PRODUCTION OF GRAIN ORIENTED SILICON STEEL SHEET HAVING LOW IRON LOSS

• Main Authors: SUGA YOZO, NOZAWA TADAO, USHIGAMI YOSHIYUKI, NAKAYAMA TADASHI, KONNO TOYOHIKO, YABUMOTO MASAO
• Format: Patent
• Language: English
• Published: 23.08.1986
• 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

PURPOSE:To produce a grain oriented silicon steel sheet having high magnetic flux density and low iron loss by heating a slab consisting of the specific compsn. for the grin oriented silicon steel sheet to a specific temp. then subjecting the slab to hot rolling, cold rolling and decarburization annealing then coating a separating agent for annealing thereon and subjecting the steel sheet to secondary recrystallization annealing under specific conditions. CONSTITUTION:The slab for the grain oriented silicon steel sheet consisting of 0.025-0.075% C, 3.0-4.5% Si, 0.010-0.060% sol. Al, 0.0030-0.0130% N, <=0.007% S, 0.08-0.45% Mn, 0.015-0.045% P, 0.07-0.25% Cr and the balance Fe and unavoidable impurities is heated to the temp. below 1,280 deg.C and is hot rolled. The hot rolled sheet is subjected to cold rolling to a final sheet thickness then to decarburization annealing. After the separating agent for annealing is coated on such steel sheet, the steel sheet is subjected to secondary recrystallization annealing while a temp. gradient of >=2.5 deg.C/cm is applied to the steel sheet in the boundary part between the primary recrystallization region and the secondary recrystallization region.