Abstract: The present invention provides fabrication methods for cold rolled, precoated and press hardened steel sheets, for which the chemical composition includes, with contents expressed by weight, 0.24%?C?0.38%, 0.40%?Mn?3%, 0.10%?Si?0.70%, 0.015%?Al?0.070%, 0%?Cr?2%, 0.25%?Ni?2%, 0.015%?Ti?0.10%, 0%?Nb?0.060%, 0.0005%?B?0.0040%, 0.003%?N?0.010%, 0.0001%?S?0.005%, 0.0001%?P?0.025%, it being understood that the titanium and nitrogen content satisfy: Ti/N>3.42, and that the carbon, manganese, chromium and silicon content satisfy: 2.6C+Mn/5.3+Cr/13+Si/15?1.1%, with the chemical composition optionally including one or more of the following elements: 0.05%?Mo?0.65%, 0.001%?W?0.30%, 0.0005%?Ca?0.005%, with the remainder made up of iron and inevitable impurities coming from preparation.

Abstract: A cold-rolled sheet is provided. The cold-rolled sheet includes a steel substrate with a carbon content C0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate has a decarburized area on the surface of each of the two principal faces. The depth p50% of the decarburized area is between 6 and 30 micrometers, and p50% is the depth at which the carbon content is equal to 50% of the content C0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.

Abstract: A cold-rolled sheet is provided. The cold-rolled sheet is annealed and pre-coated for the fabrication of press hardened parts, composed of a steel substrate for heat treatment with a carbon content C0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate comprises a decarburized area on the surface of each of the two principal faces. The depth p50% of the decarburized area is between 6 and 30 micrometers, and p50% is the depth at which the carbon content is equal to 50% of the content C0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating. Processes are also provided.

Abstract: The present invention provides a rolled steel sheet, for press hardening, for which the chemical composition includes, with contents expressed by weight, 0.24%?C?0.38%, 0.40%?Mn?3%, 0.10%?Si?0.70%, 0.015%?Al?0.070%, 0%?Cr?2%, 0.25%?Ni?2%, 0.015%?Ti?0.10%, 0%?Nb?0.060%, 0.0005%?B?0.0040%, 0.003%?N?0.010%, 0.0001%?S?0.005%, 0.0001%?P?0.025%, it being understood that the titanium and nitrogen content satisfy: Ti/N>3.42, and that the carbon, manganese, chromium and silicon content satisfy: 2.6 ? C + Mn 5.3 + Cr 13 + Si 15 ? 1.1 ? % , with the chemical composition optionally including one or more of the following elements: 0.05%?Mo?0.65%, 0.001%?W?0.30%, 0.0005%?Ca?0.005%, with the remainder made up of iron and inevitable impurities coming from preparation.

Abstract: The present invention provides a rolled steel sheet, for press hardening, for which the chemical composition includes, with contents expressed by weight, 0.24%?C?0.38%, 0.40%?Mn?3%, 0.10%?Si?0.70%, 0.015%?Al?0.070%, 0%?Cr?2%, 0.25%?Ni?2%, 0.015%?Ti?0.10%, 0%?Nb?0.060%, 0.0005%?B?0.0040%, 0.003%?N?0.010%, 0.0001%?S?0.005%, 0.0001%?P?0.025%, it being understood that the titanium and nitrogen content satisfy: Ti/N>3.42, and that the carbon, manganese, chromium and silicon content satisfy: 2.6 ? C + Mn 5.3 + Cr 13 + Si 15 ? 1.1 ? % , with the chemical composition optionally including one or more of the following elements: 0.05%?Mo?0.65%, 0.001%?W?0.30%, 0.0005%?Ca?0.005%, with the remainder made up of iron and inevitable impurities coming from preparation.

Abstract: A cold-rolled sheet is provided. The cold-rolled sheet includes a steel substrate with a carbon content C0 between 0.07% and 0.5%, expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate. The substrate has a decarburized area on the surface of each of the two principal faces. The depth p50% of the decarburized area is between 6 and 30 micrometers, and p50% is the depth at which the carbon content is equal to 50% of the content C0. The sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.

Abstract: The present invention provides a rolled steel sheet, for press hardening, for which the chemical composition includes, with contents expressed by weight, 0.24%?C?0.38%, 0.40%?Mn?3%, 0.10%?Si?0.70%, 0.015%?Al?0.070%, 0%?Cr?2%, 0.25%?Ni?2%, 0.015%?Ti?0.10%, 0%?Nb?0.060%, 0.0005%?B?0.0040%, 0.003%?N?0.010%, 0.0001%?S?0.005%, 0.0001%?P?0.025%, it being understood that the titanium and nitrogen content satisfy: Ti/N>3.42, and that the carbon, manganese, chromium and silicon content satisfy: 2.6 ? ? C + Mn 5.3 + Cr 13 + Si 15 ? 1.1 ? % , with the chemical composition optionally including one or more of the following elements: 0.05%?Mo?0.65%, 0.001%?W?0.30%, 0.0005%?Ca?0.005%, with the remainder made up of iron and inevitable impurities coming from preparation.

Abstract: This invention relates to a cold-rolled sheet that is annealed and pre-coated for the fabrication of press hardened parts, composed of a steel substrate for heat treatment with a carbon content C0 between 0.07% and 0.5%, whereby this content is expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate, characterized in that the substrate comprises a decarburized area on the surface of each of the two principal faces, whereby the depth p50% of the decarburized area is between 6 and 30 micrometers, whereby p50% is the depth at which the carbon content is equal to 50% of the content C0, and in that the sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.