Machinability of Resulfurized Steels under High Cutting Speed

Machining of several kinds of resulfurized and ordinary carbon steels under high cutting speed was investigated in order to reveal the effect of inclusions and deoxidation practices on tool wear. Also, the difference of machinability between the continuous casted and ingot casted resulfurized steels was examined. The results obtained were as follows: (1) In machining of the continuous and ingot casted resulfurized steels the difference of machinability is not certainty and it may be reversed with the kind of tool material used. (2) In comparision of the tool wear between resulfurized and regular steels the crater depth is closely related to the deposited layer on rake face, but the flank wear of carbide tool P 10 in machining resulfurized steels is always smaller than that of regular steels. (3) Increase of the content of oxide inclusions (Si0₂, A1₂0₃, etc.) in steels generally causes the increase of tool wear by abrasive, but when these oxides are controlled to form a stable protective layer on the tool face, the tool wear can be suppressed.