GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND MANUFACTURING METHOD THEREFOR
A grain-oriented electrical steel sheet according to an embodiment of the present invention contains, in a unit of wt %, Si at 2.0 wt % to 4.5 wt %, C at 0.005 wt % or less (excluding 0 wt %), Mn at 0.001 wt % to 0.08 wt %, P at 0.001 wt % to 0.1 wt %, Cu at 0.001 wt % to 0.1 wt %, S at 0.0005 wt % to 0.05 wt %, Se at 0.0005 wt % to 0.05 wt %, B at 0.0001 wt % to 0.01 wt %, Mo at 0.01 wt % to 0.2 wt %, and the remainder of Fe and inevitable impurities. A sum amount of S and Se is 0.005 to 0.05 wt %.
1 . A grain-oriented electrical steel sheet, comprising
in a unit of wt %, Si at 2.0 wt % to 4.5 wt %, C at 0.005 wt % or less (excluding 0 wt %), Mn at 0.001 wt % to 0.08 wt %, P at 0.001 wt % to 0.1 wt %, Cu at 0.001 wt % to 0.1 wt %, S at 0.0005 wt % to 0.05 wt %, Se at 0.0005 wt % to 0.05 wt %, B at 0.0001 wt % to 0.01 wt %, Mo at 0.01 wt % to 0.2 wt %, and the remainder of Fe and inevitable impurities,
wherein a sum amount of S and Se is 0.005 to 0.05 wt %.
2 . The grain-oriented electrical steel sheet of claim 1 , further comprising
B at 0.0011 to 0.01 wt %.
3 . The grain-oriented electrical steel sheet of claim 1 , further comprising
Al at 0.0001 to 0.01 wt % and N at 0.0005 to 0.005 wt %.
4 . The grain-oriented electrical steel sheet of claim 1 , further comprising
at least one of Cr at 0.001 to 0.1 wt %, Sn at 0.005 to 0.2 wt %, and Sb at 0.005 to 0.2 wt %.
5 . A manufacturing method of a grain-oriented electrical steel sheet, comprising:
preparing a slab that contains, in a unit of wt %, Si at 2.0 wt % to 4.5 wt %, C at 0.005 wt % or less (excluding 0 wt %), Mn at 0.001 wt % to 0.08 wt %, P at 0.001 wt % to 0.1 wt %, Cu at 0.001 wt % to 0.1 wt %, S at 0.0005 wt % to 0.05 wt %, Se at 0.0005 wt % to 0.05 wt %, B at 0.0001 wt % to 0.01 wt %, Mo at 0.01 wt % to 0.2 wt %, and the remainder of Fe and inevitable impurities, and in which a sum amount of S and Se is 0.005 to 0.05 wt %;
heating the slab;
hot rolling the slab to prepare a hot rolled sheet;
cold rolling the hot rolled sheet to prepare a cold rolled sheet;
primary recrystallization annealing the cold rolled sheet; and
secondary recrystallization annealing the cold rolled sheet in which the first recrystallization annealing is completed.
6 . The manufacturing method of the grain-oriented electrical steel sheet of claim 5 , wherein
after the preparing of the hot rolled sheet, the hot rolled sheet has an edge crack maximum depth of 20 mm or less.
7 . The manufacturing method of the grain-oriented electrical steel sheet of claim 5 , wherein
the cold rolled sheet in which the first recrystallization annealing is completed includes one or more precipitates of (Fe,Mn,Cu)S and (Fe,Mn,Cu)Se.
8 . The manufacturing method of the grain-oriented electrical steel sheet of claim 5 , wherein
the primary recrystallization annealing is performed in a hydrogen and nitrogen mixed atmosphere at a dew point temperature of 50° C. to 70° C.