Provided is a method for treating a surface of an aluminum article capable of imparting an effective anchoring effect to a surface of the aluminum article and enabling a strong chemical bond between the surface of the aluminum article and an organic material layer such as a coated resin layer or a laminated FRP applied to the surface without using a chemical solution that is not easy to treat. In the method for treating a surface of an aluminum article according to the present invention, the surface of the aluminum article is subjected to at least one of an etching treatment, a boehmite treatment, and a zirconium treatment, and then further subjected to at least one of a silane coupling agent treatment, an isocyanate compound treatment, and a thiol compound treatment.

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.

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.

A composition for washing a pickled steel plate and a method for washing a pickled steel plate using the same are provided. The composition for washing a pickled steel plate includes a phosphoric acid ester compound, an amine-based compound, sodium carbonate, ammonium acetate, ethylene diamine tetraacetic acid (EDTA) and a remainder of water, and the method for washing a pickled steel plate is performed using the same.

A method for preparing a metal sheet (1) is provided including at least the steps for: providing a steel substrate (3) having two faces (5), at least one of which is coated with a metal coating (7) comprising at least 40% by weight of zinc, applying on the outer surface (15) of the metal coating (7) an aqueous solution comprising an amino acid,
and the metal sheet which may be obtained.

A method for preparing a metal sheet (1) is provided including at least the steps for: providing a steel substrate (3) having two faces (5), at least one of which is coated with a metal coating (7) comprising at least 40% by weight of zinc, applying on the outer surface (15) of the metal coating (7) an aqueous solution comprising an amino acid,
and the metal sheet which may be obtained.

Provided are a treatment liquid for a black trivalent chromium conversion coating, and a trivalent chromium-containing water-soluble liquid for finishing treatment, achieving excellent corrosion resistance and scratch resistance without containing a cobalt compound, with high stability and adequate consideration for environmental issues; and a method for treating a metal substrate using the same. The treatment liquid for a black trivalent chromium conversion coating on the surface of a metal substrate contains a trivalent chromium compound, two or more organic acids or organic acid salts, or one or more organic sulfur compounds, and nitrate ions, and contains no cobalt compound.

Provided are a treatment liquid for a black trivalent chromium conversion coating, and a trivalent chromium-containing water-soluble liquid for finishing treatment, achieving excellent corrosion resistance and scratch resistance without containing a cobalt compound, with high stability and adequate consideration for environmental issues; and a method for treating a metal substrate using the same. The treatment liquid for a black trivalent chromium conversion coating on the surface of a metal substrate contains a trivalent chromium compound, two or more organic acids or organic acid salts, or one or more organic sulfur compounds, and nitrate ions, and contains no cobalt compound.

Provided are: a grain-oriented electrical steel sheet that has excellent coating adhesiveness and an excellent magnetic property after stress relief annealing; and a production method for therefor. The grain-oriented electrical steel sheet has: a steel sheet; a coating layer A which is a ceramic coating having an oxide content of less than 30 mass % and which is disposed on the steel sheet; and a coating layer B which is an insulating tensile coating containing an oxide and which is disposed on the coating layer A. When a Gaussian fitting is performed on a .sup.31P-NMR spectrum of the coating layer B within the range of 0 to −60 ppm, the proportion of a peak area of −17 to −33 ppm to the total peak area is 30% or more.

Provided are: a grain-oriented electrical steel sheet that has excellent coating adhesiveness and an excellent magnetic property after stress relief annealing; and a production method for therefor. The grain-oriented electrical steel sheet has: a steel sheet; a coating layer A which is a ceramic coating having an oxide content of less than 30 mass % and which is disposed on the steel sheet; and a coating layer B which is an insulating tensile coating containing an oxide and which is disposed on the coating layer A. When a Gaussian fitting is performed on a .sup.31P-NMR spectrum of the coating layer B within the range of 0 to −60 ppm, the proportion of a peak area of −17 to −33 ppm to the total peak area is 30% or more.