Chip-Tool Friction and Shear Characteristics of Cold Drawn Free Machining Steels in Turning

냉각인발된 쾌삭강의 외경선삭시 칩-공구 마찰 및 전단 특성

In this study, chip-tool friction and shear characteristics of cold drawn free machining steels in turning were assessed. To do this, a newly developed equivalent oblique cutting model was adopted. And for comparison with those of free machining steels, chip-tool friction and shear characteristics of conventional carbon steels were also investigated. The Pb-S free machining steel shows superior machinability to others. In case of the Bi-S free machining steel, the shear stress and the specific friction energy are relatively lower than those of conventional carbon steels, but its shear strain is relatively high, so it does not show any remarkable improvement of machinability.