CPC B23K 26/322 (2013.01) [B23K 26/362 (2013.01); B23K 26/40 (2013.01); B32B 15/012 (2013.01); C21D 9/50 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); B23K 26/14 (2013.01); B23K 26/38 (2013.01); B23K 2101/185 (2018.08); B23K 2103/20 (2018.08); C21D 2211/001 (2013.01); Y10T 428/12757 (2015.01)] | 36 Claims |
1. A method for producing a precoated steel sheet comprising the successive steps of:
providing a precoated steel strip comprising a steel substrate having, on at least one main face thereof, a precoating, the precoating comprising an intermetallic alloy layer and a metallic alloy layer extending atop the intermetallic alloy layer, the metallic alloy layer being a layer of aluminum, a layer of aluminum alloy or a layer of aluminum-based alloy;
laser cutting the precoated steel strip so as to obtain at least one precoated steel sheet, the precoated steel sheet comprising a cut edge surface resulting from the cutting operation, the cut edge surface comprising a substrate region and a precoating region and a thickness of the precoated steel sheet being between 0.8 mm and 5 mm, the cut edge surface further comprising solidification striations,
the laser cutting being carried out such that the laser cutting results directly in a corrosion-improved zone of the cut edge surface, extending over an entire height of the cut edge surface and over a length smaller than or equal to a length of the cut edge surface, a surface fraction of aluminum on the substrate region of the corrosion-improved zone of the cut edge surface directly resulting from the laser cutting operation being greater than or equal to 9% and a surface fraction of aluminum on a bottom half of the substrate region of the corrosion-improved zone of the cut edge surface directly resulting from the laser cutting operation being greater than or equal to 0.5%.
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