A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when a grain size RAα.sub.C, a grain size RAβ.sub.C, and a grain size RAγ.sub.C are defined in a transverse direction C, the grain sizes satisfy RAγ.sub.C<RAα.sub.C and RAγ.sub.C<RAβ.sub.C.

These steel sheet for hot stamping and hot-stamping formed body have predetermined chemical composition and metallographic structures, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<−1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<−1-12> are controlled.

A grain-oriented electrical steel sheet includes: a silicon steel sheet including Si and Mn; a glass film arranged on a surface of the silicon steel sheet; and an insulation coating arranged on a surface of the glass film, wherein the glass film includes a Mn-containing oxide.

A method for manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises: a step for hot-rolling a slab to produce a hot-rolled sheet; a step for cold-rolling the hot-rolled sheet to produce a cold-rolled sheet; a step for subjecting the cold-rolled sheet to primary recrystallization annealing; and a step for subjecting the primary recrystallization annealing-completed cold-rolled sheet to secondary recrystallization annealing, wherein the primary recrystallization annealing step includes a preceding step and a subsequent step, and the amount (A) of nitriding gas introduced in the preceding step with respect to the total amount (B) of nitriding gas introduced in the primary recrystallization annealing step satisfies expression 1 below.
0.05≤[A]/[B]≤[t]  [Expression 1] (In expression 1, the amount of nitriding gas introduced is in units of Nm.sup.3/hr, and [t] represents the thickness (mm) of a cold-rolled sheet.)

A high-strength steel sheet with a tensile strength of 1,180 MPa or more has a predetermined chemical composition and a steel microstructure in which the area fraction of ferrite is 5% or less, the area fraction of martensite is 2% to 10%, the area fraction of bainite is 5% to 37%, the area fraction of tempered martensite is 42% to 65%, the volume fraction of retained austenite is 3% to 15%, the average grain size of ferrite and bainite is 3 μm or less, in a region extending 50 μm from a surface of the steel sheet in a through-thickness direction, and the average grain size of prior austenite grains is 10 μm or less, the average grain size of the prior austenite grains in the through-thickness direction is 0.9 or less of the average grain size thereof in a rolling direction.

Provided are: an oriented electrical steel sheet having a high tension applied to a steel sheet and excellent adhesion to a film; and a method for producing the same. This oriented electrical steel sheet includes: a steel sheet; a film A containing a crystalline material disposed on the steel sheet; and a film B containing a vitreous material disposed on the film A, wherein an element profile, which is obtained by using a high-frequency glow discharge light-emission surface analysis method, in the direction from the film B to the steel sheet satisfies formulae (1) and (2). 0.35≤(t.sub.A/t.sub.Fe/2)≤0.75 . . . (1), 0.25≤(t.sub.A/2/t.sub.Fe/2)≤1.00 . . . (2), where t.sub.A represents the peak time of an alkali metal element profile, t.sub.A/2 represents the half time of an alkali metal.

A non-oriented electrical steel sheet with an average magnetostriction λ.sub.p-p at 400 Hz and 1.0 T of not more than 4.5×10.sup.−6, and area ratio of recrystallized grains at a section in rolling direction of steel sheet of 40 to 95% and an average grain size of 10 to 40 μm is obtained by subjecting a steel slab containing, in mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si-2Al-Mn≥0 to hot rolling, hot-band annealing, cold rolling and finish annealing under adequate cold rolling and finish annealing conditions, and a motor core is manufactured by such a steel sheet.

A double-oriented electrical steel sheet according to an example of the present invention comprises, by weight 2.0 to 4.0 wt % of Si, 0.01 to 0.04 wt % of Al, 0.0004 to 0.02 wt % of S, 0.05 to 0.3 wt % of Mn, at most 0.01 wt % (exclusive of 0 wt %) of N, at most 0.005 wt % (exclusive of 0 wt %) of C, 0.005 to 0.15 wt % of P, 0.001 to 0.005 wt % of Ti, and 0.0001 to 0.005 wt % of Mg, with the balance being Fe and other inevitable impurities, wherein the area fraction of crystal grains having an orientation within 15° from {100}<001> is 60 to 99%, and the area fraction of crystal grains having an orientation within 15° from {100}<025> is 1 to 30%.

A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg.sub.2 SiO.sub.4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 .Math.m from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 .Math.m/.Math.m.sup.2, and a number density of Al oxides is 0.02 to 0.20 /.Math.m.sup.2.