USRE47904E1 - Method for laser welding one or more workpieces of hardenable steel in a butt joint - Google Patents

Method for laser welding one or more workpieces of hardenable steel in a butt joint Download PDF

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USRE47904E1
USRE47904E1 US16/015,677 US201316015677A USRE47904E US RE47904 E1 USRE47904 E1 US RE47904E1 US 201316015677 A US201316015677 A US 201316015677A US RE47904 E USRE47904 E US RE47904E
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workpieces
filler wire
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workpiece
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Arndt Breuer
Dietmar Schaftinger
Max Brandt
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Wisco Tailored Blanks GmbH
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Wisco Tailored Blanks GmbH
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/21—Bonding by welding
    • B23K26/24—Seam welding
    • B23K26/26—Seam welding of rectilinear seams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B23K26/322—Bonding taking account of the properties of the material involved involving coated metal parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/24—Selection of soldering or welding materials proper
    • B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
    • B23K35/3053—Fe as the principal constituent
    • B23K35/3066—Fe as the principal constituent with Ni as next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/18—Sheet panels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/34—Coated articles, e.g. plated or painted; Surface treated articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/02—Iron or ferrous alloys
    • B23K2103/04—Steel or steel alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/21—Bonding by welding
    • B23K26/211—Bonding by welding with interposition of special material to facilitate connection of the parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/24—Selection of soldering or welding materials proper
    • B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C

Definitions

  • the invention relates to a method for laser welding of one or more workpieces made from press hardenable steel, particularly manganese-boron steel, in a butt joint, in which the workpiece or the workpieces have a thickness of at least 1.8 mm and/or a jump in thickness of at least 0.4 mm arises at the butt joint, and in which the laser welding takes place with the supply of filler wire into the molten bath generated with a laser beam.
  • Tailored blanks made from sheet steel are used in the automotive industry to fulfil high demands on the crash safety with the smallest possible bodywork weight.
  • individual blanks or strips of different material quality and/or sheet thickness are joined together by laser welding in a butt joint.
  • various points of the finished bodywork component can be adapted to different loads.
  • thicker or higher strength sheet steel can be used and thinner steel sheets or else sheets made from relatively weak deep-drawing grades can be used in the remaining locations. Additional reinforcing parts on the bodywork become superfluous due to such tailored sheet blanks. This saves material and enables the reduction of the total weight of the bodywork.
  • boron-alloyed steels particularly manganese-boron steels have been developed, which achieve high strengths, for example tensile strengths in the range of 1500 to 2000 MPa when hot formed with rapid cooling.
  • manganese-boron steels typically have a ferritic/pearlitic structure and have strengths of approx. 600 MPa.
  • press hardening i.e. by heating to austenising temperature and subsequent rapid cooling in the compression mould, a martensitic structure can be set however, so that the thus-treated steels can achieve tensile strengths in the range from 1500 to 2000 MPa.
  • the bodywork components for example B pillars, produced from such tailored steel blanks have a flawless hardness profile up to a certain sheet thickness or a certain thickness jump.
  • the problem occurs that the laser weld seam does not harden sufficiently during hot forming (press hardening).
  • a martensitic structure only results to a certain extent in the weld seam, so that during the loading of the finished component, a failure may occur in the weld seam.
  • This problem is presumably associated with the fact that, particularly in the case of a thickness jump, sufficient contact to the cooled forming tool or cooling tool cannot generally be ensured and as a result, the weld seam cannot be completely converted into martensite.
  • a laser-arc hybrid welding method is described in US 2008/0011720 A1, in which method blanks made from manganese-boron steel, which have an aluminium-containing surface layer, are connected to one another in a butt joint, the laser beam being combined with at least one electric arc, in order to melt the metal at the butt joint and to weld the blanks to one another.
  • the electric arc is in this case output by means of a tungsten welding electrode or is formed at the tip of a filler wire if a MIG welding torch is used.
  • the filler wire can contain elements (e.g. Mn, Ni and Cu), which induce the transformation of the steel into an austenitic structure and benefit maintenance of the austenitic transformation in the molten bath.
  • This known hybrid welding method is relatively expensive with regards to the energy consumption, owing to the generation of the electric arc.
  • the present invention is based on the object of specifying a laser welding method, by which workpieces made from pressure-hardenable steel, particularly manganese-boron steel, which have a thickness of at least 1.8 mm and/or in which a jump in thickness of at least 0.4 mm results at the butt joint, can be joined to tailored workpieces, particularly tailored blanks, in the butt joint, the weld seam of which can be hardened reliably during hot forming (press hardening) to a martensitic structure.
  • the method should stand out owing to a high productivity and a relatively low energy consumption.
  • the method according to the invention is used for laser welding of one or a plurality of workpieces of press hardenable steel, particularly manganese-boron steel, in a butt joint, in which the workpiece or the workpieces have a thickness of at least 1.8 mm, particularly at least 2.0 mm, and/or a jump in thickness of at least 0.4 mm arises at the butt joint.
  • the laser welding in this case takes place with the supply of filler wire into the molten bath generated using a laser beam.
  • the method according to the invention is furthermore characterised in that the filler wire contains at least one alloy element from the group comprising manganese, chromium, molybdenum, silicon and/or nickel, which element promotes the formation of austenite in the molten bath generated using the laser beam, wherein this at least one alloy element is present in the filler wire with a mass proportion that is larger by at least 0.1% by weight than in the press hardenable steel of the workpiece or the workpieces.
  • the filler wire contains at least one alloy element from the group comprising manganese, chromium, molybdenum, silicon and/or nickel, which element promotes the formation of austenite in the molten bath generated using the laser beam, wherein this at least one alloy element is present in the filler wire with a mass proportion that is larger by at least 0.1% by weight than in the press hardenable steel of the workpiece or the workpieces.
  • the workpieces produced according to the invention or tailored blanks offer a larger process window with regards to the hot forming (press hardening), in which window a satisfactory hardening of the component is achieved, particularly in the weld seam thereof also.
  • the method according to the invention cannot only be used when joining together a plurality of steel blanks of different material quality and/or sheet thickness in the butt joint, but rather also in the case of laser welding an individual plate- or strip-shaped steel sheet, wherein in the last-mentioned case, the edges of the workpiece that are to be welded to one another are moved towards each other by reshaping, for example by bending or roll forming, so that they are finally arranged facing one another in the butt joint.
  • the workpiece or the workpieces are selected such that the steel thereof has the following composition: 0.10 to 0.50% by weight C, max. 0.40% by weight Si, 0.50 to 2.00% by weight Mn, max. 0.025% by weight P, max. 0.010% by weight S, max. 0.60% by weight Cr, max. 0.50% by weight Mo, max. 0.050% by weight Ti, 0.0008 to 0.0070% by weight B, and min. 0.010% by weight Al, remainder Fe and unavoidable impurities.
  • the components produced from such a steel have a relatively high tensile strength after press hardening.
  • blank- or strip-shaped workpieces made from press hardenable steel are used, which have a tensile strength in the region of 1500 to 2000 MPa after the press hardening.
  • a further preferred embodiment of the method according to the invention is characterised in that the filler wire used therein has the following composition: 0.05 to 0.15% by weight C, 0.5 to 2.0% by weight Si, 1.0 to 2.5% by weight Mn, 0.5 to 2.0% by weight Cr+Mo, and 1.0 to 4.0% by weight Ni, remainder Fe and unavoidable impurities.
  • the filler wire used therein has a carbon mass proportion that is lower by at least 0.1% by weight than the press hardenable steel of the workpiece or the workpieces.
  • An embrittlement of the weld seam can be prevented by a relatively low carbon content of the filler wire.
  • a good residual elasticity can be achieved at the weld seam due to a relatively low carbon content of the filler wire.
  • a further advantageous embodiment of the method according to the invention provides that the filler wire can be supplied to the molten bath in a heated state.
  • the filler wire is heated to a temperature of at least 50° C., at least in a length section, before supply into the molten bath.
  • a further preferred embodiment of the method according to the invention provides that the molten bath is loaded with protective gas (inert gas) during the laser welding.
  • protective gas in this case, pure argon, helium, nitrogen or a mixture thereof or a mixture made up of argon, helium, nitrogen and/or carbon dioxide and/or oxygen is particularly preferably used.
  • a coating with an aluminium or aluminium/silicon basis In order to prevent the formation of a scale layer on steel strips or steel sheets, these are conventionally provided with a coating with an aluminium or aluminium/silicon basis.
  • the method according to the invention can also be applied when using such coated steel blanks or steel strips. Uncoated steel blanks or steel strips can likewise be welded to one another according to the method according to the invention.
  • the coating with an aluminium or aluminium/silicon basis can be removed in the edge region along the abutting edges to be welded to one another before the laser welding. This can take place by means of an at least one energy beam, preferably a laser beam.
  • a mechanical or high-frequency (HF) de-layering is likewise conceivable. In this manner, an impairment of the weld seam by coating material otherwise introduced therein in an undesired manner, which can or would lead to falls in the hardness profile during hot forming (press hardening), can be reliably prevented.
  • FIG. 1 shows a perspective view of parts of a device for carrying out the laser welding method according to the invention, wherein two essentially equally thick, press hardenable steel blanks are welded to one another in a butt joint;
  • FIG. 2 shows a perspective view of parts of a device for carrying out the laser welding method according to the invention, wherein here two differently thick, press hardenable steel blanks are welded to one another in a butt joint.
  • FIG. 1 A device is schematically illustrated in FIG. 1 , using which a laser welding method according to the invention can be carried out.
  • the device comprises a support (not shown), on which two strips or blanks 1 , 2 made from steel of different material quality abut bluntly along the joint 3 .
  • the one workpiece 1 or 2 has a relatively weak deep-drawing grade, whilst the other workpiece 2 or 1 consists of higher strength sheet steel.
  • At least one of the workpieces 1 , 2 is produced from press hardenable steel, for example made from manganese-boron steel.
  • the workpieces 1 , 2 are essentially of equal thickness.
  • the thickness thereof is at least 1.8 mm, for example at least 2.0 mm.
  • FIG. 1 Sketched above the workpieces 1 , 2 is a section of a laser welding head 4 , which is provided with an optical system (not shown) for supplying a laser beam and also a focussing lens 5 for the laser beam 6 . Furthermore, a pipe 7 for supplying protective gas is arranged on the laser welding head 4 . The aperture of the protective gas pipe 7 is essentially directed onto the focus area of the laser beam 6 or the molten bath 8 generated with the laser beam 6 . Pure argon or for example a mixture of argon, helium and/or carbon dioxide is preferably used as protective gas.
  • a wire feed apparatus 9 is assigned to the laser welding head 4 , by means of which, a special additional material is fed to the molten bath 8 in the form of a wire 10 , which is likewise melted by the laser beam 6 .
  • the additional wire (filler wire) 10 is fed to the molten bath 8 in a heated state.
  • the wire feed apparatus 9 is equipped with at least one heating element (not shown), for example a heating coil surrounding the wire 10 .
  • the filler wire 10 is preferably heated to a temperature of at least 50° C., particularly preferably to at least 90° C.
  • the exemplary embodiment illustrated in FIG. 2 differs from the exemplary embodiment according to FIG. 1 in that the workpieces 1 , 2 ′ are of different thickness, so that at the butt joint 3 , a jump in thickness d of at least 0.4 mm is present.
  • the one workpiece 2 ′ has a sheet thickness in the range from 0.5 mm to 1.2 mm, whilst the other workpiece 1 has a sheet thickness in the range from 1.6 mm to 2.5 mm.
  • the workpieces 1 , 2 ′ to be connected to one another in the butt joint 3 can also differ from one another in terms of the material quality thereof.
  • the thicker blank 1 is produced from higher strength sheet steel, whereas the thinner steel blank 2 ′ has a relatively weak deep-drawing quality.
  • the press hardenable steel from which at least one of the workpieces 1 , 2 or 2 ′ to be connected to one another in the butt joint 3 , can for example have the following chemical composition:
  • the workpieces or steel blanks 1 , 2 or 2 ′ can be uncoated or provided with a coating, particularly an Al—Si layer.
  • the yield point Re of the press hardenable steel blanks 1 , 2 and/or 2 ′ is preferably at least 300 MPa; the tensile strength Rm thereof is at least 480 MPa, and the elongation at break A 80 thereof is at least 10%.
  • these steel blanks After the hot forming (press hardening), i.e. austenisation at approx. 900 to 920° C. and subsequent rapid cooling, these steel blanks have a yield point Re of approx. 1,100 MPa, a tensile strength Rm of approx. 1500 to 2000 MPa and an elongation at break A 80 of approx. 5.0%.
  • the coating can be removed or partly de-layered in the edge region along the abutting edges to be welded to one another, before the laser welding. If appropriate, aluminium coating material adhering at the abutting or intersection edges 3 is also removed.
  • the removal (elimination) of the aluminium coating material can preferably take place by means of at least one laser beam.
  • the filler wire 10 used typically has for example the following chemical composition:
  • the manganese content of the filler wire 10 is in this case constantly higher than the manganese content of the press hardenable workpieces 1 , 2 or 2 ′.
  • the manganese content of the filler wire 10 is in this case higher by approx. 0.2% by weight than the manganese content of the press hardenable workpieces 1 , 2 or 2 ′.
  • the combined chromium-molybdenum content of the filler wire 10 is in this case higher by approx.
  • the nickel content of the filler wire 10 preferably lies in the range of 1 to 4% by weight. Additionally, the filler wire 10 preferably has a lower carbon content than the press hardenable steel of the workpieces 1 , 2 or 2 ′.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Plasma & Fusion (AREA)
  • Laser Beam Processing (AREA)
US16/015,677 2012-11-19 2013-08-02 Method for laser welding one or more workpieces of hardenable steel in a butt joint Active 2033-12-28 USRE47904E1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16/015,677 USRE47904E1 (en) 2012-11-19 2013-08-02 Method for laser welding one or more workpieces of hardenable steel in a butt joint

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE102012111118.9A DE102012111118B3 (de) 2012-11-19 2012-11-19 Verfahren zum Laserschweißen eines oder mehrerer Werkstücke aus härtbarem Stahl im Stumpfstoß
DE102012111118 2012-11-19
PCT/EP2013/066274 WO2014075824A1 (de) 2012-11-19 2013-08-02 Verfahren zum laserschweissen eines oder mehrerer werkstücke aus härtbarem stahl im stumpfstoss unter verwendung eines zusatdrahtes
US16/015,677 USRE47904E1 (en) 2012-11-19 2013-08-02 Method for laser welding one or more workpieces of hardenable steel in a butt joint
US14/443,441 US9623515B2 (en) 2012-11-19 2013-08-02 Method for laser welding one or more workpieces of hardenable steel in a butt joint

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US14/443,441 Ceased US9623515B2 (en) 2012-11-19 2013-08-02 Method for laser welding one or more workpieces of hardenable steel in a butt joint

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EP (1) EP2919942B1 (zh)
KR (1) KR102088470B1 (zh)
CN (1) CN104994989B (zh)
BR (1) BR112015011409B1 (zh)
CA (1) CA2891732C (zh)
DE (1) DE102012111118B3 (zh)
ES (1) ES2623839T3 (zh)
MX (1) MX367052B (zh)
PL (1) PL2919942T3 (zh)
PT (1) PT2919942T (zh)
RU (1) RU2635050C2 (zh)
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11358238B2 (en) * 2017-03-20 2022-06-14 Kirchhoff Automotive Deutschland Gmbh Method for laser welding end faces

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Publication number Priority date Publication date Assignee Title
US20140062136A1 (en) * 2012-09-06 2014-03-06 GM Global Technology Operations LLC Laser welded structural fender inner blank for mass optimization
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