Pipe vertical welding process
By processing the V-shaped bevel on the cut end face of the pipe and adopting the tungsten argon arc welding process, the problems of difficulties and frequent welding operations under the barrier pipe are solved, and the goal of high-quality welding results and reducing rework is achieved.
Patent Information
- Application Number
- CN202411504291.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-02-18
AI Technical Summary
In the presence of barrier pipes, welding operation is difficult, and welding defects such as concave, unwelded, unwoven, joint defects, tungsten clamping, arc pit cracks, burn-through, air holes, etc., resulting in poor welding quality and re-repair. A lot of workload.
A vertical welding process of pipe materials is adopted, including processing V-shaped bevels on the cut end faces of two pipes that need to be welded, positioning welding, and welding of the base layer and cover surfaces by controlling the welding angle and welding wire. Wire mode and arc swing to form a uniform molten pool to ensure welding quality.
In the presence of barrier pipes, common defects in the welding process are effectively avoided, welding quality is ensured, repair work is reduced, and overall construction period efficiency is improved.
Smart Images
Figure CN119457337A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of welding processes, and in particular to a vertical welding process for pipes. Background Art
[0002] At present, welding operations are difficult under working conditions where there are obstacle pipes. The welding process is prone to welding defects such as concave, incomplete penetration, incomplete fusion, joint defects, tungsten inclusions, arc crater cracks, burn-through, and porosity. It is difficult to ensure the welding quality, which in turn leads to an increase in the workload of rework and a great impact on the overall construction period. Summary of the invention
[0003] The purpose of the present disclosure is to provide a vertical pipe welding process to at least partially solve the problems existing in the related art.
[0004] In order to achieve the above object, the present disclosure provides a vertical welding process for a pipe, wherein the pipe has a plurality of barrier pipes in a circumferential direction, and the vertical welding process for the pipe comprises the following steps: S1. Process V-shaped grooves on the cut end faces of the two pipes to be welded; S2. Use a pipe clamp to assemble two pipes to be welded; S3, performing positioning welding on two pipes; S4. Use tungsten inert gas welding to weld the two pipes. First, bend the front end of the welding wire. Hold the welding gun with one hand and lean against the welding fulcrum at the obstacle bracket. Clamp the welding wire with the other hand. After putting on the mask, the tungsten electrode touches the groove to ignite the arc. Pull it to the welding point of the groove. The molten metal on the upper and lower sides of the groove feeds the wire to form a welding point. Pull the arc to the center of the two welding points to feed the wire, so that the molten iron bridges to form a molten pool. Then swing the arc up and down to evenly move forward for welding. S5. Use tungsten inert gas welding to cover the two pipes.
[0005] Optionally, in step S1, after the V-shaped groove is processed, dirt on the processed groove surface and both sides of the pipe is cleaned with an angle grinder, and after cleaning, a file is used to process the groove into a blunt edge.
[0006] Optionally, after step S2, take a welding wire with a diameter of 2mm~3mm, insert it between the grooves of the two pipes, maintain a gap of 2mm~3mm between the two grooves, then pull out the welding wire, pick up the matching pliers, check whether the inner walls of the two pipes are flush, and adjust the positions of the left and right pipes until the inner walls of the two pipes are flush.
[0007] Optionally, the misalignment between the inner walls of the two pipes is less than or equal to 1 mm, and the angular deformation of the pipe after positioning welding is less than or equal to 1°.
[0008] Optionally, in step S4, the base layer welding adopts symmetrical welding.
[0009] Optionally, in step S4, the pipe after positioning welding is vertically fixed on the welding frame, and when welding the base layer, the angle between the welding gun and the pipe is maintained at 70°~80°, and the angle between the welding wire and the pipe is maintained at 10°~20°.
[0010] Optionally, in step S4, the wire feeding step includes wire feeding, melting, wire breaking, and melt hole welding.
[0011] Optionally, the thickness of the primer layer is greater than 3 mm.
[0012] Optionally, in step S5, heating is performed when the arc is started so that the molten pool is completely in a molten state, and then the welding wire is filled. At this time, the welding handle swings up and down in a semi-arc shape, and the geometric shape of the molten pool is controlled by the swing of the welding handle to maintain the size and fullness of the molten pool.
[0013] Optionally, in step S5, after the weld is formed, the weld protrudes from the groove by 0.5 mm to 3 mm in the radial direction of the pipe, and the weld protrudes from the groove by 1 mm to 2 mm in the axial direction of the pipe.
[0014] Through the above technical scheme, welding operations can be carried out under the condition of the existence of obstacle pipes, and welding defects such as concave, incomplete penetration, lack of fusion, joint defects, tungsten inclusions, arc crater cracks, burn-through, porosity, etc. that are very easy to occur in the welding process can be avoided, thereby ensuring the welding quality and avoiding a large amount of rework work.
[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 is a schematic diagram of a pipe groove provided by an exemplary embodiment of the present disclosure; Figure 2 is a layout diagram of a pipe and a barrier pipe provided in an exemplary embodiment of the present disclosure; Figure 3 It is a schematic diagram of the base layer welding of a vertical pipe welding process provided by an exemplary embodiment of the present disclosure; Figure 4 It is a schematic diagram of arc extinguishing of base layer welding in a vertical welding process for pipes provided by an exemplary embodiment of the present disclosure; Figure 5 It is a schematic diagram of base layer welding and cover surface welding of a vertical welding process for pipes provided in an exemplary embodiment of the present disclosure; Figure 6 It is a partial schematic diagram of base layer welding and cover layer welding of a vertical welding process for pipes provided in an exemplary embodiment of the present disclosure.
[0017] Description of Reference Numerals 1- pipe; 11- groove; 2- barrier pipe; 3- positioning welding point DETAILED DESCRIPTION The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.
[0018] In the present disclosure, unless otherwise specified, the directional terms "upper", "lower", "top", and "bottom" used are defined based on the directions in which the relevant components are actually used. "Inside" and "outside" refer to the contours of the corresponding components themselves. In the present disclosure, when the following description refers to the drawings, unless otherwise specified, the same numbers in different drawings represent the same or similar elements.
[0019] Reference Figures 1 to 6 The present invention provides a vertical pipe welding process. A pipe 1 has a plurality of obstacle tubes 2 on its circumference. In an embodiment of the present invention, four obstacle tubes 2 are arranged at intervals on the circumference of the pipe 1. The obstacle tubes 2 and the pipe 1 form a cross. The vertical pipe welding process may include the following steps: S1. Processing V-shaped grooves 11 on the cut end faces of two pipes 1 to be welded; S2. Using a pair of pipe pliers to assemble the two pipes 1 to be welded; S3. Positioning and welding the two pipes 1; S4. Using tungsten Use tungsten inert gas welding to perform base layer welding on two pipes 1. First, bend the front end of the welding wire, hold the welding gun with one hand, lean against the welding fulcrum at the obstacle bracket, clamp the welding wire with the other hand, put on the mask, touch the tungsten electrode in the groove 11 to ignite the arc, pull it to the groove 11 to start the welding point, and the molten metal on the upper and lower sides of the groove 11 feeds the wire to form a welding point. Pull the arc to the center of the two welding points to feed the wire, so that the molten iron bridges to form a molten pool, and then swing the arc up and down to evenly move forward for welding; S5, use tungsten inert gas welding to perform cover welding on the two pipes 1.
[0020] Through the above technical scheme, welding operations can be carried out under the condition of the existence of obstacle pipes, and welding defects such as concave, incomplete penetration, lack of fusion, joint defects, tungsten inclusions, arc crater cracks, burn-through, porosity, etc. that are very easy to occur in the welding process can be avoided, thereby ensuring the welding quality and avoiding a large amount of rework work.
[0021] Among them, in step S1, after processing the V-shaped groove 11, use an angle grinder to clean the oil, rust, paint and other dirt within a range of about 10mm~20mm on the surface and both sides of the processed pipe groove 11 until the metallic luster is exposed. After cleaning, use a file to process the groove 11 into a blunt edge, and the width of the blunt edge is less than 0.5mm. Specifically, in the embodiment of the present disclosure, the pipe 1 uses a 12Cr1MoV low-alloy steel pipe with a size of Ф42mm*5mm*100mm (diameter*thickness*length), reference Figure 1 The size of the groove 11 satisfies a=60°~70°, b=2.5mm~3mm, and p=0.5mm~1.5mm. During welding, the pipe 1 is placed vertically. The welding gas is argon gas, and its purity is greater than or equal to 99.99%.
[0022] In some embodiments, after step S2, take a welding wire with a diameter of 2mm~3mm, insert it between the grooves 11 of the two pipes 1, keep a gap of 2mm~3mm between the two grooves 11, then pull out the welding wire, pick up the pair of pliers, check whether the inner walls of the two pipes 1 are flush, if there is a misalignment, immediately adjust the positions of the left and right pipes 1 until the inner walls of the two pipes 1 are flush, and after the adjustment is completed, you can perform positioning welding. Specifically, the diameter of the welding wire can be 2.5mm. Pipes smaller than φ60mm can be welded by electric welding, and the spot welding point is about 10mm~15mm long.
[0023] Furthermore, the inner wall of the pipe 1 should be flush when fitting, and there should be no misalignment as much as possible. The misalignment between the inner walls of the two pipes 1 should be less than or equal to 1 mm, and the angular deformation of the pipe 1 after positioning welding should be less than or equal to 1°. The pipe 1 after spot fixing should not be knocked hard to adjust the gap to avoid cracks. The positioning weld 3 is part of the formal weld. The welding quality is the same as the base layer requirements. The root of the weld must be fully melted to avoid defects such as weld nodules and shrinkage holes to ensure that there are no defects. After the positioning weld 3 is welded, it is necessary to carefully check it. If any defects are found, they should be corrected in time. In order to avoid unfavorable factors such as misalignment, the pipe 1 should be fixed and spot welded with matching pliers as much as possible.
[0024] As an exemplary embodiment of the present disclosure, refer to Figure 2 In step S4, the base layer welding adopts symmetrical welding. Specifically, the base layer welding can adopt unidirectional welding or symmetrical welding. In order to avoid deformation of the pipe fitting, symmetrical welding should be adopted as much as possible. The welding direction can refer to Figure 2 direction of the arrow.
[0025] Further, refer to Figure 2In step S4, the pipe 1 after positioning welding is fixed vertically on the welding frame. When welding the base layer, the height of the positioning welding point 3 is at a comfortable position with the operator's sight level. First, hold the welding gun and welding wire to simulate the welding process, that is, feel the welding gun, welding wire, the angle of sight and the body changing with the pipe 1. When it is suitable, the base layer welding can be carried out. When welding, in order to ensure good root melting and effective protection of the molten pool, the angle between the welding gun and the pipe 1 is maintained at 70°~80° during welding, which is convenient for wire feeding, and the angle between the welding wire and the pipe 1 is maintained at 10°~20°, specifically 15°.
[0026] In some embodiments, in step S4, the wire feeding method adopts a repeated intermittent wire feeding method, specifically wire feeding, melting, wire breaking, and molten hole welding.
[0027] Specifically, refer to Figure 3 In order to facilitate covering and reduce the lack of fusion between layers, it is ideal that the thickness of the base layer is greater than 3mm or greater than 4mm.
[0028] When welding the base layer, the key is to master the essentials of starting, sealing and arc closing. When starting, pay attention to the temperature and melting degree of the upper and lower bevels to prevent single-sided non-fusion or weld nodules; when welding, pay attention to the melting degree of the upper and lower bevels and the temperature of the molten pool to prevent single-sided non-fusion or upper bevel penetration biting. Continuous welding can be performed only when both sides of the bevel are melted. When starting, the arc should be struck and the molten pool should be heated 3mm~5mm back from the original arc extinguishing position to make it completely melted. Only after the molten hole appears can the welding wire be fed in, and the arc swings up and down to weld forward evenly. When welding to the sealing, when it is 6mm~8mm away from the sealing, intermittent wire feeding is performed to observe the melting situation in front. When there is still 2mm~3mm, the arc is moved to heat the opposite weld. After confirming that the weld meat on both sides is completely melted, the welding wire is fed in. After the sealing is completely fused, welding can be performed forward. The arc cannot be extinguished immediately at this time, otherwise it is most likely to cause arc crater cracks and arc shrinkage holes. The arc can be extinguished only when the arc is 10mm~15mm away from the seal. When extinguishing the arc, in order to avoid shrinkage holes caused by excessive cooling of the molten pool, the tungsten electrode should be moved to one side of the groove for manual attenuation, such as Figure 4 The arrow in the figure is the manual attenuation action curve.
[0029] According to some embodiments, reference Figure 5The current used for full argon arc welding of the cap is basically the same as that of the base. In step S5, the order of cap welding is the same as that of base welding. Due to the low temperature when starting the arc, it should be properly heated to make the entire molten pool completely in a molten state, and then fill the welding wire. Filling the wire too early can easily cause unmelted layers. At this time, the welding handle swings in an upper and lower half arc, and the geometric shape of the molten pool is controlled by the swing of the welding handle to maintain the size and fullness of the molten pool. Pay attention to the melting and filling conditions on both sides of the weld to obtain a weld with consistent width and height. The methods of arc extinguishing, joints and final arc closing are basically the same as those for base welding.
[0030] During welding, the welding wire is always at 2 / 3 of the top of the molten pool. Figure 5 As shown, the welding wire should be filled continuously as much as possible, and attention should be paid to the molten pool temperature. Too high a temperature may easily cause upper undercut and lower overheating; too low a temperature may cause defects such as incomplete fusion. As the molten pool temperature changes, the welding speed and the wire filling speed should be adjusted at any time to control the welding line energy.
[0031] Further, refer to Figure 6 In step S5, it should be noted that the width and height of the weld after forming should be basically the same. After the weld is formed, the weld protrudes from the groove by 0.5mm~3mm in the radial direction of the pipe 1, that is, d=0.5mm~3mm, and the weld protrudes from the groove by 1mm~2mm in the axial direction of the pipe 1, that is, c=1mm~2mm. The surface and the base material have a smooth transition to reduce the stress concentration of the weld joint and obtain a high-quality welded joint.
[0032] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.
[0033] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.
[0034] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A vertical welding process for a pipe, wherein the pipe has a plurality of barrier pipes in the circumferential direction, characterized in that: The vertical pipe welding process comprises the following steps: S1. Process V-shaped grooves on the cut end faces of the two pipes to be welded; S2. Use a pipe clamp to assemble two pipes to be welded; S3, performing positioning welding on two pipes; S4. Use tungsten inert gas welding to weld the two pipes. First, bend the front end of the welding wire. Hold the welding gun with one hand and lean against the welding fulcrum at the obstacle bracket. Clamp the welding wire with the other hand. After putting on the mask, the tungsten electrode touches the groove to ignite the arc. Pull it to the welding point of the groove. The molten metal on the upper and lower sides of the groove feeds the wire to form a welding point. Pull the arc to the center of the two welding points to feed the wire, so that the molten iron bridges to form a molten pool. Then swing the arc up and down to evenly move forward for welding. S5. Use tungsten inert gas welding to cover the two pipes.
2. The vertical pipe welding process according to claim 1 is characterized in that: In step S1, after the V-shaped groove is processed, dirt on the processed groove surface and both sides of the pipe is cleaned with an angle grinder, and after cleaning, a file is used to process the groove into a blunt edge.
3. The vertical pipe welding process according to claim 1 is characterized in that: After step S2, take a welding wire with a diameter of 2mm~3mm, insert it between the grooves of the two pipes, keep a gap of 2mm~3mm between the two grooves, then pull out the welding wire, pick up the matching pliers, check whether the inner walls of the two pipes are flush, and adjust the positions of the left and right pipes until the inner walls of the two pipes are flush.
4. The vertical pipe welding process according to claim 3 is characterized in that: The misalignment between the inner walls of the two pipes is less than or equal to 1 mm, and the angular deformation of the pipe after positioning welding is less than or equal to 1°.
5. The vertical pipe welding process according to claim 1, characterized in that: In step S4, the base layer welding adopts symmetrical welding.
6. The vertical pipe welding process according to claim 1, characterized in that: In step S4, the pipe after positioning welding is fixed vertically on the welding frame. When welding the base layer, the angle between the welding gun and the pipe is maintained at 70°~80°, and the angle between the welding wire and the pipe is maintained at 10°~20°.
7. The vertical pipe welding process according to claim 1 is characterized in that: In step S4, the wire feeding steps include wire feeding, melting, wire breaking, and melt hole welding.
8. The vertical pipe welding process according to claim 1, characterized in that: The thickness of the base layer is greater than 3 mm.
9. The vertical pipe welding process according to claim 1, characterized in that: In step S5, the arc is started and heated to make the molten pool completely molten, and then the welding wire is filled. At this time, the welding handle swings up and down in a semi-arc shape, and the geometric shape of the molten pool is controlled by the swing of the welding handle to maintain the size and fullness of the molten pool.
10. The vertical pipe welding process according to claim 1, characterized in that: In step S5, after the weld is formed, the weld protrudes from the groove by 0.5 mm to 3 mm in the radial direction of the pipe, and the weld protrudes from the groove by 1 mm to 2 mm in the axial direction of the pipe.