A laser correction method for welding deformation of a titanium alloy

Abstract

A laser correction method for titanium alloy welding deformation is provided. The titanium alloy welded structure is turned over and placed horizontally. The structure is 700 mm away from the ground, and the deformation position is marked. A 1500W laser machine capable of outputting triangle and circle is used. The laser gun is connected with the protection nozzle and fastened. The argon gas bottle is connected, and the argon gas flow is adjusted to 15-20 L / min. The titanium alloy welded structure deformation is measured. The correction process is set in the order of first correcting the bending deformation, then correcting the local concave-convex deformation, third correcting the angle deformation, and finally correcting the wave deformation. By using the process, the correction effect and quality of the titanium alloy structure can be effectively improved, and it is also suitable for large titanium alloy structural parts. By using the laser correction process, inert gas coverage can be achieved throughout the correction process, basically eliminating the titanium alloy weld crack problem often occurring in flame correction, and effectively ensuring the welding quality of titanium alloy.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, specifically relating to a laser correction method for welding deformation of titanium alloys. Background Technology

[0002] Titanium alloys, due to their low density, light weight, high strength, good weldability, and strong corrosion resistance, are widely used in shipbuilding, aerospace, locomotives, boilers, pressure vessels, and other manufacturing industries. In engineering practice, the large shrinkage during titanium alloy welding directly leads to significant welding deformation, severely impacting the welding quality of subsequent parts. Therefore, post-weld straightening of titanium alloy components is essential. Current conventional straightening methods primarily employ mechanical straightening, but this has significant limitations, making post-weld straightening of large structural components difficult or even impossible. Furthermore, because titanium alloys absorb hydrogen at 300°C, oxygen at 400°C, and nitrogen at 600°C, the inhalation of these gases introduces a severe tendency for cracking, making flame straightening extremely difficult.

[0003] With the rapid development of laser technology in recent years, high-power laser technology has become increasingly mature and its application range has expanded to include laser welding, laser cleaning, laser scanning, and laser weapons. Because laser heat is concentrated and the heating speed is fast, the heated area can easily be protected with inert gases such as argon. Therefore, laser heating correction is an ideal method for correcting titanium alloys.

[0004] Therefore, this laser straightening process can effectively correct the deformation of special metal materials such as titanium alloys after welding. It is suitable for titanium alloy components of various structural types and sizes, greatly improves the straightening speed, avoids various welding defects caused by excessive temperature of titanium alloy materials, and improves the overall welding quality and efficiency of titanium alloys. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a laser correction method for welding deformation of titanium alloys, aiming to improve the quality and efficiency of titanium alloy welding deformation correction while reducing correction costs. The technical solution adopted is as follows:

[0006] A laser correction method for welding deformation of titanium alloy involves flipping the titanium alloy welded structural component and placing it horizontally, 700mm above the ground, with the deformation location marked. A 1500W laser machine capable of outputting triangular and circular shapes is used, connecting the laser gun to a protective nozzle and securing it. The protective nozzle is connected to an argon gas cylinder, and the argon gas flow rate is adjusted to 15-20L / min. The deformation of the titanium alloy welded structure is measured, and the correction process is set in the following order: first, bending deformation is corrected; then, local concave-convex deformation is corrected; third, angular deformation is corrected; and finally, wavy deformation is corrected.

[0007] The method used to correct bending deformation is as follows: Based on the measured curvature, convex surface correction is performed using a triangular heating method and a straight heating method along the edge of the convex surface. The triangular heating method involves heating from the center to the edge sequentially. During heating, the laser beam is adjusted into a triangle, and the protective nozzle is placed tightly against the titanium plate. At the same time, the heating area on the back of the titanium alloy plate turns slightly yellow. The heating speed is 200-500 mm / min, and a reciprocating arc heating method is used. During the triangular heating process, pressure is applied to the titanium alloy plate to accelerate its contraction. Then, the convex end is heated. During heating, the opening of the protective nozzle is inserted into the end of the titanium plate for heating and to protect the titanium plate from oxidation. The combined correction is performed until the surface is flattened.

[0008] Method for correcting local concave-convex deformation: First, apply a certain external force to the center of the convex surface to press the original convex surface into a concave shape of 2-5mm. On the opposite side of the pressurized surface, heat the concave surface around the perimeter. During heating, adjust the laser beam into a triangle shape and press the protective nozzle tightly against the titanium plate. At the same time, the heating area on the back of the titanium plate should turn slightly yellow. The heating speed should be 200-500mm / min, and a reciprocating linear arc heating method should be used. After heating around the perimeter is completed, remove the pressurizing device after the temperature drops to room temperature.

[0009] The method used for angular deformation is as follows: First, measure and mark the highest point and weld position on the back of the weld. Apply a top force to the deformed area and use a straight reciprocating heating method to heat and straighten from the middle to both sides. When heating, adjust the laser beam into a triangle and press the protective nozzle tightly against the titanium plate. At the same time, the back of the titanium plate should be heated until the color of the heated area turns slightly yellow. The heating speed is 200-500 mm / min, and the reciprocating heating method is used. When straightening, heat and straighten from the highest point of deformation to both sides until it is flat. After the temperature of the heated area drops to room temperature, remove the pressure device.

[0010] The method used for wave deformation is as follows: First, a pressure device is used to pressurize and fix the deformed area at the highest point. When heating, the laser beam is adjusted into a triangle, and the protective nozzle is pressed tightly against the titanium plate. At the same time, the titanium plate is heated until the back of the plate turns slightly yellow. The heating speed is 200-500 mm / min, and a reciprocating heating method is used, moving from one end to the other. Heating and correction are performed from the highest point of deformation on both sides. During the correction, heating and correction are performed from the highest point of deformation to both sides until the plate is flattened. After the temperature of the heated area drops to room temperature, the pressure device is removed.

[0011] The above-mentioned laser correction method for welding deformation of titanium alloy is further improved by adjusting the laser beam to a circle for the deformed parts that cannot be corrected by applying pressure during the local concave-convex deformation correction process. During heating, the laser beam is first diffused in a circle from the center of the convex surface to the surrounding area. During heating, the laser beam is adjusted to a circle and the protective nozzle is placed tightly against the titanium plate. During heating, the laser rotates rapidly with a rotation diameter of 10mm. At the same time, the heated area on the back of the titanium plate turns slightly yellow.

[0012] Furthermore, in the aforementioned laser correction method for welding deformation of titanium alloys, the laser power of the laser machine is adjusted to between 700W and 1200W according to the thickness of the titanium alloy structural plate, and the narrowest point of the laser beam emitted by the laser gun is adjusted to be greater than 5mm.

[0013] Furthermore, in the aforementioned laser correction method for welding deformation of titanium alloys, the direct heat-affected zone of the triangular heating method does not exceed half the width of the plate.

[0014] Furthermore, the laser correction method for welding deformation of titanium alloys described above further ensures that the heating of the plate surface does not damage the plate surface during the correction process of bending deformation, local concave-convex deformation, angular deformation and wavy deformation.

[0015] Furthermore, in the laser correction method for welding deformation of titanium alloys described above, during the correction of bending deformation, local concave-convex deformation, angular deformation and wavy deformation, the heating zone is always protected by argon gas, and the titanium plate should ideally remain silvery-white after correction.

[0016] Furthermore, in the aforementioned laser correction method for welding deformation of titanium alloys, one end of the protective nozzle has a thread that matches the laser gun, the other end of the protective nozzle has a 6-8mm opening with a depth of 5-10mm, and the length of the protective nozzle is 250mm.

[0017] Furthermore, in the aforementioned laser correction method for welding deformation of titanium alloys, the protective nozzle is made of a copper tube with a wall thickness of 1mm and a diameter of 20mm.

[0018] This process effectively improves the straightening effect and quality of titanium alloy structures and is suitable for large titanium alloy structural components. By employing laser straightening, inert gas coverage can be achieved throughout the straightening process, essentially eliminating the weld cracking problem that often occurs in flame straightening of titanium alloys, thus effectively ensuring the welding quality of titanium alloys. Attached Figure Description

[0019] Figure 1 A schematic diagram of the protective nozzle structure;

[0020] Figure 2 This is a schematic diagram of bending deformation correction;

[0021] Figure 3This is a schematic diagram for correcting local concave and convex deformation.

[0022] Figure 4 This is a schematic diagram of angular deformation correction;

[0023] Figure 5 This is a schematic diagram of wave deformation correction. Detailed Implementation

[0024] The invention will be further described with reference to the accompanying drawings.

[0025] A laser correction method for welding deformation of titanium alloys, the specific steps of which are as follows:

[0026] S1: Flip the titanium alloy welded structural component and place it horizontally, 700mm above the ground, so that the operator can enter the bottom of the component to check the amount of deformation and mark the location of the deformation.

[0027] S2: Use a 1500W laser machine capable of outputting triangular and circular beams. Adjust the laser power to between 700W and 1200W according to the thickness of the titanium alloy structural plate. Adjust the width (narrowest point) of the laser beam emitted by the laser gun to be greater than 5mm. Connect the laser gun to the protective nozzle and tighten it securely. Figure 1 As shown, one end of the protective nozzle has a thread that matches the laser gun, and the other end has a 6-8mm opening with a depth of 5-10mm. The length of the protective nozzle is approximately 250mm. The protective nozzle is made of 1mm thick, 20mm diameter copper tubing. Connect it to an argon cylinder and adjust the argon flow rate to 15-20L / min.

[0028] S3: By measuring the deformation of the titanium alloy welded structure, the general deformation types include angular deformation, bending deformation, wave deformation and local concave and convex deformation. The correction process is set in the order of first correcting bending deformation, then correcting local concave and convex deformation, then correcting angular deformation, and finally correcting wave deformation.

[0029] like Figure 2 As shown, the method used to correct bending deformation is as follows: Based on the degree of curvature, convex surface correction is performed using a triangular heating method and a straight-line heating method along the edge of the convex surface. The triangular heating method should not exceed half the width of the plate. Heating is performed sequentially from the center to the edge. During heating, the laser beam is adjusted into a triangle, and the protective nozzle is placed tightly against the titanium plate. The plate surface should not be damaged during heating, while the back of the titanium plate reaches a slightly yellowish hue in the heated area. The heating speed is 200-500 mm / min, and a reciprocating arc heating method is used. The heated area is always protected by argon gas. After correction, the titanium plate remains predominantly silvery-white. During triangular heating, pressure is applied to the heating plate to accelerate its contraction. Then, the convex end is heated. During heating, the opening of the protective nozzle is inserted into the end of the titanium plate for heating and to protect the titanium plate from oxidation. This combined correction method is used until the plate is flattened.

[0030] like Figure 3 As shown, the method for correcting localized concave-convex deformation involves first applying a certain external force to the center of the convex surface, pressing it down to a concave position of 2-5mm. Then, heating is applied to the concave side of the pressed surface. During heating, the laser beam is adjusted to a triangular shape, and the protective nozzle is firmly attached to the titanium plate. Care must be taken not to damage the plate surface during heating, and the heated area on the back of the titanium plate should turn slightly yellow. The heating rate is 200-500 mm / min, using a reciprocating linear arc heating method. The heated area is always protected by argon gas. After correction, the titanium plate remains predominantly silvery-white. After heating around the perimeter is complete, the pressure device is removed once the temperature has dropped to room temperature.

[0031] For uneven or concave deformation areas where pressure cannot be applied, the laser beam is adjusted to a circular shape, and a point-heating correction method is used. During heating, the beam first spreads outwards in a circular pattern from the center of the convex surface. The laser beam is then adjusted to a circular shape, and the protective nozzle is placed firmly against the titanium plate. The laser rotates rapidly during heating, with a rotation diameter of approximately 10mm. The plate surface must not be damaged during heating. Simultaneously, the heated area on the back of the titanium plate turns slightly yellow, and this area is always protected by argon gas. After correction, the titanium plate remains predominantly silvery-white.

[0032] like Figure 4 As shown, the method used for angular deformation is as follows: First, on the back of the weld, the highest point and the position of the weld bead are measured and marked. A force is applied to the deformed area, and a linear reciprocating heating method is used, heating and straightening from the center outwards. During heating, the laser beam is adjusted to a triangle, and the protective nozzle is placed firmly against the titanium plate. The plate surface should not be damaged during heating. The back of the titanium plate should be heated until it turns slightly yellow. The heating rate is 200-500 mm / min, using a reciprocating heating method. The heating area is always protected by argon gas. After straightening, the titanium plate remains predominantly silvery-white. During straightening, heating and straightening are performed side-by-side from the highest point of deformation outwards until flattened. The pressure device is removed after the temperature of the heating area drops to room temperature.

[0033] like Figure 5 As shown, the method used for wave deformation is as follows: First, a pressure device is used to pressurize and fix the deformed area at the highest point. During heating, the laser beam is adjusted into a triangle, and the protective nozzle is tightly attached to the titanium plate. The plate surface must not be damaged during heating. Simultaneously, the titanium plate is heated until the back side turns slightly yellow. The heating rate is 200-500 mm / min, using a reciprocating heating method, moving from one end to the other, and correcting from the highest point of deformation on both sides. The heating area is always protected by argon gas. After correction, the titanium plate remains predominantly silvery-white. During correction, heating and correction are performed from the highest point of deformation outwards until flattened. The pressure device is removed after the temperature of the heating area drops to room temperature.

[0034] The difference between this process and the traditional titanium alloy welding deformation correction process is that this process uses laser as the correction energy source. By keeping the heating zone covered with inert gas to prevent the titanium alloy structure weld from reacting with the outside air, weld cracks caused by correction heating are basically eliminated. At the same time, a correction process combining mechanical-assisted correction and thermal correction is adopted, which greatly improves the correction efficiency and quality and has a wider range of applications.

Claims

1. A laser correction method for welding deformation of titanium alloys, characterized in that, The titanium alloy welded structural component was flipped over and placed horizontally, 700mm above the ground, and the deformation locations were marked. A 1500W laser machine capable of outputting triangles and circles was used. The laser gun and protective nozzle were connected and secured, and an argon cylinder was connected, with the argon flow rate adjusted to 15-20L / min. The deformation of the titanium alloy welded structure was measured, and the correction process was set in the following order: first, bending deformation was corrected; then, local concave and convex deformation was corrected; third, angular deformation was corrected; and finally, wavy deformation was corrected. The method used to correct bending deformation is as follows: Based on the measured curvature, convex surface straightening is performed using a triangular heating method and a straight heating method along the edge of the convex surface. The triangular heating method involves heating from the center to the edge sequentially. During heating, the laser beam is adjusted into a triangle, and the protective nozzle is placed tightly against the titanium plate. Simultaneously, the heated area on the back of the titanium alloy plate turns slightly yellow. The heating speed is 200-500 mm / min, and a reciprocating arc heating method is used. During the triangular heating process, pressure is applied to the titanium alloy plate to accelerate its contraction. Then, the convex end is heated. During heating, the opening of the protective nozzle is inserted into the end of the titanium plate for heating and to protect the titanium plate from oxidation. This combined straightening process continues until the surface is flattened. Method for correcting local concave and convex deformation: First, apply a certain external force to the center of the convex surface to press the original convex surface into a concave shape of 2-5mm. On the reverse side of the pressurized surface, heat the concave surface around the perimeter. During heating, adjust the laser beam into a triangle shape and press the protective nozzle tightly against the titanium plate. At the same time, the heated area on the back of the titanium plate should turn slightly yellow. The heating speed should be 200-500mm / min, and a reciprocating linear arc heating method should be used. After heating around the perimeter is completed, remove the pressurizing device after the temperature drops to room temperature. The method used for angular deformation is as follows: First, measure and mark the highest point and weld position on the back of the weld. Apply a top force to the deformed area and use a straight reciprocating heating method to heat and straighten from the middle to both sides. When heating, adjust the laser beam into a triangle and press the protective nozzle tightly against the titanium plate. At the same time, the back of the titanium plate should be heated until the color of the heated area turns slightly yellow. The heating speed is 200-500 mm / min, and the reciprocating heating method is used. When straightening, heat and straighten from the highest point of deformation to both sides until it is flat. After the temperature of the heated area drops to room temperature, remove the pressure device. The method used for wave deformation is as follows: First, a pressure device is used to pressurize and fix the deformed area at the highest point. When heating, the laser beam is adjusted into a triangle, and the protective nozzle is pressed tightly against the titanium plate. At the same time, the titanium plate is heated until the back of the plate turns slightly yellow. The heating speed is 200-500 mm / min, and a reciprocating heating method is used, moving from one end to the other. Heating and correction are performed from the highest point of deformation on both sides. During the correction, heating and correction are performed from the highest point of deformation to both sides until the plate is flattened. After the temperature of the heated area drops to room temperature, the pressure device is removed.

2. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, During the correction of local concave and convex deformation, for concave and convex deformation areas where pressure cannot be applied, the laser beam is adjusted to a circle and a point heating correction method is used. When heating, the laser beam first spreads outward from the center of the convex surface in a circle. When heating, the laser beam is adjusted to a circle and the protective nozzle is placed tightly against the titanium plate. When heating, the laser rotates rapidly with a rotation diameter of 10mm. At the same time, the heating area on the back of the titanium plate turns slightly yellow.

3. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, The laser power of the laser machine is adjusted to between 700W and 1200W according to the thickness of the titanium alloy structural plate, and the narrowest part of the laser beam emitted by the laser gun is adjusted to be greater than 5mm.

4. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, The direct heat-affected zone of the triangular heating method should not exceed half the width of the plate.

5. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, During the correction of bending deformation, local concave and convex deformation, angular deformation and wavy deformation, the plate surface must not be damaged when heating.

6. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, During the correction of bending deformation, local concave and convex deformation, angular deformation and wavy deformation, the heating zone is always protected by argon gas, and the titanium plate should remain silvery-white after correction.

7. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, One end of the protective nozzle has a thread that matches the laser gun, and the other end of the protective nozzle has a 6-8mm opening with a depth of 5-10mm. The length of the protective nozzle is 250mm.

8. The laser correction method for welding deformation of titanium alloy according to claim 1, characterized in that, The protective nozzle is made of 1mm thick copper tubing with a diameter of 20mm.

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