US 9,330,839 B2Granted

Grain oriented electrical steel sheet and method for manufacturing the same

AssigneeJfe Steel Corporation

InventorsTakeshi Omura, Hiroi Yamaguchi, Seiji Okabe

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Abstract

A grain oriented electrical steel sheet is subjected to magnetic domain refining treatment by electron beam irradiation and exhibits excellent low-noise properties when assembled as an actual transformer, in which a ratio (Wa/Wb) of a film thickness (Wa) of the forsierite film on a strain-introduced side of the steel sheet to a film thickness (Wb) of the forsierite film on a non-strain-introduced side of the steel sheet is 0.5 or higher, a magnetic domain discontinuous portion in a surface of the steel sheet on the strain-introduced side has an average width of 150 to 300 μm, and a magnetic domain discontinuous portion in a surface of the steel sheet on the non-strain-introduced side has an average width of 250 to 500 μm.

Claims2

Dependent claims

A grain oriented electrical steel sheet comprising a forsterite film formed on a surface thereof, being subjected to strain introduction by an electron beam and having a magnetic flux density B8 of 1.92 T or higher,

wherein a ratio (Wa/Wb) of a film thickness of the forsterite film on a strain-introduced side of the steel sheet (Wa) to a film thickness of the forsterite film on a non-strain-introduced side of the steel sheet (Wb) is 0.5 or higher, and
wherein a magnetic domain discontinuous portion in a surface of the steel sheet on the strain-introduced side has an average width in a direction at right angles to a longitudinal direction of the magnetic domain discontinuous portion of 150 to 300 μm, and a magnetic domain discontinuous portion in a surface of the steel sheet on the non-strain-introduced side has an average width in a direction at right angles to a longitudinal direction of the magnetic domain discontinuous portion of 250 to 500 μm.

Dependencies are inferred from the claim text.

Facts

Application: 13/814,357Filed 3 Aug 2011
Priority: JP 2010-1776196 Aug 2010
Published: US 2013/0130043 A123 May 2013
Granted: 3 May 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification32 codes

H01F 41/00
Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or
C21D 1/773
Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material: under reduced pressure or vacuum
C21D 6/001
Heat treatment of ferrous alloys: containing Ni
C21D 6/005
Heat treatment of ferrous alloys: containing Mn