Grain-oriented electrical steel sheet and method for manufacturing same
A method for manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises: a step for hot-rolling a slab to produce a hot-rolled sheet; a step for cold-rolling the hot-rolled sheet to produce a cold-rolled sheet; a step for subjecting the cold-rolled sheet to primary recrystallization annealing; and a step for subjecting the primary recrystallization annealing-completed cold-rolled sheet to secondary recrystallization annealing, wherein the primary recrystallization annealing step includes a preceding step and a subsequent step, and the amount (A) of nitriding gas introduced in the preceding step with respect to the total amount (B) of nitriding gas introduced in the primary recrystallization annealing step satisfies expression 1 below. 0.05≤[ A ]/[ B ]≤[ t ] [Expression 1] (In expression 1, the amount of nitriding gas introduced is in units of Nm 3 /hr, and [t] represents the thickness (mm) of a cold-rolled sheet.)
1. A grain-oriented electrical steel sheet satisfying the following Expression 4:
0.06≤[ D S ]/[ D L ]≤0.1 [Expression 4]
wherein [D S ] represents the number of crystal grains having a particle diameter of 5 mm or less, and [D L ] represents the number of crystal grains having a particle diameter of more than 5 mm.
2. The grain-oriented electrical steel sheet of claim 1 , wherein:
the steel sheet comprises 0.03 to 0.15 wt % of Cr.