PURPOSE: To provide a method with high-response and high-accuracy for control ling water cooling in a process for improving the added value of quality (tension, scale, etc.).
CONSTITUTION: Durring a hot rolling or when a following bar steel or wire rod is cooled, at a point C before a material to be rolled enters a cooling zone, a point B on the way of recuperation after water cooling is finished, and a point A after recuperation, the temperatures TCi, TBi, and TAi of the material to be rolled are measured respectively, such a target temperature 'TBi at the point B that the temperature at the point A becomes the target temperature 'TAi is estimated by the following numerical expression, feedback control is performed with the target temperature 'TBi at the point B as a target value to adjust the flow rate of coiling water. 7TBi=C1-C2.TCi. Therefore, since the temperature of the material to be rolled is lowered more accurately to a prescribed temperature in a state wherein a detection lag due to a recuperation time generated in the feedback control is reduced, qualities such as tension, scales, etc., can be stabilized.
OTSU YOSHIHISA
HAGIWARA HIROSHI
