PURPOSE: To prevent the front end of a steel bar from generating flaws and to improve the yield of a rolled product by forming the steel-bar reducing cross section of the caliber of a steel-bar rolling mill at the inlet side of the mill into a slightly twisted shape.
CONSTITUTION: A V-groove 4 is formed so that D1>D2; when the roll diam.s of a part of the V-groove 4 of a rolling roll 2 at the positions separated side to side from a vertical line C, passing through the center O of a caliber 6, by equal distances (l), are expressed by D1 (right side) and D2 (left side). A V-groove 5 is formed, as against this, so that the roll diam.s of a part of the V-groove 5 of a rolling roll 3 at the positions separated from the line C by the same distances (l), are D1 (left side) and D2 (right side) in contrast with said formation. As a result, the cross section of a steel bar 7 rolled by this caliber is made to be a slightly twisted rhombus which is symmetrical with respect to the line C, and the front end of steel bar is prevented from generating flaws.
FUJIWARA YUKIO
IZUNO TSUKURU
HAMADA KAZUTOSHI
KUMAMI HIROSHI
| JPS591001A | 1984-01-06 |