ArcelorMittal S.A.
Method for Mitigating the Effects of Coil Collapse on Hot Strip Mill Coils

Abstract:

A method for mitigating the effects of coil collapse on hot strip mill coils. A hot strip coil is removed from the mandrel/downcoiler and pre-sagged to create an initial sag by allowing gravity cause the coil to sag in a first specific direction for a first period of time. Then, without coil eye support to limit sagging, the direction of the sag caused by the force of gravity is modified to a direction perpendicular to the first specific direction and gravity is allowed to sag said coil for a second period of time. The first period of time and the second period of time are chosen such that the initial sag created during the first period of time is substantially mitigated by the perpendicular sag during the second period of time. The hot strip coil being cooled enough by the end of the second period of time such that the rate of sagging of the hot strip coil has become negligible.