Grain Oriented Electrical Steel Sheet Having Excellent Iron Loss Characteristics

Abstract: The present invention enables a grain-oriented electrical steel sheet in which iron loss is further reduced to be obtained by maintaining, for magnetic domain refinement, the shape of grooves, the positions of strain-introducing parts and the stresses caused thereby within specific ranges. This grain-oriented electrical steel sheet has a steel sheet surface that is provided with grooves which extend in a direction that intersects with the rolling direction (RD direction), while having the groove depth direction in the sheet thickness direction (ND direction); and this grain-oriented electromagnetic steel sheet has a residual stress due to strain in the vicinities of the grooves. The pitch of the grooves in the RD direction is 2 mm to 10 mm; the depth of the grooves is 10 µm to 40 µm; the width of the grooves is 10 µm to 200 µm; in a region within 10 µm from the wall surface (the groove surface positioned at the depth of 25% to 75% with respect to the groove depth) of the groove in the RD direction, there is 10% by area or more of regions where a residual stress of 10 MPa or more due to compressive strain in the RD direction is present; and in a region within 10 µm from the bottom surface (the groove surface positioned at the depth of 75% to 100% with respect to the groove depth) of the groove in the ND direction, there is 10% by area or more of regions where a residual stress of 10 MPa or more due to tensile strain in the RD direction is present.

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