A method for coating, a composition suitable for coating and a coating generated with the method of coating on anodizable metallic surfaces, especially on magnesium rich and aluminum rich surfaces, is disclosed. The composition is an aqueous solution including alkali metal or ammonium cations, phosphorus containing anions and silicon containing anions as well as optionally a peroxide or a compound of Al, Ti, Zr or any mixture of them. Preferably, the anodizing is carried out with a micro-arc oxidation process.

A steel sheet for containers that has excellent film adhesion qualities, and has; a chemical conversion coating formed by immersing or subjecting to electrolytic treatment a steel sheet in a solution containing Zr ions, F ions, with adhesion amount of 0.1 to 100 mg/m.sup.2 for metal Zr and no more than 0.1 mg/m.sup.2 for F; and a hydroxyl acid treatment layer formed on the chemical conversion coating, the layer having a C adhesion amount of 0.05 to 50 mg/m.sup.2.

A steel sheet for containers that has excellent film adhesion qualities, and has; a chemical conversion coating formed by immersing or subjecting to electrolytic treatment a steel sheet in a solution containing Zr ions, F ions, with adhesion amount of 0.1 to 100 mg/m.sup.2 for metal Zr and no more than 0.1 mg/m.sup.2 for F; and a hydroxyl acid treatment layer formed on the chemical conversion coating, the layer having a C adhesion amount of 0.05 to 50 mg/m.sup.2.

A black plated resin part includes a resin base material, an underlying plating layer including a copper plating layer and a nickel plating layer formed in this order on the resin base material, a black chromium plating layer formed on the nickel plating layer, formed of trivalent chromium, and having a film thickness of not less than 015 m, and a corrosion resistant film formed on the black chromium plating layer, formed of chromic phosphate or molybdenum phosphate, and having a film thickness of not less than 7 nm. A brightness of the black chromium plating layer seen through the corrosion resistant film is expressed by an L* value of not more than 54 based on the L*a*b* color system.

A hot stamped steel includes a base material that is formed of steel, a plated layer that is formed on a surface of the base material, and a phosphate coating that is formed on a surface of the plated layer; chemical composition of the plated layer contains 20.00 to 45.00 mass % of Al, 10.00 to 45.00 mass % of Fe, 4.50 to 15.00 mass % of Mg, 0.10 to 3.00 mass % of Si, 0.05 to 3.00 mass % of Ca, and the plated layer may further contain one or more of Sb, Pb, Cu, Sn, Ti, Sr, Cr, Ni, and Mn with a remainder of Zn and impurities; the phosphate coating comprises zinc phosphate crystals containing 5.0 to 50.0 mass % of Mg and 0.5 to 5.0 mass % of Ca; and the adhesion amount of the phosphate coating per one surface is in a range of 0.1 to 10.0 g/m.sup.2.

A hot stamped steel includes a base material that is formed of steel, a plated layer that is formed on a surface of the base material, and a phosphate coating that is formed on a surface of the plated layer; chemical composition of the plated layer contains 20.00 to 45.00 mass % of Al, 10.00 to 45.00 mass % of Fe, 4.50 to 15.00 mass % of Mg, 0.10 to 3.00 mass % of Si, 0.05 to 3.00 mass % of Ca, and the plated layer may further contain one or more of Sb, Pb, Cu, Sn, Ti, Sr, Cr, Ni, and Mn with a remainder of Zn and impurities; the phosphate coating comprises zinc phosphate crystals containing 5.0 to 50.0 mass % of Mg and 0.5 to 5.0 mass % of Ca; and the adhesion amount of the phosphate coating per one surface is in a range of 0.1 to 10.0 g/m.sup.2.

The invention relates to a biodegradable implant comprising a surface coated magnesium alloy or zinc alloy product, whereby the coating layer comprises oxides and/or phosphates of from rare-earth elements, Mg, Ca, Zn, Zr, Cu, Fe, Sr, Li, Mn or Ag wherein the coating is preferably generated by plasma electrolytically oxidation (PEO). The invention further comprises a method for preparing the coated magnesium or zinc alloy product of the implant.

The invention relates to a biodegradable implant comprising a surface coated magnesium alloy or zinc alloy product, whereby the coating layer comprises oxides and/or phosphates of from rare-earth elements, Mg, Ca, Zn, Zr, Cu, Fe, Sr, Li, Mn or Ag wherein the coating is preferably generated by plasma electrolytically oxidation (PEO). The invention further comprises a method for preparing the coated magnesium or zinc alloy product of the implant.

The present invention relates to a method for phosphating metal surfaces, preferably alloy-galvanized steel strip surfaces, by treating them by dipping or spray-dipping with acidic, aqueous solutions which may contain magnesium ions, phosphate ions and nitrate ions and, for further improvement of the layer formation, possibly further ions selected from ammonium ions, alkali metal ions and/or fluoride ions, wherein the workpieces are simultaneously treated cathodically with a direct current.

The present invention relates to a method for phosphating metal surfaces, preferably alloy-galvanized steel strip surfaces, by treating them by dipping or spray-dipping with acidic, aqueous solutions which may contain magnesium ions, phosphate ions and nitrate ions and, for further improvement of the layer formation, possibly further ions selected from ammonium ions, alkali metal ions and/or fluoride ions, wherein the workpieces are simultaneously treated cathodically with a direct current.