绿色切削高强度钢的刀具磨损及切屑形态

Tool Wear and Chip Formation in Green Machining of High Strength Steel

分析了微量润滑切削时润滑剂的渗透机理及润滑作用对铣削力的影响。使用传统切削、干式切削及微量润滑三种方式铣削高强度钢(PCrNi3Mo),对比切削性能并探讨微量润滑技术对刀具磨损及切屑形貌的影响。对微量润滑加工过程中切削参数(铣削速度、每齿进给量、铣削深度及润滑剂使用量)对刀具磨损的影响进行研究,利用响应曲面法建立了刀具后刀面磨损模型以确定铣削高强度钢(PCrNi3Mo)时润滑剂的最佳使用量,并利用试验验证。结果表明,微量润滑可有效抑制刀具磨损进程;建立的刀具后刀面磨损模型与试验结果误差较小,具有较高实用价值,微量润滑铣削材料PCrNi3Mo时,润滑剂的最佳使用值约为185mL/h;通过改善切削区的摩擦情况,微量润滑可降低切削区域温度并有效控制切屑形貌。

The penetration mechanism and cutting force under minimum quantity lubrication （MQL） cutting is presented. The performances of traditional cutting, dry machining and MQL in the milling of high strength steel （PCrNi3Mo） are compared, and the effect of MQL on tool wear and chip formation is discussed. The effect of cutting parameters （cutting speed, feed rate, depth of cut and lubricant quantity） on tool wear under the MQL cutting environment is investigated. Based on response surface methodology, a tool flank wear model is built and experimentally verified in order to determine the best oil usage. The experimental results show that MQL provides some advantages in terms of tool wear reduction. The tool flank wear model has the better reliability and practical value. MQL with 185 mL/h provides the lowest flank wear when milling high strength steel （PCrNi3Mo）. Lower cutting temperature and favorable change in chip deformation can be obtained under MQL conditions mainly through reduction in the cutting zone friction.