| 摘要 |
PURPOSE:To reduce the wear of the roll edge, and to surely split the steel ingot, by giving different depths to calibers provided in upper and lower rolling rolls in order to apply upward and downward differently directing bending forces to the rolled steel bars. CONSTITUTION:A billet is charged into the heating furnace to heat it to temperatures required in the rolling work, and this billet is passed through plural stages of rolling rolls and is formed into two or three or more parallel lines of steel bars 2 in a required diameter. Hereupon, the calibers 5a, 5b, are carved in outer circumferences of a couple of upper and lower rolls 3, 4, in an arbitrary stage of plural stages of rolling rolls; in which, the depth of the caliber 5a is made deeper than that of the caliber 5b, and the gravitational center G of the caliber 5a is located within the caliber 5a. Accordingly, when the steel bar 2 passes through the parallelly arranged two calibers 5a, 5b, the steel bars 2a, 2b, connected by a thin walled part, are respectively given different speeds between their upper and lower surfaces, so that upward and downward bending forces are applied to the steel bars 2a, 2b, respectively. These bending forces work as a shearing force on the thin walled connecting part of two steel bars 2a, 2b; as a result, the steel bars 2a, 2b, are split upward and downward respectively. |
