Method for producing grain-oriented electrical steel sheet and cold-rolling facility

A method of producing a grain-oriented electrical steel sheet comprising

• reheating a steel slab comprising C:
• 0.01 to 0.10 mass %, Si:
• 2.0 to 4.5 mass %, Mn:
• 0.01 to 0.5 mass %, sol. Al:
• not less than 0.0020 mass % and less than 0.0100 mass %, N:
• less than 0.0080 mass %, each of S, Se, and O:
• less than 0.0050 mass %, and the balance being Fe and inevitable impurities to a temperature of not higher than 1300° C.,
• subjecting the slab to hot rolling and then one cold rolling or more cold rollings having an intermediate annealing between each rolling to form a cold-rolled sheet with a final thickness, and
• subjecting the cold-rolled sheet to a primary recrystallization annealing working also as decarburization and to a final annealing causing secondary recrystallization after applying an annealing separator on the surface of the steel sheet,
• characterized in that
• the final cold rolling for cold rolling the steel sheet to the final thickness is performed by using a tandem rolling mill such that at a total rolling reduction is not less than 80% and at least one of the sheet temperatures between stands thereof is within 150 to 280° C. and by extending a pass line length of the steel sheet between the stands so as to satisfy the following equation (1):
• T
• ≥
• 1
• .
• 3
• ×
• L
• /
• V
• ,
• (
• 1
• )
• where a distance between the stands is defined as L(m), a speed of the steel sheet passing between the stands is defined as V (mpm), and a pass time during which the steel sheet passes between the stands is defined as T(min).