42CrMo钢窄深槽磨削表面性能的试验研究

Experimental Study on the Surface Properties of 42CrMo Steel in Narrow and Deep Groove Grinding

针对窄深槽磨削过程中磨削工艺参数对表面性能的影响规律,建立单因素试验,采用单层电镀CBN砂轮对调质42CrMo钢进行高速磨削。运用三维轮廓测量仪、金相显微镜和维氏硬度计检测窄深槽侧面的表面粗糙度Ra、表面形貌、亚表层硬度分布及显微组织,得出磨削工艺参数对窄深槽侧面的表面粗糙度值Ra、表面形貌及显微硬度分布影响规律,分析窄深槽侧面的显微组织。结果表明:随着砂轮线速度增大、工件进给速度及磨削深度减小,窄深槽侧面的表面粗糙度值Ra减小,磨痕变浅变窄,脆性剥落及磨痕锯齿状边缘减少,磨削表面质量改善;随着砂轮线速度的减小、工件进给速度及磨削深度的增加,磨削温度升高,生成更多板条马氏体组织,亚表层硬化程度增加;窄深槽侧面亚表层生成板条马氏体、残余奥氏体及残余渗碳体组织,最表层组织发生晶粒细化。

In view of the influence of grinding parameters on the surface properties in the process of narrow deep groove grinding,a single factor experiment was established.A single-layer electroplated CBN wheel was used to carry out high-speed grinding test on quenched and tempered 42CrMo steel.The surface roughness Ra,surface morphology,subsurface hardness distribution and mi⁃crostructure on the side of the narrow deep groove were measured by three dimensional surface profiler,vickers hardness tester and metallographic microscope.The influence of grinding parameters on the surface roughness Ra,surface morphology and microhardness distribution on the side of narrow deep groove was analyzed.The results show that with the increase of the linear speed of the grinding wheel and the decrease of the feed speed and grinding depth of the workpiece,the surface roughness Ra on the side of the narrow deep groove decreases,the grinding crack become shallow and narrow,the brittle peeling off and the jagged edge of the scratch decrease,and the grinding surface quality improves;with the decrease of the linear speed of the grinding wheel,the in⁃crease of the feed speed and grinding depth of the workpiece,the temperature of the grinding area increases,and more lath mar⁃tensite are generated,and the degree of subsurface hardening increases;In addition,the lath martensite,retained austenite and re⁃tained cementite are formed on the side of narrow deep grooves,and the grain refinement occurs in the surface layer.