Oriented electrical steel sheet and method for manufacturing same
A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes producing a cold-rolled plate; forming a groove in the cold-rolled plate; performing primary recrystallization annealing to the cold-rolled plate; and applying an annealing separator to the primary-recrystallized cold-rolled plate and performing secondary recrystallization annealing, wherein a weight ratio of SiO 2 /Fe x SiO y of the surface layer part of the cold-rolled plate is 0.3 to 3 after the primary recrystallization annealing of the cold-rolled plate. (Here, x is an integer from 1 to 2, and y is an integer from 2 to 4.)
1 . A grain-oriented electrical steel sheet comprising:
a groove positioned in a surface of an electrical steel sheet surface;
a metal oxide layer positioned on the groove; and
a discontinuously distributed metal oxide-based island positioned below the groove, the discontinuously distributed metal oxide-based island comprising a plurality of islands,
wherein the density of the plurality of islands positioned below the groove is 3 to 15 per groove, and
wherein the density of the plurality of islands positioned under the groove is 0.5 islands/μm 2 or less,
wherein at least one of the plurality of islands overlaps the groove in a thickness direction of the electrical steel sheet.
2 . The grain-oriented electrical steel sheet of claim 1 , wherein:
among the plurality of islands positioned under the groove, the number of islands with sphericity of 0.6 to 1.0 is 60% or more.
3 . The grain-oriented electrical steel sheet of claim 1 , wherein:
the groove includes 2 to 10 grooves intermittently formed in a direction perpendicular to a rolled direction.
4 . The grain-oriented electrical steel sheet of claim 1 , wherein:
the length direction of the groove and a rolled direction of the steel sheet form an angle of 75 to 88°.