Grain-oriented electrical steel sheet and manufacturing method therefor

• US 11,031,162 B2
• Filed: 12/08/2014
• Issued: 06/08/2021
• Est. Priority Date: 11/27/2014
• Status: Active Grant

• Current Assignee: POSCO Co. Ltd. (Posco Holdings Incorporated)
• Original Assignee: Posco Holdings Incorporated
• Inventors: Ko, Hyun-Seok, Han, Kyu-Seok, Park, Hyung-Ki, Seo, Jin-Wook, Lim, Jae-Soo, Joo, Hyung Don
• Primary Examiner(s): Zimmer, Anthony J
• Assistant Examiner(s): Kachmarik, Michael J
• Application Number:
  US15/529,870
• Publication Number:
  US 20170271061A1
• Time in Patent Office: 2,374 Days
• Field of Search: None
• CPC Class Codes: C21D 3/04 Decarburising
• CPC Class Codes: C21D 8/12 during manufacturing of articles with special electromagnetic properties
• CPC Class Codes: C21D 8/1222 Hot rolling
• CPC Class Codes: C21D 8/1233 Cold rolling
• CPC Class Codes: C21D 8/1255 with diffusion of elements, e.g. decarburising, nitriding
• CPC Class Codes: C21D 8/1261 following hot rolling
• CPC Class Codes: C21D 8/1266 between cold rolling steps
• CPC Class Codes: C21D 8/1272 Final recrystallisation annealing
• CPC Class Codes: C21D 9/46 for sheet metals
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/004 Very low carbon steels, i.e. having a carbon content of less than 0,01%
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: H01F 1/14775 in the form of sheets

Abstract

Disclosed are an oriented electrical steel sheet and a manufacturing method thereof. An exemplary embodiment of the present invention provides a method of manufacturing an oriented electrical steel sheet, including: providing a slab including Si at 1.0 to 4.0 wt %, C at 0.1 to 0.4 wt %, and the remaining portion including Fe and other inevitably incorporated impurities; reheating the slab; producing a hot rolled steel sheet by hot rolling the slab; performing annealing of the hot rolled steel sheet; cold rolling the annealed hot rolled steel sheet; decarburizing and annealing the cold rolled steel sheet; cold rolling the decarburized and annealed steel sheet; and final annealing the cold rolled steel sheet.

Claims

1. An oriented electrical steel sheet, comprising

Goss grains in which a ratio (D2/D1) of a diameter (D1) of a circumscribed circle thereof to a diameter (D2) of an inscribed circle thereof is greater than 0.5 is 95% or more of total Goss grains,

wherein grains of the oriented electrical steel sheet having a grain size of 30 μ

m to 1000 μ

m is 80% or more of total grains.

2. The oriented electrical steel sheet of claim 1, wherein

the oriented electrical steel sheet includes Mn at more than 0% and 0.1% or less, S at more than 0 wt % and 0.005 wt % or less, and the remaining portion including Fe and other inevitably impurities.

3. The oriented electrical steel sheet of claim 2, wherein

the oriented electrical steel sheet includes Si at 1.0 wt % to 4.0 wt % and C at 0.002 wt % or less (excluding 0 wt %).

4. The oriented electrical steel sheet of claim 3, wherein

a content of Mg at a depth of 2 μ

m to 5 μ

m from a surface of the electrical steel sheet is 0.0050 wt % or less.