Grain oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-10020103-B2
Application number	US-201113824722-A
Country	US
Kind code	B2
Filing date	Sep 28, 2011
Priority date	Sep 30, 2010
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A grain oriented electrical steel sheet reduces local exfoliation of insulating coating films and thus has excellent corrosion resistance and insulation properties. The grain oriented electrical steel sheet may be obtained by, assuming that a 1 (μm) is a film thickness of the insulating coating at the floors of linear grooves and a 2 (μm) is a film thickness of the insulating coating on a surface of the steel sheet at portions other than the linear grooves, controlling a 1 and a 2 to satisfy the following formulas (1) and (2):

0.3 μm≤a 2 ≤3.5 μm  (1),

and

a 1 /a 2 ≤2.5  (2).

First claim

The invention claimed is:

1. A grain oriented electrical steel sheet comprising: linear grooves having a depth of 10 μm to 50 μm and a width of 50 μm to 300 μm provided on a surface of the steel sheet; a forsterite film on the surface of the grain oriented electrical steel sheet including a surface of the linear grooves; and an insulating coating applied directly to the surface of the forsterite film, wherein assuming that a 1 (μm) denotes a film thickness of the insulating coating at the floors of the linear grooves and a 2 (μm) denotes a film thickness of the insulating coating on the surface of the steel sheet at portions other than the linear grooves, a 1 and a 2 satisfy formulae (1) and (2):
0.3 μm≤a 2 ≤3.5 μm  (1),

and
0.4 ≤a 1 /a 2 ≤2.5  (2).

2. The grain oriented electrical steel sheet according to claim 1 , wherein the insulation coating is formed by applying coating treatment liquid having a viscosity of 1.2 cP or more with a roll coater and dried.

3. The grain oriented electrical steel sheet according to claim 1 , wherein the deviation angle of secondary recrystallized grains from Goss orientation is 5.5° or less.

4. The grain oriented electrical steel sheet according to claim 2 , wherein the deviation angle of secondary recrystallized grains from Goss orientation is 5.5° or less.

Assignees

• Watanabe Makoto
• Okabe Seiji
• Takamiya Toshito
• Jfe Steel Corp

Inventors

• Watanabe Makoto
• Okabe Seiji
• Takamiya Toshito

Classifications

• C21D8/1283 Primary

  Application of a separating or insulating coating · CPC title

• H01F1/18

  with insulating coating · CPC title

• C23C22/74

  for obtaining burned-in conversion coatings · CPC title

• C22C38/34

  with more than 1.5% by weight of silicon · CPC title

• Y10T428/24545

  Containing metal or metal compound · CPC title