Research On Grinding Hardening Technical Experiment And Temperature Field Simulation Of 40Cr Steel

Grind-hardening process is a new kind of technology to quench, which makes use of the heat produced during grinding. This technology can combine grinding process and surface quenching, which leaves out the induction quenching process. Accordingly energy is saved, production process is predigested and the heat produced during grinding is fully and efficiently used.This paper takes the 40Cr steel as research object. With grinding wheel of corundum, examinations are taken on flat surface grinding machine of MMD7125. On different grinding parameters and cooling condition, the temperature curve of grind-hardening is attained by using the technology of measuring temperature with half artificial thermocouple. The microhardness of grind-hardening layer is measured by the instrument of HSX-1000. The photos of microstructure are shot on electron microscope of MM6 with digital camera. The effect and mechanism of grind-hardening are also discussed. The temperature field is simulated and the hardened depth is forecasted by finite-element method using ANSYS.The results indicate those facts as follows. By optimizing parameters, the necessary grind-hardening conditions are achieved such as warming up rate, highest temperature, action time of temperature and cooling rate. The microstructure and effect of hardening get from grind-hardening is better than the one get from induction quenching. The microstructure of entirely hardening layer is much more subtle needle-type martensite whose microhardness is more than HV800. The depth of entirely hardening layer could reach 1mm. The microstructure, microhardness and depth of grind-hardening all meet the need of surface quenching. The simulative temperature and estimating hardened depth are comparatively close to the measuring ones. The model could be utilized to forecast grind-hardening temperature and hardened depth.