为提高纯铁材料精加工时的表面质量，在相同切削参数下进行了干切、水冷、菜籽油润滑和微量润滑(MQL)4 种方式下的切削试验，分析冷却润滑方式对工件表面完整性的影响机理． 结果表明:MQL 和菜籽油润滑比水冷和干切更有利于提高表面粗糙度;4 种冷却润滑方式下已加工表面显微硬度具有相同的变化趋势，硬化层深度为 60 ～70μm;表层晶粒呈严重的扭曲拉伸状塑性变形，干切时塑性变形层深度最大，其次为菜籽油润滑和 MQL，水冷时最小;工件表面切向和轴向均呈残余拉应力，且切向应力大于轴向应力，而且冷却润滑方式对表面残余应力影响不大． 试验结果对纯铁精加工选择合适的冷却润滑方式以提高表面完整性具有重要意义．

In order to improve the surface quality of pure iron materials during the finishing turning，some experi-ments were carried out at the same cutting parameters under such four cooling/lubrication conditions as dry cutting，water-based cooling，rapeseed oil lubrication and minimum quantity lubrication (MQL)，and the influence mecha-nisms of cooling/lubrication conditions on the surface integrity of the pure iron workpiece were analyzed． The re-sults indicate that (1) as compared with the dry cutting and the water-based cooling，the MQL and the rapeseed oil lubrication are more advantageous to the improvement of the surface roughness of the workpiece; (2) the surface microhardness varies in the same trend under different cooling/lubrication conditions，and the depth of hardened layer is about 60 ～70μm; (3) the surface grains show severe tensile and distorted plastic deformation，and the dry cutting results in the deepest deformation while the water-based cooling results in the shallowest deformation; and (4) the surface residual stresses in the tangential and the axial directions are both tensile and insensitive to coo-ling/lubrication conditions，and the tangential stress is larger than the axial one． These experimental results are of great significance for selecting suitable cooling/lubrication conditions to improve the surface integrity of pure iron materials during the finish turning．