feed per tooth fz and milling width Rd)were designed and carried out,and the experimental results were subjected to range analysis and variance analysis to study the different milling parameters for different hardness Significance analysis of the effect of the rough surface of the workpiece.Finally,the Taguchi analysis method was used to optimize the milling process parameters,and the optimal milling parameter combination under different hardness was determined,which provided a basis for the selection of 3Cr2 Mo steel process parameters with high-speed milling hardness of 31 HRC and 41 HRC.In-depth analysis of the formation mechanism of surface roughness,detailed study of the geometric and physical factors affecting the surface roughness,the mathematical model of the surface residual height of the geometric factor of high-speed milling and the mechanical calculation model of the physical factor of the surface residual height were established,and the roughness value was calculated.The calculation and comparison with the high-speed milling test values verify that physical factors are the main factors affecting surface roughness.Using ABAQUS simulation software,the high-speed milling 3Cr2 Mo steel simulation simulation analysis,extract the flow stress,milling temperature and other values in the high-speed milling simulation process,and analyze and study the data.Finally,another important aspect that affects the surface quality is the surface white layer.Based on the orthogonal test data,regression analysis was used to establish two different functions of the surface white layer thickness prediction model.Through the analysis of variance,the linearity with the highest degree of fit was selected.The function prediction model provides a basis for the study of the thickness of the white layer on the surface of 3Cr2 Mo with a hardness of 41 HRC during high-speed milling.The influence of workpiece hardness and milling parameters on the surface roughness will have a guiding significance for the reduction of the roughness of 3Cr2 Mo steel.At the same time,it will also greatly facilitate the reference and selection of milling parameters for machining workers.