The present patent application relates to an aqueous composition for coating grain oriented steel, comprising aluminium cations, manganese cations, dihydrogen phosphate, hydrogen phosphate and/or phosphate anions, colloidal silica and optionally iron cations, wherein the aluminium cations, expressed as Al.sub.2O.sub.3, manganese cations, expressed as MnO, dihydrogen phosphate, hydrogen phosphate and/or phosphate anions, expressed as P.sub.2O.sub.5, colloidal silica, expressed as SiO.sub.2, and optionally iron cations, expressed as FeO, which are present in the composition, give the sum formula of (Al.sub.2O.sub.3).sub.2(MnO).sub.1,8-2,4(FeO).sub.0-0,2(P.sub.2O.sub.5).sub.5-7(SiO.sub.2).sub.≥30.

The present patent application relates to an aqueous composition for coating grain oriented steel, comprising aluminium cations, manganese cations, dihydrogen phosphate, hydrogen phosphate and/or phosphate anions, colloidal silica and optionally iron cations, wherein the aluminium cations, expressed as Al.sub.2O.sub.3, manganese cations, expressed as MnO, dihydrogen phosphate, hydrogen phosphate and/or phosphate anions, expressed as P.sub.2O.sub.5, colloidal silica, expressed as SiO.sub.2, and optionally iron cations, expressed as FeO, which are present in the composition, give the sum formula of (Al.sub.2O.sub.3).sub.2(MnO).sub.1,8-2,4(FeO).sub.0-0,2(P.sub.2O.sub.5).sub.5-7(SiO.sub.2).sub.≥30.

Provided are coated metal, the metal having improved properties due to a novel coating, a coating-forming treatment solution for forming the novel coating, and a method for producing the coated metal that has the novel coating. The coated metal includes metal and a coating formed on the metal. The coating includes Si, P, and O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn. The coating includes a compound having a Na Super Ionic Conductor-type (NASICON-type) crystal structure represented by a general formula M.sup.IM.sup.IV.sub.2(M.sup.VO.sub.4).sub.3.

Provided are coated metal, the metal having improved properties due to a novel coating, a coating-forming treatment solution for forming the novel coating, and a method for producing the coated metal that has the novel coating. The coated metal includes metal and a coating formed on the metal. The coating includes Si, P, and O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn. The coating includes a compound having a Na Super Ionic Conductor-type (NASICON-type) crystal structure represented by a general formula M.sup.IM.sup.IV.sub.2(M.sup.VO.sub.4).sub.3.

The grain-oriented electrical steel sheet according to the present invention is a grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4), and the grain-oriented electrical steel sheet includes a surface of the base steel sheet (1) having a groove (G) which extends in a direction intersecting a rolling direction of the base steel sheet (1), in which in a cross-sectional view of a plane parallel to the rolling direction and a sheet thickness direction of the base steel sheet (1), when a region between end portions of the groove (G) is defined as a groove part (R.sub.G), an average thickness of the intermediate layer (4) of the groove part (R.sub.G) is 0.5 times or more and 3.0 times or less an average thickness of the intermediate layer (4) other than the groove part (R.sub.G), and an area ratio of voids in the insulation coating (3) of the groove part (R.sub.G) is 15% or less.

An electrical steel sheet having excellent coating peel resistance that can be exhibited during a stamping process, so that sticking of the coating to a die is inhibited. The electrical steel sheet has an insulating coating disposed on at least one surface of the electrical steel sheet. The insulating coating (i) includes a composite comprising P and Al, (ii) has an aspect ratio in a range of 1 to 10, and (iii) has a thickness in a range of 500 nm to 2000 nm. The composite has a particle diameter in a range of 10 nm to 1000 nm.

An electrical steel sheet having excellent coating peel resistance that can be exhibited during a stamping process, so that sticking of the coating to a die is inhibited. The electrical steel sheet has an insulating coating disposed on at least one surface of the electrical steel sheet. The insulating coating (i) includes a composite comprising P and Al, (ii) has an aspect ratio in a range of 1 to 10, and (iii) has a thickness in a range of 500 nm to 2000 nm. The composite has a particle diameter in a range of 10 nm to 1000 nm.

A grain-oriented electrical steel sheet according to an aspect of the present invention includes an underlying steel sheet and a tension-insulation coating arranged on the surface of the underlying steel sheet, and a ten-point average roughness RzL in an L direction obtained when the tension-insulation coating is removed from the grain-oriented electrical steel sheet with an alkaline solution, and then the surface of the underlying steel sheet is measured in a rolling direction is 6.0 μm or less.

The grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, including a base steel sheet having a predetermined chemical component, a silicon-containing oxide layer provided on the base steel sheet, an iron-based oxide layer provided on the silicon-containing oxide layer, and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry, predetermined requirements are satisfied.

The grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, including a base steel sheet having a predetermined chemical component, a silicon-containing oxide layer provided on the base steel sheet, an iron-based oxide layer provided on the silicon-containing oxide layer, and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry, predetermined requirements are satisfied.