ULTRA-THIN SHEET STEEL AND METHOD FOR MANUFACTURING THE SAME

• Main Authors: RYU, NAOTOSHI, TOSAKA, AKIO, OKUDA, KANEHARU, ARATANI, MASATOSHI, KUGUMINATO, HIDEO, ARATANI, MAKOTO, OKADA, SUSUMU
• Format: Patent
• Language: English; French; German
• Published: 04.03.1998
• Edition: 6
• Subjects: ALLOYS; APPARATUS THEREFOR; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS; PUNCHING METAL; ROLLING OF METAL; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A steel slab is rough-rolled into a sheet bar and butt-joined onto a preceding sheet bar and a widthwise end portion of the sheet bar is heated by means of an edge heater and then subjected to a continuous finish rolling through pair-cross rolls rolling on at least 3 stands to provide a hot rolled steel strip having a width of not less than 950 mm, a thickness of 0.5-2 mm and a crown within +/-40 mu m, and the hot rolled steel strip is subjected to cold rolling, continuous annealing, temper rolling and, if necessary, plating treatment on the surface of the cold rolled steel strip, whereby there is obtained a steel sheet having an average thickness of not more than 0.20 mm and a width of not less than 950 mm, a thickness variation quantity in a widthwise direction is within +/- 4% of the average thickness in a region corresponding to not less than 95% of the width of the steel sheet as cold rolled and a hardness (HR30T) variation in the widthwise direction is within +/-3 of an average hardness.