干式切削20Cr表面粗糙度和残余应力研究

Study on Surface Roughness and Residual Stress of 20Cr in Dry Cutting

针对低渗碳钢20Cr材料制作齿轮轴等零件表面质量要求,如表面粗糙度低于1.6μm,零件表面耐疲劳性能良好。试验采用干式切削20Cr钢材方式,在背吃刀量固定的工序中,研究切削速度和进给量对20Cr材料表面粗糙度的影响,同时结合有限元技术,分析切削速度和进给量对20Cr表面残余应力的影响。干式切削试验采用单因素方法,进行多组干式切削20Cr工件,对比分析各组工件表面粗糙度,结果表明当进给量较小时,切削速度对工件表面粗糙度有显著影响,表现为表面粗糙度随切削速度增加而变大;当切削速度一定时,进给量增加导致表面粗糙度变大,并且进给量对表面粗糙度的影响大于切削速度;对于工件表面残余应力,增加切削速度和进给量均导致残余应力变大,因而较小的切削速度和进给量可以降低工件表面残余应力,改善应力分布状态。

According to the surface quality requirements of gear shafts and other parts made of low-carburizing steel 20Cr material,such as such as the surface roughness less than 1.6μm,and the surface fatigue resistance of the parts is good.Dry cutting of 20Cr steel was used to study the influence of cutting speed and feed on the surface roughness of 20Cr material in the process of constant cutting depth.Meanwhile,the influence of cutting speed and feed on the residual stress of 20Cr surface was analyzed with finite element method.Dry cutting experiment adopted single factor method to cut 20Cr workpiece in groups.The surface roughness of each group was compared and analyzed.The results showed that when feed was small,the cutting speed had a significant effect on the surface roughness of workpiece,which showed that the surface roughness increased with the increase of cutting speed;when cutting speed was constant,the increase of feed would lead to the increase of surface roughness,and the influence of feed on surface roughness was greater than that of cutting speed.For the surface residual stress of workpiece,the increase of cutting speed and feed would lead to the increase of residual stress,so the smaller cutting speed and feed could reduce the surface residual stress of workpiece,and improve the stress distribution.