摘要：对42CrMo合金结构钢进行了车削加工试验，探究了精加工切削速度及加工步数对表面完整性的影响规律。从表面粗糙度、显微硬度及残余应力三个方面对加工表面完整性进行了测试与表征，并对加工表面层横断面进行了扫描电镜SEM形貌分析。结果表明，在vc=150~300m/min范围内，随着切削速度的增加，加工表面粗糙度和表面硬化程度降低，加工残余应力增大，因此可适当增大切削速度以提高加工表面完整性。两工步精加工在高切削速度下，表面粗糙度和硬化程度较小，且残余应力相比单工步和三工步加工增幅不大，可获得较优的加工表面完整性。

关键词：42CrMo；表面完整性；残余应力；显微硬度；表面粗糙度

中图分类号：TG506；TH161.14文献标志码：ADOI：10.3969/j.issn.1000-7008.2021.07.009

Surface Integrity of 42CrMo Steel in Multistep Turning

Chang Jialin，Li Anhai

Abstract:The turning experiment of alloy structural steel 42CrMo is carried out to explore the influence of finishing cutting speed and processing steps on surface integrity.The surface integrity is tested and characterized from three aspects of surface roughness，microhardness and residual stress，and SEM morphology of the cross section of the machined surface layer is analyzed.The results show that in the range of vc=150~300m/min，with the increase of cutting speed，the machined surface roughness decreases obviously，the surface hardening degree decreases，and the machining residual stress increases.Therefore，the cutting speed can be appropriately increased to improve the machined surface integrity.At higher cutting speeds，the twostep finish machining has smaller surface roughness and hardening degree，and the increasing of residual stress is relatively small compared with single step and threestep finish machining，which can obtain better surface integrity.

Keywords:42CrMo；surface integrity；residual stress；microhardness；surface roughness