Study On Temperature Field And Residual Stress Of Cr12MoV Steel During Grinding

Grinding is a important processing technology in the machinery manufacturing,which can improve product accuracy, reliability and prolong the service life, widely used in the manufacturing of various kinds. At present, the extensive use of new materials of high hardness, high strength, high wear resistance and high performance bring more new challenges of grinding. Because of higher grinding energy in the grinding process, grinding process will lead to the workpiece temperature too high in the grinding zone, causing grinding workpiece surface burns.And drastic changes of coupled action of thermal stress and strain will lead to the generation of residual stresses of workpiece after grinding, causing the destruction of the product.In order to avoid the above situation, it is necessary to analyze and discusse the grinding temperature and residual stress after grinding. This article selects Cr12 Mo V die steel, and use numerical simulation and experimental analysis method of combining to study plane grinding. The main work is as follows:(1)Firstly, the related theory and calculation in the process of grinding was explored and approximate analysis of grinding temperature field was done based on the theory of heat transfer, and introduced the related parameters of affecting grinding temperature field model. Besides, the grinding force is emphasized, grinding heat distribution ratio, grinding moving heat source, in order to lay a theoretical basis for later research on grinding temperature field simulation analysis of Cr12 MoV die steel.(2)Secondly, different 3d finite element simulation was established for grinding temperature field under the different condition of grinding and made three sets of process parameters on the temperature field influence diagram by using APDL parametric design language and rectangular heat source model in ANSYS14.5. The results show that the grinding temperature with the grinding depth increased from0.05 mm to 0.20 mm, grinding wheel speed increased from 25rad/s to 40rad/s in the process, the grinding zone temperature increased significantly; Temperature change is not obvious in the process of workpiece speed increased from 0.10 m/s to 0.30 m/s.(3)Then, thermal elastic-plastic finite element method was used and the influence of the phase change of material was ignored to analyze the Cr12 Mo V steel plane grinding thermal coupling field, and acquired the distribution of residual stresses after grinding workpiece. The results show that there are residual compressive stress and tensile stress in the grinding surface at the same time. Its size increases with the increase of grinding depth and workpiece speed, smaller with the increase ofwheel speed; Along the depth direction, the residual compressive stress decreases.(4)Finally the experiment of the related parameters was carried on based on Cr12 MoV steel plane grinding, including choosing experiment specimens, grinding machine, grinding wheel and so on. At the same time, the related introduction was carried on in view of the principle of thermocouple measuring temperature, and tested the grinding forces and grinding temperature under the different parameters. Its result is closed to the result of simulation. The experiment effectively verified the validity of the simulation.