18CrNiMo7-6钢高速外圆磨削残余应力和硬度的试验分析  

Experimental analysis of residual stress and hardness of 18CrNiMo7-6 steel in high speed cylindrical grinding

作　　者：张银霞[1] 原少帅 王子乐 杨鑫[1] 郜伟[1] ZHANG Yinxia;YUAN Shaoshuai;WANG Zile;YANG Xin;GAO Wei(School of Mechanical Engineering/Henan Key Engineering Laboratory of Anti-fatigue Manufacturing Technology, Zhengzhou University, Zhengzhou 450001, China)

机构地区：[1]郑州大学机械与动力工程学院/抗疲劳制造技术河南省工程实验室,郑州450001

出　　处：《金刚石与磨料磨具工程》2021年第1期65-70,共6页Diamond & Abrasives Engineering

基　　金：国家自然科学基金重点项目(U1804254);国家留学基金委项目(201907045070);河南省自然科学基金(162300410244)。

摘　　要：针对18CrNiMo7-6渗碳钢工件,以砂轮线速度vs、工件转速nw、砂轮径向进给速度vfr和砂轮CBN磨料粒度为变量设计单因素试验,分别采用X射线残余应力分析仪和显微硬度计对工件的表面残余应力和硬度进行检测。结果表明:高速外圆磨削可为18CrNiMo7-6渗碳钢工件的表面引入残余压应力,X方向的压应力小于Y方向的压应力,同时高速外圆磨削可以提高工件表面的硬度;随着vs的增大,残余压应力先增大后趋于平稳,硬度先减小后增大且在vs为75 m/s时最小;随着nw的增大,工件表面残余压应力和硬度的变化不具单调性;vfr对工件表面残余压应力和硬度的影响较大,线性拟合后残余压应力和硬度整体上均呈减小趋势;不同CBN磨料粒度砂轮磨削在工件表面产生残余压应力和硬度的大小依次为M10/20最大,120/140次之,230/270最小;18CrNiMo7-6钢表面存在拉应力时硬度较低,表面存在压应力时硬度较高。For 18CrNiMo7-6 carburized steel workpiece,a single factor test was designed studying the wheel speed,the workpiece speed,the feed rate and the abrasive size.X-ray residual stress analyzer and micro hardness tester are used to detect the residual stress and hardness.The results show that high-speed cylindrical grinding can introduce residual compressive stress to the surface of the workpiece,and that the compressive stress in the X direction is less than that in the Y direction.Meanwhile,high-speed cylindrical grinding can improve the surface hardness of the workpiece.With the increase of wheel speed,the compressive stress increases first and then tends to be stable,while the hardness decreases first and then increases and the minimum value is obtained when the speed is 75 m/s.With the increase of workpiece speed,the change of residual compressive stress and hardness is not monotonic.The feed rate has a great influence on the compressive stress and hardness of the workpiece surface,which are reduced in general after linear fitting.Grinding wheels with different CBN abrasive grain sizes produce different compressive stress and hardness on the surface of the workpiece,namely:M10/20 produces the largest,followed by 120/140,and then 230/270 the smallest.On the surface of the workpiece,the hardness is low when there is tensile stress,and the hardness is high when there is compressive stress.

关 键 词：高速外圆磨削 砂轮线速度 砂轮CBN磨料粒度 残余应力 硬度 

分 类 号：TG58[金属学及工艺—金属切削加工及机床]