Grain-oriented electrical steel sheet and method for manufacturing same
In a grain-oriented electrical steel sheet including: a steel substrate; a forsterite base film; and an insulating coating, critical damage shear stress τ between the forsterite base film and the steel substrate is 50 MPa or more and 200 MPa or less. Thus, a grain-oriented electrical steel sheet having excellent insulation property, stacking factor, and magnetic property is provided without coating damage even when magnetic domain refining treatment by thermal strain is performed.
1. A grain-oriented electrical steel sheet comprising:
a steel substrate;
a forsterite base film; and
an insulating coating,
wherein critical damage shear stress τ between the forsterite base film and the steel substrate is 50 MPa or more and 200 MPa or less, the critical damage shear stress τ being measured in accordance with JIS R 3255,
wherein the grain-oriented electrical steel sheet has a non-heat resistant magnetic domain refining region,
wherein a heat-affected width w is 50 μm or more and (2τ+150) μm or less, the heat-affected width w being a width of a thermal strain portion in the non-heat resistant magnetic domain refining region and the τ is a value expressed in MPa, and
wherein the grain-oriented electrical steel sheet has a coating damaged part area ratio of 10% or less.
2. The grain-oriented electrical steel sheet according to claim 1 ,
wherein the critical damage shear stress τ between the base film and the steel substrate is 100 MPa or more and 200 MPa or less.
3. The grain-oriented electrical steel sheet according to claim 1 ,
wherein the critical damage shear stress τ between the base film and the steel substrate is 100 MPa or more and 200 MPa or less, and
wherein the grain-oriented electrical steel sheet has no coating damaged part.