硬车削300M钢表面的残余主应力

Residual Principle Stresses on 300M Steel Surface after Hard Turning

针对工件已加工表面周向和轴向残余应力不能体现表面残余应力极值大小和方向的问题,对淬硬后的300M钢进行车削试验,然后采用X射线衍射仪测得工件表面周向、轴向和45°方向的残余应力,并基于平面应力状态分析求出了残余主应力的大小和最大残余应力的方向,研究了车削参数对残余主应力的影响规律。结果表明:残余主应力随车削速度的增加而增大,随背吃刀量的增加而减小,随进给量的增加呈"锯齿形"变化;最大残余应力的方向角随车削速度增加变化不大,随进给量增大先减小后保持稳定,随背吃刀量增加而减小。

Aiming at the problem that the circumferential and axial residual stresses on machined workpiece surface were failed to reflect the value and direction of extreme residual stress, cutting experiments were carried out on 300M steel after hard turning, and residual principle stress values and direction angles of extreme residual stress were calculated by comhining the plane stress status analysis with the residual stresses measured by using X-ray diffraction on circumferential, axial and 45° directions. The effects of cutting parameters on residual principal stress were studied. The results show that the residual principal stress tended to increase as cutting speed increased, to decrease as cutting depth increased, and to change into a serrated pattern as feed rate increased. The direction angle of extreme residual stress changed little as cutting speed increased, first decreased and then kept steady as feed rate increased, and decreased as back cutting depth increased.