A process for producing a three-dimensionally shaped steel component from a steel sheet with a metallic coating may involve hot forming the steel sheet into the steel component. The metallic coating may involve an FeAl-based alloy. To protect the steel sheet or the steel component against scale formation, the FeAl-based alloy may be applied directly to the steel sheet by galvanic coating and/or physical vapor deposition. The coating produced in this way may contain 30-60% by weight Fe, a balance of Al, and, in some cases, 0.1-10% by weight Mg, 0.1-5% by weight Ti, 0.1-10% by weight Si, 0.1-10% by weight Li, and/or 0.1-10% by weight Ca. Before heating the coated steel sheet as part of the hot forming process, the coated steel sheet may have an FeAl phase is stable to above 900 C.

[Object] There are provided automobile parts and a method for manufacturing the automobile parts. The automobile parts have an excellent corrosion resistance after coated with a electrodeposition paint with smaller thickness, improve formability and productivity in hot pressing, and also improve chemical conversion treatability after hot press-forming.

[Solution] An automobile part according to the present invention includes: a formed steel sheet having an intermetallic compound layer formed on a surface of the steel sheet, the intermetallic compound layer being formed of AlFe intermetallic compound having a thickness of 10 m or more and 50 m or less, the intermetallic compound layer including a diffusion layer positioned in closest proximity to the steel sheet, the diffusion layer having a thickness of 10 m or less; a surface coating layer provided on a surface of the intermetallic compound layer, the surface coating layer including a coating containing ZnO and a zinc phosphate coating and having a surface roughness of 3 m or more and 20 m or less as a maximum profile height Rt in accordance with JIS B0601 (2001); and an electrodeposition paint film provided on a surface of the surface coating layer and having a thickness of 6 m or more and less than 15 m.

[Object] There are provided automobile parts and a method for manufacturing the automobile parts. The automobile parts have an excellent corrosion resistance after coated with a electrodeposition paint with smaller thickness, improve formability and productivity in hot pressing, and also improve chemical conversion treatability after hot press-forming.

[Solution] An automobile part according to the present invention includes: a formed steel sheet having an intermetallic compound layer formed on a surface of the steel sheet, the intermetallic compound layer being formed of AlFe intermetallic compound having a thickness of 10 m or more and 50 m or less, the intermetallic compound layer including a diffusion layer positioned in closest proximity to the steel sheet, the diffusion layer having a thickness of 10 m or less; a surface coating layer provided on a surface of the intermetallic compound layer, the surface coating layer including a coating containing ZnO and a zinc phosphate coating and having a surface roughness of 3 m or more and 20 m or less as a maximum profile height Rt in accordance with JIS B0601 (2001); and an electrodeposition paint film provided on a surface of the surface coating layer and having a thickness of 6 m or more and less than 15 m.

A method for making a nanodiamond article includes applying an adhesion promoting layer to a substrate, and electrophoretically depositing a nanodiamond film on the substrate with the adhesion promoting layer thereon in a solution to make the nanodiamond article. The nanodiamond article may include a substrate, a nanodiamond film over the substrate, and the adhesion promoting layer between the substrate and the nanodiamond film.

A method for making a nanodiamond article includes applying an adhesion promoting layer to a substrate, and electrophoretically depositing a nanodiamond film on the substrate with the adhesion promoting layer thereon in a solution to make the nanodiamond article. The nanodiamond article may include a substrate, a nanodiamond film over the substrate, and the adhesion promoting layer between the substrate and the nanodiamond film.

A method for forming an adhesion promoting layer and a corrosion resistant layer over the surfaces of a body-in-white (BIW) structure is provided. The method includes immersing the BIW structure in a pre-activating bath to pre-activate the surfaces of the BIW structure. The surfaces of the BIW structure comprise at least an aluminum alloy surface, at least a surface comprising ferrous metal, zinc, or TiZr, and the surfaces are substantially free of magnesium alloys. An adhesion promoting layer comprising cerium and a corrosion resistant layer comprising polymers are subsequently deposited over the pre-activated surfaces of the BIW structure by immersing the BIW structure in an aqueous bath comprising a source of cerium cations and a polymer precursor.

A method for forming an adhesion promoting layer and a corrosion resistant layer over the surfaces of a body-in-white (BIW) structure is provided. The method includes immersing the BIW structure in a pre-activating bath to pre-activate the surfaces of the BIW structure. The surfaces of the BIW structure comprise at least an aluminum alloy surface, at least a surface comprising ferrous metal, zinc, or TiZr, and the surfaces are substantially free of magnesium alloys. An adhesion promoting layer comprising cerium and a corrosion resistant layer comprising polymers are subsequently deposited over the pre-activated surfaces of the BIW structure by immersing the BIW structure in an aqueous bath comprising a source of cerium cations and a polymer precursor.

Described herein is a method for phosphating of a metallic surface, wherein a metallic surface, optionally after cleaning and/or activation, is first treated with an acidic, aqueous, substantially nickel-free phosphating composition that includes zinc ions, manganese ions, iron(III) ions and phosphate ions, and is thereafter optionally rinsed and/or dried. Also described herein are a corresponding phosphating composition and a correspondingly phosphate-coated metallic surface.

A coating method for a clad steel in which stainless sheets are combined on adjacent surfaces of an aluminum sheet may include preparing the clad steel, preparing a coating solution in which an epoxy resin and titanium dioxide (TiO.sub.2) powder are combined in an acrylic resin, etching the clad steel to improve adhesion property between the coating solution and the clad steel, heating the clad steel, and performing electrodeposition by immersing the clad steel in the coating solution.

A coating method for a clad steel in which stainless sheets are combined on adjacent surfaces of an aluminum sheet may include preparing the clad steel, preparing a coating solution in which an epoxy resin and titanium dioxide (TiO.sub.2) powder are combined in an acrylic resin, etching the clad steel to improve adhesion property between the coating solution and the clad steel, heating the clad steel, and performing electrodeposition by immersing the clad steel in the coating solution.