含钙易切钢切削机理的研究

The Mechanism of Free-Machining Steel

我们所研制的含钙易切钢(40 CrCa)的可加工性具有一个明显的特点,即在某一切削速度范围内,这种钢的可加工性是随着切削速度的提高而改善的。当切削速度V≈200米/分时,可加工性达到最佳状态。此时刀具的耐用度为切削普通钢(40Cr)时的8倍。 这种易切钢的可加工性特别好的原因在于:用钨、钛、钴类硬质合金刀具(YT15)以高的切削速度切削这种钢时,钢中的球状氧化夹杂物会软化,并且沉积在刀具表面上形成一层薄膜,这层薄膜对刀具的磨损有阻碍作用。

One of the obvious characteristics of the calcium treatad free-machining steel we have developed(40 CrCa) is that its machinabi-lity will, in a certain range of cutting speed improve as the cutting speed rises, and will reach the best of it when the cutting speed V = 200m/min. In this case, the tool will be given a life 8 times as long as that when cutting standard steel(40Cr). The reason of the superiority in machinability of this free-machining steel is that as this steel is being machined with titanium-tungsten type cemented carbide tool(YTIS) at high cutting speed, the globular oxide inclusions in the steel will soften and deposit on the surface of the cuting tool as a layer that retards the tool wear.