A laser double-arc hybrid welding device for longitudinal ring seam of pressure vessel

Abstract

The application belongs to the technical field of composite welding, and specifically discloses a laser double-arc composite welding device for longitudinal ring seam of a pressure container. The laser double-arc composite welding device comprises a shielded metal arc welding device, a laser welding device and a tungsten inert gas arc welding device. The shielded metal arc welding gun in the shielded metal arc welding device, the laser welding head in the laser welding device and the tungsten inert gas arc welding gun in the tungsten inert gas arc welding device are arranged in sequence along the same welding operation path, and the shielded metal arc welding gun is located in front of the laser welding head, and the tungsten inert gas arc welding gun is located behind the laser welding head. The laser double-arc composite welding device has the characteristics of high welding efficiency, small welding deformation, high welding seam forming quality and low production cost.

Description

Technical Field

[0001] This application belongs to the field of composite welding technology, and more specifically, relates to a laser dual-arc composite welding device for longitudinal circumferential seams of pressure vessels. Background Technology

[0002] With the rapid development of the liquefied natural gas (LNG) industry in recent years, LNG, as a clean petrochemical energy source, has seen its end-use applications expand increasingly due to its convenient transportation, flexible use, and lack of pipeline network constraints. In particular, LNG offers advantages in the transportation industry, including safety, environmental friendliness, long vehicle driving range, and significant environmental and economic benefits. Against this backdrop, pressure vessels used for storing LNG have broad development and application prospects.

[0003] Currently, pressure vessels for storing liquefied natural gas are mainly made of stainless steel plates rolled into cylinders and then welded. There are various welding processes for the longitudinal and circumferential seams (such as longitudinal seams and circumferential seams) in pressure vessels, including gas metal arc welding, plasma welding, and laser arc hybrid welding.

[0004] Among these, the relatively low welding speeds of gas metal arc welding (GMAW) and plasma welding significantly limit the production efficiency of pressure vessels for liquefied natural gas (LNG). Mainly, these welding processes suffer from high heat input and significant post-weld deformation, which can lead to large gaps during subsequent head assembly, increasing welding difficulty. In particular, due to the weak penetration of the GMAW arc, welding plates thicker than 5mm often requires a higher welding current and the creation of a weld bevel to achieve single-sided welding with double-sided forming. However, the high current results in larger weld dimensions, reducing product quality while increasing manufacturing processes and production costs.

[0005] While laser-guided single-arc hybrid welding technology boasts high welding efficiency, both modes within this technology have certain drawbacks. For instance, in laser-guided mode, the arc welding angle is push-gun welding, resulting in a flatter molten pool under the arc force and achieving a weld with a larger width-to-height ratio. However, this requires a higher weld gap and is prone to porosity defects due to laser keyhole instability during high-speed welding. Conversely, in arc-guided mode, the arc welding angle is drag-gun welding, where the arc force pushes the molten pool backward, resulting in a smaller weld bead formation coefficient and a higher likelihood of undercut and other defects. Furthermore, in both modes, the molten pool vibration during droplet transfer can easily cause burrs on the weld edges.

[0006] In summary, the use of gas metal arc welding (GMAW) and plasma welding for longitudinal and circumferential seams in pressure vessels suffers from insufficient welding efficiency, weak penetration, and high production costs. Laser single-arc hybrid welding also presents corresponding problems at high speeds and urgently needs improvement. Utility Model Content

[0007] To address the shortcomings or improvement needs of existing technologies, this application provides a laser dual-arc composite welding device for longitudinal and circumferential seams of pressure vessels, aiming to improve the problems of low efficiency, large welding deformation, poor weld formation quality, and high production costs of existing welding technologies.

[0008] This application provides a laser dual-arc composite welding device for longitudinal and circumferential seams of pressure vessels. The welding device includes a gas metal arc welding unit, a laser welding unit, and a tungsten inert gas (TIG) welding unit, wherein: The gas metal arc welding torch in the gas metal arc welding device, the laser welding head in the laser welding device, and the tungsten inert gas (TIG) welding torch in the tungsten inert gas (TIG) welding device are arranged sequentially along the same welding operation path, with the gas metal arc welding torch located in front of the laser welding head and the TIG welding torch located behind the laser welding head.

[0009] As a further preferred embodiment, the angle between the gas metal arc welding torch and the direction perpendicular to the surface to be welded on the pressure vessel is 25° to 45°.

[0010] As a further preferred embodiment, the angle between the laser welding head and the direction perpendicular to the surface to be welded on the pressure vessel is 0 to -10°.

[0011] As a further preferred embodiment, the angle between the tungsten inert gas welding torch and the direction perpendicular to the surface to be welded on the pressure vessel is -10° to -45°.

[0012] As a further preferred embodiment, the distance between the end of the welding wire and the laser spot output from the laser welding head to the surface of the pressure vessel to be welded in the gas metal arc welding device is 1mm-5mm.

[0013] As a further preferred embodiment, the distance between the end of the tungsten needle and the laser spot output from the laser welding head to the surface of the pressure vessel to be welded in the tungsten inert gas welding device is 3mm-20mm.

[0014] As a further preferred embodiment, the height of the tungsten needle and the pressure vessel to be welded in the tungsten inert gas welding device is 2mm-10mm.

[0015] As a further preferred embodiment, the relative position and / or operating parameters of the gas metal arc welding device and the laser welding device are configured such that they can form a eutectic pool on the surface to be welded of the pressure vessel, or a non-eutectic pool on the surface to be welded of the pressure vessel.

[0016] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. Compared with traditional welding methods such as gas metal arc welding and plasma welding, the design scheme of this application increases the welding speed by more than 5 times, while reducing the amount of welding wire by 70%. It can improve welding efficiency and reduce production costs at the same time.

[0017] 2. The composite welding scheme adopted in this application includes laser welding, which has excellent penetration ability and can weld extremely thick plates without beveling.

[0018] 3. Compared with laser-single-arc hybrid welding, the design scheme of this application, when the tungsten inert gas (TIG) welding and laser welding form a eutectic pool, makes the molten pool more stable during TIG welding; when the TIG welding and laser welding do not form a eutectic pool, a smaller welding current can be used to remelt the high-temperature weld, reducing undercut and avoiding defects such as weld burrs caused by droplet transfer. A weld with a large width-to-height ratio can be obtained.

[0019] 4. Compared with traditional laser single-arc hybrid welding, the technical solution of this application has a faster welding speed while ensuring the quality of weld formation; compared with laser single-arc hybrid welding, the technical solution of this application can significantly broaden the welding process window. Attached Figure Description

[0020] Figure 1 This is a welding schematic diagram of a laser dual-arc composite welding device for longitudinal and circumferential seams of pressure vessels provided in an embodiment of this application.

[0021] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Gas metal arc welding torch; 2. Laser welding head; 3. Laser beam; 4. TIG welding torch; 5. Tungsten needle; 6. TIG welding arc; 7. Formed weld; 8. Pressure vessel; 9. Molten pool; 10. Gas metal arc welding arc; 11. Welding wire. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0024] This application discloses a laser dual-arc composite welding device for longitudinal and circumferential seams of pressure vessels. (Refer to...) Figure 1The welding equipment includes a gas metal arc welding device, a laser welding device, and a tungsten inert gas (TIG) welding device. The gas metal arc welding torch 1 in the gas metal arc welding device, the laser welding head 2 in the laser welding device, and the tungsten inert gas (TIG) welding torch 4 in the TIG welding device are arranged sequentially along the same welding operation path. The gas metal arc welding torch 1 is located in front of the laser welding head 2, and the TIG welding torch 4 is located behind the laser welding head 2.

[0025] In further preferred embodiments, the angle between the gas metal arc welding torch 1 and the direction perpendicular to the surface to be welded of the pressure vessel 8 is 25° to 45°; the angle between the laser welding head 2 and the direction perpendicular to the surface to be welded of the pressure vessel 8 is 0° to -10°; and the angle between the tungsten inert gas welding torch 4 and the direction perpendicular to the surface to be welded of the pressure vessel 8 is -10° to -45°.

[0026] The 0° reference is taken as the direction perpendicular to the surface to be welded on the pressure vessel 8. When the welding torch is tilted in the opposite direction of the welding direction, the angle is recorded as a negative value. For ease of understanding, Figure 1 Arrow A indicates the welding direction. The welding path is the weld formation path shown in the diagram. The weld is continuously formed from the already formed weld at point 7 along the direction indicated by arrow A. For ease of understanding... Figure 1 The angle between the gas metal arc welding torch 1 and the direction perpendicular to the surface to be welded on the pressure vessel 8 is shown by the angle mark α, and the angle between the tungsten inert gas welding torch 4 and the direction perpendicular to the surface to be welded on the pressure vessel 8 is shown by the angle mark β.

[0027] In a further preferred embodiment, the distance between the end of the welding wire 11 in the gas metal arc welding apparatus and the laser spot output from the laser welding head 2 to the surface to be welded on the pressure vessel 8 is 1mm-5mm. The distance between the tungsten needle 5 in the tungsten inert gas welding apparatus and the laser spot output from the laser welding head 2 to the surface to be welded on the pressure vessel 8 is 3mm-20mm. The height between the tungsten needle 5 in the tungsten inert gas welding apparatus and the surface to be welded on the pressure vessel 8 (i.e., the workpiece surface) is 2mm-10mm.

[0028] Further preferred embodiments, in some embodiments, the relative positions and / or operating parameters of the gas metal arc welding apparatus and the laser welding apparatus are configured such that: the gas metal arc welding apparatus and the laser welding apparatus can form a eutectic pool on the surface to be welded of the pressure vessel 8, or can form a non-eutectic pool on the surface to be welded of the pressure vessel 8; in the case of a eutectic pool, a non-eutectic pool is formed as follows: Figure 1 like Figure 1 The molten pool 9 shown.

[0029] In a further preferred embodiment, the method for manufacturing the pressure vessel 8 includes the following steps: (1) To manufacture the components of pressure vessel 8. For example, to roll stainless steel plates into a cylinder.

[0030] (2) The components are butt welded to form a longitudinal circumferential seam (such as a circumferential seam or a longitudinal seam).

[0031] For example, the cylindrical body (usually made of stainless steel) is butt-welded to form a longitudinal seam with a gap of 0mm to 1mm. For example, when the cylindrical body of pressure vessel 8 is long and a single rolled steel plate cannot meet the length requirements, and it needs to be spliced ​​from multiple short cylindrical sections, the circumferential edges of the ends of two cylindrical sections are butt-welded to form a circumferential seam; for example, when the cylindrical body is connected to the end caps, the circumferential edges of the ends of the cylindrical body are butt-welded to the opening edges of the end caps to form a circumferential seam.

[0032] (3) Place the components (such as the cylinder) of the pressure vessel 8 at the laser dual-arc composite welding equipment so that the pre-welded weld (i.e., a certain longitudinal circumferential weld) on the component is flush with the line connecting the gas metal arc welding torch 1, the laser welding head 2, and the tungsten inert gas welding torch 4. Place the arc-starting plate and the arc-extinguishing plate at both ends of the weld and clamp them.

[0033] (4) Move the laser dual arc composite welding head (gas metal arc welding gun 1, laser welding head 2, tungsten inert gas welding gun 4) in this equipment to the arc starting point, turn on the laser dual arc composite welding equipment, and use the trajectory of the pre-welded seam as the welding operation path to carry out the welding operation until the welding of the entire pre-welded seam is completed.

[0034] It is understandable that a gas metal arc welding apparatus is a device used to perform gas metal arc welding. It includes components such as a gas metal arc welding torch 1, a wire feeder, and a gas cylinder. The arc between the continuously fed, fusible welding wire 11 and the workpiece is controlled by an electric arc (e.g., gas welder, gas cylinder). Figure 1 The gas metal arc 10 in the welding process serves as a heat source to melt the welding wire 11 and the metal at the weld, forming a molten pool 9 and a weld.

[0035] It is understandable that a laser welding device is a welding device that uses a high-energy-density laser beam 3 as a heat source. It includes a laser welding head 2, through which the laser beam 3 is output to heat the surface of the workpiece by laser radiation to form a spot; then the heat on the surface of the workpiece diffuses into the interior through heat conduction, so that the workpiece melts to form a specific molten pool, thereby realizing fusion welding.

[0036] As can be understood, a tungsten inert gas (TIG) welding apparatus is an arc welding device that generates heat between a non-consumable electrode and the workpiece. It includes components such as a TIG welding torch 4 and a tungsten needle 5. During welding, argon gas is continuously ejected from the nozzle of the TIG welding torch 4, forming a protective layer around the TIG welding arc 6 to isolate it from the air and prevent oxidation of the tungsten needle 5, the molten pool, and the adjacent heat-affected zone, thereby obtaining a high-quality weld (i.e., TIG welding technology).

[0037] In this design, a laser-dual-arc composite welding head is formed by arranging three welding devices in a specific orientation. After connecting the weld using a combination of gas metal arc welding (GMAW) and laser welding, tungsten inert gas (TIG) welding is used to refine the weld. The TIG welding can either co-melt with the laser welding in the weld pool or not. Ultimately, a weld with a large forming coefficient, uniform weld, no undercut, and no edge burrs at the weld toe can be obtained. Overall, the technical solution conceived in this application has the following main advantages compared to existing technologies.

[0038] 1. Compared with traditional welding methods, the design scheme of this application increases the welding speed by more than 5 times, while reducing the amount of welding wire 11 by 70%. This improves welding efficiency while reducing production costs.

[0039] 2. Compared with existing pressure vessel welding solutions, the design scheme of this application has stronger penetration capability of laser welding, which allows for the welding of thicker plates without beveling.

[0040] 3. Compared with laser single-arc hybrid welding, the design scheme of this application, when the tungsten inert gas (TIG) welding and laser welding form a eutectic pool, makes the molten pool more stable during TIG welding; when the TIG welding and laser welding do not form a eutectic pool, a smaller welding current can be used to remelt the high-temperature weld, reducing undercut and avoiding defects such as weld burrs caused by droplet transfer. A weld with a large width-to-height ratio can be obtained.

[0041] 4. Compared with traditional laser single-arc hybrid welding, the technical solution of this application has a faster welding speed while ensuring the quality of weld formation.

[0042] 5. Compared with laser single-arc composite welding, the technical solution of this application can significantly broaden the welding process window.

[0043] The embodiments of this application are implemented based on the technical solution of this application, and detailed implementation methods and processes are given. However, the protection scope of this application is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally based on conventional conditions.

[0044] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this application.

[0045] The process parameters in the following examples, unless otherwise specified, are generally performed under conventional conditions.

[0046] Example 1: In this embodiment, the pressure vessel 8 cylinder is made of 4mm thick 304 stainless steel, and the welding wire 11 is 308LSi with a diameter of 1.2mm. The laser dual-arc composite welding torch layout consists of a gas metal arc welding torch 1, a laser welding head 2, and a tungsten inert gas (TIG) welding torch 4, with the gas metal arc welding torch 1 in front during welding. The angle between the gas metal arc welding torch 1 and the direction perpendicular to the surface to be welded on the pressure vessel 8 is 35°, the angle between the laser welding head 2 and the direction perpendicular to the surface to be welded on the pressure vessel 8 is 0°, and the angle between the TIG welding torch 4 and the direction perpendicular to the surface to be welded on the pressure vessel 8 is -15°. The distance between the gas metal arc welding wire 11 and the laser is 2mm, and the distance between the TIG welding tungsten needle 5 and the laser is 5mm.

[0047] A laser dual-arc composite welding method for the longitudinal seam of a pressure vessel includes the following steps: (1) The stainless steel sheet is rolled into a cylinder by a rolling machine.

[0048] (2) Butt welding is performed on the stainless steel cylinder to form a longitudinal seam with a gap of 0mm to 1mm.

[0049] (3) Place the cylinder on the longitudinal seam welding equipment so that the longitudinal seam on the cylinder is parallel to the line connecting the gas metal arc welding torch-laser-tungsten inert gas welding torch. Place the arc-starting plate and the arc-extinguishing plate at both ends of the weld and clamp them.

[0050] (4) The laser dual-arc composite welding head moves to the arc initiation point, and the laser dual-arc composite welding equipment is turned on until the welding of the entire longitudinal seam is completed. During the welding process, the laser power is 4.2kw, the gas metal arc welding current is 170A, the voltage is 24.5V, the tungsten inert gas welding current is 200A, and the welding speed is 2m / min. Among them, the gas metal arc welding shielding gas is Ar+2%O2, and the gas flow rate is 16-20L / min. The tungsten inert gas welding shielding gas is 99.99%Ar, and the gas flow rate is 14L / min-17L / min.

[0051] Example 2: In this embodiment, the pressure vessel 8 is a cryogenic insulated gas cylinder body, using 10mm thick 304 stainless steel plates. The welding wire 11 is 308LSi with a diameter of 1.2mm. The laser dual-arc composite welding torch layout consists of a gas metal arc welding torch 1, a laser welding head 22, and a tungsten inert gas (TIG) welding torch 4, with the gas metal arc welding torch 1 in front during welding. The angle between the gas metal arc welding torch 1 and the vertical direction is 35°, the angle between the laser welding head 22 and the vertical direction is -7°, and the angle between the TIG welding torch 4 and the vertical direction is -15°. The distance between the gas metal arc welding wire 11 and the laser is 2mm, and the distance between the TIG welding tungsten needle 5 and the laser is 5mm.

[0052] A laser dual-arc composite welding method for longitudinal seams of cryogenic insulated gas cylinders includes the following steps: (1) The stainless steel sheet is rolled into a cylinder by a rolling machine.

[0053] (2) Butt welding is performed on the stainless steel cylinder to form a longitudinal seam with a gap of 0 to 1 mm.

[0054] (3) Place the cylinder on the longitudinal seam welding equipment so that the longitudinal seam on the cylinder is parallel to the line connecting the gas metal arc welding torch, laser and tungsten inert gas welding torch. Place the arc-starting plate and the arc-extinguishing plate at both ends of the weld and clamp them.

[0055] (4) The laser-dual-arc composite welding head moves to the arc initiation point, and the laser-dual-arc composite welding equipment is turned on until the entire longitudinal seam is welded. The laser power during the welding process is 10.0kw, the gas metal arc welding current is 190A, the voltage is 25.5V, the tungsten inert gas welding current is 210A, and the welding speed is 1.8m / min. Among them, the gas metal arc welding shielding gas is Ar+2%O2 with a gas flow rate of 16-20L / min, and the tungsten inert gas welding shielding gas is 99.99%Ar with a gas flow rate of 14-17L / min.

[0056] It should be understood that expressions such as "comprising" and "may include" as used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "comprising" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but should not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0057] It should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0059] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0060] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A laser dual-arc composite welding device for longitudinal and circumferential seams of pressure vessels, characterized in that, The welding equipment includes a gas metal arc welding device, a laser welding device, and a tungsten inert gas (TIG) welding device, wherein: The gas metal arc welding torch (1) in the gas metal arc welding device, the laser welding head (2) in the laser welding device, and the tungsten inert gas welding torch (4) in the tungsten inert gas welding device are arranged sequentially along the same welding operation path, and the gas metal arc welding torch (1) is located in front of the laser welding head (2), and the tungsten inert gas welding torch (4) is located behind the laser welding head (2). The angle between the laser welding head (2) and the direction perpendicular to the surface to be welded of the pressure vessel (8) is 0 to -10°, the angle between the tungsten inert gas welding torch (4) and the direction perpendicular to the surface to be welded of the pressure vessel (8) is -10° to -45°, and the tungsten inert gas welding device and the laser welding device form a symbiotic pool.

2. The laser dual-arc composite welding equipment as described in claim 1, characterized in that, The angle between the gas metal arc welding torch (1) and the direction perpendicular to the surface to be welded on the pressure vessel (8) is 25° to 45°.

3. The laser dual-arc composite welding equipment as described in claim 1, characterized in that, The distance between the end of the welding wire (11) and the laser spot output from the laser welding head (2) to the surface to be welded on the pressure vessel (8) in the gas metal arc welding device is 1mm-5mm.

4. The laser dual-arc composite welding equipment as described in claim 1, characterized in that, The distance between the end of the tungsten needle (5) and the laser spot output from the laser welding head (2) to the surface to be welded on the pressure vessel (8) in the tungsten inert gas welding device is 3mm-20mm.

5. The laser dual-arc composite welding equipment as described in claim 1, characterized in that, The height distance between the tungsten needle (5) and the welding surface of the pressure vessel (8) in the tungsten inert gas welding device is 2mm-10mm.

6. The laser dual-arc composite welding equipment as described in any one of claims 1-5, characterized in that, The relative position and / or operating parameters of the gas metal arc welding device and the laser welding device are configured such that they can form a eutectic pool on the surface to be welded in the pressure vessel (8), or a non-eutectic pool on the surface to be welded in the pressure vessel (8).

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