Patent ID: 8945319
Filing Date: 2015-02-03
Classification: B21B,B21C

Abstract:
1. A manufacturing method of a hot-rolled steel sheet wherein in manufacturing a hot-rolled steel sheet using a heating device which heats a material to be rolled, a descaling device disposed on a more downstream side in a transporting direction of the material to be rolled than the heating device, a row of finishing mills disposed on a more downstream side in the transporting direction of the material to be rolled than the descaling device, a cooling device disposed in the row of finishing mills, and a rapid cooling device of which at a least a part is disposed immediately after a shaft center of a roll of the final stand of the row of finishing mills, the operations of the heating device, cooling device and rapid cooling device are controlled, thereby controlling a temperature T 1 of the material to be rolled which is on an entry side of the row of finishing mills, a temperature T 2 of the material to be rolled which is on an entry side of a final stand in the row of finishing mills, and a temperature T 3 of the material to be rolled which is on an exit side of the rapid cooling device, and the rapid cooling device sprays cooling water all over the material to be rolled in a sheet width direction thereof from both faces of the material to be rolled at a water volume density of 10 m 3 /(m 2 ·min) or more for one face of the material to be rolled.