Method for tungsten inert gas (TIG) shielded welding of 5083 aluminum alloy pipes and argon protection system

Abstract

This invention discloses a tungsten inert gas (TIG) shielded welding method and argon protection system for 5083 aluminum alloy pipes. The system includes an argon source, an argon pressure regulating component, a flow regulating component, and a low-emission polymer material gas delivery hose. One end of the gas delivery hose extends into the 5083 aluminum alloy pipe to be welded, supplying gas to the back area corresponding to the weld root. The welding method includes machining a single-sided V-groove at the pipe end, forming a root gap by butt welding, performing argon gas replacement, and using TIG shielded welding for the root pass. During welding, argon gas diffuses through the root gap to the back of the molten pool, achieving back-side protection and assisting in the removal of oxide impurities and fumes. This invention can reduce the risk of argon gas transport contamination, reduce weld shadow defects, improve the stability of the back-side formation of the root pass, and increase welding efficiency.

Description

Technical Field

[0001] This invention belongs to the field of tungsten inert gas (TIG) shielded welding technology for aluminum alloys, specifically relating to a tungsten inert gas (TIG) shielded welding method and argon protection system for 5083 aluminum alloy pipes. Background Technology

[0002] 5083 aluminum alloy possesses good corrosion resistance, low-temperature toughness, and moderate strength, making it widely used in shipbuilding, cryogenic pipelines, pressure transmission pipelines, and other pipeline engineering projects with high requirements for airtightness and corrosion resistance. For circumferential butt welding of 5083 aluminum alloy pipelines, tungsten inert gas (TIG) welding is typically employed to achieve a stable arc and good weld formation. In actual construction, 5083 aluminum alloy pipelines often require single-sided welding with double-sided forming. Therefore, during welding, it is necessary not only to protect the molten pool on the weld face but also to effectively protect the back area of ​​the weld root to reduce defects such as oxidation, porosity, inclusions, and weld shadows.

[0003] In existing tungsten inert gas (TIG) welding operations on 5083 aluminum alloy pipes, argon gas is typically supplied to the pipe through ordinary gas pipelines to form a protective atmosphere on the back side of the weld. However, some construction sites still use rubber hoses, ordinary PVC flexible hoses, or other non-clean gas pipelines as argon supply lines. These pipelines are prone to aging, decomposition, or impurity precipitation under the high-temperature radiation environment of welding. The resulting trace amounts of organic contaminants, hydrocarbons, or impurities detached from the pipe wall may enter the root protection area of ​​the weld with the argon gas, reducing the cleanliness of the argon protective environment and consequently forming linear shadows, inclusions, or other defects inside the weld that affect the pass rate of radiographic inspection.

[0004] Meanwhile, in traditional 5083 aluminum alloy pipe butt welding, the bevel and root assembly structures primarily aim to achieve full penetration, without fully considering the flow path of argon gas inside the pipe and the removal path of impurities from the back of the weld pool. When using a bevel structure with no gap or an excessively small root gap, the argon gas diffusion at the weld root is uneven, and the oxide impurities and fumes generated during welding are difficult to remove in time. This can easily lead to unstable back-side formation of the root pass, large fluctuations in the back-side reinforcement height, and even affect the connection of subsequent filler and capping weld processes. In addition, gapless assembly places high demands on the pipe alignment accuracy and misalignment control, often requiring repeated adjustments to the pipe position during on-site construction, increasing assembly time and operational difficulty. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a tungsten inert gas (TIG) shielded welding method and argon protection system for 5083 aluminum alloy pipes. Through the coordinated design of clean argon gas delivery, reasonable bevel structure, root gap guidance, and welding parameter matching, the method improves the back-side protection effect of the weld root, reduces the probability of weld defects, and improves on-site assembly and construction efficiency.

[0006] The technical solution provided by this invention is as follows: A method for tungsten inert gas (TIG) shielded welding of 5083 aluminum alloy pipes includes the following steps: S1. Perform beveling on the end of the 5083 aluminum alloy pipe to be welded, so that the end of the 5083 aluminum alloy pipe to be welded forms a single-sided V-shaped bevel. S2. After cleaning the single-sided V-shaped bevel, the two 5083 aluminum alloy pipes to be welded are butted together and a root gap is formed between the two 5083 aluminum alloy pipes to be welded. S3. Insert one end of the low-precipitation polymer material gas transmission hose into the 5083 aluminum alloy pipe to be welded, and make the gas outlet position of the low-precipitation polymer material gas transmission hose correspond to the back area of ​​the weld root. S4. Turn on the argon gas source and adjust the argon gas pressure and flow rate through the argon gas pressure regulating component and the argon gas flow regulating component to replace the inside of the 5083 aluminum alloy pipe to be welded with argon gas. S5. Tungsten inert gas (TIG) welding is used for the root pass of the single-sided V-groove. During the welding process, argon gas is continuously supplied to the back area of ​​the weld root through a low-precipitation polymer material gas supply hose, so that the argon gas diffuses through the root gap and protects the back of the molten pool.

[0007] In some implementations, the bevel angle of the single-sided V-groove is 27.5°-30°, the root gap is 1mm-4mm, and the blunt edge height is 0.5mm-2mm.

[0008] In some embodiments, the inner wall of the low-emission polymer gas delivery hose is a smooth and clean inner wall, and the low-emission polymer gas delivery hose reduces or avoids the generation of organic pollutants that enter the molten pool protection area with argon gas in the high-temperature radiation environment of welding.

[0009] In some embodiments, the outer diameter of the low-emission polymer material gas delivery hose is 8mm-10mm, and the wall thickness is 2mm-2.5mm.

[0010] In some embodiments, the pressure resistance of the low-emission polymer material gas transmission hose is not less than 1.0 MPa and the elongation at break is not less than 350%.

[0011] In some embodiments, in step S4, the argon pressure is adjusted to 0.1MPa-0.4MPa by the argon pressure regulating component, and the argon flow rate is adjusted to 8L / min-20L / min by the flow regulating component.

[0012] In some embodiments, in step S4, after purging the inside of the 5083 aluminum alloy pipe to be welded with argon, the argon concentration at the port of the 5083 aluminum alloy pipe to be welded is detected and the argon concentration is not lower than 99.99%.

[0013] In some implementations, for a 5083 aluminum alloy pipe with a wall thickness of 10mm, the bevel angle of the single-sided V-groove is 30°, the root gap is 3mm, the blunt edge height is 1.5mm-2mm, the welding current is 140A-150A, the welding speed is 5mm / s-6mm / s, the tungsten electrode diameter is 3.2mm, and the argon pressure is 0.3MPa.

[0014] In some implementations, for 5083 aluminum alloy pipes with a wall thickness of 3mm-5.5mm, the bevel angle of the single-sided V-groove is 27.5°, the root gap is 1mm-2mm, the blunt edge height is 0.5mm-1.5mm, the welding current is 80A-140A, the welding speed is 5mm / s-7mm / s, the tungsten electrode diameter is 2.4mm, the argon pressure is 0.15MPa-0.25MPa, and the argon flow rate is 10L / min-12L / min.

[0015] An argon gas protection system for tungsten inert gas (TIG) shielded welding of 5083 aluminum alloy pipes, used to implement the above-mentioned TIG shielded welding method for 5083 aluminum alloy pipes, comprising: Argon gas source, argon gas pressure regulating component, flow regulating component, and low-emission polymer material gas delivery hose; The argon pressure regulating component is connected between the argon gas source and the low-emission polymer material gas delivery hose; The flow regulation component is installed on the argon delivery path from the argon source to the low-emission polymer material gas delivery hose; One end of the low-emission polymer material gas transmission hose is used to extend into the interior of the 5083 aluminum alloy pipe to be welded and to deliver argon gas to the back area of ​​the weld root. At least one end of the low-emission polymer material gas transmission hose is provided with a quick connector.

[0016] In summary, the beneficial effects of this invention are: (1) The present invention uses a low-emission polymer material gas delivery hose to deliver argon gas into the 5083 aluminum alloy pipe to be welded. The inner wall of the gas delivery hose is smooth and clean, which can reduce or avoid the generation of organic pollutants that enter the molten pool protection area with the argon gas in the high temperature radiation environment of welding. At the same time, the gas outlet of the gas delivery hose corresponds to the back area of ​​the weld root, so that the argon gas can directly act on the back of the molten pool, thereby forming a clean and stable back inert gas protection environment, reducing the probability of weld shadows, inclusions and porosity and improving the pass rate of weld radiographic inspection.

[0017] (2) The present invention combines a single-sided V-groove, root gap and back argon protection, so that the root gap not only serves as a structural space for weld penetration and back formation, but also as a channel for argon diffusion and welding impurity discharge; during the welding process, argon diffuses to the root of the weld through the root gap, which can improve the uniformity of back protection of the molten pool, reduce the deposition of oxide impurities at the root of the weld, make the back formation of the root pass more continuous and uniform, and reduce the risk of linear black shadow defects.

[0018] (3) By matching the bevel angle, root gap, blunt edge height, argon pressure, argon flow rate, welding current, welding speed and tungsten electrode diameter, the present invention enables 5083 aluminum alloy pipes of different specifications to obtain a relatively stable welding protection effect and root pass welding quality. Compared with the traditional gapless or small gap assembly method, the present invention can reduce the stringent requirements for weld joint misalignment and alignment accuracy, reduce the time for repeated on-site adjustments, improve welding construction efficiency, and facilitate its application on the basis of existing tungsten inert gas shielded welding equipment. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the weld joint of the method of the present invention.

[0020] Figure label: 1. 5083 aluminum alloy pipe; 2. Single-sided V-shaped bevel; 3. Root gap; 4. Blunt edge. Detailed Implementation

[0021] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. The following embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0022] like Figure 1-2 As shown, the tungsten inert gas (TIG) shielded welding method for 5083 aluminum alloy pipes described in this invention is mainly applicable to single-sided welding and double-sided forming operations of 5083 aluminum alloy pipes 1. The ends of the two 5083 aluminum alloy pipes 1 to be welded are machined to form a single-sided V-groove 2. After the two pipes are butt-jointed, a root gap 3 is formed at the root of the weld, and a blunt edge 4 is retained. During the welding process, argon gas is supplied to the inside of the pipes through a low-emission polymer material gas delivery hose, allowing the argon gas to directly reach the back area of ​​the weld root and diffuse towards the back of the weld pool through the root gap 3, thereby forming a stable inert gas protective environment.

[0023] In this embodiment, the argon protection system includes an argon source, an argon pressure regulating component, a flow regulating component, and a low-emission polymer material gas delivery hose. The argon source can be an industrial argon cylinder with a purity of not less than 99.99%, preferably an industrial argon cylinder with a purity of 99.999%. The argon pressure regulating component can be an argon pressure reducing valve or an argon gauge with pressure reducing function, with a pressure regulating range of 0.1 MPa-0.4 MPa. The flow regulating component can be an argon flow meter or a flow controller with flow display and regulation functions, with a flow regulation range of 8 L / min-20 L / min.

[0024] A low-emission polymer material gas delivery hose is used to deliver argon gas, after pressure and flow regulation, to the interior of the 5083 aluminum alloy pipe 1 to be welded. This gas delivery hose is made of a polymer material that meets the requirements of low emission, resistance to high and low temperatures, and a clean inner wall. The outer diameter of the gas delivery hose can be 8mm-10mm, and the wall thickness can be 2mm-2.5mm. The inner wall of the gas delivery hose is smooth and clean, free of burrs and the risk of particle shedding, which reduces or avoids the generation of organic contaminants that enter the molten pool protection area with the argon gas under the high-temperature radiation environment of welding. The pressure resistance rating of the gas delivery hose is preferably not less than 1.0MPa, and the elongation at break is preferably not less than 350%, to meet the requirements of on-site bending arrangements, long-term gas supply, and repeated disassembly and assembly.

[0025] To improve on-site assembly efficiency, at least one end of the gas delivery hose is equipped with a quick-connect coupling. Specifically, the end of the gas delivery hose closest to the argon pressure regulating component can be connected to an argon pressure reducing valve or flow meter via a quick-connect coupling. The end of the gas delivery hose extending into the pipeline can have a straight outlet or a bendable outlet for easy positioning. The quick-connect coupling can be a metal quick-connect coupling, preferably a nickel-plated brass quick-connect coupling or a stainless steel quick-connect coupling, to improve sealing reliability and reduce argon leakage.

[0026] Before welding, the ends of the 5083 aluminum alloy pipes 1 to be welded are first beveled. After beveling, the bevel angle of the single-sided V-groove 2 is 27.5°-30°. This bevel angle ensures good fusion conditions between the welding wire, base metal, and molten pool, while avoiding an excessively large bevel angle that would lead to increased filler metal usage and welding deformation. After the two 5083 aluminum alloy pipes 1 to be welded are butt-assembled, the root gap 3 is controlled to be 1mm-4mm, and the height of the blunt edge 4 is controlled to be 0.5mm-2mm. For 5083 aluminum alloy pipes with a larger wall thickness, the root gap 3 is preferably 3mm; for 5083 aluminum alloy pipes with a smaller wall thickness, the root gap 3 is preferably 1mm-2mm.

[0027] After the beveling is completed, the single-sided V-groove 2 and its adjacent area should be cleaned before welding. During cleaning, first use a stainless steel wire brush to remove the oxide film from the bevele surface and both sides of the bevele, then use acetone or other cleaning agents suitable for pre-welding aluminum alloys to wipe away oil, dust, and residual impurities from the bevele surface. After cleaning, avoid re-contamination of the bevele surface with hands or contaminated tools to reduce the entry of oxides and organic contaminants into the weld pool.

[0028] During pipe assembly, the axes of the two 5083 aluminum alloy pipes 1 should be kept as coaxial as possible. Because this invention employs a bevel structure with a root gap 3, the adjustment requirements for weld misalignment are reduced compared to traditional gapless assembly methods. Specifically, during on-site assembly, the two pipes can be fixed using positioning clamps or tack welding to ensure the root gap 3 remains uniform along the pipe's circumference. This prevents excessively small gaps that hinder argon gas diffusion or excessively large gaps that result in excessively high root pass weld formation.

[0029] After completing the pipeline assembly, insert one end of the gas delivery hose into the interior of the 5083 aluminum alloy pipe 1 to be welded, ensuring the gas outlet of the hose aligns with the back area of ​​the weld root. Connect the other end of the gas delivery hose sequentially to the flow regulating component, the argon pressure regulating component, and the argon source. After connection, check the sealing condition of each connection point, confirming no obvious leaks at the quick connectors, pressure reducing valve interface, and flow meter interface. If necessary, use soapy water leak detection or pressure holding method to check the sealing of the gas delivery path.

[0030] Before welding, turn on the argon gas source and adjust the argon pressure to the appropriate value using the argon pressure regulating component and the argon flow rate to the appropriate value using the flow regulating component. Then, purge the inside of the 5083 aluminum alloy pipe 1 to be welded with argon gas. During the purging process, argon gas enters the pipe through the gas delivery hose and gradually expels the air inside the pipe. The purging time can be determined based on the nominal pipe diameter and the internal space of the pipe. For example, for pipes with a larger nominal diameter, the purging time can be 5 minutes; for pipes with a smaller nominal diameter, the purging time can be 3 minutes. After purging, a portable argon gas concentration detector can be used to check the argon gas concentration at the pipe end. Ideally, the argon gas concentration at the pipe end should not be lower than 99.99% to ensure that the back side of the weld root is in a stable inert gas protective environment.

[0031] After argon purging, tungsten inert gas (TIG) welding is used to perform root pass welding on the single-sided V-groove 2. During welding, the TIG diameter is selected based on the pipe wall thickness; the TIG diameter can be 2.4mm-3.2mm, with cerium-tungsten electrodes being preferred. The welding current can be 80A-150A, and the welding speed can be 5mm / s-8mm / s. During welding, the angle between the welding torch and the pipe axis is preferably maintained at 70°-80° to ensure that the argon gas shield formed by the welding torch nozzle covers the weld pool, while the argon gas supplied by the gas delivery hose protects the back of the weld pool.

[0032] During the root pass welding process, the gas delivery hose continuously supplies argon gas to the back area of ​​the weld root. After entering the pipe, the argon gas diffuses into the welding area through the root gap 3, forming a stable argon protective layer on the back of the molten pool, reducing the contact between oxygen, nitrogen, and moisture in the air and the high-temperature molten pool. At the same time, the root gap 3 also serves as a gas flow channel, allowing some of the oxidation impurities and fumes generated during welding to be discharged with the argon gas flow, reducing the risk of impurities depositing at the weld root and forming shadow defects.

[0033] After the root pass welding is completed, the filler and capping welds can be performed. The welding parameters for the filler and capping welds can be determined based on the actual pipe wall thickness, bevel filling amount, and on-site welding procedure specifications. During subsequent welding, argon gas protection should still be maintained inside the pipe to prevent secondary oxidation of the back of the root pass weld and the weld root under high temperature conditions.

[0034] After welding, the weld is subjected to visual inspection and radiographic testing. During visual inspection, the focus is on checking the back-side profile height of the root pass, weld continuity, and the presence of defects such as undercut, porosity, and lack of fusion on the weld surface. Preferably, the back-side profile height is controlled between 0mm and 2mm, and the back-side profile is uniform and continuous. During radiographic testing, the focus is on checking for defects such as linear shadows, porosity, and inclusions within the weld.

[0035] Example 1 This embodiment is used for tungsten inert gas (TIG) welding of 5083 aluminum alloy pipes with a nominal diameter of 12×10mm. The wall thickness of the pipes to be welded is 10mm. Before welding, the ends of the two 5083 aluminum alloy pipes 1 are machined into single-sided V-grooves 2 with a groove angle of 30° and a blunt edge height of 2mm. After cleaning the groove surfaces, the two pipes are butt-jointed, with a root gap 3 of 3mm.

[0036] The argon protection system uses industrial argon cylinders with a purity of 99.999% as the argon source, an argon pressure reducing valve with a pressure adjustment range of 0.1MPa-0.4MPa as the argon pressure regulating component, and a flow meter with a flow rate range of 8L / min-20L / min as the flow rate regulating component. The gas delivery hose is a low-extraction hose with a specification of φ10mm×2.5mm, and quick connectors are provided at both ends of the hose.

[0037] Before welding, insert one end of the gas supply hose into the pipe to be welded, ensuring its outlet is close to the back area of ​​the weld root. Connect the other end of the hose to an argon pressure reducing valve and a flow meter. Turn on the argon gas source, adjust the argon pressure to 0.3 MPa, and the argon flow rate to 18 L / min, purging the pipe with argon for 5 minutes. After purging, check the argon concentration at the pipe end, ensuring it is not lower than 99.99%.

[0038] Subsequently, tungsten inert gas (TIG) welding was used for the root pass. A 3.2mm diameter cerium-tungsten electrode was used, with a welding current of 140A-150A and a welding speed of 5mm / s-6mm / s. The angle between the welding torch and the pipe axis was controlled at approximately 75°. During welding, argon gas was continuously supplied into the pipe via a flexible hose, allowing it to diffuse through a 3mm root gap towards the back of the molten pool. After welding, the back of the root pass was approximately 1.2mm high, with uniform back surface formation, and no obvious linear shadow defects were observed during radiographic testing.

[0039] Example 2 This embodiment is used for tungsten inert gas (TIG) shielded welding of 5083 aluminum alloy pipes with a nominal diameter of 10×10mm. Compared with Embodiment 1, the pipe wall thickness in this embodiment is also 10mm, but the nominal pipe diameter is different, so the argon flow rate is adjusted accordingly.

[0040] In this embodiment, the bevel angle of the single-sided V-groove 2 is 30°, the root gap 3 is 3mm, and the height of the blunt edge 4 is 2mm. A low-precipitation hose with a diameter of φ10mm × 2.5mm is used for the gas supply. During welding, the argon pressure is 0.3MPa, and the argon flow rate is 16L / min. The tungsten electrode diameter is 3.2mm, the welding current is 140A-150A, and the welding speed is 5mm / s-6mm / s.

[0041] During welding, argon gas was directly supplied to the back area of ​​the weld root via a low-precipitation hose. Because the root gap was maintained at 3mm, the argon gas could diffuse evenly along the weld root area, ensuring a stable protective state for the back of the molten pool and assisting in the removal of oxide impurities formed during welding. Post-weld inspection showed that the back of the root pass was continuously formed, with the back reinforcement height within the range of 0mm-2mm, and no obvious black shadow defects caused by contamination of the gas supply hose were observed inside the weld.

[0042] Example 3 This embodiment is used for tungsten inert gas (TIG) welding of 5083 aluminum alloy pipes with a nominal diameter of 3×5.5mm. The wall thickness of the pipe to be welded is 5.5mm. Before welding, the pipe end is machined into a single-sided V-groove 2 with a groove angle of 27.5°, a root gap 3 of 2mm, and a blunt edge height 4 of 1.5mm.

[0043] In this embodiment, a low-emission hose with a diameter of 8mm × 2mm is used for the gas supply hose. Before welding, the outlet end of the gas supply hose is placed inside the pipe, corresponding to the back area of ​​the weld root. After turning on the argon gas source, the argon gas pressure is adjusted to 0.25MPa and the argon gas flow rate is adjusted to 12L / min. After argon gas purging is completed, the argon gas concentration at the pipe end is checked and ensured to be no less than 99.99%.

[0044] A 2.4mm diameter cerium-tungsten electrode was used for welding, with a welding current of 120A-140A and a welding speed of 6mm / s-7mm / s. Since the pipe wall thickness in this embodiment is less than in Embodiments 1 and 2, the root gap 3 was correspondingly reduced to 2mm to avoid excessively high back-side formation during the root pass. During welding, argon gas diffused through the 2mm root gap 3, providing protection to the back side of the molten pool. After welding, the back side of the weld was uniformly formed, without significant sagging or excessive bulging.

[0045] Example 4 This embodiment is used for tungsten inert gas (TIG) welding of 5083 aluminum alloy pipes with a nominal diameter of 16×5mm. The wall thickness of the pipe to be welded is 5mm. Before welding, the pipe end is machined into a single-sided V-groove 2 with a groove angle of 27.5°, a root gap 3 of 2mm, and a blunt edge height of 0.5mm.

[0046] In this embodiment, a low-emission hose with a diameter of 8mm × 2mm is used for the gas supply. The argon pressure is 0.2MPa, and the argon flow rate is 12L / min. A cerium-tungsten electrode with a diameter of 2.4mm is used for welding, the welding current is 120A-140A, and the welding speed is 6mm / s-7mm / s.

[0047] Because the nominal pipe diameter is relatively large but the wall thickness is thin in this embodiment, a small blunt edge 4 and an appropriate root gap 3, combined with argon gas protection on the back side, ensure that the root of the weld pool can be fully melted and that the weld pool is not disturbed due to excessive argon gas pressure. During the welding process, argon gas continuously enters the pipe from the outlet end of the gas supply hose, forming a stable protective layer on the back side of the weld. Post-weld inspection shows that the back side of the root pass is continuously formed, and no obvious oxidation marks are seen at the root of the weld.

[0048] Example 5 This embodiment is used for tungsten inert gas (TIG) welding of 5083 aluminum alloy pipes with a nominal diameter of 3×4mm. The wall thickness of the pipe to be welded is 4mm. Before welding, the pipe end is machined into a single-sided V-groove 2 with a groove angle of 27.5°, a root gap 3 of 1mm, and a blunt edge height of 0.5mm.

[0049] In this embodiment, a low-emission hose with a diameter of 8mm × 2mm is used for the gas supply. The argon pressure is 0.15MPa, and the argon flow rate is 10L / min. A cerium-tungsten electrode with a diameter of 2.4mm is used for welding, the welding current is 80A-90A, and the welding speed is 5mm / s-6mm / s.

[0050] Because the pipe wall thickness is relatively small, if the root gap 3 is too large, it can easily lead to excessive back reinforcement or local burn-through in the root pass. Therefore, in this embodiment, the root gap 3 is controlled to 1mm, and a lower welding current is used. During welding, the argon gas delivered by the gas supply hose diffuses to the back of the molten pool through the 1mm root gap 3, ensuring back protection while avoiding molten pool fluctuations caused by excessive argon flow. After welding, the back height of the weld is within the range of 0mm-2mm.

[0051] Example 6 This embodiment is used for tungsten inert gas (TIG) welding of 5083 aluminum alloy pipes with a nominal diameter of 2×3mm. The wall thickness of the pipe to be welded is 3mm. Before welding, the pipe end is machined into a single-sided V-groove 2 with a groove angle of 27.5°, a root gap 3 of 1mm, and a blunt edge height 4 of 0.5mm.

[0052] In this embodiment, a low-emission hose with a diameter of 8mm × 2mm is used for the gas supply. Before welding, one end of the gas supply hose is inserted into the pipe and close to the back area of ​​the weld root. Then, the argon gas source is turned on, and the argon gas pressure is adjusted to 0.15MPa and the argon gas flow rate is adjusted to 10L / min. Due to the small internal space of the pipe, the argon gas purging time can be 3 minutes. After purging, the argon gas concentration is measured to ensure that the argon gas concentration at the pipe end is not lower than 99.99%.

[0053] A 2.4mm diameter cerium-tungsten electrode was used for welding, with a welding current of 80A-90A and a welding speed of 5mm / s-6mm / s. The welding torch angle was kept stable during welding to ensure the combined effect of argon gas protection on the front and the back of the pipe. Post-weld inspection showed that the weld root was uniformly formed, and no obvious oxidation or blackening was observed on the back side.

[0054] In the above embodiments, the low-emission polymer material gas delivery hose, the single-sided V-groove 2, the root gap 3, and the welding process parameters form a coordinated relationship. The low-emission polymer material gas delivery hose reduces the introduction of contaminants during argon gas delivery, the single-sided V-groove 2 and the root gap 3 provide channels for argon gas diffusion on the back side of the molten pool, and the argon pressure, argon flow rate, welding current, welding speed, and tungsten electrode diameter are adapted according to the pipe specifications. Through the above synergistic cooperation, the back protection effect of tungsten inert gas welding of 5083 aluminum alloy pipe 1 can be improved, the probability of weld shadow defects can be reduced, and the stability of the back formation of the root pass can be improved.

[0055] It should be noted that the specifications such as "nominal pipe diameter 12×10mm" and "nominal pipe diameter 10×10mm" mentioned in the above embodiments are used to describe the adaptation method of process parameters under different pipe specifications, and do not mean that the present invention is limited to the above-mentioned pipe specifications. For other specifications of 5083 aluminum alloy pipes, those skilled in the art can adjust the parameters according to the pipe outer diameter, wall thickness, welding position, welding current, and on-site argon protection requirements, within the range of argon pressure of 0.1MPa-0.4MPa, argon flow rate of 8L / min-20L / min, welding current of 80A-150A, and welding speed of 5mm / s-8mm / s.

[0056] The above are merely preferred embodiments of the present invention. Those skilled in the art, inspired by the technical concept of the present invention, may make various adjustments and substitutions to the yarn material, weaving structure, cross angle, anchoring method, heat treatment conditions, and coating structure. All such adjustments and substitutions should be considered to fall within the protection scope of the present invention.

Claims

1. A method of tungsten inert gas welding of 5083 aluminium alloy pipe, characterised in that, Includes the following steps: S1. The end of the 5083 aluminum alloy pipe to be welded is beveled to form a single-sided V-shaped bevel. S2. After cleaning the single-sided V-shaped bevel, the two 5083 aluminum alloy pipes to be welded are joined together and a root gap is formed between the two 5083 aluminum alloy pipes to be welded. S3. Insert one end of the low-precipitation polymer material gas transmission hose into the 5083 aluminum alloy pipe to be welded, and make the gas outlet position of the low-precipitation polymer material gas transmission hose correspond to the back area of ​​the weld root. S4. Turn on the argon gas source and adjust the argon gas pressure and flow rate through the argon gas pressure regulating component and the argon gas flow regulating component to replace the inside of the 5083 aluminum alloy pipe to be welded with argon gas. S5. The single-sided V-groove is welded using tungsten inert gas welding. During the welding process, argon gas is continuously supplied to the back area of ​​the weld root through the low-precipitation polymer material gas supply hose, so that the argon gas diffuses through the root gap and protects the back of the molten pool.

2. The method of tungsten inert gas welding of 5083 aluminum alloy pipe according to claim 1, characterized by, The bevel angle of the single-sided V-shaped bevel is 27.5°-30°, the root gap is 1mm-4mm, and the blunt edge height is 0.5mm-2mm.

3. The method according to claim 1, wherein the 5083 aluminum alloy pipe is welded by GTAW. The inner wall of the low-emission polymer material gas transmission hose is smooth and clean, and the low-emission polymer material gas transmission hose reduces or avoids the generation of organic pollutants that enter the molten pool protection area with argon gas under the high temperature radiation environment of welding.

4. The method according to claim 3, wherein the 5083 aluminum alloy pipe is welded by GTAW using an electrode having a diameter of 1.6 mm or less. The outer diameter of the low-emission polymer material gas transmission hose is 8mm-10mm, and the wall thickness is 2mm-2.5mm.

5. The method for gas tungsten arc welding of 5083 aluminum alloy pipes according to claim 4, wherein The pressure resistance of the low-emission polymer material gas transmission hose is not less than 1.0 MPa, and the elongation at break is not less than 350%.

6. The method according to claim 1, wherein the 5083 aluminum alloy pipe is welded by GTAW. In step S4, the argon pressure is adjusted to 0.1MPa-0.4MPa by the argon pressure regulating component, and the argon flow rate is adjusted to 8L / min-20L / min by the flow regulating component.

7. The method according to claim 1, wherein the 5083 aluminum alloy pipe is welded by GTAW using an electrode having a diameter of 1.6 mm or less. In step S4, after purging the inside of the 5083 aluminum alloy pipe to be welded with argon, the argon concentration at the port of the 5083 aluminum alloy pipe to be welded is detected and the argon concentration is made not less than 99.99%.

8. The method according to claim 1, wherein the 5083 aluminum alloy pipe is welded by GTAW. For a 5083 aluminum alloy pipe with a wall thickness of 10mm, the bevel angle of the single-sided V-groove is 30°, the root gap is 3mm, the blunt edge height is 1.5mm-2mm, the welding current is 140A-150A, the welding speed is 5mm / s-6mm / s, the tungsten electrode diameter is 3.2mm, and the argon pressure is 0.3MPa.

9. The method according to claim 1, wherein the 5083 aluminum alloy pipe is welded by GTAW. For 5083 aluminum alloy pipes with a wall thickness of 3mm-5.5mm, the bevel angle of the single-sided V-groove is 27.5°, the root gap is 1mm-2mm, the blunt edge height is 0.5mm-1.5mm, the welding current is 80A-140A, the welding speed is 5mm / s-7mm / s, the tungsten electrode diameter is 2.4mm, the argon pressure is 0.15MPa-0.25MPa, and the argon flow rate is 10L / min-12L / min.

10. An argon gas protection system for tungsten inert gas (TIG) shielded welding of 5083 aluminum alloy pipes, used to implement the TIG shielded welding method for 5083 aluminum alloy pipes according to any one of claims 1-9, characterized in that, include: Argon gas source, argon gas pressure regulating component, flow regulating component, and low-emission polymer material gas delivery hose; The argon pressure regulating component is connected between the argon source and the low-emission polymer material gas delivery hose; The flow regulation component is disposed on the argon gas delivery path from the argon gas source to the low-emission polymer material gas delivery hose; One end of the low-emission polymer material gas transmission hose is used to extend into the interior of the 5083 aluminum alloy pipe to be welded and to deliver argon gas to the back area of ​​the weld root. At least one end of the low-emission polymer material gas transmission hose is provided with a quick connector.

Images