Method for Producing a Welded Joint

Abstract

A method for producing a welded joint between a steel sheet and an aluminum sheet, wherein the steel sheet and the aluminum sheet are clamped horizontally and are welded together on only one side in the welding position, a corresponding welded joint and a component comprising a corresponding welded joint.

Claims

1. A method for producing a joint between a steel sheet and an aluminum sheet, the method comprising: cutting the steel sheet and the aluminum sheet, thereby forming trimming regions at respective end faces of the steel sheet and the aluminum sheet and cutting burrs at the trimming regions; clamping the steel sheet and the aluminum sheet; and forming, after horizontally clamping the steel sheet and the aluminum sheet, a welding bead on an upper side and a lower side of the steel sheet and an upper side and a lower side of the aluminum sheet by welding the steel sheet and the aluminum sheet together only at the trimming regions such that the cutting burrs point in opposite directions during the welding, and the cutting burrs of the steel sheet points upward during the welding, wherein the steel sheet and the aluminum sheet are joined together on a side facing the welding torch and on a side facing away from the welding torch.

2. The method of claim 1, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together by a CMT process.

3. The method of claim 1, wherein the clamping comprises positioning the steel sheet and the aluminum sheet to form a butt joint when clamping.

4. The method of claim 1, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together at an end face of the steel sheet.

5. The method of claim 1, wherein forming the welding bead comprises sloping the welding torch at a predetermined angle relative to the perpendicular of the steel sheet during welding.

6. The method of claim 5, wherein the predetermined angle is about 2-5 degrees.

7. A method for producing a joint, the method comprising: cutting a steel sheet and an aluminum sheet, thereby forming trimming regions at respective end faces of the steel sheet and the aluminum sheet and cutting burrs at the trimming regions such that the cutting burrs point in opposite directions during the welding process, and the cutting burrs of the steel sheet points upward during the welding process; clamping the steel sheet and the aluminum sheet, and pressing the steel sheet and the aluminum sheet down on respective upper sides thereof; and welding the steel sheet to the aluminum sheet only at the trimming regions such that the cutting burrs point in opposite directions during the welding, and the cutting burrs of the steel sheet points upward during the welding, thereby forming a welding bead on the upper side and a lower side of the steel sheet and the upper side and a lower side of the aluminum sheet.

8. The method of claim 7, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together by a CMT process.

9. The method of claim 7, wherein the clamping comprises positioning the steel sheet and the aluminum sheet to form a butt joint when clamping.

10. The method of claim 7, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together at an end face of the steel sheet.

11. The method of claim 7, wherein forming the welding bead comprises sloping the welding torch at a predetermined angle relative to the perpendicular of the steel sheet during welding.

12. The method of claim 11, wherein the predetermined angle is about 2-5 degrees.

13. A method for producing a joint, the method comprising: cutting a steel sheet and an aluminum sheet, thereby forming trimming regions at respective end faces of the steel sheet and the aluminum sheet and cutting burrs at the trimming regions such that the cutting burrs point in opposite directions during the welding process, and the cutting burrs of the steel sheet points upward during the welding process; and welding the steel sheet to the aluminum sheet only at the trimming regions such that the cutting burrs point in opposite directions during the welding, and the cutting burrs of the steel sheet points upward during the welding, thereby forming a welding bead on an upper side and a lower side of the steel sheet and an upper side and a lower side of the aluminum sheet.

14. The method of claim 13, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together by a CMT process.

15. The method of claim 13, wherein the clamping comprises positioning the steel sheet and the aluminum sheet to form a butt joint when clamping.

16. The method of claim 13, wherein forming the welding bead comprises welding the steel sheet and the aluminum sheet together at an end face of the steel sheet.

17. The method of claim 13, wherein forming the welding bead comprises sloping the welding torch at a predetermined angle relative to the perpendicular of the steel sheet during welding.

18. The method of claim 17, wherein the predetermined angle is about 2-5 degrees.

Description

DRAWINGS

[0026] Embodiments will be explained below in closer detail by reference to the drawings, in which:

[0027] FIGS. 1a through 1c illustrate steps of a prior art method for producing a welded joint.

[0028] FIGS. 2a through 2c illustrate steps of a method for producing a welded joint, in accordance with embodiments.

[0029] FIG. 3 illustrates a detailed schematic view of the method step of FIG. 2b.

[0030] FIG. 4 illustrates a schematic view of trimming regions of the sheets with cutting burrs on one side, in accordance with embodiments.

DESCRIPTION

[0031] In accordance with embodiments, the method for producing a welded joint between a steel sheet 1 and an aluminum sheet 2, e.g., Al.sub.5xxx or Al.sub.6xxx, is illustrated in FIGS. 2a through 2c. The steel sheet 1 is welded to the aluminum sheet 2 at a steel end face 4 which does not have a zinc layer since trimming to size has been performed with guillotine shears, for example. In contrast, the surface 3 of the steel sheet 1 is zinc-coated, as far as possible free from scratches in the region of the weld seam and cleaned with precision cleaner. The aluminum sheet 2 is brushed and degreased and likewise cleaned with precision cleaner.

[0032] As illustrated in FIG. 2b, the steel sheet 1 and the aluminum sheet 2 are clamped horizontally and welded together on only one side via a welding torch 8 in the welding position PA by a CMT process. Both sheets 1, 2, are placed on metal blocks 5, which are arranged spaced apart. On the upper side, the sheets 1, 2, are pressed down via a clamping device 6. The clamping device 6 comprises clamping elements 7 which rest and press on the two sheets 1, 2, over an extended area. In the region of the future weld seam, these clamping elements 7 have a spacing, thus allowing the welding torch 8 to be applied.

[0033] As illustrated in FIG. 2c, the welding gives rise to a welding bead 11 on both sides since the steel/aluminum hybrid plate is welded right through despite the unilateral torch configuration. During this process, the aluminum has been converted to a molten state, while the steel has not been. The zinc has been used as a flux.

[0034] As illustrated in FIG. 3, a detailed schematic view of a welding process in accordance with embodiments. In the region of the weld seam, the metal blocks 5 have a spacing A of 8-10 mm. The clamping elements 7 on the upper side of the sheets 1, 2, have a spacing B of at least 6 mm, which increases upward. The welding torch 8 uses the shielding gas argon 4.6-5.0 and, in the welding position PA with a butt joint, is used with a feed rate of 0.3-1 m/min. Welding is performed at 10-15 degrees using a push technique. The welding torch 8 is tilted at an angle C of about 2-5 degrees to the perpendicular to the aluminum sheet 2. The height H, both in the case of the aluminum sheet 2 and the steel sheet 1, including the zinc layer on the surface 3 thereof, is about 0.8-4 mm, preferably 1.5-2 mm. In accordance with embodiments, Z100/100-Z350/350 or ZE50/50-ZE100/100 is used for the zinc layer, for example. The following can be used as welding fillers, for example, depending on the aluminum involved: AlMg.sub.4.5MnZr for Al.sub.5xxx and AlSi.sub.3Mn.sub.1 for Al.sub.6xxx.

[0035] Aluminized steel sheets have a thin aluminum layer, in the region of 60 m, for example. The abovementioned welding fillers can also be used.

[0036] As illustrated in FIG. 4, a schematic view of the trimming regions of the sheets 1, 2, with cutting burrs 9, 10 on one side, these having formed during cutting with guillotine shears. The cutting burrs 9, 10 point in opposite directions during welding. The cutting burr 9 on steel sheet 1 points upward toward the welding torch 8.

[0037] The term coupled or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0038] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, may be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.

LIST OF REFERENCE SIGNS

[0039] 1 steel sheet

[0040] 2 aluminum sheet

[0041] 3 surface of the steel sheet

[0042] 4 steel end face

[0043] 5 block

[0044] 6 clamping device

[0045] 7 clamping element

[0046] 8 welding torch

[0047] 9 cutting burr of the steel sheet

[0048] 10 cutting burr of the aluminum sheet

[0049] 11 welding bead

[0050] A spacing of the blocks

[0051] B spacing of the clamping elements

[0052] C angle of the welding torch to the perpendicular

[0053] H height