Abstract: 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/m2. A corresponding treatment method is also provided.

Abstract: A method for manufacturing parts is provided. The method includes cold rolling a substrate with work cylinders whose work surface has a roughness Ra2.5 of less than or equal to 3.6 ?m, depositing the metal coating on at least one face of the annealed substrate by electrodeposition to form the metal sheet and deforming the cut metal sheet to form the parts. The outer surface of the metal coating has a waviness Wa0.8 of less than or equal to 0.5 ?m after the deformation step. A part and vehicle are also provided.

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.

Abstract: The invention relates to a method for preparing a metal sheet (1) comprising at least the steps of: providing a steel substrate (3) having two faces (5), for which at least one 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.

Abstract: The invention relates to a method for preparing a metal sheet (1) comprising at least the steps: 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.

Abstract: 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.

Abstract: 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/m2. A corresponding treatment method is also provided.

Abstract: A method for manufacturing parts is provided. The method includes cold rolling a substrate with work cylinders whose work surface has a roughness Ra2.5 of less than or equal to 3.6 ?m, depositing the metal coating on at least one face of the annealed substrate by electrodeposition to form the metal sheet and deforming the cut metal sheet to form the parts. The outer surface of the metal coating has a waviness Wa0.8 of less than or equal to 0.5 ?m after the deformation step. A part and vehicle are also provided.

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.

Abstract: A method for manufacturing parts is provided. The method includes cold rolling a substrate with work cylinders whose work surface has a roughness Ra2.5 of less than or equal to 3.6 ?m, depositing the metal coating on at least one face of the annealed substrate by electrodeposition to form the metal sheet and deforming the cut metal sheet to form the parts. The outer surface of the metal coating has a waviness Wa0.8 of less than or equal to 0.5 ?m after the deformation step. A part and vehicle are also provided.

Abstract: The invention relates to a method for preparing a metal sheet (1) comprising at least the steps of: providing a steel substrate (3) having two faces (5), for which at least one 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.

Abstract: 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.

Abstract: The invention relates to a method for preparing a metal sheet (1) comprising at least the steps: 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.

Abstract: A method for manufacturing parts is provided. The method includes cold rolling a substrate with work cylinders whose work surface has a roughness Ra2.5 of less than or equal to 3.6 ?m, depositing the metal coating on at least one face of the annealed substrate by electrodeposition to form the metal sheet and deforming the cut metal sheet to form the parts. The outer surface of the metal coating has a waviness Wa0.8 of less than or equal to 0.5 ?m after the deformation step. A part and vehicle are also provided.

Abstract: 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±5%?y±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±3%?y±3%?z±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.

Abstract: The invention relates to a method for the carboxylation conversion of a metal surface under oxidising 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 characterised 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±5%?y±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±3%?y±3%?z±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.

Abstract: The invention relates to a method for treating a metal surface by carboxylation before forming, said metal being selected from zinc, iron, aluminium, copper, lead and the alloys thereof as well as copper-coated, aluminium-coated, galvanised steels. Said method is carried out in oxidising conditions in relation to the metal by bringing said metal into contact with an aqueous, organic or hydro-organic bath comprising at least one organic acid in free form or in salt form. The inventive method is characterised in that: the organic acid is a saturated or unsaturated aliphatic monocarboxylic or dicarboxylic acid; the organic acid is in solution and/or emulsion in the bath at a concentration greater than 0.1 mole/litre; the pH of the bath is acid.

Abstract: An emulsion used to lubricate the surface of a steel sheet, comprising an additive corresponding to one of the following formulae: (R1-2—O—)1-2—PSS—(CH2)n—COO—(CH2)m—CH3, (R1-2—O—)1,2—PSS—CH2-&phgr;-O—H, (R1,2—O—)1,2—PSS—CH2-&phgr;-O—(CH2)n, —COO—(CH2)m, —CH3, where PSS designates a dithiophosphate function. The naked sheets of steel that are treated with said emulsion have very good tribological properties even when the density of the emulsion thus applied is less than or equal to 1 g/m2 when dry. The invention enables dry-looking oiled sheets to be obtained, whereby no re-oiling is required before forming even by die stamping.

Abstract: 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).

Abstract: 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.