Granted Patent B2

US 12,654,250 · App. 16/978,898 · Granted Jun 16, 2026

Inventors: Wolfram Ehling (Ghent, BE); Niko Van Der Borght (Herent, BE)

Assignee: ArcelorMittal

B23K11/0026B23K11/11B23K11/163B23K15/0093B23K20/122B23K26/322B23K31/02B23K2101/185B23K2101/34B23K2103/04

Abstract

Claims (33)

1 . A method for producing a welded metal blank comprising the steps of:

cutting at least a first initial metal sheet from a first metal strip and a second initial metal sheet from a second metal strip;

joining at least the first initial metal sheet and the second initial metal sheet by welding so as to obtain an initial welded metal blank having an initial contour, the initial welded metal blank comprising a weld joint joining the first and the second initial metal sheets; and

cutting the initial welded metal blank by a process involving metal melting so as to obtain at least one final welded metal blank having a final contour, the at least one final welded metal blank comprising a first metal blank portion and a second metal blank portion joined by a weld joint portion consisting of a portion of the weld joint obtained during the joining step,

wherein the first initial metal sheet and the second initial metal sheet comprise a steel substrate,

wherein at least one of the first initial metal sheet and the second initial metal sheet comprises, on at least one main face of the substrate, a 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,

wherein the at least one final welded metal blank has a thickness comprised between 0.8 mm and 5 mm and comprises a peripheral edge surface resulting from the cutting of the initial welded metal blank, the peripheral edge surface extending from one main face of the at least one final welded metal blank to the other, and

wherein the cutting step carried out on the initial welded metal blank is a laser cutting step, the laser cutting being carried out in such a way that it results directly in a surface fraction of aluminum on a substrate region of the peripheral edge surface directly resulting from the laser cutting operation greater than or equal to 9% and a surface fraction of aluminum on the bottom half of the substrate region of the peripheral edge surface directly resulting from the laser cutting operation is greater than or equal to 0.5%.

2 . The method according to claim 1 , wherein at least one of the first initial metal sheet and the second initial metal sheet has a quadrilateral-shaped contour.

3 . The method according to claim 1 , wherein the joining step is a laser welding, an electron beam welding, an arc welding, a friction stir welding or a resistance welding step.

4 . The method according to claim 1 , wherein the weld joint obtained during the joining step has a length greater than or equal to 300 mm.

5 . The method according to claim 1 , wherein the final contour of the at least one final welded metal blank includes at least one non-linear portion.

6 . The method according to claim 1 , wherein each final welded metal blank has a final contour delimiting a respective area, and the sum of the areas delimited by the final contours of all the final welded metal blanks cut from a considered initial welded metal blank is strictly smaller than the area delimited by the initial contour of the respective initial welded metal blank.

7 . The method according to claim 1 , wherein, for the at least one final welded metal blank, the weld joint portion has a length smaller than or equal to 250 mm.

8 . The method according to claim 1 , wherein the first metal strip and the second metal strip have different properties.

9 . The method according to claim 1 , further comprising, for at least one among the first initial metal sheet and the second initial metal sheet, a step of removing the precoating over at least a fraction of its thickness at a weld edge on at least one face of at least one of the first initial metal sheet and second initial metal sheet prior to joining the first initial metal sheet and second initial metal sheet through welding.

10 . The method according to claim 1 , wherein the welding is performed using a filler material.

11 . The method according to claim 1 , wherein the cutting step on the initial welded metal blank is performed so as to obtain the final welded blank which does not include any weld start or stop craters or defects.

12 . A method for producing a press-formed welded metal part comprising the steps of:

producing the at least one final welded metal blank using the method according to claim 1 ; and

press-forming the at least one final welded metal blank into a three-dimensional shape so as to obtain a press-formed welded metal part.

13 . The method as recited in claim 12 , further comprising trimming edges of the press-formed welded metal part using 3D laser cutting so as to obtain a final press-formed welded metal part, the 3D laser cutting removing material from the press-formed welded metal part over a width smaller than or equal to 10 mm.

14 . The method as recited in claim 12 , wherein the press-forming step is a hot forming step carried out in a hot forming press.

15 . The method as recited in claim 14 , wherein the first metal blank portion and second metal blank portion of the final welded metal blank comprise a steel substrate, and wherein the method further comprises a step of cooling the press-formed welded metal part so as to obtain a press-hardened press-formed welded metal part.

16 . The method as recited in claim 15 , wherein a cooling rate of the step of cooling is equal to or greater than the critical martensitic or bainitic cooling rate of at least one of the substrates of the final welded metal blank.

17 . The method as recited in claim 12 , wherein the press-forming step is a cold forming step.

18 . The method as recited in claim 1 ,

wherein, during the cutting step carried out on the initial welded metal blank, at least two final welded metal blanks are cut from the initial welded metal blank, and the at least two final welded blanks cut from one initial welded blank have differently shaped contours.

19 . The method according to claim 1 , wherein, during the cutting step carried out on the initial welded metal blank, at least two final welded metal blanks are cut from the initial welded metal blank, and

wherein a ratio between the length of the weld joint portion and a dimension of the at least one final welded metal blank taken perpendicular to the weld joint portion is smaller than or equal to 0.7.

20 . A welded metal blank comprising a first metal blank portion and a second metal blank portion joined by a weld joint, the welded metal blank comprising a peripheral edge surface extending from one main face of the welded metal blank to the other over the entire contour of the welded metal blank, the peripheral edge surface comprising solidification striations extending over the entire contour of the welded metal blank and over at least a fraction of the height of the peripheral edge surface,

wherein each of the first and second metal blank portions comprises a steel substrate carrying, on at least one of its faces, a precoating including 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,

wherein a thickness of the welded metal blank is comprised between 0.8 mm and 5 mm and the surface fraction of aluminum on a substrate region of the peripheral edge surface is greater than or equal to 9% and the surface fraction of aluminum on the bottom half of the substrate region of the peripheral edge surface is greater than or equal to 0.5%.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (46)