Effect of additional current on cutting mechanism of free machining steels in turning

It is well known that the electro motive force generated at an interface between tool and workplece in cutting influences on the shape of built-up edge and the tool life. There is, however, few reports about the current flow in the closed circuit of tool-workpiece-machine on the behavior of deposited layer called "belag" observed in machining workmaterials such as calcium deoxidized steel and BN added steel and so on. This paper deals with the machinability of steels in turning with additional current. Tested workmaterials were plane carbon steel JIS S45C and BN added steel which has good machinability at high cutting speed. Turning tests were performed by carbide tool P30 in order to investigate the influence of electrical conditions of closed circuit system on the cutting mechanism of BN added steel. The tool life, cutting force, chip geometries and others were investigated practically and these results were discussed.