速度效应对淬硬钢最小切削厚度的影响

塑性材料加工中,存在一个最小切削厚度,当切削加工中实际有效切削厚度小于工件材料的最小切削厚度时,将造成刀具与工件无法正常切削,而主要以滑擦为主,此时加工精度很难保证,确定材料的最小切削厚度对提高工件的加工质量及精度具有重要意义.针对以上问题以淬硬钢Cr12Mo V材料为研究对象,提供了一种确定工件材料最小切削厚度的试验方法,并通过提供的试验方法,确定了淬硬钢Cr12Mo V(58 HRC)不同切削速度下的最小切削厚度值,试验结果表明:在所选的速度范围内,热软化效应对淬硬钢Cr12Mo V(58 HRC)成屑机制的影响大于应变率效应的影响,淬硬钢Cr12Mo V(58 HRC)最小切削厚度值的确定,为汽车覆盖件模具精加工余量的选取提供了理论依据.

The Effect of Speed Effect on the Minimum Cutting Thickness of Hardened Steel

For the process of plastic materials working,there is a minimum cutting thickness.When the real effective cutting thickness is less than the minimum cutting thickness of workpiece materials in the actual cutting process,it will cause abnormal cutting of the tool and the workpiece,mainly in the sliding friction.So the machining accuracy is hard to guarantee.It is significant to determine the minimum cutting thickness of the materials to improve the machining quality and precision.A test method was provided to determine the minimum cutting thickness of workpiece material,focusing on the material of hardened steel Cr12MoV and the minimum cutting thickness for different cutting speed was determined by this test method.The test results show that：the thermal softening effect has greater effect on the chip formation mechanism of hardened steel Cr12MoV （58 HRC） than strain rate effect in the selected speed range.The determination of the minimum cutting thickness has provided a theoretical basis for selecting the allowance of finish machining of automobile covering mold.