Carbon-gouging-free welding process for wind tower

Abstract

The invention relates to the technical field of welding processes, and provides a wind tower carbon-gouging-free welding process which is more complete in the whole welding process, better in welding process completeness, higher in welding efficiency, further guaranteed in operation safety and better in practicability, and comprises the following steps: checking the quality of a wind tower plate; the specification, the model and the quality of a welding material are verified and confirmed; a groove is machined through machining, the groove and the periphery are cleaned, it is guaranteed that a welding area is clean, the wind tower plate is accurately assembled, it is guaranteed that a butt gap is uniform, and the unfitness of butt joint is within an allowable range; the method comprises the following steps: preheating a welded junction of a wind tower plate, carrying out welding bottoming on the welded junction of the wind tower plate, carrying out interlayer welding by adopting a multi-layer and multi-pass welding method, carrying out cosmetic welding after the interlayer welding is completed, carrying out post-welding cleaning on a welded joint, and carrying out nondestructive testing, defect finding and matched treatment on the welded joint.

Description

Technical Field

[0001] The invention relates to the technical field of welding technology, and in particular to a carbon-free planing welding process for a wind tower. Background Art

[0002] As we all know, the carbon-free planing welding process for wind towers is a technology designed for specific welding needs in wind tower manufacturing. It aims to reduce the carbon planing process in the welding process, thereby improving production efficiency and reducing the requirements for operator skills. This process is mainly used for the welding of wind tower bodies, especially in environments with high requirements for impact performance.

[0003] After searching, the invention patent with Chinese patent publication number CN106984912A discloses a flux-cored wire bottom carbon-free planing wind tower welding process, which is roughly described as including the steps of (a) bottom welding: the inner welds of the two connecting parts of the wind tower are welded by CO2 gas shielded welding, so that the inside of the two connecting parts are connected to form a bottom weld, (b) outside submerged arc welding: the outer sides of the two connecting parts of the wind tower are welded by submerged arc welding, so that the outer sides of the two connecting parts are connected to form an outer weld, and a groove is formed between the two connecting parts, (c) inside submerged arc welding: the inner sides of the two connecting parts of the wind tower are welded by submerged arc welding, so that the inner sides of the two connecting parts are connected to form an inner weld, and a groove is formed between the two connecting parts, (d) according to the flux-cored wire bottom carbon-free planing wind tower welding process of claim, the angle of the groove in step (b) and step (c) is 70°.

[0004] Although the above-mentioned existing technical solution provides a flux-cored wire base carbon-free wind tower welding process, the process only limits the specific shape of the welding groove, and the explanation of the specific welding method in the welding process is relatively weak, and the integrity of the welding process needs to be further improved. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a wind tower carbon-free planing welding process, which covers the entire welding process more comprehensively, has better welding process completeness, higher welding efficiency, further guaranteed operation safety, and better practicality.

[0006] To achieve the above object, the present invention provides the following technical solution: a wind tower carbon-free planing welding process, comprising the following steps:

[0007] S1. Check the materials before welding, check the quality of the wind tower plates, ensure that there are no defects such as cracks and delamination on the wind tower plates, and verify the specifications, models and quality of the welding materials;

[0008] S2. Perform groove processing on the welding part of the wind tower plate, use mechanical processing groove, and clean the groove and the surrounding area to ensure the cleaning of the welding area;

[0009] S3. Accurately assemble the wind tower panels to ensure that the gaps between the panels are uniform and the misalignment is within the allowable range, and fix them by positioning welding;

[0010] S4. Select the preheating temperature according to the material, thickness and welding process requirements of the wind tower, and preheat the weld of the wind tower plate;

[0011] S5. Perform welding primer on the weld joint of the wind tower plate. Strictly control the welding parameters during welding to ensure the quality of primer welding. At the same time, pay attention to the forming of the back of the weld during welding to ensure good fusion of the weld root.

[0012] S6. Use multi-layer and multi-pass welding to weld the middle layer. Clean the welding slag and spatter after each layer is welded, check the weld quality, and ensure the filling amount and forming quality of the weld.

[0013] S7. After the middle layer welding is completed, cover welding is performed to make the weld surface smooth and flat, and to ensure that the weld width and excess height meet the design requirements. Submerged arc welding is divided into internal submerged arc welding inside the wind tower and external submerged arc welding outside the wind tower;

[0014] S8. Clean the welded joints after welding and perform nondestructive testing on the welded joints;

[0015] S9. Defect treatment: When welding defects are found, appropriate treatment methods should be adopted according to the type and size of the defects.

[0016] Preferably, the cleaning range of the groove and the surrounding in step 2 includes oil stains, rust and oxide scale impurities.

[0017] Preferably, the length, spacing and welding quality of the tack weld in step S3 should meet the process requirements. Generally, the length of the tack weld is 50 mm ± 5 mm, and the spacing of the tack weld is 300 mm ± 20 mm.

[0018] Preferably, the base welding in S5 and the intermediate layer welding in step 6 are both performed by carbon dioxide gas shielded welding, and a double-point synchronous welding operation is adopted.

[0019] Preferably, when the welding position is the annular seam of the wind tower plate, the two welding points of the double-point synchronous welding operation are arranged in a centrally symmetrical form, and the selection range of the welding points is within the range of 5°-20° offset of the longitudinal section.

[0020] Preferably, when the welding position is a transverse seam of a wind tower plate, two welding points of the double-point synchronous welding operation are arranged with a transverse interval.

[0021] Preferably, the welding position of the internal submerged arc welding in step S7 is the lowest point inside the wind tower plate, and the welding position of the external submerged arc welding is the highest point outside the wind tower plate.

[0022] Compared with the prior art, the present invention provides a wind tower carbon-free planing welding process, which has the following beneficial effects:

[0023] (1) In the present invention, by realizing the overall process steps of the wind tower carbon-free planing welding process, an operation process for wind tower welding production is formed, and the welding process is more complete and more practical.

[0024] (2) In the present invention, by adding the double-point synchronous welding operation, the welding efficiency is higher and the operation safety is further guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0026] Figure 2 It is a schematic diagram of the double-point synchronous welding operation for the annular seam of the wind tower according to the present invention;

[0027] Figure 3 It is a schematic diagram of the welding position of the inner submerged arc welding and the welding position of the outer submerged arc welding when forming the annular seam of the wind tower according to the present invention;

[0028] Figure 4 It is a schematic diagram of the double-point synchronous welding operation for the transverse seam of the wind tower according to the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] See also Figure 1-Figure 3The carbon-free planing welding process of the wind tower includes the following steps: Preparation before welding: Check the materials before welding, check the quality of the wind tower plate, ensure that the wind tower plate has no defects such as cracks and delamination, confirm that the specifications and models of the welding materials meet the requirements and are of good quality, and use mechanical processing or thermal cutting methods to process the groove according to the design requirements to ensure that the groove angle, blunt edge size, etc. meet the specifications. The general angle is 70°±10°. Clean the groove and the surrounding oil, rust, oxide scale and other impurities to ensure that the welding area is clean, and accurately assemble the wind tower plate to ensure that the gap between the joints is uniform and the misalignment is within the allowable range. It is fixed with positioning welding. The length, spacing and welding quality of positioning welding should meet the process requirements. Under normal circumstances, the length, spacing and welding quality of positioning welding should meet the process requirements. Generally, the length of positioning welding is 50mm±5mm, and the spacing of positioning welding is 300mm±20mm. According to the material, thickness and welding process requirements of the wind tower, determine whether preheating is required and the preheating temperature. If preheating is required, select the preheating temperature according to the material, thickness and welding process requirements of the wind tower, and preheat the weld of the wind tower plate. Use appropriate preheating methods, such as flame heating, electric heating, etc. to ensure uniform preheating.

[0032] Welding process: welding primer is carried out at the weld joint of the wind tower plate. During the welding process, the welding parameters are strictly controlled to ensure the quality of the primer welding. At the same time, pay attention to the forming of the back of the weld during the welding process to ensure that the root of the weld is well fused. The middle layer welding is carried out by multi-layer and multi-pass welding. After each layer of welding is completed, the welding slag and spatter are cleaned, the weld quality is checked, and defects are repaired in time if there are any. The welding parameters are controlled to ensure the filling amount and forming quality of the weld. After the middle layer welding is completed, the cover welding is carried out to make the weld surface smooth and flat to ensure that the weld width and excess height meet the design requirements. Carbon dioxide gas shielded welding is used for the middle layer welding, and the double-point synchronous welding operation is adopted. When the welding position is the annular seam of the wind tower plate, the two welding points of the double-point synchronous welding operation are arranged in a centrally symmetrical form, and the selection range of the welding point is within the range of 5°-20° offset from the longitudinal section. Submerged arc welding is divided into internal submerged arc welding inside the wind tower and external submerged arc welding outside the wind tower. The welding position of the internal submerged arc welding is the lowest point inside the wind tower plate, and the welding position of the external submerged arc welding is the highest point outside the wind tower plate.

[0033] Post-weld treatment: For materials with post-heating requirements, post-heat treatment is carried out after welding is completed. The post-heating temperature and time should meet the process requirements to eliminate welding residual stress, clean the weld joints after welding, and perform non-destructive testing on the weld joints, such as ultrasonic testing, radiographic testing, magnetic particle testing, etc., check the appearance of the weld joints, including weld size, surface quality, etc., defect treatment, if welding defects are found, the corresponding treatment method should be taken according to the type and size of the defects. For minor defects, grinding, repair welding, etc. can be carried out; for serious defects, rework should be carried out.

[0034] Example 2

[0035] See also Figure 1 and Figure 4 The carbon-free planing welding process of the wind tower includes the following steps: Preparation before welding: Check the materials before welding, check the quality of the wind tower plate, ensure that the wind tower plate has no defects such as cracks and delamination, confirm that the specifications and models of the welding materials meet the requirements and are of good quality, and use mechanical processing or thermal cutting methods to process the groove according to the design requirements to ensure that the groove angle, blunt edge size, etc. meet the specifications. The general angle is 70°±10°. Clean the groove and the surrounding oil, rust, oxide scale and other impurities to ensure that the welding area is clean, and accurately assemble the wind tower plate to ensure that the gap between the joints is uniform and the misalignment is within the allowable range. It is fixed with positioning welding. The length, spacing and welding quality of positioning welding should meet the process requirements. Under normal circumstances, the length, spacing and welding quality of positioning welding should meet the process requirements. Generally, the length of positioning welding is 50mm±5mm, and the spacing of positioning welding is 300mm±20mm. According to the material, thickness and welding process requirements of the wind tower, determine whether preheating is required and the preheating temperature. If preheating is required, select the preheating temperature according to the material, thickness and welding process requirements of the wind tower, and preheat the weld of the wind tower plate. Use appropriate preheating methods, such as flame heating, electric heating, etc. to ensure uniform preheating.

[0036] It should be further explained that the welding process is as follows: welding primer is carried out at the weld joint of the wind tower plate, and the welding parameters are strictly controlled during the welding process to ensure the quality of the primer welding. At the same time, attention is paid to the forming of the back of the weld during the welding process to ensure that the root of the weld is well fused. The middle layer welding is carried out by multi-layer and multi-pass welding method. After each layer of welding is completed, the welding slag and spatter are cleaned up, the weld quality is checked, and defects are repaired in time if any, and the welding parameters are controlled to ensure the filling amount and forming quality of the weld. After the middle layer welding is completed, the cover welding is carried out to make the weld surface smooth and flat, ensuring that the weld width and excess height meet the design requirements. Carbon dioxide gas shielded welding is used for the middle layer welding, and double-point synchronous welding operation is adopted. The welding position is the wind tower plate. When welding horizontal seams, the two welding points of the double-point synchronous welding operation are set at a horizontal interval. Submerged arc welding is divided into internal submerged arc welding inside the wind tower and external submerged arc welding outside the wind tower. Post-weld treatment: For materials with post-heating requirements, post-heat treatment is carried out after welding is completed. The post-heating temperature and time should meet the process requirements to eliminate welding residual stress. The weld joints are cleaned after welding and non-destructive testing is performed on the weld joints, such as ultrasonic testing, radiographic testing, magnetic particle testing, etc. The appearance of the welded joints is checked, including weld size, surface quality, etc. Defect treatment: If welding defects are found, the corresponding treatment method should be adopted according to the type and size of the defects. For minor defects, grinding, repair welding, etc. can be carried out. For serious defects, repairs should be carried out.

[0037] In summary, taking the welding operation of a wind tower made of Q345E material as an example, the specific operation process is as follows: after completing the pre-welding preparation, remove the weld surface of the weld and the surrounding gas-cut oxidation surface and other contaminants, use external equipment to form an auxiliary structure positioning at the weld joint, during the positioning process, adjust the relative position between the two welding edges at the weld, and use carbon dioxide shielded welding to form a positioning weld. The welding positioning is achieved by intermittent multi-segment welding, and the welding sequence adopts a symmetrical jump welding method to reduce welding stress. The welding length of each segment of the positioning weld is controlled to be 50mm, and the positioning weld spacing should be controlled to be 300mm. Taking into account the actual length of the weld of the weld, when the last segment of the positioning weld is slightly greater than 300mm and less than 600mm When welding, additional welding should be performed at the middle position of the tail end. After the welding positioning is completed, preheating should be carried out before welding, and the mother plate at the weld should be heated to 150°C. After heating, the middle layer should be welded by multi-layer and multi-pass welding using carbon dioxide shielded welding. In this process, ER50-6 welding wire is used, the welding wire specification is 1.2mm, the welding current is 290A, the welding voltage is 34V, and the welding speed is 5mm / s. Finally, submerged arc welding is used to weld the outside of the weldment joint. The welding wire specification is 4mm, the welding current is 650A, the welding voltage is 33V, and the welding speed is 6mm / s. After welding, post-heat treatment is carried out, and finally the weld is cleaned and inspected. If there are problems, they are dealt with accordingly. Finally, the raised part of the weld is polished.

[0038] Furthermore, welding parameters should be strictly controlled during the welding process to ensure stable welding quality, attention should be paid to the welding environment, and welding should be avoided under adverse weather conditions. Welders should have corresponding qualifications and skills and weld in strict accordance with operating procedures. Welding equipment should be regularly maintained and serviced to ensure its good performance, strengthen quality control during the welding process, and keep records and inspections.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wind tower carbon-free planing welding process, characterized in that: The steps include: S1. Before welding, check the materials and the quality of the wind tower plates to ensure that there are no cracks or delamination defects on the wind tower plates, and verify the specifications, models and quality of the welding materials; S2. Perform groove processing on the welding part of the wind tower plate, use mechanical processing groove, and clean the groove and the surrounding area to ensure the cleaning of the welding area; S3. Accurately assemble the wind tower panels to ensure that the gaps between the panels are uniform and the misalignment is within the allowable range, and fix them by positioning welding; S4. Select the preheating temperature according to the material, thickness and welding process requirements of the wind tower, and preheat the weld of the wind tower plate; S5. Perform welding primer on the weld joint of the wind tower plate. Strictly control the welding parameters during welding to ensure the quality of primer welding. At the same time, pay attention to the forming of the back of the weld during welding to ensure good fusion of the weld root. S6. Use multi-layer and multi-pass welding to weld the middle layer. Clean the welding slag and spatter after each layer is welded, check the weld quality, and ensure the filling amount and forming quality of the weld. S7. After the middle layer welding is completed, cover welding is performed to make the weld surface smooth and flat, and to ensure that the weld width and excess height meet the design requirements. Submerged arc welding is divided into internal submerged arc welding inside the wind tower and external submerged arc welding outside the wind tower; S8. Clean the welded joints after welding and perform nondestructive testing on the welded joints; S9. Defect treatment: When welding defects are found, appropriate treatment methods should be adopted according to the type and size of the defects.

2. A wind tower carbon-free planing welding process according to claim 1, characterized in that: The cleaning range of the groove and the surrounding area in step 2 includes oil stains, rust and oxide scale impurities.

3. A wind tower carbon-free planing welding process according to claim 2, characterized in that: The length, spacing and welding quality of the tack weld in step S3 should meet the process requirements. Generally, the length of the tack weld is 50 mm ± 5 mm, and the spacing of the tack weld is 300 mm ± 20 mm.

4. A wind tower carbon-free planing welding process according to claim 3, characterized in that: The base welding in step S5 and the intermediate layer welding in step 6 are both performed by carbon dioxide gas shielded welding, and a double-point synchronous welding operation is adopted.

5. A wind tower carbon-free planing welding process according to claim 4, characterized in that: When the welding position is the annular seam of the wind tower plate, the two welding points of the double-point synchronous welding operation are arranged in a centrally symmetrical form, and the selection range of the welding points is within the range of 10°-20° offset of the longitudinal section.

6. A wind tower carbon-free planing welding process according to claim 4, characterized in that: When the welding position is a transverse seam of a wind tower plate, two welding points of the double-point synchronous welding operation are arranged with a transverse interval.

7. A wind tower carbon-free planing welding process according to claim 1, characterized in that: The welding position of the internal submerged arc welding in step S7 is the lowest point inside the wind tower plate, and the welding position of the external submerged arc welding is the highest point outside the wind tower plate.

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