Coated metal sheet having an amino acid to improve corrosion resistance
AssigneeArcelorMittal
InventorsLydia Rachiele, Herve Derule, Delphine Thai
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Abstract
A coated metal sheet is provided. The coated metal sheet includes a steel substrate, a metal coating on at least one face of the steel substrate, the metal coating comprising at least 40% by weight of zinc; and a layer coating an outer surface of the metal coating, the layer including an amino acid in a neutral or salt form, the amino acid being selected from among alanine, arginine, aspartic acid, cysteine, glutamine, lysine, methionine, proline, serine, threonine, or of a mixture thereof, the amount of said amino acid or of said mixture being from 0.1 to 200 mg/m2, and optionally a base or a mixture of bases, or an acid or a mixture of acids.
Claims18
A coated metal sheet comprising:
- a steel substrate;
- a metal coating on at least one face of the steel substrate, the metal coating comprising at least 40% by weight of zinc;
- and
- a layer coating an outer surface of the metal coating, the layer consisting of:
- an amino acid in a neutral or salt form, the amino acid being selected from among alanine, arginine, aspartic acid, cysteine, glutamine, lysine, methionine, proline, serine, threonine, or of a mixture thereof, the amount of said amino acid or of said mixture being from 0.1 to 200 mg/m2, and
- optionally a base or a mixture of bases, or an acid or a mixture of acids.
A metal sheet obtained by a method comprising at least the steps of:
- providing a steel substrate, at least one face of which is coated with a metal coating comprising at least 40% by weight of zinc,
- applying on the outer surface of the metal coating an aqueous solution consisting of:
- water;
- an amino acid selected from the group consisting of neutral and salts forms of alanine, arginine, aspartic acid, cysteine, glutamine, lysine, methionine, proline, serine, threonine, and mixtures thereof, and
- optionally a base or a mixture of bases, or an acid or a mixture of acids;
- wherein the aqueous solution is free of any compound comprising a metal from the group IIIB or from the group IVB and the mass percentage as a dry extract of the amino acid in neutral or salt form or of the mixture of amino acids in neutral or salt forms in the aqueous solution is greater than or equal to 75%,
- wherein at least one portion of at least one outer surface of the metal coating is coated with a layer comprising from 0.1 to 200 mg/m2 of said amino acid in the neutral or salt form or of a mixture of said amino acids in the neutral or salt forms.
A metal sheet obtained by a method comprising at least the steps of:
- providing a steel substrate, at least one face of which is coated with a metal coating comprising at least 40% by weight of zinc,
- applying on the outer surface of the metal coating an aqueous solution consisting of:
- water;
- an amino acid selected from the group consisting of neutral and salts forms of alanine, arginine, aspartic acid, cysteine, glutamine, lysine, methionine, proline, serine, threonine, and mixtures thereof, and
- optionally a base or a mixture of bases, or an acid or a mixture of acids;
- wherein the aqueous solution is free of any compound comprising a metal from the group IIIB or from the group IVB and the mass percentage as a dry extract of the amino acid in neutral or salt form or of the mixture of amino acids in neutral or salt forms in the aqueous solution is greater than or equal to 75%,
- wherein the steel substrate at least one face of which is coated with a metal coating is a hot galvanized steel substrate.
Dependencies are inferred from the claim text.