Method of manufacturing grain-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-12312662-B2
Application number	US-202017421774-A
Country	US
Kind code	B2
Filing date	Jan 16, 2020
Priority date	Jan 16, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A method of manufacturing a grain-oriented electrical steel sheet according to the present invention includes a process of executing hot rolling on a slab to obtain a hot-rolled sheet; a process of executing hot-rolled sheet annealing on the hot-rolled sheet to obtain an annealed hot-rolled sheet; a process of executing cold rolling on the annealed hot-rolled sheet to obtain a cold-rolled sheet; a process of executing decarburization annealing on the cold-rolled sheet to obtain a decarburization annealed sheet; a process of applying an annealing separator containing alumina as a main component to the decarburization annealed sheet; and a process of executing final annealing on the decarburization annealed sheet to which the annealing separator is applied, wherein the annealing separator contains 28% to 50% by mass of MgO, and wherein an application amount of the annealing separator is 6.0 to 14.0 g/m 2 per one surface of the decarburization annealed sheet.

First claim

The invention claimed is:

1. A method of manufacturing a grain-oriented electrical steel sheet comprising:
a process of executing hot rolling on a slab to obtain a hot-rolled sheet;
a process of executing hot-rolled sheet annealing on the hot-rolled sheet to obtain an annealed hot-rolled sheet;
a process of executing cold rolling on the annealed hot-rolled sheet to obtain a cold-rolled sheet;
a process of executing decarburization annealing on the cold-rolled sheet to obtain a decarburization annealed sheet;
a process of applying an annealing separator containing alumina as a main component to the decarburization annealed sheet; and
a process of executing final annealing on the decarburization annealed sheet to which the annealing separator is applied,
wherein the annealing separator consists of MgO and the alumina,
wherein the annealing separator contains 28% to 50% by mass of the MgO,
wherein an application amount of the annealing separator is 6.0 to 14.0 g/m 2 per one surface of the decarburization annealed sheet, and
wherein a BET specific surface area of the alumina is 3.0 to 10.0 m 2 /g.

2. The method of manufacturing a grain-oriented electrical steel sheet according to claim 1 ,
wherein the slab contains, as a chemical composition, in % by mass,
C: 0.085% or less,
Si: 0.80% to 7.00%,
Mn: 0.05% to 1.00%,
acid-soluble Al: 0.010% to 0.065%,
S: 0.01% or less,
N: 0.004% to 0.012%,
B: 0.0005% to 0.0080%,
P: 0% to 0.50%,
Ni: 0% to 1.00%,
Sn: 0% to 0.30%,
Sb: 0% to 0.30%,
Cu: 0% to 0.40%,
Cr: 0% to 0.30%,
Bi: 0% to 0.01%, and
a remainder of Fe and impurities.

Assignees

• Nippon Steel Corp

Inventors

• TAKATANI Shinsuke
• Okumura Shunsuke
• Nagano Shohji

Classifications

• C21D8/02

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

• C22C38/04

  containing manganese · CPC title

• C22C38/02

  containing silicon · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• C22C38/001

  containing N · CPC title