Grain-oriented electrical steel sheet causing low core loss and low magnetostriction

Patent metadata

Field	Value
Publication number	US-2017182591-A1
Application number	US-201515308781-A
Country	US
Kind code	A1
Filing date	May 8, 2015
Priority date	May 9, 2014
Publication date	Jun 29, 2017
Grant date	—

Abstract

A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 μm toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

First claim

1 . A grain-oriented electrical steel sheet comprising:
a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, wherein a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above, when a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5μm toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies the following expressions A and B.
15000 μm≦ S A −S C ≦35000 μm   (Expression A)

900 μm≦ S B +S C ≦14000 μm   (Expression B)

Here, S A , S B , and S C are described below. S A : a warpage amount of the grain-oriented electrical steel sheet in the unit of μm when only one surface subjected to laser irradiation is pickled, S B : a warpage amount of the grain-oriented electrical steel sheet in the unit of μm when only one surface on a side opposite to the side subjected to laser irradiation is pickled, and S C : a warpage amount of the grain-oriented electrical steel sheet in the unit of μm when both surfaces are pickled, here, warpage in the same direction as that of the pickled surface during measurement of S A and S B is expressed as a positive value, and warpage in S C in the same direction as that of S A is expressed as a positive value.

2 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein a value d t /d p obtained by dividing an average thickness d t of the tension insulation coating in the unit of μm by an average thickness d p of the primary film in the unit of μm is 0.1 or higher and 3.0 or lower.

3 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein a value d t /d p obtained by dividing an average thickness d t of the tension insulation coating in the unit of μm by an average thickness d p of the primary film in the unit of μm is 0.1 or higher and 1.5 or lower.

4 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein a value d t /d p obtained by dividing an average thickness d t of the tension insulation coating in the unit of μm by an average thickness d p of the primary film in the unit of μm is 0.1 or higher and 1.0 or lower.

5 . The grain-oriented electrical steel sheet according to any one of claims 1 to 4 ,
wherein the average thickness of the tension insulation coating is 0.5 μm or greater and 4.5 μm or smaller.

6 . The grain-oriented electrical steel sheet according to any one of claims 1 to 4 ,
wherein a total tension applied to the base steel sheet from the primary film and the tension insulation coating is 1 MPa or higher and 10 MPa or lower.

7 . The grain-oriented electrical steel sheet according to claim 5 ,
wherein a total tension applied to the base steel sheet from the primary film and the tension insulation coating is 1 MPa or higher and 10 MPa or lower.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Arai Satoshi
• Hamamura Hideyuki
• Murakami Kenichi
• Fujii Hiroyasu
• Kobayashi Hideyuki
• Fujii Norikazu
• Mizokami Masato

Classifications

• C21D2201/05

  Grain orientation · CPC title

• C22C38/00

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

• C21D8/1288

  Application of a tension-inducing coating · CPC title

• C21D8/1283

  Application of a separating or insulating coating · CPC title

• H01F1/18

  with insulating coating · CPC title