Controlling edge drop by tapered-crown work roll shifting mill and work roll crossing mill in cold strip rolling

摘要

For the purpose of controlling edge drop in cold strip rolling, a tapered-crown work roll shifting method was developed and applied to many commercial cold rolling mills, and a pair crossing mill was also developed to control the thickness profile in cold strip rolling. In this paper, the capabilities to control edge drop by work roll shifting and work roll crossing are investigated to advance the technologies needed to control edge drop in cold strip rolling. Experiments are carried out on alaboratory scale and in actual mills, in which the work roll shifting and work roll crossing devices are installed. In rolling that uses straight work rolls, edge drop is formed. In the work roll shifting mill, edge drop becomes smaller with increasingwork roll taper position, EL. The flatness of the rolled strip is quarter buckles and the maximum elongation increases with increasing EL. In the work roll crossing mill, edge drop is reduced slightly and the strip flatness of the center buckles increases with increasing crossing angle. As the strip flatness is constrained to enable stable rolling, the capability of work roll shifting to control edge drop is greater than that by work roll crossing.