Grain-oriented electrical steel sheet and iron core using same

A grain-oriented electrical steel sheet comprising:

• a chemical composition containing, in mass %, Si:
• 1.5% to 8.0%, Mn:
• 0.02% to 1.0%, and at least one selected from Sn:
• 0.010% to 0.400%, Sb:
• 0.010% to 0.400%, Mo:
• 0.010% to 0.200%, and P:
• 0.010% to 0.200%, with a balance being Fe and inevitable impurities;
• and
• a microstructure in which:
• crystal grains are made up of coarse secondary recrystallized grains of 5.0 mm or more in grain size, fine grains of more than 2.0 mm and less than 5.0 mm in grain size, and very fine grains of 2.0 mm or less in grain size;
• for each coarse secondary recrystallized grain extending through the steel sheet in a thickness direction among the coarse secondary recrystallized grains, an area ratio of a region in which projected surfaces of exposed areas of the coarse secondary recrystallized grain on a front side and a back side of the steel sheet coincide with each other to each of the exposed areas is 95% or more;
• and the fine grains of more than 2.0 mm and less than 5.0 mm in grain size are contained at a frequency of 0.2 grains to 5 grains per cm2,
• wherein the steel sheet is not magnetic domain refining treated.