ArcelorMittal S.A.
Method for producing a precoated steel sheet and associated sheet

Abstract:

A method for producing a precoated steel sheet (1) includes providing a precoated steel strip comprising a steel substrate (3) having, on at least one of its main faces, a precoating comprising an intermetallic alloy layer and a metallic alloy layer. The metallic alloy layer is a layer of aluminum, a layer of aluminum alloy or a layer of aluminum-based alloy. The method also includes laser cutting said precoated steel strip so as to obtain at least one precoated steel sheet (1) comprising a cut edge surface (13) resulting from the cutting operation. The cut edge surface (13) includes a substrate region (14) and a precoating region (15) and the thickness of the precoated steel sheet (1) is comprised between 0.8 mm and 5 mm. The laser cutting is carried out such that it results directly in a corrosion-improved zone (19) of the cut edge surface (13). The surface fraction of aluminum on the substrate region (14) of the corrosion-improved zone (19) is greater than or equal to 9% and the surface fraction of aluminum on the bottom half of the substrate region (14) of the corrosion-improved zone (19) is greater than or equal to 0.5%.