A METHOD FOR IMPROVING PRODUCTIVITY OF MANUFACTURING AN ACCELERATED COOLING STEEL

摘要

PURPOSE: A manufacturing method for improving productivity of accelerated cooling steel is provided to substantially improve productivity of accelerated cooling steel by performing controlled rolling after increasing the number of strips for waiting cooling between roughing and finishing mills when performing temperature controlled rolling. CONSTITUTION: In a method for manufacturing high tensile strength steel using heating furnace, roughing mill(120), finishing mill(130), accelerated cooling unit and hot leveling machine, the manufacturing method for improving productivity of accelerated cooling steel comprises the steps of setting a joint cooling region(12) therebetween by mounting a plurality of sensors(9f,9d,9a,9e) between the roughing mill(120) and the finishing mill(130); performing rough milling on a material to be rolled extracted from the heating furnace in the recrystallization temperature range using the roughing mill(120) so that the material reaches an intermediate target thickness (K) and an intermediate target temperature (T2); cooling the plurality of strips of the roughing milled material all at once by organizing a plurality of strips of the roughing milled material as one group after sequentially transferring the roughing milled material to the joint cooling region(12); and finish rolling the roughing rolled material to a rolling finishing thickness (L) and a rolling finishing temperature (T3) in the finishing mill(130) by sequentially taking out the cooling finished roughing milled material after a lapse of a certain period of time.