Welding method for all-position argon arc root welding of pipeline, pipeline and oil and gas conveying system

Abstract

The invention discloses a welding method for all-position argon arc root welding of a pipeline, the pipeline and an oil and gas conveying system. The method comprises the steps that groove machining is conducted on the pipeline to be welded before groove assembling; the to-be-welded pipeline subjected to groove machining is subjected to groove cleaning before groove assembling; groove assembling is conducted on the to-be-welded pipeline in a liner-free mode; a flexible track of the automatic argon arc welding device is fixed to the pipeline to be welded, a welding trolley of the automatic argon arc welding device is installed on the flexible track, and a welding torch of the automatic argon arc welding device is installed on the welding trolley; a control box of the automatic argon arc welding device is electrically connected with the welding trolley and the welding torch, and the control box communicates with a gas conveying pipeline of the welding torch; the control box is electrically connected with a handheld box of the automatic argon arc welding device; a gas conveying pipeline of an argon bottle externally connected with the control box is communicated, and a power source externally connected with the control box is communicated; the control box is controlled by the handheld box to conduct welding operation so as to control the welding trolley and the welding torch to conduct continuous welding at 0-360 degrees.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas pipeline welding, and particularly to a welding method for all-position argon arc root welding of pipelines, pipelines, and oil and gas transmission systems. Background Art

[0002] In the construction project of oil and gas pipelines, automatic welding has been widely used for welding the circumferential welds of pipeline main projects. The automatic welding technology not only has a fast welding speed and high efficiency, but also has stable welding quality. With the acceleration of the construction pace of urban oil and gas pipeline branch lines, the number of medium-caliber thin-wall pipeline constructions has increased year by year. The existing root welding method of internal welding machines is restricted by the pipe diameter size and equipment size, and can no longer meet the requirements of engineering construction applications.

[0003] Currently, in the welding of medium-caliber and thin-wall pipelines in domestic oil and gas, the combined welding process of TIG (non-consumable gas shielded arc welding) manual welding + MAG (metal active gas) gas shielded flux-cored wire upward automatic welding is mainly used. However, this process has the characteristics of low welding efficiency, high labor intensity, high personnel cost, high requirements for welder operation skills, and the welding quality is restricted by the welder's technical level. At the same time, when using manual TIG backing welding with a gap, the shrinkage amount during welding cannot be controlled, resulting in inconsistent groove widths, which in turn affects the quality of MAG automatic welding for filling and surfacing. Summary of the Invention

[0004] In order to improve the welding efficiency and enhance the weld bead quality, so as to reduce the welding cost and the requirements for the operation skills of manual welders, the present invention proposes a welding method for all-position argon arc root welding of pipelines, pipelines, and oil and gas transmission systems.

[0005] In a first aspect, an embodiment of the present invention provides a welding method for all-position argon arc root welding of pipelines, which may include:

[0006] Perform groove machining on the pipeline to be welded before groove alignment; wherein, the groove shape parameters of the pipeline to be welded after machining are: the groove angle is 3 - 30°, the root face thickness is 1.3 - 2.0 mm, and the root face length is 0.8 - 1.5 mm;

[0007] Clean the groove of the pipeline to be welded after groove machining before groove alignment, so that the surface finish of the groove of the pipeline to be welded ≯ Ra12.5;

[0008] Perform groove alignment on the pipeline to be welded in a non-gasket manner; wherein, the misalignment amount after groove alignment ≯ 1 mm, and the alignment gap ≯ 0.5 mm;

[0009] Fix the flexible track of the automatic argon arc welding device on the pipeline to be welded, install the welding vehicle of the automatic argon arc welding device on the flexible track, and install the welding torch of the automatic argon arc welding device on the welding vehicle; after installation, electrically connect the control box of the automatic argon arc welding device to the welding vehicle and the welding torch respectively, connect the gas pipeline of the control box and the welding torch; electrically connect the control box to the handheld box of the automatic argon arc welding device; connect the gas pipeline of the argon gas cylinder externally connected to the control box, and connect the power supply externally connected to the control box;

[0010] Control the control box to perform welding operations through the handheld box to control the continuous welding of the welding vehicle and the welding torch at 0-360°.

[0011] Optionally, before performing welding operations, it may further include: dividing the pipeline to be welded into regions according to the traveling direction of the welding vehicle, and setting the welding parameters of each region in the control box through the handheld box, so that the control box automatically adjusts the welding parameters of the corresponding region according to the position of the welding vehicle obtained by positioning the position sensor in the welding vehicle;

[0012] Wherein, the welding parameters include at least one of the following: welding speed, welding current, wire heating current, wire feeding speed, swing width, swing time, and edge dwell time.

[0013] Optionally, the method may further include: setting a fixed distance between the tungsten electrode of the welding torch and the surface of the pipeline to be welded in the control box through the handheld box, so that after the tungsten electrode contacts the surface of the pipeline to be welded, the welding torch is controlled to lift to the fixed distance and correct the arc length.

[0014] Optionally, the pipeline to be welded is evenly divided into 24 regions according to the traveling direction of the welding vehicle.

[0015] Optionally, before welding operations, it may further include: adjusting the angle of the welding torch so that the welding torch is perpendicular to the surface of the pipeline to be welded along the radial direction of the groove circumference; and,

[0016] Adjust the included angle and distance between the welding steel argon arc welding wire and the tungsten electrode of the welding torch, so that the included angle between the welding steel argon arc welding wire and the tungsten electrode is 70-80°, the distance between the welding steel argon arc welding wire and the tungsten electrode is 2-3 mm; and adjust the distance between the welding steel argon arc welding wire and the pipeline to be welded, so that the welding steel argon arc welding wire is 1-2 mm away from the pipeline to be welded.

[0017] Optionally, select welding materials before welding operations; among them, select gas-shielded arc welding steel argon arc welding wire for pressure-bearing equipment, and the diameter of the welding steel argon arc welding wire is 1 mm; select protective gas Ar with a purity of not less than 99.99%.

[0018] Optionally, the circumferential error of the flexible track from the edge of the groove is not more than 1 mm, so that the tungsten electrode of the welding torch is located in the central area of the groove and can swing freely within the central area of the groove.

[0019] In a second aspect, an embodiment of the present invention provides a pipeline, and the welded part between the pipelines is welded according to the welding method of all-position argon arc root welding of pipelines described in the first aspect.

[0020] In a third aspect, an embodiment of the present invention provides a pipeline groove for all-position argon arc root welding of pipelines, and the groove shape parameters are: the groove angle is 3 to 30°, the root face thickness is 1.3 to 2.0 mm, and the root face length is 0.8 to 1.5 mm.

[0021] In a fourth aspect, an embodiment of the present invention provides an oil and gas transportation system, and the oil and gas transportation system includes oil and gas pipelines; among them, the welded part between the oil and gas pipelines is welded according to the welding method of all-position argon arc root welding of pipelines described in the first aspect.

[0022] The beneficial effects of the above technical solutions provided in the embodiments of the present invention at least include:

[0023] An embodiment of the present invention provides a welding method, a pipeline and an oil and gas transportation system for all-position argon arc root welding of pipelines. This method first processes the groove shape and cleans the groove to lay a foundation for groove alignment; then, adopts a non-gasket method for groove alignment, and controls the misalignment amount and alignment gap after alignment, ensuring uniform groove dimensions after argon arc root welding and the accuracy requirements of the automatic argon arc root welding filling and covering for the groove dimensions. Finally, use an automatic argon arc welding device to perform 360° circumferential argon arc root welding for welding, and complete the all-position root welding operation of medium-caliber thin-walled pipelines with high quality and high efficiency.

[0024] Furthermore, adopting the non-gasket method does not require repeated operations for butt joint during the welding process, ensuring the consistency of the butt joint gap; at the same time, since the misalignment amount and alignment gap after alignment are effectively controlled, the shrinkage of the weld seam is consistent at different positions on the circumference during the welding process, and the influence on the groove dimensions after shrinkage is small. Overall, it reduces the alignment difficulty, improves the alignment efficiency, and completes the all-position root welding operation with high quality and high efficiency.

[0025] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description and the drawings.

[0026] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0027] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0028] Figure 1 is a flowchart of the welding method for all-position GTAW root welding of pipes provided in the embodiment of the present invention;

[0029] Figure 2 is a detailed flowchart of the welding method for all-position GTAW root welding of pipes provided in the embodiment of the present invention;

[0030] Figure 3 is a schematic diagram of the bevel butt joint of two pipes provided in the embodiment of the present invention;

[0031] Figure 4 is a schematic structural diagram of the automatic GTAW device provided in the embodiment of the present invention. Detailed Embodiments

[0032] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "far", "near", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] When the inventor performs welding on medium-diameter pipelines in actual work, the root welding process of the internal welding machine is limited by the pipe diameter and equipment size and cannot meet the requirements of engineering construction. At the same time, the quality of manual TIG backing welding is greatly affected by the technical level of welders, and there are problems such as high labor intensity of welders. In order to overcome the problems of low welding efficiency, large consumption of welding materials, many weld defects, high labor intensity, high welding cost, and high requirements for the operation skills of manual welders existing in the existing welding technology, the present invention is proposed to provide a welding method, a pipeline, and an oil and gas transportation system for all-position argon arc root welding of pipelines that can overcome or at least partially solve the above problems.

[0036] In an embodiment of the present invention, a welding method for all-position argon arc root welding of pipelines is provided. The welding method is used for the backing welding of medium-diameter thin-walled pipelines with a material grade below X70. The medium-diameter thin-walled pipelines refer to oil and gas transportation pipelines with a diameter of 219 - 508 mm and a wall thickness of 6.4 - 12.5 mm. Referring to Figure 1 As shown, the method may include the following steps:

[0037] Step S11: Process the groove of the pipeline to be welded before groove alignment; wherein, the groove shape parameters of the pipeline to be welded after processing are: the groove angle is 3 - 30°, the root face thickness is 1.3 - 2.0 mm, and the root face length is 0.8 - 1.5 mm.

[0038] Step S12: Clean the groove of the pipeline to be welded after groove processing to make the surface finish of the groove of the pipeline to be welded ≯ Ra12.5.

[0039] Step S13: Align the groove of the pipeline to be welded in a non-gasket manner; wherein, the misalignment amount after groove alignment ≯ 1 mm, and the alignment gap ≯ 0.5 mm.

[0040] Step S14: Fix the flexible track of the automatic argon arc welding device on the pipeline to be welded, install the welding vehicle of the automatic argon arc welding device on the flexible track, and install the welding torch of the automatic argon arc welding device on the welding vehicle; after installation, electrically connect the control box of the automatic argon arc welding device to the welding vehicle and the welding torch respectively, connect the gas pipeline of the control box and the welding torch; electrically connect the control box to the hand-held box of the automatic argon arc welding device; connect the gas pipeline of the argon gas cylinder externally connected to the control box, and connect the externally connected power supply of the control box.

[0041] It should be noted that a wire feeder and a swing device are also installed on the welding vehicle in this embodiment. The swing device drives the welding torch to swing, and the wire feeder feeds wire to the welding torch.

[0042] Step S15: Control the control box through the hand-held box to perform welding operations to control the welding vehicle and the welding torch to perform continuous welding at 0-360°.

[0043] In the welding method for all-position argon arc root welding of pipelines provided in the embodiment of the present invention, first, the groove shape is processed and the groove is cleaned, laying a foundation for groove alignment; then, the groove alignment is carried out in a non-backing way, and the misalignment amount and alignment gap after alignment are controlled, ensuring uniform groove dimensions after argon arc root welding and the accuracy requirements of the automatic argon arc root welding filling and covering for the groove dimensions. Finally, use the automatic argon arc welding device to perform 360° circumferential argon arc root welding for welding, and complete the all-position root welding operation of medium-diameter thin-walled pipelines with high quality and high efficiency.

[0044] Furthermore, in the non-backing method, there is no need to repeatedly operate the butt joint during the welding process, ensuring the consistency of the butt joint gap; at the same time, since the misalignment amount and alignment gap after alignment are effectively controlled, the shrinkage of the weld seam is consistent at different positions on the circumference during the welding process, and the influence on the groove dimensions after shrinkage is small. Overall, it reduces the alignment difficulty, improves the alignment efficiency, and completes the all-position root welding operation with high quality and high efficiency.

[0045] In a detailed embodiment, referring to Figure 2 as shown, the welding method for all-position argon arc root welding of the above pipelines may include the following steps:

[0046] Step S21: Process the groove of the pipeline to be welded before groove alignment; among them, the groove shape parameters of the processed pipeline to be welded are: the groove angle is 3-30°, the root face thickness is 1.3-2.0 mm, and the root face length is 0.8-1.5 mm.

[0047] Referring to Figure 3 as shown, Figure 3The figure in the middle is a schematic diagram after the bevel grooving of two pipes. In this step, the bevels at both ends of the pipes to be welded are processed. The bevel shape parameters of the above-mentioned pipes after processing in this embodiment are: the bevel angle α is 3 to 30°, the root face thickness a is 1.3 to 2.0 mm, and the root face length b is 0.8 to 1.5 mm; the inflection arc radius r = 2.4 mm in the embodiment of the present invention, which is suitable for pipes with a wall thickness h less than 32.1 mm (the wall thickness is limited by the steel pipe manufacturing standard). In this embodiment Figure 3 In this embodiment, the size d of a single bevel and the bevel size g after grooving are affected by the wall thickness h.

[0048] Within the above bevel parameter range in this embodiment, the weld has a relatively large adaptation range for parameters such as welding current and welding voltage, has greater fault tolerance during the welding process, and can obtain better appearance formation and mechanical properties; moreover, for the bevel forms after the above bevel parameter range, during bevel grooving, the grooving gap and misalignment amount will decrease, and welding defects such as burn-through and incomplete penetration are likely to occur during welding, resulting in unqualified welds and quality risks.

[0049] Step S22: Clean the bevels of the pipes to be welded after bevel processing before bevel grooving, so that the surface roughness of the bevels of the pipes to be welded ≯ Ra12.5. In this step, the bevels are cleaned to remove dirt such as oil, water, and rust on both sides of the bevels, which can improve the quality of subsequent welded joints.

[0050] Step S23: Groove the bevels of the pipes to be welded in a non-backing manner; among them, the misalignment amount after bevel grooving ≯ 1 mm, and the grooving gap ≯ 0.5 mm.

[0051] In this step, the bevels are grooved in a non-backing manner. Non-backing welding is a welding technique that does not require the use of backing materials to protect the weld. Different from traditional welding techniques, it uses advanced gas protection technology to protect the molten pool during the welding process through external gas, thereby achieving the purpose of protecting the weld. This technique can reduce the demand for backing materials, lower production costs, improve production efficiency, and at the same time improve product quality.

[0052] In this embodiment, the non-backing method refers to using an internal alignment device or an external alignment device for bevel grooving, and there is no copper or ceramic material in the welded joint after grooving to assist the formation of the weld during the welding process. The misalignment amount after the above bevel grooving in this step refers to Figure 3 When the root face thicknesses a on both sides are not on the same horizontal line during grooving, resulting in longitudinal misalignment. In this embodiment, the misalignment amount is controlled within the range of 1 mm. The above grooving gap c ≯ 0.5 mm to achieve zero-gap grooving, laying a foundation for subsequent welding.

[0053] Step S24: Select welding materials before welding operations; specifically, select gas shielded arc welding steel argon arc welding wire for pressure-bearing equipment, and the diameter of the welding steel argon arc welding wire is 1 mm; select shielding gas Ar with a purity of not less than 99.99%. This step is to prepare welding materials, and the welding wire is ER50-6 in accordance with the standard NB / T47018-2017 The welding wire, and the shielding gas is Ar with a purity of not less than 99.99%.

[0054] Step S25: Fix the flexible track of the automatic argon arc welding device on the pipeline to be welded, install the welding vehicle of the automatic argon arc welding device on the flexible track, and install the welding torch of the automatic argon arc welding device on the welding vehicle; after installation, electrically connect the control box of the automatic argon arc welding device to the welding vehicle and the welding torch respectively, connect the gas pipeline of the control box and the welding torch; electrically connect the control box to the handheld box of the automatic argon arc welding device; connect the gas pipeline of the argon gas cylinder externally connected to the control box, and connect the externally connected power supply of the control box.

[0055] The automatic argon arc welding device in the embodiment of the present invention is composed of a handheld box, a control box, a welding torch, a welding vehicle, a flexible track, etc., as shown in reference to Figure 4 As shown, among them, the welding torch has a hot wire function, that is, the control system can control the welding torch to output a certain value of hot wire current to preheat the welding wire, and the opening and closing and parameters can be set through the control box (detailed values can be set through the interface in the control box, or this function can be turned off). This function can increase the deposition efficiency and the stability of the molten pool during the welding process, and improve the welding efficiency and quality.

[0056] Specifically, in this step, the flexible track is installed, and the circumferential error of the flexible track from the edge of the groove is not more than 1 mm, so that the tungsten electrode of the welding torch is located in the central area of the groove and can swing freely within the central area of the groove.

[0057] Step S26: Divide the pipeline to be welded according to the traveling direction of the welding vehicle, and set the welding parameters of each area in the control box through the handheld box, so that the control box automatically adjusts the welding parameters of the corresponding area according to the position of the welding vehicle obtained by positioning the position sensor in the welding vehicle; among them, the welding parameters include at least one of the following: welding speed, welding current, wire heat current, wire feeding speed, swing width, swing time, and edge dwell time.

[0058] In the specific implementation, this step divides the pipeline to be welded into 24 areas evenly according to the direction of travel of the welding vehicle. That is, the steel pipe is divided into 24 areas 360° according to the running direction of the welding vehicle, and the welding speed, welding current, hot wire current, wire feeding speed, swing width, swing time, edge dwell time and other parameters are set separately for each area. When the welding vehicle runs in different partitions, according to its circumferential position, the control box automatically calls the parameters of the corresponding partition to control the argon arc welding power supply, hot wire power supply and welding trolley action to complete the welding operation.

[0059] Step S27, setting a fixed distance between the tungsten electrode of the welding torch and the surface of the pipe to be welded in the control box through the handheld box, so that after the tungsten electrode contacts the surface of the pipe to be welded, the welding torch is controlled to be raised to the fixed distance and the arc length is corrected.

[0060] Step S28, adjust the angle of the welding torch so that the welding torch is perpendicular to the surface of the pipe to be welded along the circumference of the groove; and adjust the angle and distance between the welding steel argon arc welding wire in the welding torch and the tungsten electrode of the welding torch so that the angle between the welding steel argon arc welding wire and the tungsten electrode is 70-80°, and the distance between the welding steel argon arc welding wire and the tungsten electrode is 2-3 mm; and adjust the distance between the welding steel argon arc welding wire and the pipe to be welded so that the welding steel argon arc welding wire is 1-2 mm away from the pipe to be welded.

[0061] Step S29, the welding operation is performed by controlling the control box through the handheld box to control the welding vehicle and the welding torch to perform 0-360° continuous welding.

[0062] In this step, the moving direction of the welding vehicle is 0-180° from top to bottom welding, which is a downward welding method, and 180-360° from bottom to top welding, which is an upward welding method. The welding process is 0-360° continuous welding, without stopping in the middle, and there is only one welding joint. Compared with the traditional double-sided upward welding process, the number of welding joints that are most prone to welding defects is reduced, thereby reducing the workload of welders for joint grinding and reducing the risk of defects. At the same time, compared with the construction method of double-sided upward welding that requires two welders to use two equipment to perform welding operations, the above method provided in the embodiment of the present invention can use one welder to use one 360° automatic argon arc equipment to complete the welding operation, saving equipment and labor costs.

[0063] The above method provided in the embodiments of the present invention is a welding technique for orbital automatic GTAW root welding of medium-caliber thin-walled pipes without backing, with 0-gap butt joint and 360° circumferential root welding. It has the characteristics of automatic centering, automatic arc length adjustment, and low requirements for welder operation skills; only one welder is required to complete the whole circle of welding, reducing labor costs; the welding speed > 150 mm / min, which is twice the speed of 60 - 80 mm / min for manual GTAW root welding, improving the welding speed. At the same time, after root welding with no backing and 0-gap butt joint, the groove dimensions are more uniform than those of manual GTAW, ensuring the precision requirements of the automatic welding filling and capping process for groove dimensions (the traditional manual welding requires a 3 - 5 mm butt joint gap, which is difficult to ensure during the welding process. The butt joint often requires repeated operations and it is difficult to maintain the consistency of the butt joint gap. Due to the large gap, the shrinkage of the weld during the welding process cannot be guaranteed to be consistent at different positions on the circumference, and the consistency of the groove dimensions ( Figure 4 in g) cannot be guaranteed either. However, it is easier to operate with a direct 0-gap face-to-face butt joint. During the welding process, the weld is smaller, and the influence on the groove dimensions after shrinkage is also smaller), improving the welding quality. The present invention breaks through the current technical barriers of automatic pipe root welding and fills the technical gap of 360° full-circle automatic GTAW root welding for medium-caliber thin-walled pipes.

[0064] Furthermore, the entire welding process is controlled by a handheld box to start and stop welding. The welding stop process includes a linear slow-down of the welding current, continuous output of a low current for arc extinguishing, and delayed gas supply. The whole process requires no manual intervention and is automatically completed by program presetting, ensuring the stability and consistency of arc extinguishing and reducing the influence of human factors.

[0065] Even further, the orbital automatic GTAW 360° circumferential root welding method with no backing and 0-gap butt joint overcomes the problems existing in the existing welding technologies, such as low welding efficiency, high consumption of welding materials, many weld defects, high labor intensity, high welder cost, and high requirements for manual welder operation skills, by designing a 360° circumferential automatic GTAW device, optimizing the groove type design, and determining the welding process parameters for automatic GTAW root welding. This welding method has the characteristics of high welding efficiency, good weld quality, excellent performance of the welded joint, and high automation level, effectively reducing the welding cost and the labor intensity of the operator, and facilitating popularization and use.

[0066] Based on the same inventive concept, an embodiment of the present invention also provides a pipe, which is formed by welding at least two short pipes. The welding part between the pipes is welded according to the above-mentioned all-position GTAW root welding method for pipes. In this embodiment, a weld is formed at the welding joint of the short pipes. The width of the back of the weld is 3 - 5 mm, and the reinforcement of the weld is 0 - 2 mm.

[0067] Based on the same inventive concept, an embodiment of the present invention further provides a pipe groove for all-position argon arc root welding of pipes, and the groove shape parameters are as follows: the groove angle is 3 to 30°, the root face thickness is 1.3 to 2.0 mm, and the root face length is 0.8 to 1.5 mm.

[0068] Based on the same inventive concept, an embodiment of the present invention provides an oil and gas transportation system, and the oil and gas transportation system includes an oil and gas pipeline; wherein, the oil and gas pipeline is the above-mentioned pipeline, and the welded part between the pipelines is welded according to the welding method of all-position argon arc root welding of the above-mentioned pipeline.

[0069] For the beneficial effects and specific descriptions of the above-mentioned pipeline, the pipe groove for all-position argon arc root welding of the pipe, and the oil and gas transportation system in the embodiments of the present invention, reference may be made to the relevant introduction of the welding method of all-position argon arc root welding of the above-mentioned pipeline, and the embodiments of the present invention will not be elaborated herein.

[0070] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. The present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A welding method for all-position GTAW root welding of pipelines, characterized in that, Including: Performing bevel machining on the pipeline to be welded before bevel alignment; wherein, the shape parameters of the bevel of the pipeline to be welded after machining are: the bevel angle is 3 - 30°, the root face thickness is 1.3 - 2.0 mm, and the root face length is 0.8 - 1.5 mm; Cleaning the bevel of the pipeline to be welded after bevel machining before bevel alignment, so that the surface finish of the bevel of the pipeline to be welded ≯ Ra12.5; Performing bevel alignment on the pipeline to be welded in a non-gasket way; wherein, the misalignment amount after bevel alignment ≯ 1 mm, and the alignment gap ≯ 0.5 mm; Fixing the flexible track of the automatic argon arc welding device on the pipeline to be welded, installing the welding carriage of the automatic argon arc welding device on the flexible track, and installing the welding torch of the automatic argon arc welding device on the welding carriage; after installation, electrically connecting the control box of the automatic argon arc welding device to the welding carriage and the welding torch respectively, connecting the gas pipeline of the control box and the welding torch; electrically connecting the control box to the hand-held box of the automatic argon arc welding device; connecting the gas pipeline of the argon gas cylinder externally connected to the control box, and connecting the power supply externally connected to the control box; Controlling the control box to perform welding operations through the hand-held box to control the continuous welding of the welding carriage and the welding torch at 0 - 360°; 2. The method according to claim 1, characterized in that, Before performing welding operations, it also includes: dividing the pipeline to be welded into regions according to the traveling direction of the welding carriage, and setting the welding parameters of each region in the control box through the hand-held box, so that the control box automatically adjusts the welding parameters of the corresponding region according to the position of the welding carriage obtained by positioning the position sensor in the welding carriage; Wherein, the welding parameters include at least one of the following: welding speed, welding current, wire heating current, wire feeding speed, swing width, swing time, and edge dwell time.

3. The method according to claim 2, characterized in that, It also includes: Setting the fixed distance between the tungsten electrode of the welding torch and the surface of the pipeline to be welded in the control box through the hand-held box, so that after the tungsten electrode contacts the surface of the pipeline to be welded, the welding torch is lifted to the fixed distance and the arc length is corrected.

4. The method according to claim 2, wherein Evenly dividing the pipeline to be welded into 24 regions according to the traveling direction of the welding carriage.

5. The method according to claim 2, characterized in that, Before welding operations, it also includes: adjusting the angle of the welding torch so that the welding torch is perpendicular to the surface of the pipeline to be welded along the circumferential radial direction of the bevel; and, Adjusting the included angle and distance between the welding steel argon arc welding wire and the tungsten electrode of the welding torch, so that the included angle between the welding steel argon arc welding wire and the tungsten electrode is 70 - 80°, the distance between the welding steel argon arc welding wire and the tungsten electrode is 2 - 3 mm; and adjusting the distance between the welding steel argon arc welding wire and the pipeline to be welded, so that the welding steel argon arc welding wire is 1 - 2 mm away from the pipeline to be welded.

6. The method according to claim 1, wherein Selecting welding materials before performing welding operations; wherein, selecting a gas shielded welding steel argon arc welding wire for pressure-bearing equipment, and the diameter of the welding steel argon arc welding wire is 1 mm; the purity of the selected shielding gas Ar ≮ 99.99%.

7. The method according to any one of claims 1 to 6, characterized in that, The circumferential error of the flexible track from the edge of the groove is not more than 1 mm, so that the tungsten electrode of the welding torch is located in the central area of the groove and can swing freely within the central area of the groove.

8. A pipeline, characterized in that, The welded part between the pipes is welded according to the welding method of all-position GTAW root welding of pipes described in any one of claims 1 to 6.

9. A pipe groove for all-position GTAW root welding of a pipe, characterized in that, The groove shape parameters are as follows: the groove angle is 3 to 30°, the root face thickness is 1.3 to 2.0 mm, and the root face length is 0.8 to 1.5 mm.

10. An oil and gas transportation system, characterized in that, The oil and gas transportation system includes oil and gas pipelines; wherein, the welded part between the oil and gas pipelines is welded according to the welding method of all-position GTAW root welding of pipes described in any one of claims 1 to 6.

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