Grain-oriented electrical steel sheet and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2016177413-A1
Application number	US-201414907046-A
Country	US
Kind code	A1
Filing date	Jul 22, 2014
Priority date	Jul 24, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

Disclosed are a grain-oriented electrical steel sheet and a method of manufacturing the same. The method for manufacturing a grain-orientated electrical steel sheet according to an exemplary embodiment of the present invention includes: providing an electrical steel sheet before forming primary recrystallization or after forming the primary recrystallization; and forming a groove in a surface of the electrical steel sheet by radiating laser and simultaneously spraying gas onto the electrical steel sheet, in which energy density E d and a laser scanning speed V s of the radiated laser satisfy the following conditions,
1.0 J/mm 2 ≦E d ≦5.0 J/mm 2 ,

0.0518 mm/μsec≦V s ≦0.2 mm/μsec

First claim

1 . A grain-oriented electrical steel sheet, which has a surface which is formed with grooves for a magnetic domain refinement treatment,
wherein a scattering alloy layer in the groove is eroded in a Goss texture during a recrystallization annealing process.

2 . The grain-oriented electrical steel sheet of claim 1 , wherein:
when a thickness of the scattering alloy layer on a bottom surface of the groove is defined as T B , and a thickness of the scattering alloy layer at a point that is one-half the distance between any one end of the groove and the bottom surface of the groove is defined as T L , T B /T L is 0.2 to 0.8.

3 . The grain-oriented electrical steel sheet of claim 2 , wherein:
a thickness of the scattering alloy layer is 4% to 12% of a depth of the groove.

4 . The grain-oriented electrical steel sheet of claim 3 , wherein:
the depth of the groove is 4% to 11% of a thickness of the electrical steel sheet.

5 . The grain-oriented electrical steel sheet of claim 4 , wherein:
the groove is formed diagonally with respect to a width direction of the electrical steel sheet.

6 . The grain-oriented electrical steel sheet of claim 5 , wherein:
the groove is formed at an angle greater than 0° and equal to or smaller than 5° with respect to the width direction of the electrical steel sheet.

7 . The grain-oriented electrical steel sheet of claim 6 , wherein:
three to six grooves are intermittently formed in the width direction of the electrical steel sheet.

8 . A method of manufacturing a grain-oriented electrical steel sheet, the method comprising:
providing electrical steel sheet before forming primary recrystallization or after forming the primary recrystallization; and forming a groove in a surface of the electrical steel sheet by radiating laser and simultaneously spraying gas onto the electrical steel sheet, wherein energy density E d and a laser scanning speed V s of the radiated laser satisfy the following conditions,
1.0 J/mm 2 ≦E d ≦5.0 J/mm 2 ,

0.0518 mm/μsec≦ V s ≦0.2 mm/μsec

9 . The method of claim 8 , wherein:
pressure of the sprayed gas is 0.2 kg/cm 2 to 5.0 kg/cm 2 .

10 . The method of claim 9 , wherein:
an angle formed between the spray direction of the gas and the laser radiation direction is 0° to 50° (here, a state in which the angle formed between the spray direction of the gas and the laser radiation direction is 0° means that the spray direction of the gas and the laser radiation direction are parallel to each other).

11 . The method of claim 10 , wherein:
in the radiating of the laser, a laser beam is radiated on the surface of the electrical steel sheet at an angle greater than 0° and equal to or smaller than 5° with respect to a width direction of the electrical steel sheet.

12 . The method of claim 11 , wherein:
in the radiating of the laser, a movement speed V L of the electrical steel sheet is at least 0.9 m/s.

13 . The method of claim 12 , wherein:
in the radiating of the laser, when a beam length in the width direction of the electrical steel sheet is d t , and a beam length in a rolling direction of the electrical steel sheet is L, a light collecting shape of the laser satisfies the following condition,
0.20≦ L/d t ≦1.0

14 . The method of claim 13 , wherein:
d 1 is 50 μm or smaller.

15 . The method of claim 14 , wherein:
in the radiating of the laser, a scattering alloy layer in which a melted portion of the electrical steel sheet by the radiation of the laser scatters and is resolidified is generated, and when a thickness of the scattering alloy layer on a bottom surface of the groove is defined as T B , and a thickness of the scattering alloy layer at a point that is one-half the distance between any one end of the groove and the bottom surface of the groove is defined as T L , T B /T L is 0.2 to 0.8.

16 . The method of claim 15 , wherein:
a thickness of the scattering alloy layer is 4% to 12% of a depth of the groove.

17 . The method of claim 16 , wherein:
in the radiating of the laser, the laser is radiated diagonally with respect to a width direction of the electrical steel sheet.

18 . The method of claim 17 , wherein:
in the radiating of the laser, the laser is radiated at an angle greater than 0° and equal to or smaller than 5° with respect to the width direction of the electrical steel sheet.

19 . The method of claim 18 , wherein:
in the radiating of the laser, three to six grooves are intermittently formed in the width direction of the electrical steel sheet.

Assignees

• Posco

Inventors

• Kwon Oh Yeoul
• Shin Sun Mi
• Moon Chang Ho
• Lee Won Gul

Classifications

• C21D8/02

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

• C21D8/0247

  characterised by the heat treatment · CPC title

• C22C38/00

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

• C21D8/0294

  involving a localised treatment · CPC title

• B23K26/40

  taking account of the properties of the material involved · CPC title