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 carrying, on at least one of its faces, a precoating. The precoating includes an intermetallic alloy layer and a metallic alloy layer extending atop the intermetallic 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 the precoated steel strip so as to obtain at least one precoated steel sheet (1). The precoated steel sheet (1) includes at least one cut edge surface (13). The cut edge surface (13) includes a substrate region (14) and a precoating region (15) and the thickness of the precoated steel sheet (1) being comprised between 1 mm and 5 mm. The laser cutting is carried out such that it results directly in a reduced-aluminum zone (20), extending over the entire height (h) of the cut edge surface (13) and over a length smaller than or equal to the length thereof. The surface fraction of aluminum on the substrate region (14) of the reduced-aluminum zone (20) directly results from the laser cutting operation being comprised between 0.3% and 6%.