GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME
The grain-oriented electrical steel sheet according to one embodiment of the present invention includes, by weight, Si: 1.0 to 7.0%, B: 0.001 to 0.1%, and Ba and Y individually or in a total amount of 0.005 to 0.5%, and the remainder includes Fe and other unavoidable impurities.
1 . A grain-oriented electrical steel sheet comprising, by weight, Si: 1.0 to 7.0%, B: 0.001 to 0.1%, and Ba and Y individually or in a total amount of 0.005 to 0.5%, and the remainder comprising Fe and other unavoidable impurities.
2 . The grain-oriented electrical steel sheet according to claim 1 ,
satisfying the following formula (1).
0.5≤([Ba]+[Y])/([B]*10)≤3 [Formula 1]
(In the Formula (1), [Ba], [Y], and [B] represent the contents (% by weight) of Ba, Y and B, respectively.)
3 . The grain-oriented electrical steel sheet according to claim 1 ,
further comprising C: 0.005% or less (excluding 0%), Al: 0.005% or less (excluding 0%), N: 0.0055% or less (excluding 0%), and S: 0.0055% or less (excluding 0%).
4 . The grain-oriented electrical steel sheet according to claim 1 ,
further comprising Mn: 0.01% to 0.5%.
5 . The grain-oriented electrical steel sheet according to claim 1 ,
wherein the average particle diameter of the grains having a particle diameter of 2 mm or more is 10 mm or more.
6 . The grain-oriented electrical steel sheet according to claim 1 ,
comprising B and, Ba or Y segregated in the grain boundaries.
7 . A method for manufacturing grain-oriented electrical steel sheet comprising:
a step of heating the slab comprising, by weight, Si: 1.0 to 7.0%, B: 0.001 to 0.1%, and Ba and Y individually or in a total amount of 0.005 to 0.5%, and the remainder comprising Fe and other unavoidable impurities;
a step of hot-rolling the slab to produce a hot-rolled sheet;
a step of cold-rolling the hot-rolled sheet to produce a cold-rolled sheet;
a step of the primary recrystallization annealing the cold-rolled sheet; and
a step of the second recrystallization annealing the cold-rolled sheet after the primary recrystallization annealing is completed.
8 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the slab satisfies the following Formula (1).
0.5≤([Ba]+[Y])/([B]*10)≤3 [Formula 1]
(In the formula (1), [Ba], [Y], and [B] represent the contents (% by weight) of Ba, Y, and B, respectively.)
9 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the slab further comprises C: 0.001 to 0.1%, Al: 0.01% or less (excluding 0%), N: 0.0055% or less (excluding 0%), and S: 0.0055% or less (excluding 0%).
10 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the slab further comprises Mn: 0.01 to 0.5%.
11 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the slab is heated to 1000 to 1280° C. in the step of heating the slab.
12 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the final reduction roll is 80% or more in the step of cold-rolling the hot-rolled sheet to produce a cold-rolled sheet.
13 . The method for manufacturing grain-oriented electrical steel sheet according to claim 7 ,
wherein the second recrystallization annealing step comprises a temperature elevating step and a cracking step, and the temperature of the cracking step is 900 to 1250° C.