Oriented electrical steel sheet and method for manufacturing same
AssigneePosco
InventorsJong-Tae Park, Oh-Yeoul Kwon, Woo-Sin Kim
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Abstract
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 SiO2/FexSiOy 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.)
Claims4
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/μm2 or less,
- wherein at least one of the plurality of islands overlaps the groove in a thickness direction of the electrical steel sheet.
Dependencies are inferred from the claim text.