Grain-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-9646749-B2
Application number	US-201214368806-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Dec 27, 2011
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

The present invention proposes a method that can reduce the noise generated by a transformer core and the like when formed by laminations of a grain-oriented electrical steel sheet in which core loss has been reduced by a magnetic domain refinement process. In this steel sheet, linear distortion extending with an orientation in which an angle formed with a direction perpendicular to the rolling direction of the steel sheet is an angle of 30° or less is periodic in the direction of rolling of the steel sheet, core loss (W 17/50 ) is 0.720 W/kg or less, and magnetic flux density (B 8 ) is 1.930 T. The volume of the closure domain arising in the distortion part is 1.00-3.00% of the total magnetic domain volume within the steel sheet.

First claim

The invention claimed is:

1. A grain-oriented electrical steel sheet, comprising:
periodic linear strain in a rolling direction of the steel sheet, the linear strain extending in a direction that forms an angle of 30° or less with a direction orthogonal to the rolling direction of the steel sheet,
iron loss W 17/50 being 0.720 W/kg or less,
a magnetic flux density B 8 being 1.930 T or more, and a volume fraction ξ of a closure domain occurring in the strain portion being 1.00% or more and 3.00% or less of a total magnetic domain volume in the steel sheet,
wherein the volume fraction ξ is defined by following formula (A) using a magnetic strain constant λ 100 in [100] orientation, 23×10 −6 , and a difference λ P-P between the maximum and minimum of the magnetic strain measurement with an alternating magnetic field under saturated flux density

ξ
=

-

2
3

⁢

λ

p
-
p

λ
100

.

(
A
)

2. The grain-oriented electrical steel sheet according to claim 1 , wherein the linear strain is applied by continuous laser beam irradiation.

3. The grain-oriented electrical steel sheet according to claim 1 , wherein the linear strain is applied by irradiation with an electron beam.

4. The grain-oriented electrical steel sheet according to claim 1 , wherein a deviation of the [001] orientation is 4° or less.

5. The grain-oriented electrical steel sheet according to claim 1 , wherein a contribution of magnetization rotation to magnetic strain is (6×10 −4 )λ 100 or less.

6. The grain-oriented electrical steel sheet according to claim 1 , wherein the steel comprises by mass %, C: 0.002% to 0.10%, Si: 1.0% to 7.0%, and Mn: 0.01% to 0.8%.

7. The grain-oriented electrical steel sheet according to claim 6 , wherein the steel further comprises at least one element selected from the group consisting of Al: 0.005% to 0.050%, N: 0.003% to 0.020%, Se: 0.003% to 0.030%, and S: 0.002% to 0.03%.

Assignees

• Jfe Steel Corp

Inventors

• Suehiro Ryuichi
• Yamaguchi Hiroi
• Okabe Seiji
• Inoue Hirotaka
• Takajo Shigehiro

Classifications

• C21D8/1294

  involving a localised treatment · CPC title

• C22C38/02

  containing silicon · CPC title

• C21D8/12

  during manufacturing of articles with special electromagnetic properties · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• C22C38/04

  containing manganese · CPC title