ORIENTED ELECTRICAL STEEL SHEET AND MANUFACTURING METHOD THEREOF

1 . A method for manufacturing an oriented electrical steel sheet, comprising:

providing a slab including, as wt %, Si at equal to or less than 4.0% (excluding 0%), C at 0.001% to 0.4%, and Mn at 0.001 to 2.0%, and including a balance including Fe and inevitably mixed and input impurities;

reheating the slab;

manufacturing a hot steel sheet by hot-rolling the slab;

performing hot-rolled steel sheet annealing to the hot steel sheet;

primarily cold-rolling the hot-rolled steel sheet annealed hot steel sheet;

decarburization-annealing the cold-rolled steel sheet;

secondarily cold-rolling the decarburization-annealed steel sheet; and

finally annealing the cold-rolled steel sheet,

wherein, regarding the finally annealed steel sheet, a size 2L of a magnetic domain existing in a grain is less than a thickness D of the steel sheet.

2 . The method of claim 1 , wherein

the slab includes Si at equal to or less than 1 wt % (excluding 0 wt %).

3 . The method of claim 1 , wherein the slab further includes Al at equal to or less than 0.01 wt % (excluding 0 wt %).

4 . The method of claim 1 , wherein

a reheating temperature of the slab is 1050° C. to 1350° C.

5 . The method of claim 1 , wherein

reduction rates in the primarily cold-rolling and the secondarily cold-rolling are respectively 50% to 70%.

6 . The method of claim 1 , wherein

the decarburization-annealing of the cold-rolled steel sheet and the secondarily cold-rolling of the decarburization-annealed steel sheet are repeated at least twice.

7 . The method of claim 1 , wherein

the decarburization-annealing is performed in an atmosphere including hydrogen with a dew point temperature of 0° C. at a temperature of 800° C. to 1150° C.

8 . The method of claim 1 , wherein

the finally annealing includes a first step for performing the same in an atmosphere with the dew point temperature of 10° C. to 70° C. at the temperature of 850° C. to 1150° C., and a second step for performing the same in a mixed gas atmosphere including hydrogen and nitrogen with a dew point temperature that is equal to or less than 10° C. at a temperature of 900° C. to 1200° C.

9 . The method of claim 8 , wherein

the first step is performed for equal to or less than 300 seconds, and the second step is performed for 60 seconds to 300 seconds.

10 . The method of claim 1 , wherein

the finally annealing is continuously performed after the cold-rolling.

11 . The method of claim 1 , wherein

an amount of carbon in the electrical steel sheet is equal to or less than 0.003 wt % (excluding 0 wt %) after the finally annealing.

12 . The method of claim 1 , wherein

regarding the finally annealed steel sheet, a volumetric fraction of a grain with an orientation that is within 15 degrees from an orientation {110}<001> is equal to or greater than 50%.

13 . The method of claim 1 , wherein

regarding the finally annealed steel sheet, a volumetric fraction of a grain with a particle diameter of 20 μm to 1000 μm is equal to or greater than 50%.