Grain-oriented electrical steel sheet and method for improving iron loss properties thereof

Patent metadata

Field	Value
Publication number	US-10062483-B2
Application number	US-201214368975-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Dec 28, 2011
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A grain-oriented electrical steel sheet, on which magnetic domain refining treatment by strain application has been performed, has an insulating coating with excellent insulation properties and corrosion resistance. The grain-oriented electrical steel sheet is obtained by irradiating a steel sheet with a high-energy beam to apply, to the steel sheet, linear strain extending in a direction that intersects a rolling direction of the steel sheet, and then re-forming an insulating coating on the steel sheet, in which in an irradiation mark region due to the high-energy beam, a ratio of an area containing defects on the insulating coating is 40% or less, a maximum width of the irradiation mark region in the rolling direction is 250 μm or less, and a thickness of the insulating coating is 0.3 μm or more and 2.0 μm or less.

First claim

The invention claimed is:

1. A grain-oriented electrical steel sheet having an insulating coating thereon having linear strain resulting from a high-energy beam irradiation extending in a direction that intersects a rolling direction of the steel sheet, and having a re-formed insulating coating on the insulating coating, wherein
in an irradiation mark region caused by the high-energy beam, a ratio of an area containing defects on the re-formed insulating coating is 40% or less,
a maximum width of the irradiation mark region in the rolling direction is 250 μm or less, and
a thickness of the re-formed insulating coating is 0.3 μm or more and 2.0 μm or less.

2. The grain-oriented electrical steel sheet according to claim 1 , wherein the direction in which the linear strain extends forms an angle of 30° or less with a direction orthogonal to the rolling direction.

3. The grain-oriented electrical steel sheet according to claim 1 , wherein a maximum width of the irradiation mark region in the rolling direction is 39 μm to 250 μm.

Assignees

• Jfe Steel Corp

Inventors

• Inoue Hirotaka
• Takajo Shigehiro
• Yamaguchi Hiroi
• Okabe Seiji
• Hanazawa Kazuhiro

Classifications

• C23C22/74

  for obtaining burned-in conversion coatings · CPC title

• C22C38/06

  containing aluminium · CPC title

• C23C8/50

  of ferrous surfaces · CPC title

• Y10T428/24851

  Intermediate layer is discontinuous or differential · CPC title

• C22C38/02

  containing silicon · CPC title