TOP ROLL FLAW PREVENTION APPARATUS FOR HOT ROLLING STEEL STRIP AND TOP ROLL FLAW PREVENTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a top roll flaw prevention apparatus and a top roll flaw prevention method that prevent a multifold flaw from being generated in a pinch roll installed on the inlet side of a winding machine by multifold deformation having occurred at a rear end in an advance direction of a steel strip discharged out of a finish rolling machine on a hot rolling line, and thereby prevent occurrence of a top roll flaw due to transfer of the multifold flaw to a top face of the steel strip.;SOLUTION: A top roll flaw prevention apparatus and method enable: calculation of a differential load that is a difference between measurement values obtained by respectively measuring loads acting on both ends in an axial direction of a pair of top and bottom work rolls installed on a final stand 2b of a finish rolling machine 2 in a hot rolling line; determination that a multifold deformation 5 occurs at a rear end in an advance direction of a steel strip when the differential load exceeds a preset threshold value; and a subsequent tracking of the multifold deformation on the hot rolling line from the outlet side of the finish rolling machine, thereby making the top roll rise by 150-250 mmm when the multifold deformation reaches a range of 2-10 m that is a distance to a center of a top roll 3a.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT