# US 12,763,237 B2 · Grain-oriented electrical steel sheet and manufacturing method therefor

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- Number: US 12,763,237 B2
- Document ID: US12763237B2
- Status: Granted
- Kind: B2
- Application number: 18/729,419
- Filed: 2023-03-27
- Published: 2025-04-10
- Granted: 2026-10-13
- Earliest claimed: 2022-03-28
- Assignees: Nippon Steel Corporation
- Applicants: Nippon Steel Corporation
- Inventors: Yusuke Kawamura
- Web page: https://patentgrep.com/patent/US12763237B2

## CPC

- H01F 1/14791: {Fe-Si-Al based alloys, e.g. Sendust}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

On a surface of the grain-oriented electrical steel sheet, a rate (a groove existence rate) of a part (a groove formation line) where a groove having a depth of 5 μm to 50 μm and a width of 10 μm to 300 μm exists among a total extension of magnetic domain control treatment lines which forms an angle of 0° to 45° with respect to an orthogonal-to-rolling direction and are arranged in a rolling direction is 50% or more in a first region which is a region where a β angle which is a deviation angle of a grain from a Goss orientation around an axis in the orthogonal-to-rolling direction is 1° or less, and the groove existence rate is less than 50% in a second region where the β angle is more than 2°.

## Claims

### Claim 1

A grain-oriented electrical steel sheet, wherein
on a surface of the grain-oriented electrical steel sheet, a groove existence rate which is a rate of a part where a groove having a depth of 5 μm to 50 μm and a width of 10 μm to 300 μm exists among a total extension of magnetic domain control treatment lines which forms an angle of 0° to 45° with respect to an orthogonal-to-rolling direction and are arranged in a rolling direction is 50% or more in a first region which is a region where a β angle which is a deviation angle of a grain from a Goss orientation around an axis in the orthogonal-to-rolling direction is 1° or less, and
the groove existence rate is less than 50% in a second region where the β angle is more than 2°.

### Claim 2 (depends on 1)

The grain-oriented electrical steel sheet according to claim 1, wherein the groove existence rate is 20% or more and 80% or less in a third region which is a region where the β angle is more than 1° and 2° or less, and
the groove existence rate in the first region≥the groove existence rate in the third region≥the groove existence rate in the second region.

### Claim 3 (depends on 1)

The grain-oriented electrical steel sheet according to claim 1, wherein the groove having the depth of 5 μm to 50 μm and the width of 10 μm to 300 μm exists at an interval of 1 mm to 20 mm in the rolling direction.

### Claim 4

A method for manufacturing a grain-oriented electrical steel sheet, the method comprising:
acquiring a magnetic domain image of a grain-oriented electrical steel sheet;
determining, based on a spatial distribution of a magnetic domain width of the magnetic domain image and a β angle which is a deviation angle of a grain from a Goss orientation around an axis in the orthogonal-to-rolling direction, a point in which a groove having a depth of 5 μm to 50 μm and a width of 10 μm to 300 μm is formed among magnetic domain control treatment lines which forms an angle of 0° to 45° with respect to an orthogonal-to-rolling direction of the grain-oriented electrical steel sheet and are arranged in a rolling direction; and
forming the groove to the point determined during the determining among the magnetic domain control treatment line.

### Claim 5 (depends on 4)

The method for manufacturing a grain-oriented electrical steel sheet according to claim 4, wherein in the determining, a point having the β angle of 1° or less in the magnetic domain control treatment line is determined as a point in which the groove is formed.

### Claim 6 (depends on 4)

The method for manufacturing a grain-oriented electrical steel sheet according to claim 4, wherein in the determining, a spatial distribution of the magnetic domain width is derived from the magnetic domain image by using two-dimensional Fourier transform.

### Claim 7 (depends on 2)

The grain-oriented electrical steel sheet according to claim 2, wherein the groove having the depth of 5 μm to 50 μm and the width of 10 μm to 300 μm exists at an interval of 1 mm to 20 mm in the rolling direction.

### Claim 8 (depends on 5)

The method for manufacturing a grain-oriented electrical steel sheet according to claim 5, wherein in the determining, a spatial distribution of the magnetic domain width is derived from the magnetic domain image by using two-dimensional Fourier transform.