| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a grain-oriented magnetic steel sheet excellent in magnetic properties and having little variation in magnetic properties in a coil longitudinal direction.SOLUTION: The method of producing a grain-oriented magnetic steel sheet is provided in which an a steel raw material containing, by mass%, C:0.002 to 0.10%, Si:2.0 to 8.0% and Mn:0.005 to 1.0% is hot rolled, cold rolled after subjected to hot rolled sheet annealing as needed, and the resulting cold rolled sheet is subjected to primary recrystallization annealing acting also as decarbonization annealing, then final annealing. In the method, each aging treatment conducted between path in the final cold rolling satisfies the following expression: (Dt/T)≤2.0×10, where D=0.394exp(-(8.02×10)/8.31T), T:aging temperature (K), t:aging time (second), and the cold rolled steel sheet is subjected to a soaking treatment for holding the cold rolled steel sheet at any temperature between 250 to 600°C for 1 to 10 seconds when the cold rolled steel sheet is rapidly heated at 50°C/s or more between 200 to 700°C in a heating process of the primary recrystallization annealing. |
