GB1498851A - Method for rolling metallic material - Google Patents

Abstract

1498851 Rolling NIPPON STEEL CORP 4 April 1975 [10 April 1974 15 May 1974 (2) 17 Dec 1974] 13888/75 Heading B3M A metal workpiece is pushed into the rolling gap between two work rolls so that the angle subtended at the roll axis by the area of contact between roll and workpiece exceeds the arc tangent of the coefficient of friction between roll and workpiece, the pushing preventing slipping between roll and workpiece and enabling higher thickness reduction to be achieved in a single pass. In Fig. 3, the ram 3 of a hydraulic cylinder 2 pushes a workpiece W through rolls 1, until just before the ram contacts the rolls, whereupon an inner ram 4 completes the pushing operation. In Fig. 5, the pushing force is provided by a linear induction motor 6. In other embodiments, the pushing force is provided by pinch rolls, by an upstream rolling mill driven faster than the rolls 1, or by apparatus which removes the workpiece from a furnace. Successive workpieces may be joined end-to-end, e.g. welded each then pushing its predecessor into the working gap. Permanent joins may be made by this process. Guides such as rolls may be provided to prevent buckling. A billet may be rolled into an H-section by a universal mill, Fig. 21, having driven rolls 24 rolling the flanges and smaller diameter idler rolls 25 rolling the web. As in this figure, tension may be applied by a gripper 26 downstream of the work rolls 23, or alternatively by pinch rolls or a subsequent rolling mill driven faster than rolls 23. In Fig. 16, the amount of reduction in mill 14 and/or its roll surface speed, and the surface speed of upstream and downstream pinch rolls 13, 15 are controlled by a photoelectric device 16 responsive to the width of the rolled product. The method may be applied to roll continuous castings. Various plant lines are described, Figs. 27-32 (not shown) in which a high reduction mill is preceeded by casting or heating and descaling units, and followed by an edger, further reduction mills, a shearer, and/or a coiler.