公开(公告)号：US10675701B2

公开(公告)日：2020-06-09

申请号：US15638699

申请日：2017-06-30

Applicant: GM Global Technology Operations LLC

Inventor： David Yang ,  Wu Tao ,  Qi Lu ,  Blair E Carlson

IPC: B23K11/11 ,  B23K11/16 ,  B23K11/36 ,  B32B15/01

Abstract: A method of resistance spot welding a workpiece stack-up comprising overlapping first and second steel workpieces is disclosed, wherein at least one of the steel workpieces comprises an advanced high-strength steel substrate. The workpiece stack-up is positioned between a pair of opposed first and second welding electrodes. A cover is disposed between at least one of the first steel workpiece and the first welding electrode or the second steel workpiece and the second welding electrode at an intended weld site. The workpiece stack-up is clamped between the first and second welding electrodes at the weld site such that at least one of the weld faces of the first and second welding electrodes presses against the cover. The first and second steel workpieces are welded together by passing an electrical current between the first and second welding electrodes at the weld site.

公开(公告)号：US20200094350A1

公开(公告)日：2020-03-26

申请号：US16484010

申请日：2017-02-09

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Yu Pan ,  David Yang ,  Wu Tao ,  Paolo Novelletto

IPC: B23K26/22 ,  B23K26/08 ,  B23K26/082 ,  B23K26/244

Abstract: A method for joining together metal workpiece (12,14 or 12,150,14) includes forming a laser weld joint (66) in a workpiece stack-up (10) that fusion welds two or more overlapping metal workpiece (12,14 or 12,150 or 14) together. The laser weld joint (66) has an initial top surface (76). Once the laser weld joint (66) is formed, the method calls for impinging the laser weld joint (66) with a laser beam (24) and moving the laser beam (24) along the initial joint (66) including the initial top surface (76). The laser beam (24) is eventually removed from the laser weld joint (66) to allow the melted upper portion (78) of the joint (66) to resolidify and provide the laser weld joint (66) with a modified top surface (84) that is smoother than the initial top surface (76). By providing the laser weld joint with a smoother modified top surface, residual stress concentration points are removed and the laser weld joint is less liable to damage seal strips.

公开(公告)号：US20190240780A1

公开(公告)日：2019-08-08

申请号：US16312141

申请日：2016-07-14

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/322 ,  B23K26/067 ,  B23K26/22 ,  B23K26/244

CPC classification number: B23K26/322 ,  B23K26/0676 ,  B23K26/22 ,  B23K26/244 ,  B23K2101/35

Abstract: A method of laser spot welding a workpiece stack-up (10) that includes at least two overlapping steel workpieces (12, 14, 150) is disclosed. The method includes directing a plurality of laser beams (24, 24′, 24″) at the top surface (20) of the workpiece stack-up to create a molten steel weld pool (92) that penetrates into the stack-up. The molten steel weld pool is then grown to penetrate further into the stack-up by increasing an overall combined irradiance of the laser beams while reducing the total projected sectional area (88) of the laser beams at a plane of the top surface of the workpiece stack-up. Increasing the overall combined irradiance of the laser beams may be accomplished by moving the focal points (66, 66′, 66″) of the laser beams closer to the top surface or by reducing the mean angle of incidence (86) of the laser beams so as to reduce the eccentricity of the individual projected sectional areas of the laser beams.

公开(公告)号：US10329639B2

公开(公告)日：2019-06-25

申请号：US15668751

申请日：2017-08-04

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Charles Enloe ,  Curt D. Horvath ,  David Yang ,  Qi Lu ,  Wu Tao

IPC: C21D9/46 ,  C21D8/02 ,  C21D3/04 ,  C23C2/06 ,  B32B15/01 ,  B23K11/11 ,  B23K11/16 ,  B23K26/22 ,  B23K26/322 ,  C23C30/00 ,  C23C2/28 ,  C23C2/40 ,  C23C2/02 ,  C23C2/26 ,  B23K103/16

Abstract: A multilayer steel includes a core formed of transformation-induced plasticity (TRIP) steel. A decarburized layer is exterior to the core on at least one side thereof. The decarburized layer has reduced carbon content relative to the core. A zinc-based layer is exterior to the decarburized layer. The decarburized layer may have a composition of at least 80 percent ferrite, such that LME is reduced or mitigated. In some configurations, the decarburized layer is between 10-50 microns thick. A method of creating a coated advanced high-strength steel component is also provided. An apparatus for forming a coated advanced high-strength steel is also provided. The core of the multilayer steel may have a carbon weight-percent of less than or equal to 0.4. The decarburized layer of the multilayer steel may have a carbon weight-percent of less than or equal to 50 percent of the carbon weight-percent of the core.

公开(公告)号：US20190126402A1

公开(公告)日：2019-05-02

申请号：US15800481

申请日：2017-11-01

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/323 ,  B23K26/00 ,  B23K26/044

Abstract: A method of welding a workpiece stack-up assembly that includes dissimilar metal workpieces involves melting a portion of a top metal workpiece that overlies an underlying metal workpiece and covers at least one intruding hollow feature defined in the underlying metal workpiece. The molten material of the top metal workpiece flows into the at least one intruding feature defined in the underlying metal workpiece and, upon solidification therein, establishes a weld joint that metallurgically secures the top and underlying metal workpieces together. The top metal workpiece comprises a base metal substrate and the underlying metal workpiece comprises a base metal substrate. The base metal substrate of the top metal workpiece is different than the base metal substrate of the underlying metal workpiece and has a melting point that is less than a melting point of the base metal substrate of the underlying metal workpiece.

公开(公告)号：US20190126398A1

公开(公告)日：2019-05-02

申请号：US16089038

申请日：2016-04-14

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao

IPC: B23K26/22 ,  B23K26/082 ,  B23K26/32

Abstract: A method of laser welding a workpiece stack-up (10) that includes at least two overlapping aluminum workpieces comprises advancing a laser beam (24) relative to a plane of a top surface (20) of the workpiece stack-up (10) and along a beam travel pattern (74) that lies within an annular weld area (82) defined by an inner diameter boundary (86) and an outer diameter boundary (84) on the plane of the top surface (20). The beam travel pattern (74) of the laser beam (24) surrounds a center area encircled by the annular weld area (82) on the plane of the top surface (20) so as to force entrained porosity inwards into a region of the weld joint (72) beneath the center area on the plane of the top surface (20) of the workpiece stack-up (10).

公开(公告)号：US20190118307A1

公开(公告)日：2019-04-25

申请号：US16085283

申请日：2016-11-23

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： Hui-Ping Wang ,  Yu Pan ,  Blair E. Carlson ,  Joshua L. Solomon ,  William P. Payne ,  David Yang ,  Wu Tao

IPC: B23K26/60 ,  B23K26/082 ,  B23K26/322 ,  B23K26/244 ,  B23K26/26

Abstract: A method of laser welding a workpiece stack-up (10) of overlapping steel workpieces (12, 14) involves heat-treating a region (64) of the stack-up (10) followed by forming a laser weld joint (66) that is located at least partially within the heat-treated region (64). During heat-treating, one or more pre-welding laser beams (68) are sequentially directed at a top surface (20) of the workpiece stack-up (10) and advanced along a pre-welding beam travel pattern (70) so as to reduce an amount of vaporizable zinc within the stack-up (10). Thereafter, the laser weld joint (66) is formed by directing a welding laser beam (82) at the top surface (20) of the workpiece stack-up (10) and advancing the welding laser beam (82) along a welding beam travel pattern (84) that at least partially overlaps with a coverage area of a pre-welding beam travel pattern (70) or a shared coverage area portion of multiple pre-welding beam travel patterns (70). The method can help reduce an amount of vaporizable zinc within the stack-up (10).

公开(公告)号：US20190105728A1

公开(公告)日：2019-04-11

申请号：US16212147

申请日：2018-12-06

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David R. Sigler ,  James G. Schroth ,  Blair E. Carlson ,  Yelena Myasnikova ,  David Yang

IPC: B23K11/20 ,  B23K11/11 ,  B23K35/02

Abstract: A resistance spot welding method may involve spot welding a workpiece stack-up that includes a steel workpiece and an aluminum alloy workpiece. A pair of opposed welding electrodes are pressed against opposite sides of the workpiece stack-up with one welding electrode contacting the aluminum alloy workpiece and the other welding electrode contacting the steel workpiece. The welding electrodes are constructed so that, when an electrical current is passed between the electrodes and through the workpiece stack-up, the electrical current has a greater current density in the steel workpiece than in the aluminum alloy workpiece to thereby concentrate heat within a smaller zone in the steel workpiece. Concentrating heat within a smaller zone in the steel workpiece is believed to modify the solidification behavior of the resultant molten aluminum alloy weld pool in a desirable way.

公开(公告)号：US10252369B2

公开(公告)日：2019-04-09

申请号：US14792656

申请日：2015-07-07

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Blair E. Carlson ,  David R. Sigler

IPC: B23K11/00 ,  B23K11/11 ,  B23K11/20 ,  B23K37/00 ,  B23K103/20

Abstract: A workpiece stack-up that includes at least a steel workpiece and an aluminum-based workpiece can be resistance spot welded by a spot welding method in which the welding current is controlled to perform one or more stages of weld joint development. When it is desired to terminate weld current flow and to solidify a liquid weld pool into a weld nugget (of mostly aluminum-based composition), additional cooling is applied to the outer surface of the aluminum-based workpiece around the contact area of the spot welding electrode engaging the surface of the aluminum-based workpiece surface. The additional cooling is applied and controlled so as to increase the rate of solidification of the liquid aluminum-based material and to control the direction of solidification of the weld nugget to better confine impurities, and the like, originally in the melt, at the surface of the steel workpiece.

公开(公告)号：US20190061055A1

公开(公告)日：2019-02-28

申请号：US15684398

申请日：2017-08-23

Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC

Inventor： David Yang ,  Wu Tao ,  Blair Carlson

IPC: B23K26/244 ,  B23K26/046 ,  B23K26/082 ,  B23K26/322

Abstract: A method of laser welding together two or more overlapping metal workpieces (12, 14 or 12, 504, 14) that define a welding region (16) in which at least a portion of an accessible top surface (20, 120, 220, 520) of a workpiece stack-up (10, 110, 210, 510) is curved or angled includes advancing a laser beam (24) along a beam travel pattern (74) that at least partially lies on the portion of the top surface that is curved or angled while maintaining a constant focal distance (64) of the laser beam during such advancing travel. The beam travel pattern may be projected onto a curved portion (20″, 220″) of the top surface, an angled portion (120″) of the top surface, or two or more portions (20′, 20″, 120′, 120″, 220′, 220″, 220′″) of the top surface that lack planarity.