# US 12,215,403 B2 · Non-oriented electrical steel sheet and method for manufacturing same

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- Number: US 12,215,403 B2
- Document ID: US12215403B2
- Status: Granted
- Kind: B2
- Application number: 17/787,023
- Filed: 2020-12-09
- Published: 2023-01-19
- Granted: 2025-02-04
- Earliest claimed: 2019-12-20
- Assignees: Posco
- Applicants: Posco
- Inventors: Hunju Lee; Jae-Hoon Kim; Seung-Gon Lee; Seung Il Kim
- Web page: https://patentgrep.com/patent/US12215403B2

## CPC

- C21D 1/76: Adjusting the composition of the atmosphere
- C21D 9/46: for sheet metals
- C21D 1/26: Methods of annealing
- C21D 6/004: {containing Cr and Ni}
- C21D 6/005: {containing Mn}
- C21D 6/008: {containing Si}
- C21D 6/02: Hardening by precipitation
- C21D 8/00: 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)
- C21D 8/1222: {Hot rolling}
- C21D 8/1233: {Cold rolling}
- C21D 8/1261: {following hot rolling}
- C21D 8/1272: {Final recrystallisation annealing}
- C21D 8/1283: {Application of a separating or insulating coating}
- C22C 38/001: {containing N}
- C22C 38/002: {containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60}
- C22C 38/004: {Very low carbon steels, i.e. having a carbon content of less than 0,01%}
- C22C 38/008: {containing tin}
- C22C 38/02: containing silicon
- C22C 38/04: containing manganese
- C22C 38/06: containing aluminium
- C22C 38/08: containing nickel {(C22C38/105 takes precedence)}
- C22C 38/12: containing tungsten, tantalum, molybdenum, vanadium, or niobium
- C22C 38/18: containing chromium
- C22C 38/34: with more than 1.5% by weight of silicon
- C22C 38/44: with molybdenum or tungsten
- C22C 38/50: with titanium or zirconium
- H01F 1/16: in the form of sheets (H01F1/147 takes precedence)
- C21D 2201/05: Grain orientation
- C22C 2202/02: Magnetic
- Y02P 10/20: Recycling
- Y02T 10/64: Electric machine technologies in electromobility
- C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B)
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 1.5 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.015 to 0.1%, P: 0.005 to 0.05%, Ga: 0.001 to 0.004%, and Bi: 0.0005 to 0.003%, and the balance of Fe and inevitable impurities. An area fraction of texture in a {118}//ND orientation is higher than that of texture in a {111}//ND orientation.

## Claims

### Claim 1

A non-oriented electrical steel sheet including, in wt %, C: 0.005 wt % or less, Si: 1.5 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.015 to 0.1%, P: 0.005 to 0.05%, Ga: 0.001 to 0.004%, and Bi: 0.0005 to 0.003%, and the balance of Fe and inevitable impurities,
wherein an area fraction of texture in a {118}//ND orientation is higher than that of texture in a {111}//ND orientation.

### Claim 2 (depends on 1)

The non-oriented electrical steel sheet of claim 1, further comprising
Cr: 0.005 to 0.03 wt %,
wherein the non-oriented electrical steel sheet satisfies Formula 1:
0.005≤[Cr]≤0.03×[Al] [Formula 1]
(in Formula 1, [Cr] and [Al] are a content (wt %) of Cr and Al in the steel sheet, respectively).

### Claim 3 (depends on 1)

The non-oriented electrical steel sheet of claim 1, further comprising Mo: 0.001 to 0.01 wt % and Ni: 0.005 to 0.04 wt %,
wherein the non-oriented electrical steel sheet satisfies Formula 2:
10×[Mo]≤([Sn]+[P])≤4×[Ni] [Formula 2]
(in Formula 2, [Mo], [Sn], [P], and [Ni] represent a content (wt %) of Mo, Sn, P, and Ni in the steel sheet, respectively).

### Claim 4 (depends on 1)

The non-oriented electrical steel sheet of claim 1, further comprising Cu: 0.001 to 0.05 wt %, S: 0.005 wt % or less, and Ti: 0.005 wt % or less,
wherein the non-oriented electrical steel sheet satisfies Formula 3:
0.5≤[Cu]/([Ti]+[S])≤7.5 [Formula 3]
(in Formula 3, [Cu], [Ti], and [S] represent a content (wt %) of Cu, Ti, and S in the steel sheet, respectively).

### Claim 5 (depends on 1)

The non-oriented electrical steel sheet of claim 1, wherein
among sulfides formed inside a base material, the number of sulfides with a diameter of 100 nm or more satisfies three or more times the number of sulfides of less than 100 nm.

### Claim 6 (depends on 1)

The non-oriented electrical steel sheet of claim 1, further comprising
N: 0.005 wt % or less.

### Claim 7 (depends on 1)

The non-oriented electrical steel sheet of claim 1, wherein
an oxide layer is present in an inner direction from a surface of the electrical steel sheet, and a thickness of the oxide layer is 10 to 50 nm.

### Claim 8 (depends on 7)

The non-oriented electrical steel sheet of claim 7, wherein
the oxide layer includes O: 40 to 70 wt %, Al: 25 to 55 wt %, P: 0.01 to 0.1 wt %, and Sn: 0.01 to 0.1 wt %, and the balance of Fe and inevitable impurities.

### Claim 9 (depends on 1)

The non-oriented electrical steel sheet of claim 1, wherein
an average grain size is 50 to 100 μm.

### Claim 10 (depends on 1)

The non-oriented electrical steel sheet of claim 1, wherein
the non-oriented electrical steel sheet has a thickness of 0.10 to 0.30 mm.

### Claim 11 (depends on 1)

The non-oriented electrical steel sheet of claim 1, wherein
a difference between a thickness (tcenter) of a center in a width direction of the steel sheet and a thickness (t500) at a position away by 500 mm vertically from the center to an edge is 10 μm or less.

### Claim 12

A manufacturing method of a non-oriented electrical steel sheet, comprising:
hot-rolling a slab including, in wt %, C: 0.005% or less, Si: 1.5 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.015 to 0.1%, P: 0.005 to 0.05%, Ga: 0.001 to 0.004%, and Bi: 0.0005 to 0.003%, and the balance of Fe and inevitable impurities to manufacture a hot-rolled sheet;
cold-rolling the hot-rolled sheet at a reduction ratio of 85% or more to manufacture a cold-rolled sheet; and
final annealing the cold-rolled sheet,
wherein after final annealing, an area fraction of texture in a {118}//ND orientation is higher than that of texture in a {111}//ND orientation.

### Claim 13 (depends on 12)

The manufacturing method of the non-oriented electrical steel sheet of claim 12, further comprising
after the manufacturing of the hot-rolled sheet, annealing the hot-rolled sheet at a temperature of 850 to 1150° C.

### Claim 14 (depends on 12)

The manufacturing method of the non-oriented electrical steel sheet of claim 12, wherein
the final annealing is performed for 100 seconds or less in an atmosphere including hydrogen (H2) and nitrogen (N2) and at a temperature ranging from 400 to 1000° C.