| 摘要 |
PROBLEM TO BE SOLVED: To suppress the spread of flanges in its transverse direction and to improve dimensional accuracy by subjecting a rough rolling stock to simultaneous shaping of the welding bevels at the front ends of flanges and the projecting lines on the outside surface of the flanges by means of the perpendicular rolls of universal rolling, trimming the bevel shapes by means of the horizontal rolls of an edger of the ensuing stage and forming the projection lines to projections by means of the perpendicular rolls of finish universal rolling of the final stage. SOLUTION: The rough rolling stock is rolled by means of the perpendicular rolls 21a, 21b of the finish universal rolling mill having box type calipers 22a, 22b consisting of side walls 23 of the perpendicular rolls opening and inclining to an outer peripheral side and bases 24 inscribed with plural grooves 26 parallel with the circumferential direction, by which the bevelings of the front ends of the flanges and the projection lines 13 on the outside surface of the flanges are simultaneously formed. Next, the rolling stock is rolled down in the transverse direction of the flanges by the edger, by which the bevel shapes are trimmed and the variations in the transverse spread of the flanges are corrected. The rolling stock is thereafter subjected to finish rolling by the perpendicular rolls 21a, 21b inscribed with plural grooves 26 parallel with the axial direction on the outer peripheral surfaces, by which the projection lines 13 formed up to the previous stage are rolled down and parted to form the plural small square projections. |
