Spreading rolling mill and associated method

Abstract

A rolling mill has a pair of cooperating work rolls with first and second chock pairs associated with each work roll. At least one work roll is rocked in a direction generally perpendicular to the longitudinal axis of the work roll during operation of the rolling mill to enhance shear rolling and create regions of irregular thickness in the workpiece. This reduces friction between the work rolls and the workpiece in subsequent rolling thereby permitting greater lateral spread of the workpiece. The rocking may be effected in a generally vertical direction by a pair of cylinders secured to a pair of chocks or may be effected in a generally horizontal direction which may be that of the path of flow of the workpiece through the rolling mill by pairs of cylinders associated with each work roll or may involve rocking in both directions. A method of rolling a metal workpiece involves an initial reduction which establishes reduced portions and enlarged portions of the workpiece which are longitudinally spaced from each other and may be angularly disposed with respect to the rolling direction. Subsequently the workpiece is laterally expanded and a workpiece of desired width and generally uniform thickness is established.