切向车铣18CrNiMo7-6钢V形缺口表面三维形貌研究

Study on Three-Dimensional Morphology of V-Notch Surface of 18CrNiMo7-6 Steel by Tangential Turning-Milling

疲劳试样的缺口加工一直是一个亟需解决的难题。提出一种全新的切向车铣加工缺口工艺,通过理论与试验结合的方法探究了切向车铣对V形缺口表面形貌的影响规律。结果表明:在不同的工艺参数下,切向车铣V形缺口底部会呈现出不同的加工纹理方向,提出的理论公式计算出的纹理方向与工件轴线的夹角与实际结果误差很小;缺口底部三维表面粗糙度R_(a)随着铣刀转速n_(c)的升高而减小,随着工件转速n_(w)的升高而变大,随着每齿进给量f_(z)的增加先减小后增大;得到表面粗糙度最优参数组合为n_(c)=6000 r/min,n_(w)=100 r/min,f_(z)=0.0375μm,在此切削参数组合下得到的V形缺口表面粗糙度R_(a)可达到0.075μm。

Notch machining of fatigue specimens has always been a difficult problem to be solved urgently.A new notch cutting technology for tangential turning-milling was proposed,and the influence of tangential turning and milling on the surface morphology of V-notch was investigated by combining theory with experiment.The results show that the bottom of tangential turning-milling V-notch will show different processing texture directions under different process parameters;the angle between the texture direction and the axis of the workpiece calculated by the proposed theoretical formula has a small error with the actual result;the 3D surface roughness R_(a) of notch bottom decreases with the increase of milling speed n_(c),increases with the increase of workpiece speed n_(w) and decreases first and then increases with the increase of feed per tooth f_(z);the optimum parameter combination for surface roughness is n_(c)=6000 r/min,n_(w)=100 r/min,f_(z)=00375μm,with this combination of cutting parameters,the surface roughness R_(a) of V-notch can reach 0.075μm.