Application of induction heating to control sheet flatness in cold rolling mills

Abstract

A system for rolling metal sheet having a substantially uniform flatness including a rolling mill including a pair of work rollers for reducing the thickness of a metal sheet, an induction heating apparatus in close proximity to at least one roller, bending jacks corresponding to each of the rollers, and a cooling spray system in proximity to rollers; a flatness measuring device positioned to measure a differential in flatness of the metal sheet; and an mill control interface connected between the flatness measuring device and the rolling mill's actuators, in which the mill control interface is configured to actuate the induction heating apparatus, the bending jacks and the cooling spray system to substantially eliminate flatness differentials is the metal sheet's flatness. The induction coil heating apparatus is configured to eliminate high tension on the strip edges caused by the temperature gradients in the work rolls at the edges of the metal strip.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present invention claims the benefit of U.S. provisional patent application 60 / 774,974 filed Feb. 17, 2006 the whole contents and disclosure of which is incorporated by reference as is fully set forth herein.FIELD OF THE INVENTION [0002] In one embodiment, the invention relates to cold rolling, and a method of improving sheet flatness in cold rolled metal sheets utilizing induction heating. BACKGROUND OF THE INVENTION [0003] Strip products composed of metal, such as aluminum, are typically rolled in four high or six high rolling mill stands. Prior methods for forming aluminum strip have been unable to roll the strip uniformly over its entire width, and have not been able to provide rolled products being free of undesirable flatness undulations in the middle area, the edge area or the quarter area of the strip. Unevenly distributed internal stresses resulting from the material being processed with prior methods typically result in ed...

AI Technical Summary

Benefits of technology

[0019] In one embodiment, the induction heating apparatus is configured to eliminate high tension on the strip edges that may be caused by the temperature gradient in the work rolls at the edges of the metal strip. In one embodiment, the induction heating apparatus may further include bending jacks, work roll axial sliding mechanisms and a spray cooling system, wherein the bending jacks, axial sliding mechanism and spray cooling system may also be actuated by the mill control interface in response to flatness measurements.

Problems solved by technology

Prior methods for forming aluminum strip have been unable to roll the strip uniformly over its entire width, and have not been able to provide rolled products being free of undesirable flatness undulations in the middle area, the edge area or the quarter area of the strip.

Unevenly distributed internal stresses resulting from the material being processed with prior methods typically result in edge cracking, wherein edge cracks need to be discarded resulting in sections of the rolled product being cut away and scrapped.

Edge cracking in the middle of a coil, can require that the entire coil may need to be scrapped.

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