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 μm 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.

There is provided a non-oriented electrical steel sheet that includes a base metal steel sheet and an insulating coating film that is formed on a surface of the base metal steel sheet, wherein the insulating coating film mainly contains metal phosphate, organic resin, and water-soluble organic compound, the metal phosphate contains at least aluminum as a metallic element, the organic resin has an SP value being within a range of 18.0 (MPa).sup.0.5 or more to less than 24.0 (MPa).sup.0.5, the water-soluble organic compound has an SP value being within a range of 19.0 (MPa).sup.0.5 or more to less than 35.0 (MPa).sup.0.5, and when measurement by X-ray diffractometry is performed on the insulating coating film, a degree of crystallinity of aluminum phosphate calculated from a peak from the metal phosphate is within a range of 0.5 to 5.0%.

A method of forming a protective coating. The method includes providing a substrate including at least one chemical element and a surface; forming a basecoat composition including an aluminium phase including aluminium;

applying the basecoat composition on the surface of the substrate to form a basecoat layer; heating the basecoat layer to a first temperature for a predetermined period of time; applying a glow discharge plasma on the basecoat layer; and heating the basecoat layer to a second temperature greater than the first temperature, in order to activate an exothermic reaction between at least the aluminium phase of the basecoat layer and the at least one chemical element of the substrate, wherein the exothermic reaction forms the protective coating on the surface of the substrate.

A method of forming a protective coating. The method includes providing a substrate including at least one chemical element and a surface; forming a basecoat composition including an aluminium phase including aluminium;

applying the basecoat composition on the surface of the substrate to form a basecoat layer; heating the basecoat layer to a first temperature for a predetermined period of time; applying a glow discharge plasma on the basecoat layer; and heating the basecoat layer to a second temperature greater than the first temperature, in order to activate an exothermic reaction between at least the aluminium phase of the basecoat layer and the at least one chemical element of the substrate, wherein the exothermic reaction forms the protective coating on the surface of the substrate.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2), the insulating film (3) containing a polyvalent metal phosphate and Fe. A maximum value of a parameter Q expressed by “Q=C.sub.Fe—O/C.sub.P” is equal to or less than 1.3 times an average value of the parameter Q in a region from a first depth from a surface of the insulating film to a second depth, C.sub.Fe—O denoting a proportion (atom %) of Fe bonded to O relative to all elements, and C.sub.P denoting a proportion (atom %) of P relative to all elements. The first depth is 20 nm from the surface, and the second depth is a depth where the proportion of P is equal to a proportion of metal Fe.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphate of one or more selected from the group consisting of Al, Zn, Mg and Ca. A proportion of an amount by mole (mol) of Fe atoms relative to an amount by mole (mol) of P atoms in the insulating film (3) is more than 0.1 nor more than 0.65.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphate of one or more selected from the group consisting of Al, Zn, Mg and Ca. A proportion of an amount by mole (mol) of Fe atoms relative to an amount by mole (mol) of P atoms in the insulating film (3) is more than 0.1 nor more than 0.65.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphates of one or more selected from the group consisting of Al, Zn, Mg and Ca. The phosphate exhibits a specific peak having a top within a range of −26 ppm to −16 ppm in a solid .sup.31P-NMR spectrum, and a proportion of an integrated intensity of the specific peak relative to an integrated intensity of all peaks in the solid .sup.31P-NMR spectrum is 30% or more.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphates of one or more selected from the group consisting of Al, Zn, Mg and Ca. The phosphate exhibits a specific peak having a top within a range of −26 ppm to −16 ppm in a solid .sup.31P-NMR spectrum, and a proportion of an integrated intensity of the specific peak relative to an integrated intensity of all peaks in the solid .sup.31P-NMR spectrum is 30% or more.

Disclosed is an activating rinse for treating at least a portion of a substrate, comprising a dispersion of metal phosphate particles having a D.sub.90 particle size of no greater than 10 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof; a dispersant; and a metal sulfate salt. Methods of treating a substrate with the activating rinse also are disclosed. Optionally, substrates treated with the activating rinse also are disclosed.