METHOD OF MANUFACTURING STEEL PLATE

PROBLEM TO BE SOLVED: To provide a method of manufacturing steel plates by hot rolling, while suppressing the generation of scale defects. SOLUTION: The finish rolling temperature of a steel plate S is set to ≥900°C at the final pass for easily performing the finish rolling and descaling of the steel plate S. In such a case, water is jetted, within at least 5 sec after the finish rolling, from water jetting devices 4 arranged between a finishing mill 1 and a hot straightening machine 3 and, because scale (specifically, swelling of thick scale which is called a blister) is generated on the surface of the steel plate S during at least the surface temperature of the steel plate S exceeds 850°C, the surface of the steel plate S is set in a state where the surface is covered with water so that the surface of the steel plate S is not oxidized during that period. In this way, the generation of the scale on the surface of the steel plate S after finish rolling is suppressed and yet the steel plate is softly cooled between the finishing mill 1 and the hot straightening machine 3 so that irregular cooling is not caused on the steel plate S. COPYRIGHT: (C)2009,JPO&INPIT