硬态切削表面残余应力分析研究

Study on Surface Residual Stress of Hard Cutting

以轴承钢GCr15为研究对象,根据热-弹塑性有限元理论,建立了热力耦合的二维正交硬态切削模型。根据硬态切削的特点,在硬态切削有限元模型中设置了未预先设置分离线的点面接触并选择了Johnson-Cook材料本构模型,通过有限元分析计算,得到了不同切削参数和刀具几何参数条件下已加工表面残余应力的模拟结果。对结果进行比较分析得出,最大压残余应力出现在工件表面,沿着深度的增加工件内部的残余应力由残余压应力转化为残余拉应力,并逐渐趋向于零。这对于控制和提高硬态切削工件表面质量具有重要的理论指导意义。

Taking bearing steel GCr15 as the object, the thermal-mechanical 2D orthogonal hard cutting simulation model is established based on the thermal elastic-plastic mechanics. The finite element model of hard cutting is established with the point-surface contact of failing to set separation line and the Johnson-Cook material constitutive model according to the characteristics of the hard cutting. The effects of the cutting parameters and cutting tool＇s geometric on the residual stress of the machined surface are obtained by the ABAQUS software. The results indicate that maximum compressive residual stress exists in surface, the compressive residual stress translates into tensile residual stress along the increasing of depth inside the workpiece, and gradually tends to zero. It has important theoretical guiding significance for controlling and improving the workpiece surface of hard cutting.