Method for manufacturing grain-oriented electrical steel sheet

A method for manufacturing a grain-oriented electrical steel sheet, comprising:

• a silicon steel material production process of producing a silicon steel material;
• a hot rolling process of obtaining a hot rolled sheet by subjecting the silicon steel material to hot rolling;
• a cold rolling process of obtaining a steel sheet of a final sheet thickness by subjecting the hot rolled sheet to a single cold rolling process or multiple cold rolling processes having intermediate annealing performed between the cold rolling processes;
• a decarburization annealing process of subjecting the steel sheet to decarburization annealing;
• and
• a final annealing process of applying an annealing separator containing alumina as a main component to the steel sheet and subjecting the steel sheet to final annealing,
• wherein the silicon steel material contains:
• in terms of mass %,
• Si:
• 0.8 to 7.0%;
• C:
• 0.085% or less;
• acid-soluble Al:
• 0.010 to 0.065%;
• N:
• 0.004 to 0.012%;
• Mn:
• 1.00% or less;
• S:
• 0.050% or less;
• a total of 0.01 to 0.20% of one or both of Sn and Sb;
• and
• the remainder:
• Fe and impurities,
• wherein the decarburization annealing process includes:
• performing the decarburization annealing using a decarburization annealing furnace including a heating area and a soaking area,
• an oxidation degree P1 of an atmosphere gas in the heating area satisfies the following Expression 1, and
• an oxidation degree P2 of an atmosphere gas in the soaking area satisfies the following Expression 2, and
• wherein the P1 and the P2 described above satisfy the following Expression 3:
• 0.01≤P1≤0.15 (Expression 1);
• 0.01≤P2≤0.15 (Expression 2);
• and
• P1>P2 (Expression 3).