Grain-oriented electrical steel sheet and hot-rolled steel sheet for grain-oriented electrical steel sheet

1. A grain-oriented electrical steel sheet, comprising:

a chemical composition represented by, in mass %,

Si: 2.0% to 5.0%,

Mn: 0.03% to 0.12%,

Cu: 0.60% to 1.00%,

Sb or Sn, or both thereof: 0.000% to 0.3% in total,

Cr: 0% to 0.3%,

P: 0% to 0.5%,

Ni: 0% to 1%, and

the balance: Fe and impurities, wherein

an L-direction average diameter of crystal grains observed on a surface of the steel sheet in an L direction parallel to a rolling direction is equal to or more than 3.6 times a C-direction average diameter in a C direction vertical to the rolling direction.

2. A manufacturing method of the grain-oriented electrical steel sheet according to claim 1 , comprising:

obtaining a slab by continuous casting a molten steel;

obtaining a hot-rolled steel sheet by hot rolling the slab heated in a temperature zone of 1300° C. to 1490° C.;

coiling the hot-rolled steel sheet in a temperature zone of 600° C. or less;

annealing the hot-rolled steel sheet;

after the hot-rolled sheet annealing, obtaining a cold-rolled steel sheet by cold rolling;

decarburization annealing the cold-rolled steel sheet; and

after the decarburization annealing, coating an annealing separating agent containing MgO and finish annealing, wherein

the hot rolling comprises rough rolling with a finishing temperature of 1200° C. or less and finish rolling with a start temperature of 1000° C. or more and a finishing temperature of 950° C. to 1100° C.,

in the hot rolling, the finish rolling is started within 300 seconds after start of the rough rolling,

cooling at a cooling rate of 50° C/second or more is started within 10 seconds after finish of the finish rolling,

a holding temperature of the hot-rolled sheet annealing is 950° C. to (Tf +100)° C. when the finishing temperature of the finish rolling is Tf, and

the molten steel comprises a chemical composition represented by, in mass%,

C: 0.015% to 0.10%,

Si: 2.0% to 5.0%,

Mn: 0.03% to 0.12%,

acid-soluble Al: 0.010% to 0.065%,

N: 0.0040% to 0.0100%,

Cu: 0.60% to 1.00%,

Cr: 0% to 0.3%,

P: 0% to 0.5%,

Ni: 0% to 1%,

S or Se, or both thereof: 0.005% to 0.050% in total,

Sb or Sn, or both thereof: 0.000% to 0.3% in total,

Y, Te, La, Ce, Nd, Hf, Ta, Pb, or Bi, or any combination thereof: 0.0000% to 0.01% in total, and

the balance: Fe and impurities.

3. The manufacturing method according to claim 2 , wherein the casting comprises magnetically stirring the molten steel in a region where a thickness of one-side solidified shell is equal to or more than 25% of a thickness of the slab.

4. The manufacturing method according to claim 2 , wherein the chemical composition satisfies: at least one of

Sb or Sn, or both thereof: 0.003% to 0.3% in total and

Y, Te, La, Ce, Nd, Hf, Ta, Pb, or Bi, or any combination thereof: 0.0005% to 0.01% in total.