DIRECTLY QUENCHED THICK STEEL PLATE WITH THIN WALL AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thick steel plate which has the excellent uniformity of material properties in a longitudinal direction of the steel plate, with the use of a passage type cooling device.;SOLUTION: This manufacturing method employs a rolling and cooling method which uses a rolling-cooling apparatus having a first passage type cooling device and a second passage type cooling device which are sequentially arranged downstream of a reversible type of a hot rolling mill, and which comprises the following steps of: 1. cooling a steel plate after having been finish-rolled, in the first passage type cooling device so that cooling starting temperatures at the front end area and the rear end area of the steel plate can be the same when the steel plate is cooled in the second passage type cooling device; and 2. cooling the steel plate while passing the steel plate through the second passage type cooling device at a constant rate.;COPYRIGHT: (C)2009,JPO&INPIT