刃口钝化对高速钢丝锥耐磨性及寿命的影响

Edge Passive Influence on High Speed Steel Tap Wear Resistance and Life

以W6Mo5Cr4V2高速钢丝锥为研究对象,首先运用电解强化技术对丝锥进行钝化处理,得出不同钝圆半径丝锥;然后进行攻丝试验,通过对丝锥切削齿后刀面磨损值VB的测量和寿命的检测确定丝锥最优钝圆半径;再分别对未钝化与最优钝圆半径丝锥进行典型磨损曲线的绘制。最后对这两组丝锥进行攻丝扭矩的测量,得出丝锥在加工过程中扭矩的变化规律。结果表明:钝圆半径为15μm的丝锥寿命提高最明显,约为未钝化丝锥的2.5倍;两组丝锥的磨损过程都符合典型磨损曲线的发展趋势,经钝化处理后的丝锥磨损值小、磨损速率慢;在初期磨损阶段,未经钝化处理的丝锥扭矩比钝化处理后丝锥的小,但波动范围较大,加工过程不稳定;整个切削过程未钝化丝锥扭矩增长速率快,丝锥很快失效。

Making study on W6MoSCr4V2 HSS tap, first, passivating the tap by accelerated？ electrolysis, and the different blunt round radius taps had achieved. Then tapping experiment carried out, ensuring the optimal blunt round radius by testing VB and working life of tap cutter flank, and respectively drawing a typical wear curve of tap without passivation and with the optimal blunt round radius. Measuring their tapping torques and getting the change rule of the torque in process. The？ results indicate that the most obvious improvement occurred when the blunt round radius is 15 μm, it is two- and-a-half times more to the tap without passivation. Both the tap process conformed to the trend of development of typical wear curve. The attrition value was low and the wear rate was slow after passivation. In the early stage of wear, the torque value of tap without passivation is lower than the tap after passivation, but the wave range is large and the machining is not stable. The growth rate of the tap without passivation improved very fast, and the tap failure quickly.