A laser-cmt composite welding device and method for k-type joint of medium plate

Abstract

The application discloses a kind of medium plate K type joint laser-CMT composite welding device and method, including base metal and welding device, base metal includes first support plate, second support plate and bottom plate;First support plate, second support plate and bottom plate butt joint gap are reserved at place;Welding device includes welding torch assembly and laser;Welding assembly and laser are respectively arranged in the three-angled space formed at butt joint place;Along welding direction, welding torch assembly is arranged in front of laser welding;Each laser is equipped with light splitting module, and light splitting module is used to divide laser beam in laser into heat conduction welding laser beam and spoon hole welding laser beam.The present application can use lower laser energy to weld K type joint once forming by setting three groups of welding torch assembly and laser, reduces the welding workpiece deformation of larger laser energy welding K type joint and the welding stress concentration problem generated by multiple welding, improves weld structure and weld mechanical property.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser energy welding, and particularly relates to a laser-CMT composite welding device and method for a K-shaped joint of a medium plate. BACKGROUND

[0002] The welding seam forming quality of a K-shaped joint is required to be high in the field of aerospace, laser welding has the advantages of high energy density, small welding deformation, high welding seam quality, and can be precisely and efficiently welded compared with traditional welding methods. The conventional welding method for laser welding of a K-shaped joint is to implement three times of laser beam welding on the K-shaped connecting piece, but this method is prone to stress concentration due to different heating and cooling temperatures of the welding seam, welding deformation, and influence on the welding seam forming quality, and further reduces the welding productivity.

[0003] Currently, there are related patents of a K-shaped joint double-arc preheating laser swing welding method and a double-beam laser welding method for a K-shaped joint. The two patents are both aimed at the gap between the two support plates being 0mm and the gap between the support plate and the bottom plate being 0mm. However, when there is a gap between the two support plates and between the support plate and the bottom plate, the welding seam after welding will have welding defects such as undercut and underfoot due to the absence of the addition of filler wire in the two invention patents.

[0004] Therefore, it is urgent to design a laser-CMT composite welding device and method for a K-shaped joint of a medium plate. SUMMARY

[0005] The purpose of the application is to provide a laser-CMT composite welding device for a K-shaped joint of a medium plate to solve the above problems.

[0006] To achieve the above purpose, the application provides the following solutions.

[0007] A laser-CMT composite welding device for a K-shaped joint of a medium plate, comprising a base material and a welding device, the base material comprising a first support plate, a second support plate and a bottom plate; the first support plate, the second support plate and the bottom plate are provided with a welding gap at the butt joint;

[0008] The welding device comprises a welding gun assembly and a laser; the welding assembly and the laser are respectively arranged in a three-angle space formed at the butt joint; along the welding direction, the welding gun assembly is arranged in front of the laser; a light splitting module is installed in each laser, and the light splitting module is used to split the laser beam in the laser into a heat conduction welding laser beam and a keyhole welding laser beam.

[0009] The welding gun assembly comprises a first welding gun, a second welding gun and a third welding gun which are structurally identical, and three CMT power sources; the positive poles of the three CMT power sources are connected with the first welding gun, the second welding gun and the third welding gun respectively, and the negative pole of the CMT power source is connected with the base material; the first welding gun, the second welding gun and the third welding gun are all CMT welding guns.

[0010] The axes of the first welding gun, the second welding gun and the third welding gun are coplanar with the hot conduction welding laser beams and the keyhole welding laser beams respectively split by the three lasers; the first welding gun and the third welding gun form an included angle of 5°-70° with the bottom plate;

[0011] The keyhole-shaped molten pool is formed at the butt joint by the keyhole welding laser beam, and the light wire gap between the keyhole-shaped molten pool and the CMT welding wire of the CMT welding gun is 0-1mm;

[0012] The hot conduction welding molten pool is formed at the butt joint of the keyhole-shaped molten pool by the hot conduction welding laser beam, and the gap between the hot conduction welding laser beam and the keyhole welding laser beam is 0.6-2mm.

[0013] The included angle between the first / second supporting plate and the bottom plate is 40°-80°.

[0014] The welding gap between the first / second supporting plate and the bottom plate is 0.01-2mm.

[0015] An ultrasonic amplitude transformer is arranged on one side of the bottom plate, and the ultrasonic amplitude transformer is used to generate ultrasonic cavitation effect at the butt joint.

[0016] A gas injection system is further arranged, and the gas injection system is used to inject shielding gas at the butt joint.

[0017] A laser-CMT composite welding method for K-shaped joints of medium plate, comprising the following steps:

[0018] Step one: surface treatment is performed on the base material to remove surface impurities; the base material with adjusted welding gap is fixed on the welding fixture;

[0019] Step two: the first welding gun, the second welding gun and the third welding gun are respectively connected with one electrode of the CMT power source, and the other electrode of the CMT power source is connected with the base material; the first welding gun, the second welding gun, the third welding gun and the three lasers are respectively arranged in three included angle spaces;

[0020] Step three: the laser and the first welding gun, the second welding gun and the third welding gun are started synchronously for welding, and the gas injection system is turned on to inject shielding gas at the butt joint to prevent the weld from being oxidized.

[0021] Compared with the prior art, the present application has the following advantages and technical effects: the present application can use lower laser energy to weld the K-shaped joint once by setting three groups of welding gun assemblies and lasers, reduces the welding workpiece deformation of welding the K-shaped joint with larger laser energy and the welding stress concentration problem caused by multiple welding, and improves the weld structure and mechanical properties of the weld. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on these drawings.

[0023] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0024] Figure 2 It is a schematic diagram of laser beam splitting of the present application;

[0025] Figure 3 It is a schematic diagram of a weld with defects;

[0026] Figure 4 It is a schematic diagram of another weld with defects;

[0027] Figure 5 It is a schematic diagram of the weld of the present application;

[0028] Among them, 1, first welding gun; 2, first laser; 3, first support plate; 4, second welding gun; 5, second laser; 6, second support plate; 7, third welding gun; 8, third laser; 9, bottom plate; 10, ultrasonic horn; 11, mirror; 12, heat-conducting welding laser beam; 13, spoon-shaped welding laser beam; 14, spoon hole; 15, spoon-shaped welding pool; 16, light splitting module; 17, shielding gas injection system. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0031] A laser-CMT composite welding device for K-type joint of medium plate, comprising a base material and a welding device, the base material comprising a first branch plate 3, a second branch plate 6 and a bottom plate 9; the first branch plate 3, the second branch plate 6 and the bottom plate 9 are provided with a welding gap at the butt joint;

[0032] The welding device comprises a welding gun assembly and a laser; the welding assembly and the laser are respectively arranged in a three-angled space formed at the butt joint; along the welding direction, the welding gun assembly is arranged in front of the laser; a light splitting module 16 is arranged in each laser, and the light splitting module 16 is used for splitting the laser beam in the laser into a heat conduction welding laser beam 12 and a keyhole welding laser beam 13.

[0033] The welding gun assembly comprises a first welding gun 1, a second welding gun 4 and a third welding gun 7 which are the same in structure, and three CMT power sources; the positive poles of the three CMT power sources are respectively connected with the first welding gun 1, the second welding gun 4 and the third welding gun 7, and the negative pole of the CMT power source is connected with the base material; the first welding gun 1, the second welding gun 4 and the third welding gun 7 are all CMT welding guns.

[0034] The axes of the first welding gun 1, the second welding gun 4 and the third welding gun 7 are respectively coplanar with the heat conduction welding laser beams and the keyhole welding laser beams split by the three lasers; the first welding gun 1 and the third welding gun 7 are both formed with an angle of 5°-70° with the bottom plate 9;

[0035] The keyhole welding laser beam 13 forms a keyhole-shaped molten pool 15 at the butt joint, and the light-silicon distance between the keyhole-shaped molten pool 15 and the CMT welding wire of the CMT welding gun is 0-1mm;

[0036] The heat conduction welding laser beam 12 forms a heat conduction welding pool at the butt joint with the keyhole-shaped molten pool 15, and the distance between the heat conduction welding laser beam 12 and the keyhole welding laser beam 13 is 0.6-2mm.

[0037] The angle between the first branch plate 3 / the second branch plate 6 and the bottom plate 9 is 40°-80°.

[0038] The welding gap between the first branch plate 3 and the second branch plate 6 and between the first branch plate 3 / the second branch plate 6 and the bottom plate 9 is 0.01-2mm.

[0039] An ultrasonic amplitude transformer 10 is further arranged on one side of the bottom plate 9; the ultrasonic amplitude transformer 10 is used for generating ultrasonic cavitation effect at the butt joint.

[0040] A gas injection system is further arranged, and the gas injection system is used for injecting protective gas at the butt joint.

[0041] In one embodiment of the present application, the gas injection system is a shielding gas injection system 17, the shielding gas injected by the shielding gas injection system 9 is argon or helium, and the flow rate of the gas injection system is 10-100 L / min.

[0042] A laser-CMT composite welding method for K-type joints of medium plate, comprising the following steps:

[0043] Step one: surface treatment of the base material to remove surface impurities; the base material with adjusted welding gap is fixed on the welding fixture respectively;

[0044] Step two: connecting the first welding torch, the second welding torch and the third welding torch with one electrode of the CMT power source respectively, and connecting the base material with the other electrode of the CMT power source; arranging the first welding torch, the second welding torch, the third welding torch and the three lasers in three angle spaces respectively;

[0045] Step three: starting the laser and synchronously welding the first welding torch, the second welding torch and the third welding torch, and opening the injection system to inject shielding gas to the butt joint to prevent the weld from oxidizing.

[0046] In one embodiment of the present application, the ultrasonic horn 10 is used to remove surface impurities of the base material; the ultrasonic vibration frequency of the ultrasonic horn 10 is 10-110 KHz, and the ultrasonic amplitude is 1-120 um.

[0047] In one embodiment of the present application, as shown in Figure 1 The three lasers are a first laser 2, a second laser 5 and a third laser 8 respectively; the first laser 2, the second laser 5 and the third laser 8 are matched with the first welding torch 1, the second welding torch 4 and the third welding torch 7 respectively to improve the stability of the CMT arc; due to the low heat input of the CMT arc, the welding deformation can be obviously reduced, the CMT welding wire is melted to fill the butt joint in advance, and the stability of the base material welding and the laser energy utilization rate can be improved.

[0048] Further, the power of the first laser 2, the second laser 5 and the third laser 8 is 500-10000 W; the welding current of the first welding torch 1, the second welding torch 4 and the third welding torch 7 is 5-300 A, the welding speed is 0.1 m-8 m / min, and the CMT welding process specification is a wire feeding speed of 1-20 m / min.

[0049] In one embodiment of the present application, the first welding torch 1, the second welding torch 4 and the third welding torch 7 are synchronously welded, once forming, the welding workpiece deformation of the large laser energy welding K-type joint and the welding stress concentration problem caused by multiple welding are reduced, and the weld structure and the weld mechanical properties are improved.

[0050] In one embodiment of the present application, the liquid droplets can be quickly realized into the gap between the first support plate 3 and the second support plate 6, the first support plate 3 and the bottom plate 9, and the second support plate 6 and the bottom plate 9 by the ultrasonic cavitation effect and the preheating melting effect of the laser beam forming the keyhole-shaped molten pool 14, the wetting and spreading property is improved, and the welding forming efficiency and the weld quality are improved.

[0051] Further, when the CMT welding wire is forwarded or the CMT welding wire is retracted, the light-wire distance between the heat conduction welding laser beam 12 and the welding wire is close, which can play a combined effect of attracting and compressing the arc, and the stability of the arc and the stability of the droplet transfer are improved.

[0052] Further, as shown in Figure 2 The light beams emitted by the first laser 2, the second laser 5 and the third laser 8 enter the light splitting module 16 through the reflection of the reflector 11, and the light splitting module splits the light beams into the heat conduction welding laser beam 12 and the keyhole welding laser beam 13.

[0053] Further, the preheating of the heat conduction welding laser beam 12 can also solve the problem that when the CMT welding wire is forwarded or the CMT welding wire is retracted, the light-wire distance between the heat conduction welding laser beam 12 and the welding wire is close, which can play a combined effect of attracting and compressing the arc, and the stability of the arc and the stability of the droplet transfer are improved; when the welding wire is forwarded or the welding wire is retracted, the welding wire is far away from the keyhole welding laser beam 13 with large energy, and the welding wire cannot impact the keyhole formed by the keyhole welding laser beam 13, the stability of the keyhole is improved, and the porosity of the weld is reduced, which is obviously different from the conventional laser-CMT composite welding.

[0054] The heat conduction welding laser beam 12 can improve the utilization rate of the laser energy forming the keyhole welding molten pool 15 and the stability of the keyhole, reduce the number of welding spatters of the keyhole welding molten pool 15, and improve the mechanical properties of the weld structure.

[0055] Further, the keyhole welding laser beam 13 mainly melts the base material and forms a “interconnected” molten pool between the first support plate 3, the second support plate 6 and the bottom plate 9, which improves the welding efficiency and the weld forming quality.

[0056] Further, as shown in Figure 2 The keyhole welding laser beam 13 irradiates on the first support plate 3, the second support plate 6 and the bottom plate 9 to form the keyhole 14 first, and then forms the keyhole welding molten pool 15 around the keyhole 14.

[0057] In one embodiment of the present application, the laser is a YAG laser, a CO2 laser or a fiber laser.

[0058] In one embodiment of the present application, the output type of the laser is continuous output or pulse output; and the CMT power supply can adopt direct current or alternating current output form.

[0059] In one embodiment of the present application, as shown in the accompanying Figure 3 Figure, it is a schematic diagram of the weld appearance of a double-beam laser welding method patent for K-type joints; the weld appears a welding defect of incomplete fusion, and the weld between the support plates is severely recessed (since a gap is reserved between the support plates, laser self-melting welding is prone to the welding defect of weld recess), and a protruding welding defect appears at the joint between the support plate and the bottom plate, which is mainly because, since the spot of the beam is small (generally 0.2 mm), in order to obtain a larger melting area, a larger beam spacing of the laser beam needs to be ensured, so that the problems of incomplete fusion and incomplete penetration of the weld are prone to occur.

[0060] Further, as shown in the accompanying Figure 4 Figure, it is a schematic diagram of the weld appearance of a double-arc preheating laser oscillating welding method patent for K-type joints; the weld between the support plates and the weld between the support plate and the bottom plate all appear welding defects of recess and undercut, which is mainly because, since a gap is reserved between the support plates and the support plate and the bottom plate, laser self-melting welding is prone to the welding defect of weld recess), and the recess between the support plate and the bottom plate is more obvious under the action of the arc blowing force.

[0061] In one embodiment of the present application, as shown in the accompanying Figure 5 Figure, the weld quality obtained by using the welding method of the present application is good, and no welding defects such as recess, undercut, and protrusion appear; the laser-CMT composite method can not only improve the stability of the CMT arc, but also significantly reduce the welding deformation due to the low heat input of the CMT arc, and the welding stability and laser energy utilization rate can be improved due to the early melting of the CMT wire to fill the butt joint gap. The K-type joint can be formed once by using a lower laser energy, which reduces the welding workpiece deformation of the K-type joint welded by a larger laser energy and the welding stress concentration problem caused by multiple welding, and improves the weld structure and mechanical properties of the weld. Relying on the ultrasonic cavitation effect and the preheating melting effect of the heat-conducting welding laser beam 12, liquid droplets can be quickly melted into the reserved gap, the wetting and spreading properties are improved, and the welding forming efficiency and weld quality are improved.

[0062] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0063] The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application.

Claims

1. A laser-CMT hybrid welding apparatus for K-type joint of a medium-thick plate, comprising a base material and a welding apparatus, characterized in that, The base material comprises a first branch plate (3), a second branch plate (6) and a bottom plate (9); the first branch plate (3), the second branch plate (6) and the bottom plate (9) are provided with a welding gap at the butt joint; The welding device comprises a welding gun assembly and a laser; the welding gun assembly and the laser are arranged in a three-angled space formed by the butt joint; along the welding direction, the welding gun assembly is arranged in front of the laser; each laser is provided with a light splitting module (16) for splitting the laser beam into a heat conduction welding laser beam (12) and a keyhole welding laser beam (13); The welding gun assembly comprises a first welding gun (1), a second welding gun (4) and a third welding gun (7) which are identical in structure and three CMT power sources; the positive poles of the three CMT power sources are connected with the first welding gun (1), the second welding gun (4) and the third welding gun (7) respectively, and the negative pole of the CMT power source is connected with the base material; the first welding gun (1), the second welding gun (4) and the third welding gun (7) are all CMT welding guns; The axes of the first welding gun (1), the second welding gun (4) and the third welding gun (7) are coplanar with the heat conduction welding laser beams (12) and the keyhole welding laser beams (13) split by the three lasers respectively; the first welding gun (1) and the third welding gun (7) form an angle of 5°-70° with the bottom plate (9); The keyhole welding laser beams (13) form a keyhole-shaped molten pool (15) at the butt joint; The heat conduction welding laser beams (12) form a heat conduction welding pool at the butt joint with the keyhole-shaped molten pool (15); the heat conduction welding laser beams (12) can attract and compress the electric arc; the distance between the heat conduction welding laser beams (12) and the keyhole welding laser beams (13) is 0.6-2mm; The bottom plate (9) is further provided with an ultrasonic amplitude transformer (10) on one side; the ultrasonic amplitude transformer (10) is used to generate ultrasonic cavitation effect at the butt joint.

2. The laser-CMT hybrid welding device for K-type joint of a medium plate according to claim 1, characterized in that: The angle between the first branch plate (3) / the second branch plate (6) and the bottom plate (9) is 40°-80°.

3. The laser-CMT hybrid welding device for K-type joint of a medium plate according to claim 1, characterized in that: The welding gap between the first branch plate (3) and the second branch plate (6) and between the first branch plate (3) / the second branch plate (6) and the bottom plate (9) is 0.01-2mm.

4. The laser-CMT hybrid welding device for K-type joint of a medium plate according to claim 1, characterized in that: An air injection system is further provided, which is used to inject shielding gas at the butt joint.

5. A laser-CMT hybrid welding method for a K-type joint of a plate, comprising the laser-CMT hybrid welding apparatus for a K-type joint of a plate according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: Step one: surface treatment is performed on the base material to remove surface impurities; the base material with adjusted welding gap is fixed on the welding fixture; Step two: the first welding gun, the second welding gun and the third welding gun are connected with one electrode of the CMT power source respectively, and the other electrode of the CMT power source is connected with the base material; the first welding gun, the second welding gun, the third welding gun and the three lasers are arranged in the three-angled space respectively; Step three: the laser and the first welding gun, the second welding gun and the third welding gun are started to be synchronously welded, and the injection system is turned on to inject shielding gas at the butt joint to prevent the weld from being oxidized.

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