Grain-oriented electrical steel sheet and magnetic domain refinement method therefor

Patent metadata

Field	Value
Publication number	US-11772199-B2
Application number	US-202217705987-A
Country	US
Kind code	B2
Filing date	Mar 28, 2022
Priority date	Dec 22, 2016
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

A grain-oriented electrical steel sheet incudes a groove formed on a surface and a solidified alloy layer formed under the groove, wherein the solidified alloy layer includes particles of a certain average diameter.

First claim

The invention claimed is:

1. A magnetic domain refining method of a grain-oriented electrical steel sheet, comprising:
preparing a grain-oriented electrical steel sheet;
irradiating a laser to a surface of the grain-oriented electrical steel sheet to form a groove; and
quenching a portion where the groove is formed with a cooling speed of 400 to 1500° C./s.

2. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 1 , wherein
the quenching is simultaneous quenching with the groove formation.

3. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 1 , further comprising,
after the quenching,
stress relaxation annealing.

4. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 1 , wherein,
in the forming of the groove,
the laser is a continuous wave laser having a Gaussian energy distribution and an output of 1 kW or more.

5. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 4 , wherein
the laser is a continuous wave laser that is a TEM 00 mode and has a beam quality factor M 2 of 1.0 to 1.1 and output of 1 to 10 kW.

6. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 1 , further comprising
removing a hill-up or a spatter formed on the electrical steel sheet surface after forming the groove.

7. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 1 , wherein
the preparing the grain-oriented electrical steel sheet includes:
forming an oxide layer on the surface of the steel sheet by decarburization-annealing or nitriding-annealing cold-rolled steel sheet; and
forming a non-metallic oxide layer on the surface of the steel sheet by coating an annealing separator on the surface of the steel sheet on which the oxidation layer is formed.

8. The magnetic domain refining method of the grain-oriented electrical steel sheet of claim 7 , further comprising,
after forming the non-metallic oxide layer,
forming an insulating coating layer on the non-metallic oxide layer.

Assignees

• Posco

Inventors

• Kwon Oh-Yeoul
• Park Se-Min
• Park Jong-Tae
• Lee Won-Gul

Classifications

• B23K26/364 Primary

  for making a groove or trench, e.g. for scribing a break initiation groove · CPC title

• B23K26/16

  Removal of by-products, e.g. particles or vapours produced during treatment of a workpiece (by a fluid stream B23K26/142) · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• C21D3/04

  Decarburising · CPC title

• C21D9/46

  for sheet metals · CPC title