FINISHER DELIVERY TEMPERATURE CONTROL METHOD OF ROLLED STEEL SHEET IN HOT ROLLING LINE

摘要

PROBLEM TO BE SOLVED: To accurately grasp a transfer prediction time (time for a prescribed cut plate to pass through a finish rolling mill) immediately after the beginning of a speed holding control, and to control a finishing delivery temperature of a rolled steel sheet immediately after the beginning of the speed holding control with high accuracy.;SOLUTION: In a hot rolling line, the finisher delivery temperature FDT of a rolled steel sheet 11 which is finishing-rolled by a finish rolling mill 10 while being cooled by cooling devices 12a-12f is controlled in a target value, and the speed holding control is performed that stops the acceleration of a temperature rise because a cooling capacity does not suffice when the transferring speed of the rolled steel sheet is fast. The rolled steel sheet is longitudinally divided into two or more virtual cut plates P1-P10, and the calculation finisher delivery temperature of the rolled steel sheet when the cooling devices demonstrate the largest cooling capacity to each of cut plates based on the result finisher inlet side temperature of the rolled steel sheet is calculated. This calculation finisher delivery temperature and the finisher delivery temperature to be objected are compared, and a prescribed cut plate P10 in which the calculation finisher delivery temperature exceeds the target finisher delivery temperature is made an cut plate immediately after the beginning of the speed holding control.;COPYRIGHT: (C)2013,JPO&INPIT