晶粒度对纯铁精密切削刀具磨损影响

Influence of grain size on tool wear in finish turning pure iron material

在相同切削工艺参数下主要研究精加工时晶粒度对刀具磨损的影响,同时分析晶粒度对粗糙度的影响.结果表明,不同晶粒度的纯铁材料精加工时刀具磨损形式一致;切削细晶纯铁的平均后刀面磨损小于切削粗晶的平均后刀面磨损,在低速时晶粒大小控制着主沟槽磨损大小,而在高速时对主沟槽磨损影响很小,切削一定时间后,切削细晶纯铁的副沟槽磨损大于切削粗晶纯铁的副沟槽磨损;沟槽磨损是黏结磨损、扩散磨损以及氧化磨损共同作用的结果;切削粗晶纯铁时的表面粗糙度更小.实验结果对于提高刀具寿命及加工表面质量具有重要的参考意义.

The effect of grain sizes on tool wear was studied in finish turning under the same cutting parameters,and the effect of grain sizes on surface roughness was also analyzed.The results show that tool wear patterns are consistent in finish turning pure iron materials with different grain sizes.The average flank wear of fine-grain pure iron is smaller than that of coarse-grain pure iron.The grain size is the overall controlling factor for major notch wear at low speed,but the grain size has little influence on major notch wear at high speed.After cutting for a certain period of time,minor notch wear for cutting fine grains is larger than one for cutting coarse grains.Notch wear is caused by a combination of adhesion,diffusion and oxidation.The surface roughness is smaller when turning coarse-grain pure iron.The test results have important significance on improving tool life and machining surface quality.