Abstract: The invention relates to a steel substrate 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 conversion layer comprising: zincsulphate hydrate, aluminium in an amount up to 14 mg·m?2, wherein the conversion layer comprises neither zinc hydroxysulphate, nor free water molecules nor any compounds having free hydroxyl groups, the surface density of sulphur in the conversion layer being greater than or equal to 5.0 mg/m2. The invention also relates to the corresponding treatment method.

Abstract: A method for creating a fan cowl with a hollow hat stiffener includes pressing a resin film between a non-crimp fabric (NCF) and a release poly-film to create a resin-fabric sheet. The method further includes cutting the resin-fabric sheet to a pre-determined shape to create at least one of a first resin-fabric preform, a second resin-fabric preform, and a third resin-fabric preform, draping at least the first resin-fabric preform over a tool to create an outer layer of the fan cowl, setting a mandrel over the outer layer, and draping the second resin-fabric preform over at least a portion of the mandrel and at least a portion of the first resin-fabric preform to form the hollow hat stiffener having a geometry similar to a shape of the mandrel.

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: 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 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.