Research On Consistency Of Hardening Layer Of 40Cr Pre-stressed Hardening Grinding

With the quick development of society,manufacturing industry how to achieve energy saving,high efficiency,environmental protection become increasingly focus on the core of the people.Pre-stressed Hardening Grinding technology is advance certain tensile stress,creates a large amount of heat in the process of using grinding workpiece surface quenching effect.This method realized the purpose of surface quenching,at the same time,using pre-stressed exert effective control of the residual stress of workpiece surface.Not only can improve the fatigue strength and service life of the workpiece,also reducing the production cost,improve work efficiency and avoid the cooling fluid discharge pollution to the environment,accord with today’s theme of sustainable development.Through the analysis of Pre-stressed Hardening Grinding Strengthening layer consistency in this paper,and the consistency on the basis of pre-stressed grinding hardening experiment,using ANSYS analysis software for grinding hardening temperature field are simulated.Using the curve of hardened surface layer temperature,time,combination of grinding hardening theory knowledge and the formula of surface quenching hardness,you can get the distribution of surface hardness.Use of 40Cr austenite transformation temperature along the depth direction of the temperature curve,can get the depth of the hardened layer distribution.And analyzed the factors to the affecting the distribution of the hardness and depth of hardened layer.With 40Cr as the test materials,pre-stressed grinding hardening experiment was carried out,After measuring the grinding surface hardness and roughness of the hardening layer,observation of microstructure of the section of,analysis of test results,draw a grinding process parameters on structure and hardness of hardened layer distribution.Using ANSYS analysis software on the grinding temperature field are simulated,the grinding hardening process,the temperature field distribution on the surface of the workpiece,and by using calculation formula based on the model’s hardness in combination with surface temperature change curve over time,calculate the hardness on the surface of the grinding hardening layer,and use of 40Cr in austenite phase transition temperature(750℃)and martensite phase transformation temperature of cooling,combined with the simulation results of the change in temperature curve along the depth direction,can estimate the depth of hardening layer,and it is concluded that the depth of hardening layer along the workpiece on the length direction,compare the simulation results with the experimental results,and Analysis the verify whether it is right.Using ANSYS analysis software,to simulate the different grinding depth and feed speed on the depth of hardened layer of hardness and consistency,the conclusion is,with the increase of grinding depth of hardening layer hardness and depth increases gradually,with the increase of feed speed surface hardness and depth of hardened layer gradually decreases,and the effect factors of grinding hardening layer consistency mechanism analyzed,at the same time puts forward the way to improve the consistency of the hardening layer.According to the studies have shown,using grinding heat from the workpiece surface hardening layer is feasible,and the hardness and depth of the overall distribution of the hardening layer consistency is poor,but there is good consistency in the middle section of the hardening layer.In the pre-stressing force under the action of the same,with the increase of grinding depth,hardness and depth of the hardened layer is increased.At the same time,pre-stressed has inhibitory effect on the generation of grinding heat,the hardness and depth of the hardening layer has fallen slightly,but the effect was not significant.Hardening layer of different positions with the same organization partition,divided into completely hardened zone,transition zone and substrate.