Arcelormittal

Sollac

Arcelormittal France

Total France

Herve Derule

Lydia Rachiele

Jean Steinmetz

Delphine Thai

Nicole Genet

Frida Gilbert

Delphine Thaï

Emmanuel Rocca

Valerie Bour Beucler

Sophie Jacques

A steel substrate is provided, coated on at least one of its faces with a metallic coating based on zinc or its alloys wherein the metallic coating is itself coated with a zincsulphate-based layer including at least one of the compounds selected from among zincsulphate monohydrate, zincsulphate tetrahydrate and zincsulphate heptahydrate, wherein the zincsulphate-based layer has neither zinc hydroxysulphate nor free water molecules nor free hydroxyl groups, the surface density of sulphur in the zincsulphate-based layer being greater than or equal to 0.5 mg/m. A corresponding treatment method is also provided.

Metal sheet treatment method and metal sheet treated with this method

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/m, and optionally a base or a mixture of bases, or an acid or a mixture of acids.

Coated metal sheet having an amino acid to improve corrosion resistance

The invention relates to a method for preparing a metal sheet () comprising at least the steps of:

Method for the preparation of a coated metal sheet, comprising the application of an aqueous solution containing an amino acid, and associated use in order to improve corrosion resistance

A method for preparing a metal sheet () is provided including at least the steps for:

Preparation method of a coated sheet comprising the application of an aqueous solution comprising an amino acid and its associated use for improving the compatibility with an adhesive

The invention relates to a method for the carboxylation conversion of a metal surface under oxidizing conditions in relation to the metal, consisting in bringing the metal into contact with a hydro-organic or aqueous bath containing a mixture of organic acids. The invention is characterized in that; the organic acids comprise saturated linear carboxylic acids having between 10 and 18 carbon atoms; the mixture comprises a binary or ternary mixture of such acids; the respective proportions of said acids are such that (i) for a binary mixture x&#xb1;5%&#x2212;y&#xb1;5%, wherein x and y represent the respective proportions, in molar percentages, of the two acids in a mixture with the composition of the eutectic and (ii) for a ternary mixture x&#xb1;3%&#x2212;y&#xb1;3%&#x2212;z&#xb1;3%, wherein x, y and z represent the respective proportions, in molar percentages, of the three acids in a mixture with the composition of the eutectic; and the concentration of the mixture in the bath is greater than or equal to 20 g/l.

Method for treating metal surfaces by carboxylation, use of the method for temporary protection against corrosion, and method for manufacturing a shaped metal sheet thus carboxylated

According to the invention, the solution contains a water-soluble salt of heptanoic acid and an oxidizing agent and, preferably, a wetting agent. By virtue of the combination of these compounds, low concentrations are sufficient to obtain satisfactory corrosion protection, which makes it possible to maintain a nonfatty surface appearance (on the treated sheet) and facilitates the treatment of the solution effluent (or that of the subsequent degreasing effluent).

Aqueous solution for the cold-working treatment of steel sheet

An aqueous solution useful for protecting steel from corrosion containing an alkaline aliphatic monocarboxylic acid salt having a linear chain of 6 to 12 carbon atoms, a triazole or diazole hydrocarbon and a non-ionic surfactant, the solution having a pH below 7. This aqueous solution is especially suited to the treatment of sheets at the outlet of an electrogalvanization line, particularly in a chloride medium.

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Montoy Flanville, France

Herve Derule