Method of controlling cooling of hot-rolled steel sheet and system therefor.

摘要

In controlling the cooling of a hot-rolled steel sheet (12) after hot rolling, a target value of a transformation rate required for obtaining mechanical properties ultimately expected from the hot-rolled steel plate is previously determined, a rate of gamma to alpha transformed fraction of the hot-rolled steel sheet (12) in a section, in which the cooling is controlled, is detected by transformed fraction detector (A1 - A8) and an elapsed time from the start of cooling is measured to determine the transformation rate of the steel sheet (12) in a cooling stage, and the conditions of cooling are controlled so that the transformation rate can coincide with the target value.