抄録
The present paper deals with the effects of various metal carbide particles and inclusions such as MC, M6C, M23C6, Fe3C, MnS, MnTe and Pb on the formation of damage and surface roughness in a ground skin layer. Particular attention is paid to the effects due to the difference of hardness of metal crystal grain and matrix structure. Main results obtained are as follows.
(1) As the mean diameter Dp of carbide particles (MC, M6C, M23C6) becomes greater than about 2μm, various changes in the metal grain are observed in the ground skin surface layer. Namely, they are divided into three typical types ; (i) crushed carbide, (ii) partly disappearing carbide, and (iii) cracked carbide.
(2) As the grain size becomes smaller than about 1μm, MC, M6C, M23C6 and Fe3C contribute as factors to the formation of surface roughness.
(3) Inclusions of lower or nearly equal hardness (Pb, MnS, MnTe) as compared with the hardness of matrix structure contribute to formation of void in various ground and damaged surfaces.
