Simulation And Experimental Study On Grinding Hardening Effect Of 48MnV Non-quenched And Tempered Steel

This thesis takes the 48MnV steel as research object and studies the depth of hardening layer, residual stress and friction wear of 48MnV after grinding hardening. This thesis mainly finishes the work as follows.Grinding hardening process is taken on grinding machine of MMD7125. During grinding process, grinding force is measured by Kistler9265B and temperature curve is attained by using the technology of half artificial thermocouple. Grinding force and temperature increase with the increases of grinding depth, but cooling rate shows different change trend. The temperature field is simulated by using ANSYS. Compared with experimental result, the relative error of maximum temperature is less than 10% and the temperature curve is roughly same.The microhardness of grinding hardening layer is measured by the instrument of HSX-1000. The photos of microstructure are shot on three-dimensional digital microscope of KH-7700. Then a deep analysis is done on hardness curves and photos of microstructure to respectively obtain the depth of hardening layer. The two results are very close. The depth of hardening layer is also calculated by using the simulation calculation of temperature field. Compared with experimental result, the relative error of depth is between 11.9% and 18%.The surface residual stress of grinding hardening layer is measured with the instrument of MSF-3M. After the calculation of temperature field, grinding residual stress is also calculated by ANSYS. The simulation result of grinding hardening layer is roughly the same as the experimental result.The experiments for the friction and wear properties of grinding hardening samples are done by using tribometer of UMT-2. Then micro-morphologies of the wear scars on samples were observed as well as their wear widths are measured by using the instrument of MicroXAM. Wear width is considered as a parameter to evaluate the abrasion value. The experimental results indicate that grinding hardening has a positive effect to reduce abrasion on the surface of samples and that wear width minishes because of the generation of martensite.