A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention, includes: manufacturing a cold-rolled sheet; forming a groove by irradiating a laser beam on the cold-rolled sheet; and partially removing an oxide layer formed on a surface of the cold-rolled sheet so that a thickness of the oxide layer remains at 1 to 5 nm, wherein the grain-oriented electrical steel sheet has islands of 0.25 or less having sphericity of 0.5 to 0.9 under the oxide layer under the groove.

This grain-oriented electrical steel sheet includes a base steel sheet, a forsterite-based primary film disposed on a surface of the base steel sheet, and a phosphate-based tension-imparting film containing no chromium, which is disposed on a surface of the primary film. In a case where a Ti content and a S content are respectively expressed as XTi and XS, by mass %, the forsterite-based primary film satisfies Expression (1) and Expression (2). A strain-introduced magnetic domain control is performed on the grain-oriented electrical steel sheet.

0.10≤XTi/XS≤10.00   Expression (1)

XTi+XS≥0.10 mass %.   Expression (2)

Coated grain oriented electrical steel plates and methods of producing the same are provided. In an exemplary embodiment, a method includes producing molten steel with from about 2.5 to about 4 weight percent silicon, from about 0.005 to about 0.1 weight percent carbon, and from about 90 to about 97.5 weight percent iron. The molten steel is cast into a slab and then cold rolled into a plate having a surface. The plate is decarbonized using a decarbonization anneal, and then recrystallized using a recrystallization anneal to produce grain oriented electrical steel. A coating is applied overlying the surface, where the coating includes an organic radiation curable crosslinking agent and a photo-initiator. The coating is cured by exposing it to a radiation source.

A double oriented electrical steel sheet according to an embodiment of the present invention includes: in wt %, Si at 2.0 to 4.0 wt %, Al at 0.01 to 0.04 wt %, S at 0.0004 to 0.002 at %, Mn at 0.05 to 0.3 wt %, N at 0.008 wt % or less (excluding 0 wt %), C at 0.005 wt % or less (excluding 0 wt %), P at 0.005 to 0.15 wt %, Ca at 0.0001 to 0.005 wt %, Mg at 0.0001 to 0.005 wt %, and the balance including Fe and other impurities unavoidably added thereto.

[Problem] To provide: a coating liquid for forming an insulation coating for grain-oriented electrical steel sheets, which enables the achievement of excellent coating properties including high coating tension and excellent corrosion resistance even without using a chromium compound; a grain-oriented electrical steel sheet; and a method for producing a grain-oriented electrical steel sheet. [Solution] A coating liquid for forming an insulation coating for grain-oriented electrical steel sheets, which contains boric acid and hydrated silicate particles containing aluminum.

Provided is a method of producing a grain-oriented electrical steel sheet having uniform and good coating properties and magnetic properties throughout the length and/or width of the steel sheet. The method comprises: subjecting a steel slab to hot rolling, to cold rolling once or twice or more with intermediate annealing therebetween, and to primary recrystallization annealing; applying a liquid or slurry annealing separator to a resultant steel sheet; and thereafter coiling the steel sheet and subjecting the steel sheet to final annealing, wherein, before, after, or simultaneously with the application of the annealing separator, an additive for changing a composition of the annealing separator is adhered to the steel sheet at a weight ratio of 15% or less to a total of the annealing separator and the additive so as to vary the composition of the annealing separator in a longitudinal direction and/or width direction of the steel sheet.

There is provided a water-based alkaline composition for forming an insulating layer of an annealing separator on a soft magnetic alloy, this composition comprising ceramic particles with a particle size of less than 0.5pm and at least one polymer dispersion as a binding agent, the polymer dispersion comprising one or more mixed polymerisates from the group made up of acrylate polymers, methacrylate polymers, polyvinyl acetate, polystyrene, polyurethane, polyvinyl alcohol, hydroxylated cellulose ether, polyvinyl pyrrolidone, and polyvinyl butyral, and having a pH value of between 8 and 12, preferably between 9 and 11.

There is provided a water-based alkaline composition for forming an insulating layer of an annealing separator on a soft magnetic alloy, this composition comprising ceramic particles with a particle size of less than 0.5pm and at least one polymer dispersion as a binding agent, the polymer dispersion comprising one or more mixed polymerisates from the group made up of acrylate polymers, methacrylate polymers, polyvinyl acetate, polystyrene, polyurethane, polyvinyl alcohol, hydroxylated cellulose ether, polyvinyl pyrrolidone, and polyvinyl butyral, and having a pH value of between 8 and 12, preferably between 9 and 11.

A soft magnetic alloy comprising 2 wt %≤Co≤30 wt %, 0.3 wt %≤V≤5.0 wt % and iron is provided. The soft magnetic alloy has a area proportion of a {111}<uvw> texture of no more than 13%, preferably no more than 6%, including grains with a tilt of up to +/−10°, or preferably of up to +/−15°, when compared to the nominal crystal orientation.

In an embodiment a FeCoV alloy is provided with a composition consisting essentially of 30 wt %≤Co≤55 wt %, 0.4 wt %≤V≤1.5 wt %, 0 wt %≤Nb≤0.15 wt %, 0.0 wt %≤Ta≤0.20 wt %, 0.04 wt %≤Nb+0.5.Math.Ta≤0.15 wt %, max. 0.02 wt % C, 0.0 wt %≤Si≤0.50 wt %, 0.0 wt %≤Al≤0.50 wt %, max. 0.5 wt % Mn, max. 0.5 wt % Cr, max. 0.5 wt % Ni, max. 0.5 wt % W, max. 0.5 wt % Mo, max. 0.5 wt % Zr, the rest Fe and up to 1 wt % of other impurities, and having a phase transition from a ferritic α-phase region to a mixed ferritic/austenitic α+γ-region that takes place at a transition temperature T(α/α+γ), where T(α/α+γ)≥900° C., preferably ≥920° C., preferably ≥940° C.