Non-oriented electrical steel sheet and manufacturing method therefor
Abstract
A non-oriented electrical steel sheet according to one embodiment of the present disclosure comprises 0.005 wt % or less of C (excluding 0 wt %), 1.0-4.0 wt % of Si, 0.15-1.5 wt % of Al, 0.1-1.0 wt % of Mn, 0.2 wt % or less of P (excluding 0 wt %), 0.005 wt % or less of N (excluding 0 wt %), 0.001-0.006 wt % of S, 0.005 wt % or less of Ti (excluding 0 wt %), and 0.005 wt % or less of O (excluding 0 wt %), and the remainder being Fe and other inevitable impurities, and satisfies formula 1 below, wherein a mean size of oxides in the precipitates is larger than a mean size of non-oxides. [ Si ] 1.8 + 1.3 × [ Al ] > 3.7 × [ Mn ] × [ Mn ] Formula ( 1 ) (Here, [Si], [Al] and [Mn] represent the contents (in wt %) of Si, Al and Mn, respectively.)
Claims
exact text as granted — not AI-modified1 . A non-oriented electrical steel sheet, comprising:
0.005 wt % or less of C (excluding 0 wt %), 1.0-4.0 wt % of Si, 0.15-1.5 wt % of Al, 0.1-1.0 wt % of Mn, 0.2 wt % or less of P (excluding 0 wt %), 0.005 wt % or less of N (excluding 0 wt %), 0.001-0.006 wt % of S, 0.005 wt % or less of Ti (excluding 0 wt %), and 0.005 wt % or less of O (excluding 0 wt %), and the remainder being Fe and other inevitable impurities, and satisfies formula 1 below, wherein a mean size of oxides in the precipitates is larger than a mean size of non-oxides.
[
Si
]
1.8
+
1.3
×
[
Al
]
>
3.7
×
[
Mn
]
×
[
Mn
]
Formula
(
1
)
(Here, [Si], [Al] and [Mn] represent the contents (in wt %) of Si, Al and Mn, respectively.)
2 . The non-oriented electrical steel sheet of claim 1 , wherein
a number of oxides in the precipitates is larger than that of non-oxides.
3 . The non-oriented electrical steel sheet of claim 1 ,
further comprising 0.01 to 0.2 wt % of Sn and Sb, individually or in combination, respectively.
4 . The non-oriented electrical steel sheet of claim 1 ,
wherein a number of FeO in the precipitates or precipitates containing FeO is 40% or more.
5 . The non-oriented electrical steel sheet of claim 1 ,
wherein a mean particle size is 50 to 180 μm.
6 . A method for manufacturing a non-oriented electrical steel sheet, comprising steps of:
heating a slab comprising 0.005 wt % or less of C (excluding 0 wt %), 1.0-4.0 wt % of Si, 0.15-1.5 wt % of Al, 0.1-1.0 wt % of Mn, 0.2 wt % or less of P (excluding 0 wt %), 0.005 wt % or less of N (excluding 0 wt %), 0.001-0.006 wt % of S, 0.005 wt % or less of Ti (excluding 0 wt %), and 0.005 wt % or less of O (excluding 0 wt %), and the remainder being Fe and other inevitable impurities, and satisfying formula 1 below and then hot rolling the slab to prepare a hot rolled sheet; winding and then cooling the hot rolled sheet; annealing and then cooling the hot rolled sheet; cold rolling the hot rolled annealing sheet to prepare a cold rolled sheet; and final annealing and then cooling the cold rolled sheet, wherein, the step of winding and cooling the hot rolled sheet comprises cooling at 600° C. or higher for 30 minutes or more, the step of annealing and then cooling the hot rolled sheet includes cooling at 600° C. or higher for 5 seconds or more, and the step of annealing and then cooling the cold rolled sheet includes cooling at 600° C. or higher for 5 seconds or more.
[
Si
]
1.8
+
1.3
×
[
Al
]
>
3.7
×
[
Mn
]
×
[
Mn
]
Formula
(
1
)
(Here, [Si], [Al] and [Mn] represent the contents (in wt %) of Si, Al and Mn, respectively.)
7 . The method of claim 6 , wherein
wherein the slab further comprises 0.01 to 0.2 wt % of Sn and Sb, individually or in combination.
8 . The method of claim 6 , wherein
the step of preparing the hot rolled sheet comprises heating the slab at 1200° C. or lower.
9 . The method of claim 6 , wherein
a temperature of the winding is 600 to 800° C. in the step of winding and then cooling the hot rolled sheet.
10 . The method of claim 6 , wherein
a temperature of the hot rolled sheet annealing is 850 to 1150° C. in the step of annealing and then cooling the hot rolled sheet.
11 . The method of claim 6 , wherein
wherein the step of cold rolling the hot rolled annealing sheet to prepare a cold rolled sheet comprises cold rolling to a thickness of 0.1 to 0.7 mm.
12 . The method of claim 6 , wherein
the step of cold rolling the hot rolled annealing sheet to prepare a cold rolled sheet comprises primary cold rolling, intermediate annealing, and secondary cold rolling.
13 . The method of claim 6 , wherein
a cracking temperature of the cold rolled sheet annealing during annealing is 850 to 1100° C. in the step of annealing and then cooling the cold rolled sheet.
14 . The method of claim 6 , wherein
a mean size of oxides in the precipitates of a manufactured electrical steel sheet is larger than a mean size of non-oxides.
15 . The method of claim 14 , wherein
a number of oxides in the precipitates is larger than that of non-oxides.
16 . The method of claim 14 , wherein
a number of FeO in the precipitates or precipitates containing FeO is 40% or more.
17 . The method of claim 14 ,
wherein a mean particle size is 50 to 180 μm.Join the waitlist — get patent alerts
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