Abstract: A fabrication method for a press hardened part is provided. A sheet or a steel substrate blank for heat treatment is provided. A pre-coating is applied. The pre-coating has at least one layer of aluminum or aluminum alloy in contact with the steel substrate on at least one of the principal faces of the sheet or blank. Then a polymerized layer is deposited on the pre-coating. The polymerized layer has a thickness between 2 and 30 ?m. The polymerized layer does not contain silicon, has a nitrogen content of less than 1% by weight and carbon pigments in a quantity between 3 and 30% by weight. The blank or the sheet is heated to obtain an interdiffusion between the steel substrate and the pre-coating and to give the steel a partly or totally austenitic structure. Then the blank or the sheet is hot stamped to obtain a part. The part is cooled by holding the part in a stamping tool so that the microstructure of the steel substrate includes, at least in a portion of the part, martensite or bainite.

Abstract: A fabrication method for a press hardened part is provided. A sheet or a steel substrate blank for heat treatment is provided. A pre-coating is applied. The pre-coating has at least one layer of aluminum or aluminum alloy in contact with the steel substrate on at least one of the principal faces of the sheet or blank. Then a polymerized layer is deposited on the pre-coating. The polymerized layer has a thickness between 2 and 30 ?m. The polymerized layer does not contain silicon, has a nitrogen content of less than 1% by weight and carbon pigments in a quantity between 3 and 30% by weight. The blank or the sheet is heated to obtain an interdiffusion between the steel substrate and the pre-coating and to give the steel a partly or totally austenitic structure. Then the blank or the sheet is hot stamped to obtain a part. The part is cooled by holding the part in a stamping tool so that the microstructure of the steel substrate includes, at least in a portion of the part, martensite or bainite.

Abstract: This invention relates to a sheet or pre-coated blank comprising a steel substrate for heat treatment, overlaid on at least a part of at least one of its principal faces, by a pre-coating having, at least one layer of aluminum or aluminum alloy overlaid, on at least a part of the above-mentioned pre-coating, by a polymerized layer having a thickness between 2 and 30 ?m composed of a polymer that does not contain silicon, and the nitrogen content of which, is greater than 1% by weight expressed in relation to the above-mentioned layer, wherein the above-mentioned polymerized layer contains carbon pigments in a quantity between 3 and 30% by weight, expressed in relation to said layer.

Abstract: A sheet or blank is provided which includes a substrate and pre-coating on at least one face of the substrate. A polymerized layer overlies at least a part of the pre-coating and has a thickness from 2 ?m to 30 ?m, a nitrogen content of less than 1% by weight, carbon pigments in a quantity from 3 to 30% by weight and does not include a polymer with silicon. A welded blank, part and fabrication methods are also provided.

Abstract: A fabrication method for a press hardened part is provided. A sheet or a steel substrate blank for heat treatment is provided. A pre-coating is applied. The pre-coating has at least one layer of aluminum or aluminum alloy in contact with the steel substrate on at least one of the principal faces of the sheet or blank. Then a polymerized layer is deposited on the pre-coating. The polymerized layer has a thickness between 2 and 30 ?m. The polymerized layer does not contain silicon, has a nitrogen content of less than 1% by weight and carbon pigments in a quantity between 3 and 30% by weight. The blank or the sheet is heated to obtain an interdiffusion between the steel substrate and the pre-coating and to give the steel a partly or totally austenitic structure. Then the blank or the sheet is hot stamped to obtain a part. The part is cooled by holding the part in a stamping tool so that the microstructure of the steel substrate includes, at least in a portion of the part, martensite or bainite.

Abstract: A part obtained by austenitization followed by hot stamping and hardening by holding in the stamping tool a sheet or blank is provided, including, a steel substrate, a precoating having at least one layer of aluminum or aluminum alloy, a microstructure of a steel substrate including martensite and/or bainite, a coating on at least one face of the steel substrate resulting from the interdiffusion between the steel substrate and the pre-coating and an oxide layer overlying the coating, an average content by weight of oxygen between 0 and 0.01 ?m below a surface of the part being less than 25%, and the average percent by weight of oxygen between 0.1 and 0.2 ?m below the surface being less than 10%.

Abstract: A part obtained by austenitization followed by hot stamping and hardening by holding in the stamping tool a sheet or blank is provided, including, a steel substrate, a precoating having at least one layer of aluminum or aluminum alloy, a microstructure of a steel substrate including martensite and/or bainite, a coating on at least one face of the steel substrate resulting from the interdiffusion between the steel substrate and the pre-coating and an oxide layer overlying the coating, an average content by weight of oxygen between 0 and 0.01 ?m below a surface of the part being less than 25%, and the average percent by weight of oxygen between 0.1 and 0.2 ?m below the surface being less than 10%.

Abstract: A fabrication method for a press hardened part is provided. A sheet or a steel substrate blank for heat treatment is provided. A pre-coating is applied. The pre-coating has at least one layer of aluminum or aluminum alloy in contact with the steel substrate on at least one of the principal faces of the sheet or blank. Then a polymerized layer is deposited on the pre-coating. The polymerized layer has a thickness between 2 and 30 ?m. The polymerized layer does not contain silicon, has a nitrogen content of less than 1% by weight and carbon pigments in a quantity between 3 and 30% by weight. The blank or the sheet is heated to obtain an interdiffusion between the steel substrate and the pre-coating and to give the steel a partly or totally austenitic structure. Then the blank or the sheet is hot stamped to obtain a part. The part is cooled by holding the part in a stamping tool so that the microstructure of the steel substrate includes, at least in a portion of the part, martensite or bainite.

Abstract: A sheet or blank is provided which includes a substrate and pre-coating on at least one face of the substrate. A polymerized layer overlies at least a part of the pre-coating and has a thickness from 2 ?m to 30 ?m, a nitrogen content of less than 1% by weight, carbon pigments in a quantity from 3 to 30% by weight and does not include a polymer with silicon. A welded blank, part and fabrication methods are also provided.

Abstract: This invention relates to a sheet or pre-coated blank comprising a steel substrate for heat treatment, overlaid on at least a part of at least one of its principal faces, by a pre-coating having, at least one layer of aluminum or aluminum alloy overlaid, on at least a part of the above-mentioned pre-coating, by a polymerized layer having a thickness between 2 and 30 ?m composed of a polymer that does not contain silicon, and the nitrogen content of which, is greater than 1% by weight expressed in relation to the above-mentioned layer, wherein the above-mentioned polymerized layer contains carbon pigments in a quantity between 3 and 30% by weight, expressed in relation to said layer.