Grain-oriented electrical steel plate and production method therefor

Patent metadata

Field	Value
Publication number	US-2018010206-A1
Application number	US-201515539637-A
Country	US
Kind code	A1
Filing date	Dec 21, 2015
Priority date	Dec 24, 2014
Publication date	Jan 11, 2018
Grant date	—

Abstract

Provided is an oriented electrical steel sheet including a groove existing on the surface of the electrical steel sheet and a forsterite layer formed on a part or all of the surface of the electrical steel sheet, in which forsterite which is extended from the forsterite layer and penetrates to a base steel sheet in an anchor form is present on the surface of the side of the groove.

First claim

1 - 29 . (canceled)

30 . An oriented electrical steel sheet comprising:
a groove existing on the surface of the electrical steel sheet; and a forsterite layer formed on a part or all of the surface of the electrical steel sheet, wherein one or more forsterite anchors having a 3D network structure which are integrally extended from the forsterite layer and formed to a base steel sheet are present on the surface of the side of the groove.

31 . The oriented electrical steel sheet of claim 30 , wherein:
two or more forsterite anchors having the 3D network structure which is formed to the base steel sheet are present within 50 μm from the surface of the side of the groove.

32 . The oriented electrical steel sheet of claim 31 , wherein:
the forsterite anchor having the 3D network structure which is formed to the base steel sheet has a length of ⅓ or more of a mean thickness of the forsterite layer.

33 . The oriented electrical steel sheet of claim 32 , wherein:
a length in a thickness direction of the electrical steel sheet of the forsterite anchor having the 3D network structure which is formed to the base steel sheet is 0.3 to 10 μm.

34 . The oriented electrical steel sheet of claim 30 , wherein:
when a rolling direction of the electrical steel sheet is referred to as an x axis, a width direction of the electrical steel sheet is referred to as a y axis, a normal direction of an xy plane is referred to as a z axis, and the forsterite anchor having the 3D network structure which is formed to the base steel sheet is observed in an xz plane, the forsterite anchor has a hook shape or an anchor shape.

35 . The oriented electrical steel sheet of claim 34 , wherein:
a width of the forsterite anchor having the 3D network structure which is formed to the base steel sheet is 3.5 μm or less, and a mean thickness of the forsterite layer is 0.1 μm to 3 μm.

36 . The oriented electrical steel sheet of claim 35 , wherein:
an insulation coating layer is further formed in the electrical steel sheet, the insulation coating layer includes silicate and metal phosphate, and the insulation coating layer includes 25 wt % or more of Mg or Al based on the weight of the insulation coating layer.

37 . The oriented electrical steel sheet of claim 36 , wherein:
a depth of the groove is 3% to 10% of the thickness of the electrical steel sheet.

38 . The oriented electrical steel sheet of claim 37 , wherein:
an angle between the groove and a width direction of the steel sheet is parallel or 5° or less (not including 0°).

39 . A manufacturing method of an oriented electrical steel sheet, comprising:
manufacturing a cold-rolled steel sheet by heating at 1300° C. or less, hot-rolling, and then cold-rolling a slab including O: 0.0020 to 0.0080 wt % and a remainder of Fe and impurities based on the entire composition 100 wt % of the slab; subjecting the cold-rolled steel sheet to primary recrystallization annealing; applying an annealing separator containing MgO to the steel sheet subjected to the primary recrystallization annealing and subjecting the steel sheet to secondary recrystallization annealing; and refining a magnetic domain by forming a groove on the steel sheet, wherein the refining of the magnetic domain is performed after the manufacturing of the cold-rolled steel sheet, after the primary recrystallization annealing is completed, or after the secondary recrystallization annealing is completed, and a weight ratio of SiO 2 /Fe 2 SiO 4 of an oxide layer on the surface of the steel sheet formed in the primary recrystallization annealing process is 0.1 to 1.5.

40 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
the primary recrystallization annealing is performed in a dew point atmosphere of 60 to 70° C. (50% N 2 +50% H 2 ) in a temperature range of 800 to 890° C.

41 . The manufacturing method of an oriented electrical steel sheet of claim 40 , wherein:
an oxygen amount of the oxygen layer on the surface of the steel sheet formed in the primary recrystallization annealing process is in a range of 600 to 1,000 ppm.

42 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
the annealing separator is applied with 2.5 to 12 g/m 2 per side of the steel sheet in a slurry form by containing MgO as a main component and mixing a Ti compound, a Cl compound, a sulfide, a boride, a nitride, or an oxide as a reaction promoter singly or in plural therein, MgO as the main component of the annealing separator has a mean powder particle diameter of 2.5 μm or less, and MgO as the main component of the annealing separator having a mean powder particle diameter of 2 μm or less is 10% or more.

43 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
the secondary recrystallization annealing is performed by dividing a primary cracking process at 550 to 750° C. and a secondary cracking process at 1,000 to 1,250° C., and during temperature rising, the temperature rises to 30 to 100° C. per hour in a temperature section of 650 to 950° C. and rises to 45° C. or less per hour in a temperature section of 950 to 1250° C.

44 . The manufacturing method of an oriented electrical steel sheet of claim 43 , wherein:
in the secondary recrystallization annealing, the primary cracking time is 10 minutes or more and the secondary cracking time is 8 hours or more.

45 . The manufacturing method of an oriented electrical steel sheet of claim 44 , wherein:
the secondary recrystallization annealing is performed in a mixed atmosphere of nitrogen and hydrogen up to the secondary cracking temperature and performed in a hydrogen atmosphere after reaching the secondary cracking temperature.

46 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
the refining of the magnetic domain is performed by irradiating a continuous wave laser in a Gaussian beam form.

47 . The manufacturing method of an oriented electrical steel sheet of claim 46 , further comprising:
insulation-coating with an insulation coating solution containing colloidal silica and metal phosphate on the steel sheet after the refining of the magnetic domain, the metal phosphate in the insulation coating solution is Al phosphate, Mg phosphate, or a combination thereof, and the content of Al, Mg, or a combination thereof with respect to the weight of the insulation coating solution is 15 wt % or more.

48 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
the slab further includes Si: 2.5 to 4.0 wt %, C: 0.02 to 0.10 wt %, Al: 0.02 to 0.04 wt %, Mn: 0.05 to 0.20 wt %, N: 0.002 to 0.012 wt %, S: 0.001 wt % to 0.010 wt % and P: 0.01 to 0.08 wt % based on the entire composition 100 wt % of the slab.

49 . The manufacturing method of an oriented electrical steel sheet of claim 39 , wherein:
a forsterite coating and an insulation coating are sequentially formed on the surface of the electrical steel sheet, and the forsterite coating is integrally extended in a lower direction of the electrical steel sheet and penetrates to form a forsterite anchor having a 3D network structure.

Assignees

• Posco

Inventors

• Kwon Oh-Yeoul
• Lee Seung Gon
• Park Hyun-Chul
• Park Jung Hun
• See Seong-Kyu
• Won Sung-Yeun
• Kim Jae-Kyoum
• Park Jong-Tae
• Park Se Min

Classifications

• C21D2201/05

  Grain orientation · CPC title

• C21D8/1283 Primary

  Application of a separating or insulating coating · CPC title

• C22C38/001

  containing N · CPC title

• C22C38/04

  containing manganese · CPC title

• B23K2101/34

  Coated articles {; Surface treated articles} · CPC title