METHOD FOR PRODUCING GRAIN ORIENTED MAGNETIC STEEL SHEET

• Main Authors: ARAGAKI YUKIHIRO, TAKAMIYA TOSHITO, OKUBO TOMOYUKI, WATANABE MAKOTO
• Format: Patent
• Language: English; Japanese
• Published: 17.11.2016
• 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 increase product yield by reducing shape defect generated in final annealing.SOLUTION: There is provided a method for producing a grain oriented magnetic steel sheet by subjecting a coil for grain oriented magnetic steel sheet after cold rolling to a primary recrystallization annealing, applying an annealing separator thereon, and conducting final annealing. In the method, rapid heating is conducted at a rate of 80°C/sec. or more from 500°C to 700°C in the course of heating for the primary recrystallization annealing, and soaking treatment is conducted for holding temperature for 2 to 100 hours from 700°C to 1000°C in the course of heating for the final annealing by laying a thermal insulation material on an upper surface of a coil supporting stand in an annealing furnace used for the final annealing concentrically from the outer periphery of the coil supporting stand and over an area of 20% or more of the radius of the coil supporting stand, preferably further final annealing is conducted by laying the thermal insulation material on the top face of the coil supporting stand of the annealing furnace used for final annealing concentrically from the outer periphery of the coil supporting stand and over an area of 20% or more of the radius of the coil supporting stand.SELECTED DRAWING: Figure 1 【課題】仕上焼鈍において発生する形状不良を低減し、製品歩留りを向上させる。【解決手段】冷間圧延後の方向性電磁鋼板用コイルを一次再結晶焼鈍し、焼鈍分離剤を塗布し、仕上焼鈍する方向性電磁鋼板の製造方法において、上記一次再結晶焼鈍の加熱過程における５００〜７００℃間を８０℃／ｓｅｃ以上で急速加熱すると共に、上記仕上焼鈍に用いる焼鈍炉のコイル受台の上面に、外周側から同心円状にかつコイル受台の半径の２０％以上に、断熱材を敷設し、仕上焼鈍の加熱過程の７００〜１０００℃間で２〜１００時間保持する保定処理を施す、好ましくは、さらに、仕上焼鈍に用いる焼鈍炉のコイル受台上面に、外周側から同心円状にかつコイル受台の半径の２０％以上に、断熱材を敷設して仕上焼鈍する方向性電磁鋼板の製造方法。【選択図】図１