A new and improved method for producing electrical steel sheet enabling production of electrical steel sheet excellent in magnetic characteristics and coating film adhesion, the method for producing electrical steel sheet containing a process of bringing an electrical steel sheet containing, by mass %, C: more than 0% and 0.10% or less, Si: 2.5% or more and 4.5% or less, Mn: 0.01% or more and 5.0% or less, a total of one or more of S, Se, and Te: more than 0% and 0.050% or less, acid soluble Al: more than 0% and 5.0% or less, N: more than 0% and 0.015% or less, and P: more than 0% and 1.0% or less and having a balance of Fe and impurities into contact with a solution, the solution containing one or more elements from among Cu, Hg, Ag, Pb, Cd, Co, Zn, and Ni, a total of concentrations of the elements being 0.00001% or more and 1.0000% or less.

Grain-oriented electrical steel sheet excellent in coating adhesion and magnetic properties is provided. The method for manufacturing grain-oriented electrical steel sheet excellent in coating adhesion and magnetic properties includes a process of heating to 1280° C. or more and hot rolling a slab containing, by mass %, Bi and a predetermined composition of constituents and having a balance of Fe and impurities so as to obtain hot rolled steel sheet, a process, after hot rolling annealing the hot rolled steel sheet, of cold rolling it one time or cold rolling it two times or more with process annealing performed interposed so as to obtain cold rolled steel sheet, a process of rapidly heating then decarburization annealing the steel sheet, a process of coating the surface of the cold rolled steel sheet after decarburization annealing with an annealing separator containing predetermined compounds including sulfates or sulfides and having MgO as its main constituent, then performing finish annealing, a process of performing strictly controlled finish annealing, and a process of coating an insulating coating, then performing flattening annealing.

An electrical steel sheet provided with an insulating coating is disclosed. Therefore, a pre-treatment liquid used on an electrical steel sheet having a forsterite coating on a surface thereof is provided before applying an insulating coating treatment liquid containing at least one salt selected from the group consisting of phosphate, borate, and silicate, the pre-treatment liquid. The pre-treatment liquid includes: at least one inorganic acid selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid; and acetic acid, wherein a content of the acetic acid is not less than 1 mass ppm and not more than 3000 mass ppm.

A grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes a grain-oriented magnetic steel sheet and an insulating tension coating containing a phosphate salt and silica on a surface of the grain-oriented magnetic steel sheet, the coating further including a crystalline compound represented by the general formula (1): M.sup.II.sub.3M.sup.III.sub.4(X.sup.VO.sub.4).sub.6 . . . (1). A method for producing a grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes applying an insulating tension coating liquid to a surface of a finish annealed grain-oriented magnetic steel sheet, the coating liquid including colloidal silica, a phosphate salt and a metal element M-containing compound in a specific ratio, and heat treating the steel sheet at least one time at a temperature of not less than 900° C. in an atmosphere including a non-oxidizing gas and having a dew point of not more than 0° C.

A grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes a grain-oriented magnetic steel sheet and an insulating tension coating containing a phosphate salt and silica on a surface of the grain-oriented magnetic steel sheet, the coating further including a crystalline compound represented by the general formula (1): M.sup.II.sub.3M.sup.III.sub.4(X.sup.VO.sub.4).sub.6 . . . (1). A method for producing a grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes applying an insulating tension coating liquid to a surface of a finish annealed grain-oriented magnetic steel sheet, the coating liquid including colloidal silica, a phosphate salt and a metal element M-containing compound in a specific ratio, and heat treating the steel sheet at least one time at a temperature of not less than 900° C. in an atmosphere including a non-oxidizing gas and having a dew point of not more than 0° C.

A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 μm among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMP.sub.C100, ave-AMP.sub.C100 is 0.0001 to 0.050 μm.

A solution for forming an insulation coating of grain-oriented electrical steel sheet includes an aqueous solution prepared by mixing a phosphate solution and colloidal silica. Chromium is not added to the aqueous solution. The colloidal silica includes silica particles surface-modified by an aluminate or is prepared by adding an aluminate to colloidal silica such as conventional colloidal silica.

A solution for forming an insulation coating of grain-oriented electrical steel sheet includes an aqueous solution prepared by mixing a phosphate solution and colloidal silica. Chromium is not added to the aqueous solution. The colloidal silica includes silica particles surface-modified by an aluminate or is prepared by adding an aluminate to colloidal silica such as conventional colloidal silica.

A grain oriented electrical steel sheet includes a base steel sheet, an oxide layer, and a tension-insulation coating. When a glow discharge spectroscopy is conducted in a region from a surface of the tension-insulation coating to an inside of the base steel sheet, a sputtering time Fe.sub.0.5 at which a Fe emission intensity becomes 0.5 times as compared with a saturation value thereof and a sputtering time Fe.sub.0.05 at which a Fe emission intensity becomes 0.05 times as compared with the saturation value satisfy 0.01<(Fe.sub.0.5−Fe.sub.0.05)/Fe.sub.0.5<0.35. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.

Provided is a non-oriented electrical steel sheet having excellent adhesion with an insulating coating even if the thickness of the insulating coating is reduced. The non-oriented electrical steel sheet of the present disclosure has an insulating coating on at least one surface of the steel sheet, where the insulating coating has a P-concentrated layer on both a surface side and an interface side with a steel substrate, and a P concentration of the P-concentrated layer is higher than a P concentration in the steel substrate.