Reduction of off-centering at tail end caused by unstable work roll position with mill stabilizing device in hot rolling

Abstract

Abstract In hot rolling, the strip has been needed to be rolled harder and faster to obtain thinner and higher quality strip, such as high strength steel. As the strip is rolled harder, the strip steering tends to become unstable because of the unstable work roll position caused by the clearance between the work chocks and housing. Pinching might occur, especially for tail end of rolled strip. The mechanism of unstable strip steering is not clear. When rolls position is not stable, roll skew between the work and back-up roll occurs and thrust force in the roll-axial direction is also generated. Asymmetrical roll deformation occurs caused by the force distribution along the roll-axis direction. As a result, thickness difference in width direction and off-centering at tail end of rolled strip occurs. The coupled analysis was carried out and it is found that rolls position has much effect on the thickness difference and off-centering at tail end and Mill Stabilizing Device, which eliminates the clearance between the roll chocks and housing, is effective to reduce off-centering at tail end.