切削比能的尺寸效应现象是切削机理研究中最具挑战的问题之一，关于它的形成机理目前尚未达成共识，尤其是切削温度对尺寸效应的影响更是鲜有研究。在此开展了不同初始温度下的正交切削实验，发现尺寸效应现象与温度作用密切相关，工件初始温度越低尺寸效应越显著。进一步建立了正交切削有限元模型，研究了温度对尺寸效应的贡献。研究结果表明，在主剪切区两端沿剪切方向存在两个温度梯度区，其长度与切削厚度无关。温度梯度区的存在使得主剪切区的平均温度随切削厚度的减小而下降，致使工件材料流动应力相应提高，从而导致了切削比能的非线性上升。

The scaling effect of specific cutting energy is one of the most challenging problems in metal cutting. There is no consensus reached on the mechanism of the scaling effect, and the contribution of the cutting temperature on the scaling effect was rarely studied. Here the orthogonal cutting experiments under different initial temperature were conducted. It shows significant dependence of the scaling effect phenomenon on the temperature effect. The scaling effect phenomenon becomes more obvious at lower initial temperature. The finite element model of orthogonal cutting was further developed to study the contribution of temperature on the scaling effect. The results show that, there exists two temperature gradient zones near the ends of the primary shear zone along the shear direction. The length of the gradient zones are independent on the uncut chip thickness. The existence of the temperature gradient zones causes the average temperature in the primary shear zone to drop with decreased uncut chip thickness, which gives rise to the increase of flow stress, leading to the nonlinear increase of the specific cutting energy.