Study On Formation And Control Technology Of Burr In Grind-Hardening

Grind-hardening is a integrated manufacturing technology of abrasive machining and surface quenching which has the characteristics and advantages of energy saving and environmental protection,its application has broad prospects in Engineering.Based on the grinding-hardening test,the formation mechanism and control technology of 42 CrMo steel grinding burrs were systematically studied in this paper.The main contents and innovations of this paper are as follow:(1)Based on the 42 CrMo steel grinding hardening test,the macro morphology of burrs was observed and analyzed,and the influence of grinding conditions on the formation and change of two-side direction burr and cut-out direction burr was revealed.The results indicated that the influence of grinding conditions on two-side direction burr and cut-out direction burr are similar.The two-side direction burr along the length of the workpiece can be divided into three distribution,and there are different change rules of burr in different distribution areas.(2)Based on response surface methodology(RSM),the mathematical prediction model of two-side direction burr and cut-out direction burr were established.According to the results of Analysis of Variance(ANOVA)and residual normal distribution test,the optimization model of burr was acquired,and based on the 3D response surface and contour map obtained from that optimization model,the mutual influence of the grinding parameters on the burr size and the sensitivity of the burr size to the grinding parameters were analyzed.Finally,the multi-objective optimization for the burr height H,the burr root thickness B and the thickness of the grinding hardened layer h was carried out to find the optimal parameters combination of the grinding under the two optimization criterions,and experiments were conducted to validate the optimal results.(3)Based on the experimental and theoretical analysis of burr formation in grinding hardening,the major influence factors of burr formation and transformation in grinding hardening were pointed out,and according to the basic principle of burrless machining,the workpiece chamfering control method,adding baffle control method,workpiece superposition control method,grinding parameters optimization method and other control methods were put forward which provides a technical way for the effective control of burr in the grinding-hardening,and has certain practical value in Engineering.The research results of this paper enrich and perfect the theory of surface integrity of grinding hardening,which has important theoretical and practical value.