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

Abstract: 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 vs, workpiece speed vw, radial feed rate vf 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 vs. 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 100~150 μm, 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 80～100 μm, 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.

Key words: high speed cylindrical grinding, cubic boron nitride(CBN), highspeed grinding, residual stress, split fixture