磨削硬化深度预测

磨削硬化是利用磨削过程中产生的热、机械复合作用直接对工件进行表面淬火的新工艺。通过建立磨削温度三维分析模型和热金属效应分析,实现磨削硬化加工工件硬度的预测。基于瞬时温度分布和运动非稳定三维热传导微分方程,并考虑砂轮与工件及冷却液与工件交互作用时热传导情况和材料本身的热扩散,建立了磨削温度三维分析预测模型,结合对加工过程奥氏体相位比例的计算及珍珠岩、残余奥氏体和马氏体的转变等热冶金效应分析,得出磨削硬化加工后硬化深度,实现随加工参数变化的硬化深度分布预测。将此模型与有限元模型进行对比,并通过实验进行了验证。

Prediction of Grind -hardening Depth

The grind-hardening process uses the heat generated within the grinding zone in order to produce surface hardening of the workpiece combined with mechanical compound function .A three dimensional ( 3D) analytical model to predict grinding tempera-ture is given, the thermo-metallurgical effects are analysed and the hardness of workpiece after grinding hardening is predicted .Based on the transient temperature distribution and the differential equation of nonsteady -state three-dimensional ( 3D ) heat conduction , where the interdependence among the grinding wheel , the workpiece and the coolant were described , also the thermal diffusivity in ma-terial was considered .A 3D analytical model to predict grinding temperature was given .Combining the calculation for the proportion of the austenite phase and the analysis for thermo-metallurgical effects in transition of perlite in engineering process , residue austenite and martensite , the hardening depth of workpiece machined was predicted .The predication was realized for distribution of hardening depth along with changing of machining parameters .All these of the model are well coincided with the finite element model ( FEM) and the experimental measurement results .