earticle

영어

Surface affected layer characteristic is an important index to check machined surface integrity, which has great influence on work piece fatigue and wear resistance. Based on the definition of four filed characteristics parameters-filed gradient, field impact depth, filed mean value and field peak value, the combination of quantitative and qualitative description of high-speed milling process physical field is realized. According to finite element analysis method, characteristic parameters of stress filed and temperature filed in the process of hardened steel high-speed milling are calculated, and the field characteristic parameters changing regulation under different cutting parameters is analyzed. Based on micro hardness experiment results of the surface layer and sub surface layer materials of machined surface obtained from experiment and the surface residual stress distribution obtained from data simulation, surface affected layer character, such as residual stress and hardness changing, forming mechanism and altering regulation is discovered based on filed characteristic parameter analysis. The results show that the residual stress along the depth direction is compression stress, the stress field peak value and the temperature field gradient have greatest influence on residual stress among these filed characteristic parameters; stress field peak value can be used as the symbol of strain rate hardening, which is the main factors affecting pieces hardening along the layer depth direction.