A non-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes, by weight %, Si: 2.5 to 6.0%, Al: 0.2 to 3.5%, Mn: 0.2 to 4.5%, Cr: 0.01 to 0.2%, P: 0.005 to 0.08%, Mg: 0.0005 to 0.05%, and a remainder including Fe and inevitable impurities, while satisfying Equation 1 below, and formed with an inner oxidation layer of a 0.2 to 5 μm thickness inside a base steel sheet.
−2.5≤[P]/[Cr]−[Mg]×100≤6.5  [Equation 1]
(In Equation 1, [P], [Cr], and [Mg] respectively represent a content (by wt %) of P, Cr, and Mg).

Provided is a method for manufacturing a grain-oriented electrical steel sheet. The method comprises: hot rolling a slab to obtain a hot rolled sheet; subjecting the hot rolled sheet to hot band annealing as necessary; subjecting the hot rolled sheet to cold rolling; subjecting the cold rolled sheet to decarburization annealing; applying an annealing separator having MgO as a main component onto a surface of the decarburization annealed sheet and subjecting the decarburization annealed sheet to final annealing to form the forsterite film; and applying an insulating coating treatment liquid onto the final annealed sheet and subjecting the final annealed sheet to flattening annealing to form a tension-applying insulating coating. A difference in total tensions between one and opposite surfaces of the sheet is less than 0.5 MPa. A difference in tensions between the forsterite films in one and opposite surfaces of the sheet is 0.5 MPa or more.

A grain-oriented electrical steel sheet according to an embodiment of the present invention may comprise: by weight %, 2.0-4.0% of Si, 0.04-0.2% of Mn, 0.010% or less (exclusive of 0%) of N, 0.01-0.05% of Sb, 0.005% or less (exclusive of 0%) of C, 0.03-0.08% of Sn, 0.01-0.2% of Cr, and the balance of Fe and inevitable impurities; and precipitates which have an average particle size of 5-50 nm and contain at least one of AIN, (Al, Si)N, (Al, Si, Mn)N, Mns, and CuS.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 2.1 to 3.8%, Mn: 0.001 to 0.6%, Al: 0.001 to 0.6%, Bi: 0.0005 to 0.003%, and Ge: 0.0003 to 0.001%, and the balance of Fe and inevitable impurities.

In a double-oriented electrical steel sheet according to an embodiment of the present invention, the fraction of crystal grains having an orientation within 15° from {100}<001> is 50 to 75%, and the fraction of crystal grains having an orientation within 15° from {100}<380> is 50 to 75%.

The present invention relates to a non-oriented electrical steel sheet including 1.5 to 4.0 wt % of Si, 0.1 to 1.5 wt % of Al, 0.1 to 1.5 wt % of Mn, 0.005 wt % or less (excluding 0%) of C, 0.005 wt % or less (excluding 0%) of N, 0.005 wt % or less (excluding 0%) of Ti, 0.001 to 0.005 wt % of S, 0.1 wt % or less (excluding 0%) of P, 0.02 to 0.2 wt % of at least one of Sn and Sb, and a balance of Fe and other inevitable impurities; and satisfying the following Formulas 1, 2, and 3.
0.9≤[Al]+[Mn]≤2.1  [Formula 1]
0.2≤([Si]+[Al]+[Mn]/2)*([P]+[Sn]+[Sb])≤0.4  [Formula 2]
(Gs.sub.center−Gs.sub.surface)/(Gs.sub.center*t)≤0.5  [Formula 3] (In Formula 1 and Formula 2, [Al], [Mn], [Si], [P], [Sn], and [Sb] represent the content (weight %) of Al, Mn, Si, P, Sn, and Sb, respectively, and in Formula 3, t represents the thickness (mm) of the non-oriented electrical steel sheet, Gs.sub.surface represents the average grain size (μm) from 0 to t/4 or 3t/4 to t based on the thickness direction of the non-oriented steel sheet, Gs.sub.center represents the average grain size (μm) from more than t/4 to less than 3t/4 based on the thickness direction of the non-oriented steel sheet.)

A method for manufacturing a non-oriented electrical steel sheet includes a step of obtaining a hot-rolled steel sheet by performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling on the hot-rolled steel sheet, and a step of performing first annealing after the first cold rolling. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, and cooling of which an average cooling rate is in a range of 50 to 500° C./sec is started in 0.1 sec from completion of rolling of the final pass of the finish rolling and is performed up to a temperature range higher than 250° C. and equal to or lower than 700° C.

The purpose of the present invention is to provide a method for manufacturing a grain-oriented electrical steel sheet, whereby it becomes possible to manufacture a grain-oriented electrical steel sheet having further improved iron loss properties stably. (Solution) According to one aspect of the present invention, a method for manufacturing a grain-oriented electrical steel sheet is provided, the method being characterized by comprising a re-heating step, a hot rolling step, a hot-rolled sheet annealing step, a cold rolling step, a decarburization annealing step and a final annealing step, wherein the decarburization annealing step includes a heating step of heating a cold-rolled sheet from an inlet side temperature T0° C. to a soaking temperature T2° C. and a soaking step of keeping the temperature of the cold-rolled sheet at the soaking temperature T2° C., and the heating rate HR1 from the time point when the temperature of the cold-rolled sheet is an inlet side temperature T0° C. to the time point when the temperature of the cold-rolled sheet reaches a attained temperature T1° C. is 40° C./sec or more and the heating rate HR2 from the time point when the temperature of the cold-rolled sheet is the desired temperature T1° C. to the time point when the temperature of the cold-rolled sheet reaches the soaking temperature T2° C. is more than 15° C./sec to 30° C./sec in the heating in the decarburization annealing step.

A grain oriented electrical steel sheet includes a base steel sheet, a glass film, and a tension-insulation coating. When a glow discharge emission spectroscopy is conducted from a surface of the glass film toward a depth direction, an analysis starting time Ts, a time T.sup.Al.sub.p at which Al shows a maximum emission intensity, an Al emission intensity F(T.sup.Al.sub.p) at the T.sup.Al.sub.p, a time T.sup.Si.sub.p at which Si shows a maximum emission intensity, and an Al emission intensity F(T.sup.Si.sub.p) at the T.sup.Si.sub.p satisfy 0.05≤F(T.sup.Si.sub.p)/F(T.sup.Al.sub.p)≤0.50 and 2.0≤(T.sup.Al.sub.p−Ts)/(T.sup.Si.sub.p−Ts)≤5.0.

[Problem] To provide a grain-oriented electrical steel sheet which is further improved in terms of iron loss before magnetic domain control, while achieving a sufficient iron loss improvement effect even in the control of a heat-resistant magnetic domain where a sufficient iron loss improvement effect has not been achieved. [Solution] A grain-oriented electrical steel sheet according to one aspect of the present invention comprises abase steel sheet and a glass coating that is formed on the surface of the base steel sheet, and is characterized in that: the base steel sheet contains as chemical components, in mass %, 0.010% or less of C, from 2.00% to 4.00% of Si, from 0.05% to 1.00% of Mn, from 0.010% to 0.065% of Al, 0.004% or less of N and 0.010% or less of S, with the balance being made up of Fe and impurities; the oxygen concentration in the glass coating and the base steel sheet is 2,500 ppm or less; and if I.sub.Al_1 is the first peak intensity of Al and I.sub.Al_2 is the second peak intensity of Al in the concentration profile of Al, the relationship of mathematical formula (1) is satisfied.

I.sub.Al_1<I.sub.Al_2   Formula (1):