低炭素鋼切削における構成刃先現象

抄録

In this paper, for the purpose of clearing the mechanism of formation of the built-up edge, the observations and the experiments on the forms of its formation and omission, the periodic time of its formation-omission, its grown shape, its structure, the cutting temperature and the variation of the coefficient of the friction on tool face in cutting of low carbon steel (JIS S 25 C) are reported.
From these results, one hypothesis on the mechanism of formation of the built-up edge is proposed. The main results obtained are as follows :
(1) From the observation of the plastic flows in the built-up edge, it is clear that slips exist in their flows distinctly. This result convinces us that the mechanism of growth of the built-up edge is performed as if the small blocks of the chip are built up successively rather than that is done as if the thin sheets are piled up as mentioned hitherto.
(2) The mechanism of formation of the built-up edge is so considered that the first slip line in the plastic region in the chip moves near to the boundary line of the dead metal zone ahead of the tool edge and as a result of this, the built-up edge occurs by the shear deformations along this line and along the shear plane from the cutting point.