The Experiment And Numberical Simulation Studies For High-speed Hard Cutting Surface Characteristics

Hard cutting machining technology is developing rapidly in variouscountries of the world, and its processing performance has been able to achieve ahigh level of performance. However, the white layer and residual stress ofmachined surface seriously affects the life and performance of parts, and restrictsits promotion and development in actual production. Therefore, for this newtechnology, the study on residual stress characteristics and white layer formationmechanism in hard machining is of great significance.This article are based on GCrl5hardened steel cutting process, performed ahigh-speed hard turning cutting force and cutting temperature, stress and strainexperiments.First using the scanning electron microscope (SEM) and x-raydiffraction (XRD) testing instrument research on the microstructure and residualstress in the high speed machining surface.Second, the effect of cutting parameters on cutting force and cuttingtemperature is studied. On the basis of this, the formation mechanism of themachined surface white layer formation and micro-structural features andresidual stress characteristics in the high speed machining surface are studied.At last， the prediction model of white layer in high speed hard turning isbased on the theory of materials science and physical chemistry. Cuttingparameters, as well as the effect of interactions among factors affecting the hardmachining surface white layer has been studied. It can be found that the whitelayer hardness increases with the increase of cutting speed, and then decreasedslightly, while the thickness of the white layer increases with the increase of cutting speed; there exists white layer on the surface of machined workpiece eventhough the flank of tool is in a fresh state. On the basis of the white layer model,the prediction model of residual stress based on thermal-elastic-plastic theory isestablishmented. The influence of different cutting parameters on residual stresswas studied in high-speed hard turning.In this article, both use experimental and simulation methods tosystematically study a high-speed hard cutting surface characteristics, whichprovide theoretical and technical support for hard cutting machining technologyapplication.