method of manufacturing a thin grain-oriented electrical steel sheet thickness

摘要

A method for manufacturing a grain-oriented electrical steel sheet with thin thickness is provided to reduce manufacturing costs and improve magnetic properties through the optimization of stable precipitate distribution, texture, and first recrystallized grains. In a method for manufacturing a grain-oriented electrical steel sheet, comprising heating a grain-oriented electrical steel sheet slab comprising, by weight percent, 2.5 to 4% of Si, 0.02 to 0.07% of C, 0.05 to 0.5% of Mn, 0.025 to 0.04% of soluble Al, 0.002 to 0.01% of N, 0.01 to 0.04% of P, 0.001 to 0.010% of S and the balance of Fe and inevitably added impurities to a temperature range of 1100 to 1300 deg.C, hot rolling the heated grain-oriented electrical steel sheet slab, annealing the hot rolled steel sheet, cold rolling the annealed steel sheet, simultaneously subjecting the cold rolled steel sheet to decarburization annealing and nitriding, and subjecting the decarburization annealed and nitrided steel sheet to second recrystallization annealing, a method for manufacturing a grain-oriented electrical steel sheet with thin thickness comprises controlling an accumulated reduction ratio of final three stands to at least 80% in the final hot rolling process, heating the steel sheet at a heating rate of at least 15 deg.C/sec in a temperature increasing range of 400 to 800 deg.C in the carburizing, nitriding and first recrystallization annealing processes, and holding the steel sheet at a temperature of 900 to 1100 deg.C for less than 1 minute in the second half of the annealing and soaking process.