Grain-oriented electrical steel sheet and method for manufacturing same and annealing separator

Patent metadata

Field	Value
Publication number	US-2022098688-A1
Application number	US-202017421562-A
Country	US
Kind code	A1
Filing date	Jan 8, 2020
Priority date	Jan 8, 2019
Publication date	Mar 31, 2022
Grant date	—

Abstract

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg 2 SiO 4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm 2 , and a number density of Al oxides is 0.02 to 0.20/μm 2 .

First claim

1 . Grain-oriented electrical steel sheet comprising a base steel sheet having a chemical composition containing, by mass %, C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg 2 SiO 4 as a main constituent formed on a surface of the base steel sheet,
in which grain-oriented electrical steel sheet, a peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction of the grain-oriented electrical steel sheet is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction, a sum of perimeters of Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm 2 , and a number density of Al oxides is 0.02 to 0.20/μm 2 .

2 . A method of manufacturing grain-oriented electrical steel sheet according to claim 1 comprising
a cold rolling process cold rolling hot rolled steel sheet having a chemical composition containing, by mass %, C: 0.100% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.002 to 0.050%, sol. Al: 0.005 to 0.050%, and N: 0.001 to 0.030% and having a balance of Fe and impurities by a cold rolling rate of 80% or more to produce cold rolled steel sheet,
a decarburization annealing process decarburization annealing the cold rolled steel sheet, and
a finish annealing process coating a surface of the cold rolled steel sheet after the decarburization annealing with an aqueous slurry containing an annealing separator having MgO as a main constituent, drying the aqueous slurry on the surface of the cold rolled steel sheet in a 400 to 1000° C. furnace, then finish annealing the cold rolled steel sheet, in which
the annealing separator contains MgO, at least one of a hydroxide, sulfate, or carbonate of Ca, Sr, or Ba, and at least one of a Ti compound, Y compound, La compound, or Ce compound,
a particle size distribution of MgO is a content of particles with a particle size of 1.0 μm or less of 20 to 30 mass % and a content of particles with a particle size of 10 μm or more of 2 to 5 mass % with respect to a content of MgO,
the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is contained in a range of a total of 0.5 to 10.0 mass % with respect to a content of MgO and a value of a content of a hydroxide, sulfate, or carbonate of Ca with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Ca, a value of a content of a hydroxide, sulfate, or carbonate of Sr with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Sr, and a value of a content of a hydroxide, sulfate, or carbonate of Ba with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Ba, when respectively designated as [Ca], [Sr], and [Ba], satisfy a range of 0.80 to 1.00 of X/([Ca]+[Sr]+[Ba]),
a mean particle size of the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is 1.0 to 10.0 μm and a ratio of a mean particle size of the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba to a median size of MgO is 0.8 to 2.5, and
a content of a Ti compound, Y compound, La compound, or Ce compound is a total of 1.0 to 15.0 mass % with respect to the content of MgO,
where, X means the highest value among [Ca], [Sr], or [Ba].

3 . The method for manufacturing grain-oriented electrical steel sheet according to claim 2 , wherein a mean particle size of a hydroxide, sulfate, or carbonate of an element with the highest content in the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is 1.0 to 10.0 μm.

4 . The method for manufacturing grain-oriented electrical steel sheet according to claim 2 , wherein the hot rolled steel sheet contains one or more of Sb, Sn, and Cu in a total of 0.30 mass % or less.

5 . The method for manufacturing grain-oriented electrical steel sheet according claim 2 , wherein the hot rolled steel sheet contains one or more of Bi, Te, and Pb in a total of 0.0300 mass % or less.

6 . An annealing separator having MgO as a main constituent, wherein
the annealing separator contains at least one of a hydroxide, sulfate, or carbonate of Ca, Sr, or Ba and at least one of a Ti compound, Y compound, La compound, or Ce compound, a particle size distribution of MgO is a content of particles with a particle size of 1.0 μm or less of 20 to 30 mass % and a content of particles with a particle size of 10 μm or more of 2 to 5 mass % with respect to a content of MgO, the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is contained in a range of a total of 0.5 to 10.0 mass % with respect to a content of MgO and a value of a content of a hydroxide, sulfate, or carbonate of Ca with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Ca, a value of a content of a hydroxide, sulfate, or carbonate of Sr with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Sr, and a value of a content of a hydroxide, sulfate, or carbonate of Ba with respect to a content of MgO divided by a molecular weight of the hydroxide, sulfate, or carbonate of Ba, when respectively designated as [Ca], [Sr], and [Ba], satisfy a range of 0.80 to 1.00 of X/([Ca]+[Sr]+[Ba]), a mean particle size of the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is 1.0 to 10.0 μm and a ratio of a mean particle size of the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba to a median size of MgO is 0.8 to 2.5, and a content of a Ti compound, Y compound, La compound, or Ce compound is a total of 1.0 to 15.0 mass % with respect to the content of MgO, where, X means the highest value among [Ca], [Sr], or [Ba].

7 . The annealing separator according to claim 6 , wherein a mean particle size of a hydroxide, sulfate, or carbonate of an element with the highest content in the hydroxide, sulfate, or carbonate of Ca, Sr, or Ba is 1.0 to 10.0 μm.

8 . The method for manufacturing grain-oriented electrical steel sheet according to claim 3 , wherein the hot rolled steel sheet contains one or more of Sb, Sn, and Cu in a total of 0.30 mass % or less.

9 . The method for manufacturing grain-oriented electrical steel sheet according claim 3 , wherein the hot rolled steel sheet contains one or more of Bi, Te, and Pb in a total of 0.0300 mass % or less.

10 . The method for manufacturing grain-oriented electrical steel sheet according claim 4 , wherein the hot rolled steel sheet contains one or more of Bi, Te, and Pb in a total of 0.0300 mass % or less.

11 . The method for manufacturing grain-oriented electrical steel sheet according claim 8 , wherein the hot rolled steel sheet contains one or more of Bi, Te, and Pb in a total of 0.0300 mass % or less.

Assignees

• Nippon Steel Corp

Inventors

• Tanaka Ichiro
• Yamagata Ryutaro
• Morishige Nobusato
• Kataoka Takashi
• Takahashi Masaru

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C21D8/1272

  Final recrystallisation annealing · CPC title

• H01F1/16

  in the form of sheets (H01F1/147 takes precedence) · CPC title

• H01F1/14775

  in the form of sheets · CPC title

• C21D6/005

  containing Mn · CPC title