| 摘要 |
PROBLEM TO BE SOLVED: To simplify the whole rolling equipment by realizing the low aspect ratio/high area-reduction ratio rolling, in hot rolling of a bar-wire.SOLUTION: When imparting back tension to a pre-rolling steel material, the steel material 2 is heated so as to become the highest temperature just before biting-in, and the back tension corresponding to yielding force of a biting-in part is imparted to the steel material by specifying two conditions of the roll 1' diameter ratio and the roll peripheral velocity ratio, and drawing is induced before biting in the steel material. Widening disappears by pre-reduction in the draft-width both directions, and an increase in the aspect ratio by draft is restrained, and the high area-reduction ratio of the draft ratio or more is provided. Stable over-tension rolling becomes possible without rupture and a reduction cut by the high temperature setting of the biting-in part and front tension after rolling, and the low widening/high area-reduction ratio is provided. |
