Provided is a grain-oriented electrical steel sheet having better transformer iron loss property than conventional grain-oriented electrical steel sheets. A grain-oriented electrical steel sheet comprises: a steel substrate; a forsterite film on a surface of the steel substrate; and a Cr-depleted layer at a boundary between the steel substrate and the forsterite film, the Cr-depleted layer having a Cr concentration that is 0.70 times to 0.90 times a Cr concentration of the steel substrate.

A non-oriented electrical steel sheet according to one embodiment of the invention has a chemical composition represented by C: 0.0030% or less, Si: 2.00% or less, Al: 1.00% or less, Mn: 0.10% to 2.00%, S: 0.0030% or less, one or more selected from the group consisting of Mg, Ca, Sr, Ba, Nd, Pr, La, Ce, Zn, and Cd: 0.0003% or greater and less than 0.0015% in total, a parameter Q represented by Q=[Si]+2×[Al]−[Mn]: 2.00 or less; Sn: 0.00% to 0.40%, Cu: 0.00% to 1.00%, and a remainder: Fe and impurities, and a parameter R represented by R−(I.sub.100+I.sub.310+I.sub.411+I.sub.521)/(I.sub.111+I.sub.211+I.sub.332+I.sub.221) is 0.80 or greater.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt%, Si: 2.2 to 4.5 %, Mn: 0.5 % or less (excluding 0 %), AI: 0.001 to 0.5 %, Sn: 0.07 to 0.25 %, and N: 0.0010 to 0.0090 %, and the balance of Fe and inevitable impurities.

A surface layer portion existing in an inner direction from a surface of the steel sheet and a central portion existing inside the surface layer portion are included, and the central portion includes N at 0.005 wt% or less, and the surface layer portion further includes N at 0.001 wt% or more compared to the central portion; and the surface layer portion has an average grain size of 60 .Math.m or less, while the central portion has an average grain size of 70 to 300 .Math.m.

A method for manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of: hot-rolling a slab to prepare a hot-rolled sheet, the slab containing, in wt %, 2.0 to 6.0% of Si, 0.04 to 0.12% of Mn, 0.001 to 0.022% of N, 0.027 to 0.060% of C, 0.01 to 0.08% of Nb, 0.01% or less of Ti, and the balance of Fe and other inevitable impurities; cold-rolling the hot-rolled sheet to prepare a cold-rolled sheet; and subjecting the primarily recrystallization-annealed cold-rolled sheet to secondary recrystallization annealing.

An exemplary embodiment in the present disclosure provides a grain-oriented electrical steel sheet containing, by wt %: 3.0 to 4.5% of Si; 0.05 to 0.2% of Mn; 0.015 to 0.035% of Al; 0.0015% or less (excluding 0%) of C; 0.0015% or less (excluding 0%) of N; 0.0015% or less (excluding 0%) of S; and a balance of Fe and other unavoidable impurities, wherein the grain-oriented electrical steel sheet satisfies the following Relational Expressions 1 and 2:

(W.sub.13/50/W.sub.17/50)≤0.57  [Relational Expression 1]

(W.sub.15/50/W.sub.17/50)≤0.76  [Relational Expression 2] where Wx/y represents a core loss value under conditions in which a magnitude of an applied magnetic field is x/10 T and a frequency is y Hz.

Provided is a grain-oriented electrical steel sheet that has excellent magnetic properties and can be manufactured by secondary recrystallization orientation control using coil annealing with high productivity. A grain-oriented electrical steel sheet comprises a specific chemical composition, wherein an average value of a deviation angle (α.sup.2+β.sup.2).sup.1/2 calculated from a deviation angle α from ideal Goss orientation around an ND rotation axis and a deviation angle β from ideal Goss orientation around a TD rotation axis is 5.0° or less, and an area ratio R.sub.β of crystal grains with β≤0.50° is 20% or less.

A grain-oriented electrical steel sheet includes: a base steel sheet having a predetermined chemical composition; a glass coating provided on the surface of the base steel sheet; and a tension-applying insulation coating provided on the surface of the glass coating, in which linear thermal strains having, a predetermined angle (φ) with respect to a transverse direction which is a direction orthogonal to a rolling direction are periodically formed on the surface of the tension-applying insulation coating at predetermined intervals along the rolling direction, a full width at half maximum F1 on the linear thermal strain and a full width at half maximum F2 at an intermediate position between the two linear thermal strains adjacent to each other satisfy 0.00<(F1−F2)/F2≤0.15, the width of the linear thermal strain is 10 μm or more and 300 μm or less, and in the base steel sheet, an orientation distribution angle γ around a rolling direction axis of secondary recrystallization grains, an orientation distribution angle α around an axis parallel to a normal direction, and an orientation distribution angle β around an axis perpendicular to each of the RD axis and the ND axis in units of ° satisfy 1.0≤γ≤8.0 and 0.0≤(α.sup.2+β.sup.2).sup.0.5≤10.0.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 1.5 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.015 to 0.1%, P: 0.005 to 0.05%, Ga: 0.001 to 0.004%, and Bi: 0.0005 to 0.003%, and the balance of Fe and inevitable impurities. An area fraction of texture in a {118}//ND orientation is higher than that of texture in a {111}///ND orientation.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 1.5% or less, C: 0.01% or less (excluding 0%), Mn: 0.03 to 3%, P: 0.01 to 0.2%, S: 0.001 to 0.02%, Al: 0.01% or less (excluding 0%), N: 0.005% or less (excluding 0%), Cu: 0.02 to 0.3%, 0.0001 to 0.005 wt % of Ca and Mg either alone or in total, 0.001 to 0.2 wt % of Sb and Sn either alone or in total, and a balance of Fe and inevitable impurities.

A grain-oriented electrical steel sheet according to the present invention includes a base steel sheet having plural grooves on a surface and a glass film formed on the surface of the base steel sheet. In case of viewing region including grooves in cross section orthogonal to groove longitudinal direction, a straight line passing through peak point present on profile line of glass film and parallel to groove width direction orthogonal to sheet thickness direction in cross section is defined as reference line, a point present on boundary line between glass film and base steel sheet and present at lowest location in sheet thickness direction is defined as deepest point, and a point present on boundary line and present at the highest location in the sheet thickness direction in region having the deepest point in a center and having length of 2 μm in groove width direction is defined as shallowest point, a relationship between shortest distance A between reference line and deepest point and shortest distance B between reference line and shallowest point satisfies Expression (1).
0.1 μm≤A−B≤5.0 μm  (1)