Grain-oriented electrical steel sheet having excellent magnetic characteristics and coating adhesion

Patent metadata

Field	Value
Publication number	US-10395807-B2
Application number	US-201415028841-A
Country	US
Kind code	B2
Filing date	Oct 23, 2014
Priority date	Oct 30, 2013
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

There is provided a grain-oriented electrical steel sheet stably having excellent magnetic characteristics and coating adhesion even when a rapid heating is conducted in a primary recrystallization annealing (decarburization annealing). Concretely, it is a grain-oriented electrical steel sheet provided on its sheet surface with a tension-applying type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of an oxide and a coating layer B formed on a surface side and mainly composed of glass, characterized in that a ratio R (σB/σA) of a tension σB of the coating layer B on the surface side applied to the steel sheet to a tension σA of the coating layer on the steel sheet side A applied to the steel sheet is within a range of 1.20-4.0.

First claim

The invention claimed is:

1. A grain-oriented electrical steel sheet provided on its sheet surface with a tension-imparting type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of an oxide and a coating layer B formed on the coating layer A and mainly composed of glass, characterized in that a ratio R (σ B /σ A ) of a tension σ B to a tension σ A is within a range of 1.20-4.0, wherein:
the tension σ A is a tensile stress applied to the steel sheet by the coating layer A as a result of a difference between the coefficient of thermal expansion of the steel sheet and the coefficient of thermal expansion of the coating layer A, and
the tension σ B is a tensile stress applied to the steel sheet by the coating layer B as a result of a difference between the coefficient of thermal expansion of the steel sheet and the coefficient of thermal expansion of the coating layer B.

2. The grain-oriented electrical steel sheet according to claim 1 , wherein the oxide of the coating layer A is forsterite and the glass of the coating layer B is silicophosphate based glass containing one or more metallic elements selected from Mg, Al, Ca, Ti, Nd, Mo, Cr, B, Ta, Cu and Mn.

3. The grain-oriented electrical steel sheet according to claim 1 , wherein the tension σ A is not more than 6 MPa.

4. The grain-oriented electrical steel sheet according to claim 1 , wherein a coating weight of the coating layer A is 1.0-3.0 g/m 2 as converted to oxygen.

5. The grain-oriented electrical steel sheet according to claim 1 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

6. The grain-oriented electrical steel sheet according to claim 2 , wherein the tension σ A is not more than 6 MPa.

7. The grain-oriented electrical steel sheet according to claim 2 , wherein a coating weight of the coating layer A is 1.0-3.0 g/m 2 as converted to oxygen.

8. The grain-oriented electrical steel sheet according to claim 3 , wherein a coating weight of the coating layer A is 1.0-3.0 g/m 2 as converted to oxygen.

9. The grain-oriented electrical steel sheet according to claim 6 , wherein a coating weight of the coating layer A is 1.0-3.0 g/m 2 as converted to oxygen.

10. The grain-oriented electrical steel sheet according to claim 2 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

11. The grain-oriented electrical steel sheet according to claim 3 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

12. The grain-oriented electrical steel sheet according to claim 4 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

13. The grain-oriented electrical steel sheet according to claim 6 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

14. The grain-oriented electrical steel sheet according to claim 7 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

15. The grain-oriented electrical steel sheet according to claim 8 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

16. The grain-oriented electrical steel sheet according to claim 9 , which is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

17. A grain-oriented electrical steel sheet provided on its sheet surface with a tension-imparting type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of forsterite and a coating layer B formed on the coating layer A and mainly composed of a silicophosphate based glass containing one or more metallic elements selected from Mg, Al, Ca, Ti, Nd, Mo, Cr, B, Ta, Cu and Mn, characterized in that a ratio R (σ B /σ A ) of a tension σ B applied to the steel sheet by the coating layer B to a tension σ A applied to the steel sheet by the coating layer A is within a range of 1.20-4.0.

18. A grain-oriented electrical steel sheet provided on its sheet surface with a tension-imparting type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of an oxide and a coating layer B formed on the coating layer A and mainly composed of glass, characterized in that a ratio R (σ B /σ A ) of a tension σ B applied to the steel sheet by the coating layer B to a tension σ A applied to the steel sheet by the coating layer A is within a range of 1.20-4.0,
wherein the grain-oriented electrical steel sheet is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.

Assignees

• Jfe Steel Corp

Inventors

• Terashima Takashi
• Watanabe Makoto
• Uesaka Masanori
• Suehiro Ryuichi
• Takamiya Toshito

Classifications

• C21D8/02

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• H01F1/18

  with insulating coating · CPC title

• C21D8/12 Primary

  during manufacturing of articles with special electromagnetic properties · CPC title

• C21D8/1283

  Application of a separating or insulating coating · CPC title

• C21D2201/05

  Grain orientation · CPC title