18CrNiMo7-6钢高速外圆磨削的残余应力  

Residual Stress of High Speed Cylindrical Grinding of 18CrNiMo7-6 Steel

作　　者：张银霞 杨鑫 原少帅 朱建辉 王栋 ZHANG Yinxia;YANG Xin;YUAN Shaoshuai;ZHU Jianhui;WANG Dong(Henan Key Engineering Laboratory of Anti-fatigue Manufacturing Technology,Zhengzhou University,Zhengzhou,450001;State Key Laboratory of Superabrasives,Zhengzhou,450001)

机构地区：[1]郑州大学抗疲劳制造技术河南省工程实验室,郑州450001 [2]超硬材料磨具国家重点实验室,郑州450001

出　　处：《中国机械工程》2021年第5期540-546,共7页China Mechanical Engineering

基　　金：国家自然科学基金(U1804254);国家留学基金管理委员会项目(201907045070);河南省重点科技攻关项目(152102210045)。

摘　　要：为探究高速外圆磨削工艺对18CrNiMo7-6钢残余应力层分布的影响,使用陶瓷结合剂CBN砂轮进行高速磨削试验,对砂轮线速度v_(s)、工件线速度v_(w)、砂轮径向进给速度v_(fr)和砂轮粒度等工艺参数进行了单因素试验分析;设计制作了圆柱工件外圆面辅助剖层夹具,采用X射线衍射仪对工件应力分布进行检测。研究结果表明:高速磨削工艺为工件表面引入残余压应力,工件表面残余压应力随vs的提高小幅增大,v_(w)和v_(fr)对工件表面残余应力的影响规律不明显;X、Y方向的残余应力分布趋势基本一致,但Y方向的应力略大;v_(fr)对残余应力分布影响较大,应力影响层深达到100~150μm,应力分布中出现残余拉应力;v_(s)对残余应力分布的影响小于v_(fr)的影响,60 m/s时的残余应力呈“塔”形分布;v_(w)没有明显影响规律;230/270粒度的砂轮对残余应力分布影响较大,应力影响层深为80~100μm,120/140、W20粒度的砂轮影响较为接近;辅助剖层夹具有效提高了圆柱工件残余应力的检测精度和效率,检测效率提高一倍以上。In order to investigate the effects of high-speed cylindrical grinding processes on the residual stress distributions of 18CrNiMo7-6 steel,high-speed grinding tests were carried out by using ceramic bond CBN grinding wheels,and single factor tests were carried out to analyze the influences of wheel speed v_(s),workpiece speed v_(w),radial feed rate v_(f) and granularity of grinding wheels.An auxiliary split fixture used for cylindrical workpiece outer surfaces was designed and made.The X-Ray diffractometer was used to detect stress distributions of workpieces.The results show that the high-speed grinding processes may produce compressive stress on surfaces of the workpieces.The residual stress on the surface increases slightly with the increase of wheel speed v_(s).The effects of workpiece speed and feed speed on the surfaces stress is not obvious.The stress distributions in X and Y directions are almost the same,while the one in Y direction is slightly larger.The feed speed has a great influence on the stress distribution,with the thickness of the influenced layer reaching 100~150μm,and the tensile stress appears.The influence of the wheel speed on stress distribution is less than the feed speed.When the wheel speed is 60 m/s,distribution of residual stress is“tower-shape”.The workpiece speed has no obvious influence rule.The granularity of 230/270 has a great influence on the stress distribution,depth of the stress influenced layer is 80~100μm,and the granularity of 120/140 and W20 on the distribution is close.The auxiliary fixture effectively improves the accuracy and efficiency of the residual stress,and the detection efficiency is more than doubled.

关 键 词：高速外圆磨削 立方氮化硼(CBN) 高速磨削 残余应力 剖层夹具 

分 类 号：TG581.1[金属学及工艺—金属切削加工及机床]