Laser additive repairing method for bolt

Abstract

The invention relates to a laser additive repairing method for a bolt, which is used for carrying out laser additive repairing on a damaged part in an engineering in-situ state after the bolt at an important node of constructional engineering has a quality problem of damage, and comprises the following steps: S1, marking and detecting the damaged part; s2, mechanically polishing the damaged part; s3, repairing the damaged part through laser additive; s4, stress relief; s5, quality detection and cleaning; according to the method, the application of the laser additive repairing technology in building construction and later operation is improved, in-situ repairing of the damaged part is carried out, and compared with a method of repairing the damaged part by disassembling the damaged part and carrying out secondary installation during conventional damage repairing, the bolt damage repairing efficiency can be better improved, the bolt damage repairing cost is greatly saved, and the bolt repairing efficiency is improved. And the repairing process is safe and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering repair, and particularly to a laser additive repair method for bolts. Background Art

[0002] In the field of building engineering, during the construction process and later operation, due to the influence of harsh environment, construction defects, fatigue damage, earthquake and other natural disasters, quality problems such as rust, surface cracks, and screw fractures occur in bolts at box-type hinge joints, steel column base screws, large hanging column pins, etc., which cannot effectively ensure the force transmission of hinge joints, thus affecting the safety of building structures; the traditional solution to the quality problem of bolts at box-type hinge joints is to gas gouge and disconnect the box body components from the weld to replace the bolts. The traditional solution to the quality problem of steel column base screws is to reinforce them by combining steel column stiffening and concrete reinforcement, while for large hanging column pin joints, temporary supports need to be set up to replace the pins.

[0003] These construction methods consume too much in terms of labor and time costs, and require the evaluation of structural stability during bolt replacement. Considering the setting of temporary supports to ensure the stability of the original structure, however, during the construction and operation processes, the stress environment is complex and the original structure stress cannot be simulated 100%, thus there are major safety hazards. Therefore, solving these quality problems under load conditions is a construction difficulty. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a laser additive repair method for bolts, so as to solve the problems of complex and difficult construction for repairing bolt damage at important nodes in the prior art.

[0005] To achieve the above purpose, the present invention provides a laser additive repair method for bolts, which is used to perform laser additive repair on the damaged part in-situ after quality problems occur in bolts at important nodes of building engineering. The repair method includes:

[0006] S1. Marking and detecting the damaged part;

[0007] S2. Mechanically grinding the damaged part;

[0008] S3. Laser additive repairing the damaged part;

[0009] S4. Stress relief;

[0010] S5. Quality inspection and cleaning.

[0011] By adopting this technical solution, the application of laser additive repair technology in building construction and later operation is improved, and in-situ repair of damaged parts is carried out. Compared with the method of disassembling damaged parts for repair and then reinstalling them during conventional damage repair, it can more effectively improve the efficiency of bolt damage repair, greatly save the cost of bolt damage repair, and the repair process is safe and reliable.

[0012] Further, the damage part marking in step S1 includes cleaning the damaged part to remove foreign objects and expose the metallic luster, and marking the position of this part.

[0013] By adopting this technical solution, the cleaning of foreign objects can avoid the influence of foreign objects on damage repair; the position marking facilitates the rapid positioning of the damaged part.

[0014] Further, the detection in step S1 includes flaw detection and base layer detection; among them,

[0015] The flaw detection includes performing ultrasonic non-destructive testing on the damaged part, archiving the original state of the detection structure, and recording the detailed damage depth and range in a graphic and text manner;

[0016] The base layer detection includes performing material testing on the damaged part, analyzing the specific content of each metal element, and using a hardness tester to detect to determine the specific hardness required for subsequent repair.

[0017] By adopting this technical solution, the flaw detection can obtain the damaged condition of the damaged part in detail, and provide a numerical basis for subsequent precise repair through recording; the base layer detection can analyze the metal element content of the bolt, and cooperate with the hardness tester to detect the hardness to provide a numerical basis for meeting the quality requirements of subsequent repair.

[0018] Further, step S2 includes using a grinding wheel to perform mechanical removal of the fatigue layer on the damaged part, and at the same time forming a chamfer at the junction of the damaged and undamaged parts by grinding.

[0019] By adopting this technical solution, the surface of the damaged part is mechanically removed to expose the deep structure for subsequent laser cladding bonding, and a chamfer is formed to facilitate subsequent laser cladding transition.

[0020] Further, step S2 also includes coloring detection and hardness detection, confirming whether there are potential defects after mechanical grinding of the damaged part, and recording the size of the damaged part after grinding.

[0021] By adopting this technical solution, it is ensured that the requirements for processing are met before the laser cladding repair operation of the damaged part.

[0022] Further, step S3 includes using nickel-based powder as the repair material, and performing cladding processing by means of coaxial powder feeding technology by inputting the previously recorded data into the on-site assembled laser cladding equipment.

[0023] By adopting this technical solution, the nickel-based powder as a repair material has excellent adhesion, close adhesion, hardness and wear resistance, and can more easily meet the quality requirements after laser cladding repair of the damaged part; the nickel-based powder has a high bonding degree with the base metal, a low temperature rise during the cladding process, a small heat influence, and reliable damage repair.

[0024] Furthermore, in step S3, the cladding process is divided into planar repair and vertical surface repair according to different repair working surfaces; the specific control is as follows.

[0025] Planar repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each layer of the cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder feeding rate is 18 g / min, and the gas supply speed is 15 Pa·L / min.

[0026] Vertical surface repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each layer of the cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder feeding rate is 12 - 14 g / min, and the gas supply speed is 15 Pa·L / min.

[0027] By adopting this technical solution, different control data are provided according to different repair working surfaces to ensure reliable repair under different working surfaces.

[0028] Furthermore, when adjacent cladding layers need to overlap during the cladding operation in step S3, the variable opening should be polished to keep it flat and smooth.

[0029] By adopting this technical solution, the cladding quality of the overlapping layer is guaranteed.

[0030] Furthermore, step S4 includes removing the bolt stress by ultrasonic impact strengthening vibration after laser additive repair.

[0031] By adopting this technical solution, the tensile stress and deformation of the repaired part are reduced, the material influence is improved, the surface precision characteristics are improved, especially the anti-wear and contact fatigue characteristics are improved.

[0032] Furthermore, step S5 includes using penetrant testing to detect and confirm the repair quality of the repair area, and at the same time performing hardness testing to ensure that the hardness of the cladding layer matches the hardness of the base metal.

[0033] After the quality is qualified, manual polishing treatment is carried out, and at the same time, surface cleaning is carried out.

[0034] By adopting this technical solution, it is ensured that the repaired bolt meets the use requirements.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. Improve the application of laser additive repair technology in building construction and post - operation, conduct in - situ repair of damaged parts. Compared with the method of disassembling damaged parts for repair and then reinstalling them during conventional damage repair, it can more effectively improve the repair efficiency of bolt damage, greatly save the cost of bolt damage repair, and the repair process is safe and reliable.

[0037] 2. The cladding layer and bonding layer of the laser additive repair technology have dense structures, strong corrosion resistance, and good finished - product protection effects. At the same time, the heat - affected zone during laser additive technology repair is extremely small, causing little damage to the coatings around the repair area. Compared with the extensive damage of the traditional overall replacement method, the finished - product protection is more in - place and the durability is stronger.

[0038] 3. The laser additive repair technology can control the construction accuracy by changing process parameters. Slow down the scanning speed in areas sensitive to accuracy and speed up the scanning speed in areas insensitive to accuracy, so as to achieve dual control of excellent construction accuracy and fast construction time.

[0039] 4. It is pollution - free, reduces the subsequent maintenance cost of the project, is green and energy - saving, and is low - carbon and environmentally friendly. Brief Description of the Drawings

[0040] Figure 1 It is a schematic flow chart of the laser additive repair method for the bolts of the present invention;

[0041] Figure 2 It is a schematic diagram of damage to a conventional bolt part;

[0042] Figure 3 It is a schematic diagram of damage to a conventional connection node part;

[0043] Figure 4 It is a schematic diagram of the laser cladding equipment in the laser additive repair method for the bolts of the present invention.

[0044] Description of the reference numerals: 1. Teaching box; 2. Robot controller; 3. Computer; 4. Intelligent robot; 5. Six - axis robotic arm; 6. Laser; 7. Conductive optical fiber; 8. Processing platform; 9. Optical fiber output end; 10. Powder feeding system; 11. Gas supply system. Detailed Embodiments

[0045] The present invention will be further described below with reference to the drawings and specific embodiments.

[0046] Please refer to the attached Figure 1 . The present invention provides a laser additive repair method for bolts, which is used for important nodes in construction projects. After quality problems such as damage occur to the bolts as shown in the attached Figure 2 , laser additive repair of the damaged parts is carried out under the load state, and the repair method is as follows:

[0047] S1. Marking and detecting the damaged part. The marking of the damaged part includes cleaning the damaged part to remove foreign objects and expose the metallic luster, and marking the position of this part. The detection includes flaw detection and base layer detection. The flaw detection includes performing ultrasonic non-destructive testing on the damaged part, archiving the original state of the detection structure, and recording the detailed damage depth and scope in the form of pictures and texts. The base layer detection includes performing material testing on the damaged part, analyzing the specific content of each metal element, and using a hardness tester to determine the specific hardness required for subsequent repair.

[0048] S2. Mechanically grinding the damaged part, including using a grinding machine to perform mechanical removal of the fatigue layer on the damaged part, and at the same time forming a chamfer at the junction of the damaged and undamaged parts through grinding to facilitate subsequent laser cladding transition. It also includes coloring detection and hardness detection. After mechanically grinding the damaged part, check for potential defects and record the size of the damaged part after grinding to ensure that the requirements for processing are met before the laser cladding repair operation of the damaged part.

[0049] S3. Laser additive repair of the damaged part, including using nickel-based powder as the repair material and adopting coaxial powder feeding technology to perform cladding processing by inputting the previously recorded data into the on-site assembled laser cladding equipment. The nickel-based powder as the repair material has excellent adhesion, close adhesion, hardness and wear resistance, and can more easily meet the quality requirements after laser cladding repair of the damaged part. The nickel-based powder has a high bonding degree with the base layer parent material, a low temperature rise during the cladding process, a small heat influence, and reliable damage repair.

[0050] Further, please refer to the appendix Figure 4 The laser cladding equipment includes a teaching box 1, a robot controller 2, a computer 3, an intelligent robot 4, a six-axis robotic arm 5, a laser 6, a conduction optical fiber 7, a processing platform 8, an optical fiber output end 9, a powder feeding system 10 and a gas supply system 11. During actual processing, for example, when repairing a damaged part on the processing platform 8, the computer 3 inputs the damaged part information obtained in the previous steps, and jointly controls the robot controller 2, the laser 6, the powder feeding system 10 and the gas supply system 11 in cooperation with the teaching box 1, and completes the repair of the damaged part through the cooperation of the six-axis robotic arm 5, the laser 6, the powder feeding system 10 and the gas supply system 11. In this application, there is no processing platform 8, and other components are assembled in the in-situ state of the damaged bolt, and the damaged bolt in the in-situ state is directly repaired.

[0051] Furthermore, the cladding process is divided into planar repair and vertical surface repair according to different repair working surfaces: Planar repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder feeding rate is 18 g / min, and the gas supply speed is 15 Pa·L / min; Vertical surface repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder feeding rate is 12 - 14 g / min, and the gas supply speed is 15 Pa·L / min; Different control data are provided according to different repair working surfaces to ensure reliable repair under different working surfaces.

[0052] Furthermore, when adjacent cladding layers need to overlap during the cladding operation, the variable opening should be polished to keep it flat and smooth to ensure the cladding quality of the overlapping layer.

[0053] S4. Stress relief: After laser additive repair, ultrasonic impact strengthening vibration is used to remove the bolt stress, reduce the tensile stress and deformation of the repaired part, improve the material influence, and improve the surface precision characteristics, especially the anti-wear and contact fatigue characteristics.

[0054] S5. Quality inspection and cleaning: Penetrant inspection is used to detect the repaired area to confirm the repair quality, and at the same time, hardness inspection is carried out to ensure that the hardness of the cladding layer matches the hardness of the base material; After passing the quality inspection, manual polishing treatment is carried out, and at the same time, surface cleaning is carried out.

[0055] In addition to the damage repair of the bolt itself, the same repair method can also be used for the damage repair of other parts of the construction project, such as the damage of the connection node part shown in Figure 3 the figure.

[0056] The present invention has been described in detail with reference to the accompanying drawings and embodiments. Those of ordinary skill in the art can make various variations of the present invention according to the above description. Therefore, some details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope of the appended claims.

Claims

1. A laser additive repair method for bolts, which is used to perform laser additive repair on the damaged part under the load state after the quality problem of bolt damage occurs at important nodes of construction projects. It is characterized in that, The repair method includes: S1. Marking and detecting the damaged part; S2. Mechanically grinding the damaged part; S3. Laser additive repairing the damaged part; S4. Stress relief; S5. Quality inspection and cleaning.

2. The laser additive repair method of the bolt according to claim 1, characterized in that: The marking of the damaged part in step S1 includes cleaning the damaged part to remove foreign matters and expose the metallic luster, and marking the position of this part.

3. The laser additive repair method for the bolt according to claim 2, wherein: The detection in step S1 includes flaw detection and base layer detection; among them, The flaw detection includes performing ultrasonic non-destructive detection on the damaged part, archiving the original state of the detection structure, and recording the detailed damage depth and range in a graphic and text manner; The base layer detection includes performing material detection on the damaged part, analyzing the specific content of each metal element, and using a hardness tester to detect to determine the specific hardness required for subsequent repair.

4. The laser additive repair method of the bolt according to claim 1, characterized in that: Step S2 includes using a angle grinder to perform mechanical removal of the fatigue layer on the damaged part, and at the same time forming a chamfer at the junction of the damaged and undamaged parts by grinding.

5. The laser additive repair method of the bolt according to claim 3, characterized in that: Step S2 also includes coloring detection and hardness detection, confirming whether there are potential defects after mechanically grinding the damaged part, and recording the size of the damaged part after grinding.

6. The laser additive repair method of the bolt according to claim 5, characterized in that: Step S3 includes using nickel-based powder as the repair material, and performing cladding processing by means of coaxial powder feeding technology by inputting the previously recorded data into the on-site assembled laser cladding equipment.

7. The laser additive repair method of the bolt according to claim 6, characterized in that: The cladding processing in step S3 is divided into planar repair and vertical surface repair according to different repair working surfaces; the specific control is as follows, Planar repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder output rate is 18 g / min, and the gas supply speed is 15 Pa·L / min; Vertical surface repair: The laser scanning speed is 1000 - 1200 mm / min, the thickness of each cladding layer is 0.8 - 0.9 mm, the overlapping rate is 60%, the laser power is 2200 W, the powder output rate is 12 - 14 g / min, and the gas supply speed is 15 Pa·L / min.

8. The laser additive repair method of the bolt according to claim 6, characterized in that: When adjacent cladding layers need to overlap during the cladding processing operation in step S3, the variable port should be ground to keep it flat and smooth.

9. The laser additive repair method of the bolt according to claim 1, characterized in that: Step S4 includes removing bolt stress by ultrasonic impact strengthening vibration after laser additive repair.

10. The laser additive repair method of the bolt according to claim 6, characterized in that: Step S5 includes using penetrant testing to detect the repaired area to confirm the repair quality, and at the same time performing hardness detection to ensure that the hardness of the cladding layer matches the hardness of the base material; After passing the quality inspection, manual polishing treatment is carried out, and at the same time surface cleaning is performed.

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