The Study of Precision Hard Turning of the Hardened Mold Steel

Abstract

Hard turning has the advantage of rapidly, elasticity and low energy consuming. It has been a trend to replace the complex grinding processes, especially for small batch machining.The surface roughness value of steel after being grinded will ranged in 0.1 to 1.6 μm Ra. This paper points to the precision hard turning of the hardened mold steel, seeking the cutting conditions that can be received in the surface roughness value below 0.1μm Ra, in order to replace the grinding processes. The precision dry turning test were conducted with ceramic cutting tools. The nose radius of the cutting tool was 1.2 mm and the depth of cut was fixed at 0.05 mm. Through a series of turning test, it can be found that, when cutting speed was at 80 to 200 m / min, and feed rate at 0.005 to 0.009 mm / rev, the surface roughness value would be all below 0.1μm Ra. It was superior to grinding process. So we can say that, it is possible to replace the grinding process by hard turning when machining the hardened mold steel.