GRAIN-ORIENTED MAGNETIC STEEL SHEET AND METHOD FOR PRODUCING THE SAME

• Main Authors: IMAMURA TAKESHI, MAKIISHI NORIKO, ISHIDA TOMOHARU, YAMASHITA TAKAKO, MURAKI MINEO
• Format: Patent
• Language: English
• Published: 14.06.2012
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INDUCTANCES; MAGNETS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a grain-oriented magnetic steel sheet excellent in magnetic properties and a method for producing the same.SOLUTION: The method for producing the grain-oriented magnetic steel sheet includes hot rolling a slab having a component composition comprising, by mass, 0.002 to 0.100% C, 2.0 to 8.0% Si, 0.005 to 1.00% Mn, 0.010% or less Al, 0.005% or less N, 0.005% or less S, 0.005% or less Se, and 0.001 to 0.015% Nb, and the balance consisting of Fe and unavoidable impurities. Then, the hot-rolled steel sheet is subjected to recrystallizing annealing by applying one or two or more cold rolling with intermediate annealing. Then, after finish annealing, the resulting steel sheet is cooled at an average cooling rate of 0.3°C/min or less from the finish annealing temperature to 600°C. The amount of dissolved Nb of the grain-oriented magnetic steel sheet produced in this way will be 0.0006% or less.