Laser helium arc hybrid welding method and welding system for thick-wall aluminum alloy storage tank

Abstract

The invention provides a laser helium arc hybrid welding method and system for a thick-wall aluminum alloy storage tank, and relates to the technical field of welding technologys.The method comprises the following steps that S1, positioned welding is conducted, specifically, surface oxide of a workpiece is removed through a cleaning light beam, and meanwhile positioned welding is conducted at the two ends of the clamped workpiece, the position of the workpiece is prevented from moving during subsequent backing welding; laser welding and helium arc welding are adopted for bottoming welding, a laser beam and a helium arc act on a workpiece at the same time for welding, and before welding, the laser is started prior to the helium arc; and S3, cosmetic welding is conducted, specifically, argon arc welding is adopted for cosmetic welding, and a cosmetic welding seam completely covers the backing welding seam. According to the method, the one-time penetration rate of fusion welding can be improved by 100% through laser beam induction, helium arc compression and increase of stiffness and penetrating power of helium arc, beveling and multi-layer filling welding are not needed, the production efficiency is greatly improved, the machining cost is reduced, and the welding performance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding technology, and in particular relates to a laser helium arc composite welding method and a welding system for a thick-walled aluminum alloy tank. Background Art

[0002] Aluminum alloys are widely used in the manufacture of fuel tanks for launch vehicles due to their excellent physical and chemical properties. At present, the thickness of the welding area of ​​aluminum alloy tanks is 3-10mm. For the welding of aluminum alloy tanks in this thickness range, the TIG single-sided two-layer welding process is usually used. This process is divided into base welding and cover welding, which can effectively control the heat input and ensure the quality of tank welding. In order to meet the strength requirements of the fuel tank of the manned lunar launch vehicle, the thickness of the tank body has been continuously increased and has far exceeded 10mm, which has exceeded the existing single-sided welding capacity, which has posed a challenge to the welding method and welding capacity of the tank. For the welding of thick-walled aluminum alloy tanks, the current fusion welding manufacturing process is beveled multi-layer TIG welding. TIG welding has the following disadvantages: 1. Beveled multi-layer TIG welding can solve the welding needs of thick-walled aluminum alloy tanks, but during the welding process, the entire tank needs to be beveled, which increases the number of welding times. Compared with the traditional single-sided two-layer welding, the production efficiency is greatly reduced; 2. Beveled multi-layer TIG welding requires 2-4 filling welding and one cover welding after the base welding. Compared with the traditional single-sided two-layer welding method, 2-4 welds are added, the welding heat input is increased, and a large amount of welding wire is filled. After each layer of welding is completed, the weld needs to be cleaned and polished. The multi-layer welding process is also easy to increase the probability of defects such as pore inclusions, which is not conducive to controlling the quality of the weld and the performance of the joint. 3. During the welding process, the melting process is affected by the quality of the previous weld, and it is difficult to effectively monitor, collect and analyze the welding pool data, and make adaptive adjustments. The welding process has certain unpredictable characteristics and cannot achieve intelligent welding. Summary of the invention

[0003] In view of this, the present invention aims to provide a laser helium arc hybrid welding method and welding system for thick-walled aluminum alloy tanks to solve the above-mentioned problems existing in the prior art.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A laser helium arc hybrid welding method for a thick-walled aluminum alloy tank comprises the following steps:

[0006] S1. Positioning welding

[0007] Use the cleaning beam to remove the oxide on the surface of the workpiece, and perform positioning welding on both ends of the clamped workpiece to prevent the workpiece from moving during subsequent base welding;

[0008] S2. Bottom welding

[0009] Laser welding and helium arc welding are used for base welding. The laser beam and helium arc act on the workpiece at the same time for welding. Before welding, the laser takes precedence over the helium arc in starting the arc.

[0010] S3, cover welding

[0011] TIG welding is used for cover welding, and the cover weld completely covers the base weld.

[0012] Furthermore, in S1, the monitoring system monitors the relative position between the workpiece butt surface and the welding molten pool and the distance between the electrode and the workpiece in real time, and feeds back to the control system for analysis, adjusts the workpiece position and the electrode position, and ensures that the relative position between the welding molten pool and the workpiece, and the electrode and the workpiece remain stable.

[0013] Furthermore, the helium arc and the laser beam act on the workpiece at an interval of 0-5s.

[0014] Furthermore, in S2, the monitoring system monitors the relative position of the welding device and the workpiece, the relative position of the molten pool and the workpiece, and the relative position of the welding beam and the electrode in real time, and feeds back to the control system for analysis, and uses the control system to regulate the working state of the welding device.

[0015] Furthermore, in S2, the welding beam power range is 2000-3500W, the welding speed is 8-15m / h; the front width of the base weld is 10-14mm, and the back width is 9-12mm.

[0016] Furthermore, in S3, the welding current of the cap welding is 330-370A, the arc voltage is 19-22V, the welding speed is 5-14m / h, and the wire feeding speed is 1500-3000mm / min; the welding angle of the electrode is 0-20°; and the cap weld is 8-14mm wider than the base weld.

[0017] Furthermore, in S3, the shielding gas for the cap welding is a mixture of helium and argon; the helium gas flow rate is 3-5 L / min, and the argon gas flow rate is 9-11 L / min.

[0018] The present invention provides a laser helium arc hybrid welding system for thick-walled aluminum alloy tanks, which is used to implement the laser helium arc hybrid welding method for the thick-walled aluminum alloy tanks;

[0019] The laser helium arc hybrid welding system for thick-walled aluminum alloy tanks comprises a welding device and a cleaning device, wherein the cleaning device is used to remove impurities and oxide films on the surface of the workpiece;

[0020] The welding device comprises a laser welding head, a helium arc welding gun and an adjusting device. The laser welding head and the helium arc welding gun are rotatably mounted on a mounting frame. The helium arc welding gun is located behind the laser welding head and is arranged at a certain angle to the laser welding head to ensure that the laser welding acts on the workpiece first during welding.

[0021] The mounting frame is connected to the adjusting device, and the adjusting device is used to adjust the height and horizontal position of the laser welding head and the helium arc welding gun; a dial is provided between the laser welding head and the mounting frame, and is used to observe the adjustment angle of the laser welding head;

[0022] The cleaning device is arranged in front of the laser welding head;

[0023] A wire feeding device is provided in the welding device.

[0024] Furthermore, the laser-helium-arc hybrid welding system for the thick-walled aluminum alloy tank also includes a monitoring system and a control system. The monitoring system monitors the relative position of the workpiece butt surface to the welding molten pool in real time and feeds back to the control system, and the control system adjusts the position of the laser welding head and the helium-arc welding gun.

[0025] Furthermore, the adjustment device includes a first linear module and a second linear module, the first linear module is vertically arranged, and the mounting frame is installed on a slider of the first linear module; the second linear module is horizontally arranged, and the first linear module is slidably installed on the second linear module and moves in a horizontal direction.

[0026] Compared with the prior art, the laser helium arc hybrid welding method and welding system for thick-walled aluminum alloy tanks of the present invention have the following beneficial effects:

[0027] The laser helium arc composite welding method for a thick-walled aluminum alloy tank described in the present invention can increase the stiffness and penetration ability of the helium arc by inducing and compressing the helium arc with a laser beam, thereby increasing the one-time penetration rate of fusion welding by 100%, eliminating the need for groove opening and multi-layer filling welding, greatly improving production efficiency, reducing processing costs, and improving welding performance.

[0028] The laser helium arc hybrid welding method for thick-walled aluminum alloy tanks described in the present invention adopts a relatively low-cost, low-power (<5000W) laser-induced helium arc, which can effectively reduce the welding arc current and significantly improve the product's penetration ability. Conventional general equipment is coupled and superimposed to achieve a capability level that cannot be achieved by a single equipment or a single process, while significantly reducing equipment costs.

[0029] The laser helium arc hybrid welding method for a thick-walled aluminum alloy tank described in the present invention automatically tracks the welding status during the welding process through a monitoring system, cooperates with a control system to regulate the state of the welding device, predicts the quality and performance of the weld, realizes intelligent welding and quality monitoring of the weld, and effectively controls the welding quality.

[0030] The laser helium arc composite welding system for a thick-walled aluminum alloy tank described in the present invention realizes a high degree of integration of the whole-process processing functions of the product, can be adapted to the welding of all launch vehicle tanks, and has a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a schematic diagram of the method of the present invention;

[0033] Figure 2 is a flow chart of the method of the present invention;

[0034] Figure 3 It is a structural schematic diagram of the welding system of the present invention;

[0035] Figure 4 For the present invention Figure 3 A partial enlarged view of part A in the middle.

[0036] In the figure, 1-helium arc welding gun; 2-mounting frame; 3-laser welding head; 4-first linear module; 5-second linear module; 6-cleaning device; 7-dial. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] The present invention provides a laser helium arc hybrid welding method for a thick-walled aluminum alloy tank, which is characterized by comprising the following steps:

[0040] S1. Positioning welding

[0041] The cleaning beam is used to remove the oxide on the surface of the workpiece. The cleaning beam acts on the front 10-30mm of the molten pool. By controlling the frequency and energy of the laser beam of the cleaning module, the oxide on the surface of the workpiece is broken to achieve the purpose of cleaning the workpiece. At the same time, positioning welding is performed at both ends of the clamped workpiece to prevent the workpiece position from moving during subsequent base welding.

[0042] Before welding, the workpiece to be welded is clamped on the welding pad. After assembly, the gap is ≤0.5mm and the misalignment is ≤0.5mm. Specifically, a welding groove is processed in the center of the pad. The width of the welding groove is 20mm, the depth is 2mm, and the root is chamfered.

[0043] The monitoring system monitors the relative position between the workpiece butt surface and the welding molten pool, as well as the distance between the electrode and the workpiece in real time, and feeds back to the control system for analysis, and adjusts the workpiece position and the electrode position to ensure that the relative position between the welding molten pool and the workpiece, and between the electrode and the workpiece remain stable.

[0044] When performing positioning welding, be careful not to form weld leaks on the back. By melting the surface metal, the position of the workpiece can be fixed to ensure that the position of the workpiece does not move during subsequent base welding.

[0045] S2. Bottom welding

[0046] Laser welding and helium arc welding are used for base welding. The laser beam and helium arc act on the workpiece at the same time for welding. The laser takes precedence over the helium arc before welding. Specifically, the helium arc and the laser beam act on the workpiece at an interval of 0-5s to ensure that the welding beam is at the front end of the argon arc welding gun in the welding direction. The laser beam acts on the workpiece first, relying on the conductive particles and plasma formed by the welding beam at the bottom of the molten pool to compress the arc, increase the density and stiffness of the arc, and thus increase the penetration ability of the helium arc. During the base welding process, the oxide layer and impurities are broken by cleaning the beam to ensure the cleanliness of the workpiece.

[0047] The monitoring system monitors the relative position of the welding device and the workpiece, the relative position of the molten pool and the workpiece, and the relative position of the welding beam and the electrode in real time, and feeds back to the control system for analysis, and uses the control system to regulate the working state of the welding device.

[0048] The welding beam power range is 2000-3500W, the welding speed is 8-15m / h; the front width of the base weld is 10-14mm, and the back width is 9-12mm.

[0049] The base welding is protected by 99.999% helium, with a gas flow rate of 11-14L / min and a welding current of 260A-330A.

[0050] S3, cover welding

[0051] TIG welding is used for cover welding, and the cover weld completely covers the base weld.

[0052] The welding current of the cap welding is 330-370A, the arc voltage is 19-22V, the welding speed is 5-14m / h, and the wire feeding speed is 1500-3000mm / min; the welding angle of the electrode is 0-20°; the cap weld is 8-14mm wider than the base weld.

[0053] Specifically, the shielding gas for cap welding is a mixed gas of helium and argon; the gas flow rate of helium is 3-5 L / min, and the gas flow rate of argon is 9-11 L / min.

[0054] The present invention provides a laser helium-arc hybrid welding system for a thick-walled aluminum alloy tank for realizing the laser helium-arc hybrid welding method for the thick-walled aluminum alloy tank. The laser helium-arc hybrid welding system for the thick-walled aluminum alloy tank comprises a welding device and a cleaning device 6, wherein the cleaning device 6 is used to remove impurities and oxide films on the surface of a workpiece; the welding device comprises a laser welding head 3, a helium-arc welding gun 1 and an adjusting device, wherein the laser welding head 3 and the helium-arc welding gun 1 are rotatably mounted on a mounting frame 2, wherein the helium-arc welding gun 1 is located behind the laser welding head 3 and is arranged at a certain angle to the laser welding head 3, so as to ensure that the laser welding acts on the workpiece preferentially during welding; the mounting frame 2 is connected to the adjusting device, wherein the adjusting device is used to adjust the height and horizontal position of the laser welding head 3 and the helium-arc welding gun 1; a dial plate 7 is arranged between the laser welding head 3 and the mounting frame 2, for observing the adjustment angle of the laser welding head 3; the cleaning device 6 is arranged in front of the laser welding head 3; and a wire feeding device is arranged in the welding device.

[0055] Furthermore, the laser-helium-arc hybrid welding system for the thick-walled aluminum alloy tank also includes a monitoring system and a control system. The monitoring system monitors the relative position of the workpiece butt surface to the welding molten pool in real time and feeds back to the control system, and the control system adjusts the position of the laser welding head 3 and the helium-arc welding gun 1.

[0056] The monitoring system and the control system are both prior art, so they are not described in detail. In the present invention, the monitoring system is used in conjunction with the control system to control the welding system, which can achieve the following functions: (1) The contour morphology of the product before welding is collected by the laser beam, and the assembly morphology such as the butt gap and staggered seam before the product is assembled can be recorded. The collected and recorded data is compared with the control requirement data to determine the assembly quality; (2) The position information of the workpiece and the molten pool, and the workpiece and the welding system is monitored and collected by the control system through the control beam, and the analysis is performed. The analysis results act on the mechanical system to drive the welding system to make adaptive adjustments; (3) The control beam collects the position relationship between the tungsten electrode tip, the welding beam and the welding molten pool, and fits and compares them with the theoretical optimal energy coupling form and position, and feeds back to the welding mechanism and the welding beam to make dynamic adjustments to ensure the stability and quality of the welding process; (4) The welding process is analyzed by monitoring and collecting the molten pool thermal field information during the welding process and acting on the control system. Analyze and reconstruct the weld pool, thermal field and other information to simulate weld formation. Based on the collected information on weld formation and thermal field distribution, analyze the influence of factors such as heat input, energy distribution, and energy coupling form on the welding process, and further control the welding process based on the analysis results; (5) Collect the morphology of weld formation, including the base morphology and the cover morphology, reconstruct the overall joint morphology after welding, compare it with the ideal weld morphology, and preliminarily judge the weld quality.

[0057] The cleaning device 6 adopts the principle of laser cleaning. During welding, the cleaning module acts in front of the welding pool and preferentially acts on the workpiece to clean the oxide film, thereby saving the implementation of manual cleaning and greatly improving the integration, automation and production efficiency of welding.

[0058] Furthermore, the adjusting device includes a first linear module 4 and a second linear module 5, the first linear module 4 is vertically arranged, and the mounting frame 2 is installed on a slider of the first linear module 4; the second linear module 5 is horizontally arranged, and the first linear module 4 is slidably installed on the second linear module 5 and moves in a horizontal direction.

[0059] In the several embodiments provided in the present application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser helium arc hybrid welding method for thick-walled aluminum alloy tanks, characterized in that: The following steps are involved: S1. Positioning welding Use the cleaning beam to remove the oxide on the surface of the workpiece, and perform positioning welding on both ends of the clamped workpiece to prevent the workpiece from moving during subsequent base welding; S2. Bottom welding Laser welding and helium arc welding are used for base welding. The laser beam and helium arc act on the workpiece at the same time for welding. Before welding, the laser takes precedence over the helium arc in starting the arc. S3, cover welding TIG welding is used for cover welding, and the cover weld completely covers the base weld; In S2, the monitoring system monitors the relative position of the welding device and the workpiece, the relative position of the molten pool and the workpiece, and the relative position of the welding beam and the electrode in real time, and feeds back to the control system for analysis, and uses the control system to adjust the working state of the welding device in real time; No need for beveling and multi-layer filling welding.

2. The laser helium arc hybrid welding method for thick-walled aluminum alloy tank according to claim 1 is characterized in that: In S1, the monitoring system monitors the relative position between the workpiece butt surface and the welding molten pool and the distance between the electrode and the workpiece in real time, and feeds back to the control system for analysis, adjusts the workpiece position and the electrode position, and ensures that the relative position between the welding molten pool and the workpiece, and the electrode and the workpiece remain stable.

3. The laser helium arc hybrid welding method for thick-walled aluminum alloy tank according to claim 1 is characterized in that: The helium arc and the laser beam act on the workpiece at an interval of 0-5s.

4. The laser helium arc hybrid welding method for thick-walled aluminum alloy tank according to claim 1, characterized in that: In S2, the welding beam power range is 2000-3500W, the welding speed is 8-15m / h; the front width of the base weld is 10-14mm, and the back width is 9-12mm.

5. The laser helium arc hybrid welding method for thick-walled aluminum alloy tank according to claim 1, characterized in that: In S3, the welding current of the cap welding is 330-370A, the arc voltage is 19-22V, the welding speed is 5-14m / h, and the wire feeding speed is 1500-3000mm / min; the welding angle of the electrode is 0-20°; the cap weld is 8-14mm wider than the base weld.

6. The laser helium arc hybrid welding method for thick-walled aluminum alloy tank according to claim 1, characterized in that: In S3, the shielding gas for cap welding is a mixture of helium and argon; the helium gas flow rate is 3-5 L / min, and the argon gas flow rate is 9-11 L / min.

7. A laser helium arc hybrid welding system for thick-walled aluminum alloy tanks, characterized in that: A laser helium arc hybrid welding method for realizing the thick-walled aluminum alloy tank described in any one of claims 1 to 6; The laser helium arc hybrid welding system for thick-walled aluminum alloy tanks comprises a welding device and a cleaning device, wherein the cleaning device is used to remove impurities and oxide films on the surface of the workpiece; The welding device comprises a laser welding head, a helium arc welding gun and an adjusting device. The laser welding head and the helium arc welding gun are rotatably mounted on a mounting frame. The helium arc welding gun is located behind the laser welding head and is arranged at a certain angle to the laser welding head to ensure that the laser welding acts on the workpiece first during welding. The mounting frame is connected to the adjusting device, and the adjusting device is used to adjust the height and horizontal position of the laser welding head and the helium arc welding gun; a dial is provided between the laser welding head and the mounting frame, and is used to observe the adjustment angle of the laser welding head; The cleaning device is arranged in front of the laser welding head; A wire feeding device is provided in the welding device.

8. The laser helium arc hybrid welding system for thick-walled aluminum alloy tanks according to claim 7, characterized in that: It also includes a monitoring system and a control system. The monitoring system monitors the relative position of the workpiece butt surface to the welding pool in real time and feeds back to the control system. The control system adjusts the position of the laser welding head and the helium arc welding gun.

9. The laser helium arc hybrid welding system for thick-walled aluminum alloy tanks according to claim 7, characterized in that: The adjusting device includes a first linear module and a second linear module, the first linear module is vertically arranged, and the mounting frame is installed on a slider of the first linear module; the second linear module is horizontally arranged, and the first linear module is slidably installed on the second linear module to move in a horizontal direction.

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