A production method for a treatment solution for forming an insulating coating. The method includes mixing a solution A containing, on a PO.sub.4.sup.3− basis, 0.20 mol/L or more and 10 mol/L or less of at least one of (i) phosphoric acid and (ii) a phosphate salt, and containing, on a metal basis, less than 0.50 mol/L of one or more particulate metal compounds, and a solution B containing, on a metal basis, 0.50 mol/L or more and 20.0 mol/L or less of the one or more particulate metal compounds, and containing, on a PO.sub.4.sup.3− basis, less than 0.20 mol/L of at least one of (i) phosphoric acid and (ii) a phosphate salt, and stirring with a turbine stator-type high-speed stirrer such that a peripheral speed of a turbine reaches 10 m/s or more within 60 seconds after starting the mixing of the solution A and the solution B.

Provided are an insulating-coated oriented magnetic steel sheet having an insulating coating of excellent heat resistance, and a method for manufacturing the same. This insulating-coated oriented magnetic steel sheet has an oriented magnetic steel sheet, and an insulating coating arranged on the surface of the oriented magnetic steel sheet. The insulating coating contains Si, P, and O, and at least one element selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn, the K-absorption edge of the P in the insulating coating having an XAFS spectrum that exhibits three absorption peaks from 2156 eV to 2180 eV.

Provided are an insulating-coated oriented magnetic steel sheet having an insulating coating of excellent heat resistance, and a method for manufacturing the same. This insulating-coated oriented magnetic steel sheet has an oriented magnetic steel sheet, and an insulating coating arranged on the surface of the oriented magnetic steel sheet. The insulating coating contains Si, P, and O, and at least one element selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn, the K-absorption edge of the P in the insulating coating having an XAFS spectrum that exhibits three absorption peaks from 2156 eV to 2180 eV.

An insulating coating-attached electrical steel sheet has, on at least one surface, an insulating coating including an insulating tensile coating layer A. A tension applied to the steel sheet by an insulating tensile coating layer having a coating weight of M/2 from a surface of the insulating tensile coating layer A is 0.80.sub.A or more, where M is a weight of the insulating tensile coating layer A, and .sub.A is the tension applied to the steel sheet by the insulating tensile coating layer A. The insulating coating-attached electrical steel sheet has excellent adhesion of the insulating coating. A method for manufacturing the insulating coating-attached electrical steel sheet is also provided.

A grain oriented electrical steel sheet includes: a base steel sheet; a lower layer which is arranged in contact with the base steel sheet; and an insulation coating which is arranged in contact with the lower layer and which includes a phosphate and a colloidal silica as main components. The base steel sheet includes the predetermined chemical composition and includes a B compound whose major axis length is 1 to 20 m and whose number density is 110 to 110.sup.6 pieces/mm.sup.3. The lower layer is a glass film which includes a forsterite as main component or an intermediate layer includes a silicon oxide as main component.

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.

A coating solution for forming an insulating film for a grain-oriented electrical steel sheet which contains one or more types of hydrous silicate powders having an average particle size of 2 m or less, and one or more types of phosphoric acids and phosphates satisfying a relation of n.sub.iM.sub.i/P.sub.i0.5, and satisfies (Formula 1). 1.5(n.sub.iM.sub.i+n.sub.jM.sub.j)/P.sub.i15 . . . (Formula 1) (P represents the number of moles of phosphorus, M represents the number of moles of metal ions derived from the phosphate, n represents the valence of the metal ions derived from the phosphate, i represents the number of types of phosphates, M represents the number of moles of metal elements in the hydrous silicate, n represents the valence of the metal elements in the hydrous silicate, and j represents the number of types of hydrous silicates).

A grain oriented electrical steel sheet includes: a base steel sheet; a glass film which is arranged in contact with the base steel sheet; and an insulation coating which is arranged in contact with the glass film and which includes a phosphate and a colloidal silica as main components. The base steel sheet includes the predetermined chemical composition. A BN whose average particle size is 50 to 300 nm is included at a predetermined number density in a region which is from an interface between the glass film and the insulation coating till 5 m toward the base steel sheet in a depth direction. A B emission intensity obtained inside the glass film is more than a B emission intensity obtained inside the base steel sheet, when a B emission intensity is measured from a surface of the insulation coating by a glow discharge emission spectroscopy.

A coating-forming composition for an electrical steel sheet that maintains excellent insulating properties, corrosion resistance, adhesion, and the like required in a coating for an electrical steel sheet, and exhibits excellent viscosity stability, with an increase in viscosity over time being kept gradual. A coating-forming composition for an electrical steel sheet comprises colloidal silica, a phosphate, phenylphosphonic acid or a salt thereof, and an aqueous medium.

A pre-coating agent composition for a grain-oriented electrical steel sheet, a grain-oriented electrical steel sheet including the same, and a manufacturing method thereof are provided. Particularly, a pre-coating agent composition for a grain-oriented electrical steel sheet including an acid containing boron (B); and a solvent, a grain-oriented electrical steel sheet including the same, and a manufacturing method thereof are provided.