高速铣削淬硬钢时的切屑形态试验研究

Experiment Investigation Into Chip Morphology in High Speed Milling of Hardened Steels

使用Ti Al N涂层整体圆柱立铣刀,以(151~942)m/min的铣削速度,对淬硬的45钢和3Cr2Mo钢进行了高速铣削试验,研究了各种切削速度下的宏观及微观切屑形态。发现在高的铣削速度下形成了带有绝热剪切带的锯齿形切屑,并分析了切屑形态的演化过程。工件材料的硬度、强度、导热性能及切削速度对切屑形态和绝热剪切带的形成有着重要的影响。工件材料越硬、强度越高、导热系数越低,切削速度越大,越容易形成带有绝热剪切带的锯齿形切屑,而且,随着切削速度的增加,切屑的形态由卷曲向平坦发展。

Using solid tungsten carbide cylindrical end milling cutter with TiAlN coating,hardened 45 steel and 3Cr2Mo steel were machined in the milling speed range of 151 to 942 m/min.The chip morphology at various speeds were investigated.The results show that saw-tooth chips with ASB(adiabatic shear bands)are are observed at high speeds,and evolution of chip morphology was described.Workpiece hardness,yield strength,coefficient of heat conductivity and cutting speed are found to have significant influences on chip morphology and ASB.The harder the workpiece material,the higher the strength,the lower the thermal conductivity,and the faster the cutting speed,the easier it is to form serrated chips with adiabatic shear bands.Moreover,as the cutting speed increases,the shape of the chips changes from curl to flat.