复合镗杆,是在同一镗杆上安装几把镗刀进行镗孔的工具。由于制造、刃磨及调整比较容易,在组合机床上被广泛采用。工作过程中,镗杆高速旋转,传递刀矩带功刃具切削。这就要求镗杆应有较高的韧性、耐磨性和足够的刚度。据资料介绍,细而长的复合镗杆在多数情况下除应配有足够的导向外,镗杆应选用较好的材料。如采用40Cr钢进行调质或用38CrMoAlA钢调质后渗氮。由于制造成本较高,某些厂家采用45钢、40 The compound boring bar is a tool for boring several boring tools on the same boring bar. Because of manufacturing, sharpening and adjustment is relatively easy, is widely used in the combination of machine tools. In the course of work, the boring bar rotates at a high speed, delivering the cutting edge with cutting edge and cutting power. This requires boring bar should have higher toughness, wear resistance and sufficient rigidity. According to the information, thin and long composite boring bar in most cases should be equipped with adequate guidance, the boring bar should use better materials. Such as the use of 40Cr steel quenched or tempered with 38CrMoAlA steel after nitriding. Due to higher manufacturing costs, some manufacturers use 45 steel, 40