立方氮化硼等刀具加工淬硬钢的切削性能探讨

THE PERFORMANCE OF CBN AND OTHER TOOLS WHEN CUTTING HARDENED STEEL

本文探讨了立方氮化硼(CBN)、陶瓷、硬质合金刀具精车55~#淬火钢(HRC45～55)时的刀具耐用度和加工表面粗糙度的变化规律.研究表明:在本文的试验条件下,陶瓷刀具比 CBN 刀具耐用度高,而用 CBN 刀具切削可以得到极佳的表面粗糙度.在一定条件下,一些刀具的耐用度随切削速度的升高而提高,对于 CBN 刀具来说,其原因是高速下磨损带上形成的保护膜减轻了刀具磨损.文章还揭示了工件材料硬度、刀具几何参数、切削用量等因素对加工表面粗糙度的影响.文章对于在无积屑瘤的切削条件下切削速度和工件硬速度对加工表面粗糙度的影响提出了新的见解.

The tool lives and the machined surface roughness when cutting hardened 55~# steel (HRC45～55)with CBN,ceramic and carbide tools are studied.Under the conditions outlined in the paper the tool lives of ceramic tools are longer than those of CBN tools. However,the latter can produce excellent surface finish.In certain cases the lives of some tools increase with the increase of cutting speed.As long as CBN tools are concerned,the phenomenon is at- tributed to the formation of a protective film on the wear lands at high cutting speed.The paper reveals the influences of such factors as workpiece hardness,tool geometry and cutting regime,etc.,on the machined surface roughness.Now understanding is presented to explain some of the influences when no BUE is visible.