Abstract
In the 1st report it was demonstrated that the belag on the tool surface of carbide tool improved the machinability when cutting resulfurized steels at high cutting speed. Since ceramic tool mainly consists of alumina, it may be estimated that the forming condition and the effect of belag are not similar in cutting with carbide tool. The purposes of this report are to clarify the wear characteristics of ceramic tool and build up a relationship model between the crater wear and the contents of Al, Si and O in the work material. Main results obtained are as follows. (1) The protective layer was not formed when cutting rimmed steels or extremely low oxygen content killed steels, in such case the crater wear of ceramic tool in machining resulfurized steels is larger than that of regular steels. (2) Resulfurized steels containing high level oxygen and proper contents of Al and Si form a stable layer on the tool surface and it reduces the wear of ceramic tool. (3) The wear of ceramic tool in cutting FeSi deoxidized resulfurized steels is serious, and in some case the crater depth is larger than that of carbide tool.
