Pre-coating agent composition for grain-oriented electrical steel sheet, grain-oriented electrical steel sheet comprising same, and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-2017233871-A1
Application number	US-201415502440-A
Country	US
Kind code	A1
Filing date	Dec 4, 2014
Priority date	Aug 7, 2014
Publication date	Aug 17, 2017
Grant date	—

Abstract

A pre-coating agent composition for a grain-oriednted electrical steel sheet, a grain-oriednted electrical steel sheet including the same, and a manufacturing method thereof are provided. Particularly, a pre-coating agent composition for a grain-oriednted electrical steel sheet including an acid containing boron (B); and a solvent, a grain-oriednted electrical steel sheet including the same, and a manufacturing method thereof are provided.

First claim

1 - 38 . (canceled)

39 . A pre-coating agent composition for a grain-oriednted electrical steel sheet comprising: acid containing boron (B); and solvent,
wherein the acid containing boron (B) is at least one selected from the group consisting of borinic acid, boronic acid, boric acid and a combination thereof, and the pre-coating agent composition comprises 20 to 40 parts by weight of the silicate compound, 5 to 15 parts by weight of the acid containing boron (B), and 300 to 500 parts by weight of the solvent, based on 100 parts by weight of the metal dihydrogen phosphates.

40 . The pre-coating agent composition of claim 39 , further comprising:
metal dihydrogen phosphates; and a silicate compound.

41 . The pre-coating agent composition of claim 39 , wherein:
the metal dihydrogen phosphates are one or more selected from the group consisting of aluminum dihydrogen phosphate (Al(H 2 PO 4 ) 3 ), magnesium dihydrogen phosphate (Mg((H 2 PO 4 ) 2 ) and a combination thereof.

42 . The pre-coating agent composition of claim 41 , wherein:
the metal dihydrogen phosphates include aluminum dihydrogen phosphate (Al(H 2 PO 4 ) 3 ) and magnesium dihydrogen phosphate (Mg((H 2 PO 4 ) 2 ), and aluminum dihydrogen phosphate (Al(H 2 PO 4 ) 3 ) is included at 20 to 80 wt %, based on total 100 wt % of the metal dihydrogen phosphates.

43 . The pre-coating agent composition of claim 41 , wherein:
the silicate compound is one or more selected from the group consisting of silica dispersed in a dispersion medium in a colloid form, solid silica in a powder form and a combination thereof.

44 . A grain-oriednted electrical steel sheet comprising:
a pre-coating layer formed on a surface of the grain-oriednted electrical steel sheet; and a tension coating layer formed on a surface of the pre-coating layer, wherein the grain-oriednted electrical steel sheet is a grain-oriednted electrical steel sheet from which a forsterite (Mg 2 SiO 4 ) film is removed, the pre-coating layer includes an acid containing boron (B) and a solvent, and adhesion between the grain-oriednted electrical steel sheet and the tension coating layer is controlled by the pre-coating layer, wherein the acid containing boron (B) is at least one selected from the group consisting of borinic acid, boronic acid, boric acid and a combination thereof, and the pre-coating layer comprises 20 to 40 parts by weight of the silicate compound, 5 to 15 parts by weight of the acid containing boron (B), and 300 to 500 parts by weight of the solvent, based on 100 parts by weight of the metal dihydrogen phosphates.

45 . The grain-oriednted electrical steel sheet of claim 44 , wherein:
the pre-coating layer further includes: metal dihydrogen phosphates; and a silicate compound.

46 . The grain-oriednted electrical steel sheet of claim 44 , wherein:
the metal dihydrogen phosphates in the pre-coating layer are one or more selected from the group consisting of aluminum dihydrogen phosphate (Al(H 2 PO 4 ) 3 ), magnesium dihydrogen phosphate (Mg((H 2 PO 4 ) 2 ) and a combination thereof.

47 . The grain-oriednted electrical steel sheet of claim 46 , wherein:
the silicate compound in the pre-coating layer is one or more selected from the group consisting of silica dispersed in a dispersion medium in a colloid form, solid silica in a powder form and a combination thereof.

48 . The grain-oriednted electrical steel sheet of claim 46 , wherein:
a composition of the grain-oriednted electrical steel sheet includes Sn: 0.03 to 0.07 wt %, Sb: 0.01 to 0.05 wt %, P: 0.01 to 0.05 wt %, Fe and other inevitably added impurities.

49 . A method of manufacturing a grain-oriednted electrical steel sheet, comprising:
preparing a grain-oriednted electrical steel sheet from which a forsterite (Mg 2 SiO 4 ) film is removed; forming a pre-coating layer on a surface of the grain-oriednted electrical steel sheet from which the forsterite (Mg 2 SiO 4 ) coat is removed; and forming a tension coating layer on a surface of the pre-coated grain-oriednted electrical steel sheet, wherein the pre-coating layer includes an acid containing boron (B) and a solvent, and adhesion between the grain-oriednted electrical steel sheet from which the forsterite (Mg 2 SiO 4 ) film is removed and the tension coating layer is controlled by the pre-coating layer.

50 . The method of claim 49 , wherein:
the preparing of a grain-oriednted electrical steel sheet from which a forsterite (Mg 2 SiO 4 ) film is removed includes: preparing a steel slab including Sn: 0.03 to 0.07 wt %, Sb: 0.01 to 0.05 wt %, P: 0.01 to 0.05 wt %, Fe and other inevitably added impurities; hot-rolling the steel slab to prepare a hot-rolled sheet; subjecting the hot-rolled sheet to annealing and acid-washing; Cold-rolling the annealed and acid-washed steel sheet to prepare a cold-rolled sheet; decarbonizing and nitriding-annealing the cold-rolled sheet; and high temperature annealing the decarbonized and nitrided-annealed steel sheet, wherein the decarbonizing and nitriding-annealing is carried out at dew point in a range of 35 to 55° C., and the high temperature annealing is carried out by applying an additive containing MgO.

51 . The method of claim 49 , wherein:
the additive includes: MgO; an annealing separating agent including antimony oxychloride (SbOCl) and antimony sulfate (Sb 2 (SO 4 ) 3 ); and water.

52 . The method of claim 49 , wherein:
the high temperature annealing is carried out at a heating rate of 18 to 75° C./hr in a temperature range of 700 to 950° C., and at a heating rate of 10 to 15° C./hr in a temperature range of 950 to 1200° C.

53 . The method of claim 49 , wherein:
the forming of a pre-coating layer on a surface of the grain-oriednted electrical steel sheet from which the forsterite (Mg 2 SiO 4 ) film is removed includes: preparing a mixed solution of an acid containing boron (B) and water; applying the mixed solution on the grain-oriednted electrical steel sheet; and drying the grain-oriednted electrical steel sheet on which the mixed solution is applied.

54 . The method of claim 49 , wherein:
the acid containing boron (B) is at least one selected from the group consisting of borinic acid, boronic acid, boric acid and a combination thereof.

55 . The method of claim 54 , wherein:
the mixed solution further includes: metal dihydrogen phosphates; and a silicate compound.

56 . The method of claim 55 , wherein:
the preparing of a mixed solution including an acid containing boron (B) and water is carried out by adding and mixing 20 to 40 parts by weight of the silicate compound, 5 to 15 parts by weight of the acid containing boron (B), and 300 to 500 parts by weight of the water, based on 100 parts by weight of the metal dihydrogen phosphates.

57 . The method of claim 53 , wherein:
the applying of the mixed solution on the grain-oriednted electrical steel sheet is carried out by evenly distributing 0.5 to 3.0 g/m 2 of the mixed solution on a surface of the grain-oriednted electrical steel sheet.

58 . The method of claim 53 , wherein:
the drying of the grain-oriednted electrical steel sheet on which the mixed solution is applied is carried out at a temperature range of 250 to 550° C. for 15 to 30 seconds.

Assignees

• Posco

Inventors

• Han Min Soo
• Park Soon-Bok
• Shon Bungkwan

Classifications

• C23C22/07 Primary

  containing phosphates · CPC title

• C22C38/02

  containing silicon · CPC title

• C04B2111/00525

  for metallic surfaces · CPC title

• C21D8/1222

  Hot rolling · CPC title

• C21D8/1255

  with diffusion of elements, e.g. decarburising, nitriding · CPC title