US 11,786,993 B2
Method for producing a precoated steel sheet and associated sheet
Francis Schmit, Clermont (FR); and Quentin Bernardi, Paris (FR)
Assigned to ARCELORMITTAL, Luxembourg (LU)
Appl. No. 16/757,451
Filed by ArcelorMittal, Luxembourg (LU)
PCT Filed Oct. 19, 2018, PCT No. PCT/IB2018/058129
§ 371(c)(1), (2) Date Apr. 20, 2020,
PCT Pub. No. WO2019/077394, PCT Pub. Date Apr. 25, 2019.
Claims priority of application No. PCT/IB2017/056546 (WO), filed on Oct. 20, 2017.
Prior Publication US 2021/0107092 A1, Apr. 15, 2021
Int. Cl. B23K 26/322 (2014.01); B23K 26/362 (2014.01); B23K 26/40 (2014.01); B32B 15/01 (2006.01); C21D 9/50 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); B23K 101/18 (2006.01); B23K 103/20 (2006.01); B23K 26/14 (2014.01); B23K 26/38 (2014.01)
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
OG exemplary drawing
 
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%.