Effect of Desulfurization on the Machinability of SCM420H Steel

Abstract

Machinability of low alloy steels with extra-low and ordinary sulfur contents was studied by means of turning tests using sintered carbide tools under conventional machining conditions. The results are as follows. Reduction in sulfur contents decreases chip breakability, improves surface roughness and topography at cutting speeds of 100m/min or higher, and exerts only a minor effect on tool life and cutting forces. On the whole, the desulfurized steel can be machined at a high removal rate without any serious problem, provided proper cutting conditions are selected and the smooth machined surface thus obtained promises a good tribological effect.
It was discussed and found that there was no difference between the mechanisms accounting for the effects of desulfurization and those of resulfurization on the machinability of steel.