| 摘要 |
PROBLEM TO BE SOLVED: To provide a rough rolling caliber of H-shaped steel and a rough rolling method of the H-shaped steel, capable of eliminating a variation in a lateral shape of a flange part as much as possible, without leaving a flaw on an outer surface of a flange in a raw material steel piece, even when a caliber is stored in the roll barrel length by continuing a second split caliber and a push-expanding caliber.SOLUTION: In a rough rolling caliber of H-shaped steel, respective left sidewall surface 12a and right sidewall surface 12b of a second projection part 12 of a second split caliber k-2, comprise first inclination parts 12a1 and 12b1 where an angle θ21 formed with a perpendicular L to the roll barrel length direction is substantially the same as an angle θ1 formed by a left sidewall surface 11a and a right sidewall surface 11b of a first projection part 11 and the perpendicular L, second inclination parts 12a2 and 12b2 where an angle θ22 formed with the perpendicular L is larger by 2° or more to an angle θ21 and third inclination parts 12a3 and 12b3 where an angle θ23 formed with the perpendicular L is the same as an angle θ4 formed by a sidewall surface 13d of a push-expanding caliber k-3 and the perpendicular L.SELECTED DRAWING: Figure 1 |
