2004 Volume 44 Issue 3 Pages 598-602
SCM415 steel was machined with carbide tools in as hot rolled condition and after normalizing heat treatment. In the as-rolled sample, a significant amount of Al and N existed as solid solution; whereas, in the normalized sample, Al and N existed as AlN precipitates. Reduction of tool wear for the as-rolled sample was observed. On the rake face of the tool machined for the as-rolled sample, the presence of AlN deposit was observed. It is believed that Al and N in solid solution form AlN deposit on the tool face due to temperature rise during machining, and that the deposition of the AlN layer on the tool face prevents diffusion between the tool and chip and reduces tool wear.