| 摘要 |
PURPOSE:To prevent an edge crack and lapping in the stage of cold rolling a steel strip with a Sendzimir mill by locally rolling the edges of the steel strip to be rolled at a high draft to positively roll said parts to the state of an edge wave. CONSTITUTION:A step part 6 which the roll length (a) is <=5mm and the height (b) is 0.5-7% of the thickness on the inlet side of the steel strip to be rolled is provided to each part on both sides in the cylindrical longitudinal direction of a work roll 1'. The edge parts 9 of the strip 5' are rolled down at both ends 7 at the draft higher than the draft in the central part 10 of the strip 5' by using the rolls 1' formed to have the diameter A at both ends 7 of the roll larger than the diameter B in the central part 8 of the roll. The strip 5' is thus rolled to the edge wave stage, by which the tension to be exerted to the edge parts is decreased. The transverse movement of the strip 5' which is elongated at the edge parts and tends to bias thereto is restrained by the steps 6 while the edge crack is prevented. The lapping of the strip 5' to the roll 1' by the biasing to one side is simultaneously prevented. |
