Method of manufacturing grain-oriented electrical steel sheet

Patent metadata

Field	Value
Publication number	US-10629346-B2
Application number	US-201715606074-A
Country	US
Kind code	B2
Filing date	May 26, 2017
Priority date	Apr 26, 2012
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A method of manufacturing a grain oriented electrical steel sheet includes subjecting a steel slab to a rolling process including cold rolling to obtain a steel sheet with a final sheet thickness, the steel slab containing by mass % C: 0.01% to 0.20%, Si: 2.0% to 5.0%, Mn: 0.03% to 0.20%, sol. Al: 0.010% to 0.05%, N: 0.0010% to 0.020%, at least one element selected from S and Se in a total of 0.005% to 0.040%, and the balance including Fe and incidental impurities; forming, by a chemical process, a linear groove extending in a direction forming an angle of 45° or less with a direction orthogonal to a rolling direction of the steel sheet; subjecting the steel sheet to decarburization annealing; applying an annealing separator thereon mainly composed of MgO; and subjecting the steel sheet to final annealing to manufacture a grain oriented electrical steel sheet.

First claim

The invention claimed is:

1. A method of manufacturing a grain oriented electrical steel sheet comprising:
subjecting a steel slab to a rolling process to obtain a steel sheet with a final sheet thickness, the steel slab containing by mass %
C: 0.01% to 0.20%,
Si: 2.0% to 5.0%,
Mn: 0.03% to 0.20%,
sol. Al: 0.010% to 0.05%,
N: 0.0010% to 0.020%,
at least one element selected from S and Se in a total of 0.005% to 0.040%, and the balance including Fe and incidental impurities;

forming, by electrolytic etching or pickling treatment, a linear groove extending in a direction forming an angle of 45° or less with a direction orthogonal to a rolling direction of the steel sheet;
subjecting the steel sheet to decarburization annealing;
applying an annealing separator thereon mainly composed of MgO;
subjecting the steel sheet to final annealing to manufacture a grain oriented electrical steel sheet, wherein
the MgO used has a viscosity of 20 cP to 100 cP 30 minutes after mixing with water, and
the rolling process includes one or more optional cold rolling with intermediate annealing, and the rolling process includes final cold rolling, in which
the final cold rolling includes subjecting the steel sheet to rolling at least once during which an entry temperature or a delivery temperature of a rolling stand, whichever is higher, is 170° C. or lower, and to rolling at least twice during which the higher temperature of the entry temperature and the delivery temperature is 200° C. or higher.

2. The method according to claim 1 , wherein the steel slab further contains by mass % at least one element selected from Cu: 0.01% to 0.2%, Ni: 0.01% to 0.5%, Cr: 0.01% to 0.5%, Sb: 0.01% to 0.1%, Sn: 0.01% to 0.5%, Mo: 0.01% to 0.5% and Bi: 0.001% to 0.1%.

3. The method according to claim 1 , wherein the rolling process further includes subjecting the steel slab to heating and subsequent hot rolling to obtain a hot rolled sheet, then subjecting the steel sheet to hot band annealing.

4. The method according to claim 2 , wherein the rolling process further includes subjecting the steel slab to heating and subsequent hot rolling to obtain a hot rolled sheet, then subjecting the steel sheet to hot band annealing.

5. The method according to claim 1 , wherein the rolling process includes one or more cold rolling with intermediate annealing, followed by final cold rolling.

Assignees

• Jfe Steel Corp

Inventors

• Senda Kunihiro
• Inoue Hirotaka
• Okabe Seiji

Classifications

• C21D2201/05

  Grain orientation · CPC title

• C21D8/1283

  Application of a separating or insulating coating · CPC title

• C21D8/1244

  characterised by the heat treatment · CPC title

• C25F3/14 Primary

  locally · CPC title

• H01F1/16

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