Non-oriented electrical steel sheet and manufacturing method therefor
A non-oriented electrical steel sheet according to an embodiment of the present invention, comprises: Si: 2.0 to 3.5%, Al: 0.05 to 2.0%, Mn: 0.05 to 2.0%, In: 0.0002 to 0.003% by wt % and Fe and inevitable impurities as the remainder.
1. A non-oriented electrical steel sheet, comprising:
Si: 2.0 to 3.5%, Al: 0.05 to 2.0%, Mn: 0.05 to 2.0%, In: 0.0002 to 0.003%, Bi: 0.0005 to 0.05 by wt % and Fe and inevitable impurities as the remainder.
2. The non-oriented electrical steel sheet of claim 1 , further comprising
at least one of C: 0.005 wt % or less, S: 0.005 wt % or less, N: 0.004 wt % or less, Ti: 0.004 wt % or less, Nb: 0.004 wt % or less, and V: 0.004 wt % or less.
3. The non-oriented electrical steel sheet of claim 1 , further comprising
at least one of B: 0.001 wt % or less, Mg: 0.005 wt % or less, Zr: 0.005 wt % or less, and Cu: 0.025 wt % or less.
4. The non-oriented electrical steel sheet of claim 1 , comprising
20% or less of crystal grains having a crystal orientation with respect to a cross section which is perpendicular to the rolling direction of a steel sheet has an orientation within 15 degrees from {111}<uvw>.
5. The non-oriented electrical steel sheet of claim 1 , wherein
the YP0.2 obtained when the tensile test is subjected at 120° C. is 0.7 times or more of the YP0.2 obtained when the tensile test is subjected at 20° C.,
the YP0.2 means offset yield strength in the stress-strain graph obtained through the tensile test.
6. The non-oriented electrical steel sheet of claim 1 , wherein an iron loss W 15/50 is 2.30 W/kg or less, and a magnetic flux density B 50 is 1.67 T or more.
7. A method for manufacturing a non-oriented electrical steel sheet comprising:
heating a slab comprising Si: 2.0 to 3.5%, Al: 0.05 to 2.0%, Mn: 0.05 to 2.0%, In: 0.0002 to 0.003%, Bi: 0.0005 to 0.05 by wt % and Fe and inevitable impurities as the remainder;
performing hot rolling on a slab to manufacture a hot rolled sheet;
performing cold rolling on the hot rolled sheet to manufacture a cold rolled sheet; and
performing final annealing on the cold rolled sheet, thereby producing the non-oriented electrical steel sheet of claim 1 .
8. The method of claim 7 , wherein
the slab further comprises at least one of C: 0.005 wt % or less, S: 0.005 wt % or less, N: 0.004 wt % or less, Ti: 0.004 wt % or less, Nb: 0.004 wt % or less, and V: 0.004 wt % or less.
9. The method of claim 8 , further comprising
the slab further comprises at least one of B: 0.001 wt % or less, Mg: 0.005 wt % or less, Zr: 0.005 wt % or less, and Cu: 0.025 wt % or less.
10. The method of claim 8 , further comprising
performing hot rolled sheet annealing on the hot rolled sheet after the step of manufacturing a hot rolled sheet.