Non-oriented electrical steel sheet, sra heat treated non-oriented electrical steel sheet and manufacturing methods therefor
AssigneePosco
InventorsJae-Wan Hong, Sang-Woo Lee, Hyun-Woo Mun
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Abstract
The present invention relates to a non-oriented electrical steel sheet and a manufacturing method therefor. One aspect of the present invention is to provide a non-oriented electrical steel sheet having excellent strength characteristics after final annealing, and a manufacturing method therefor. Another aspect of the present invention is to provide a non-oriented electrical steel sheet having excellent high-frequency iron loss characteristics after SRA heat treatment, and a manufacturing method therefor.
Claims18
A non-oriented electrical steel sheet comprising:
- in wt %, Si:
- 2.8 to 4.0%, Mn:
- 0.05 to 1.2%, Al:
- 0.1 to 1.2%, C:
- 0.005% or less (excluding 0%), S:
- 0.003% or less (excluding 0%), N:
- 0.005% or less (excluding 0%), Ti:
- 0.005% or less (excluding 0%), B:
- 0.0005% or less (excluding 0%), Bi:
- 0.005% or less (excluding 0%), and at least one of Sn:
- 0.001 to 0.08% and Sb:
- 0.001 to 0.08%, and a remainder of Fe and inevitable impurities,
- wherein the non-oriented electrical steel sheet satisfies Relational Expression 1 below and an average grain size is 5 to 25 m.
- B
- /
- 10.81
- +
- Bi
- /
- 20
-
- 8
- .
- 9
-
- 8
- ≤
- 0.00007
- [
- Relational
-
- Expression
-
- 1
- ]
An SRA heat-treated non-oriented electrical steel sheet comprising:
- in wt %, Si:
- 2.8 to 4.0%, Mn:
- 0.05 to 1.2%, Al:
- 0.1 to 1.2%, C:
- 0.005% or less (excluding 0%), S:
- 0.003% or less (excluding 0%), N:
- 0.005% or less (excluding 0%), Ti:
- 0.005% or less (excluding 0%), B:
- 0.0005% or less (excluding 0%), Bi:
- 0.005% or less (excluding 0%), and at least one of Sn:
- 0.001 to 0.08% and Sb:
- 0.001 to 0.08%, and a remainder of Fe and inevitable impurities,
- wherein the SRA heat-treated non-oriented electrical steel sheet satisfies Relational Expression 1 below and an average grain size is 70 to 110 m.
- B
- /
- 10.81
- +
- Bi
- /
- 20
-
- 8
- .
- 9
-
- 8
- ≤
- 0.00007
- [
- Relational
-
- Expression
-
- 1
- ]
A method of manufacturing a non-oriented electrical steel sheet, the method comprising:
- heating a slab including, in wt %, Si:
- 2.8 to 4.0%, Mn:
- 0.05 to 1.2%, Al:
- 0.1 to 1.2%, C:
- 0.005% or less (excluding 0%), S:
- 0.003% or less (excluding 0%), N:
- 0.005% or less (excluding 0%), Ti:
- 0.005% or less (excluding 0%), B:
- 0.0005% or less (excluding 0%), Bi:
- 0.005% or less (excluding 0%), and at least one of Sn:
- 0.001 to 0.08% and Sb:
- 0.001 to 0.08%, and a remainder of Fe and inevitable impurities;
- finishing hot-rolling the heated slab to obtain a hot-rolled sheet;
- hot-rolled sheet annealing the hot-rolled sheet;
- pickling the hot-rolled sheet annealed hot-rolled sheet;
- cold-rolling the pickled hot-rolled sheet to obtain a cold-rolled sheet;
- and
- finally annealing the cold-rolled sheet at 710 to 830° C.,
- wherein Relational Expression 2 is satisfied during the final annealing,
- B
- /
- 10.81
- +
- Bi
- /
- 20
-
- 8
- .
- 9
-
- 8
- ≤
- 0.00007
- [
- Relational
-
- Expression
-
- 1
- ]
- 0.07
- 7
- ≤
- (
- B
- /
- 10.81
- +
- Bi
- /
- 20
-
- 8
- .
- 9
-
- 8
- )
- ×
- e
- (
- final
-
- annealing
-
- temperature
- /
- 100
- )
- ≤
- 0.17
- [
- Relational
-
- Expression
-
- 2
- ]
18-25. (canceled)
Dependencies are inferred from the claim text.