In-situ laser welding equipment and method for improving performance of alloy laser welding head through laser shock

Abstract

The invention discloses an in-situ laser welding device and method for improving the performance of an alloy laser welding head through laser shock. The in-situ laser welding device comprises a PC control end, a control system, a laser galvanometer, a clamp and a workbench. The method comprises the following steps of: fixing a to-be-welded base material by using a clamp after butting the to-be-welded base material, acquiring the size information of the to-be-welded base material, pre-treating the to-be-welded base material, arranging a laser galvanometer along the direction of a welding path, determining welding process parameters, controlling the laser galvanometer to output welding laser, and welding along the direction of the welding path; and impact process parameters are determined, the laser galvanometer is controlled to output impact laser, and laser impact is conducted on the welded plate obtained after welding is completed in the impact path direction. Laser shock is carried out on the welded Fe-Cr-Al alloy, so that the surface layer of the material is subjected to plastic deformation, a residual compressive stress layer is generated, the performance of an alloy laser welding head is improved, meanwhile, laser welding and laser shock are integrated on one device, the device does not need to be frequently replaced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of laser welding, and in particular relates to in-situ laser welding equipment and a method for improving the performance of alloy laser welding heads by laser shock. Background Art

[0002] Fe-Cr-Al alloy is a kind of iron-based alloy. It is widely used in electric heating elements, high-temperature furnace components, nuclear reactor cladding materials and other fields due to its excellent high-temperature mechanical properties, high-temperature oxidation resistance, corrosion resistance, low resistance temperature coefficient and high resistivity. Fe-Cr-Al alloy is an alloy that is strengthened by oxide dispersion strengthening (ODS) mechanism and solid solution strengthening mechanism. However, the ODS strengthening mechanism, the high temperature in laser melting welding will lead to the redistribution of alloy elements and changes in microstructure. O atoms will combine with each other to form oxygen and be burned in large quantities. The melting and rapid cooling and solidification process of laser welding is not enough to disperse small particles of oxide phase everywhere. Related studies have also observed that the re-precipitated oxide phase will grow significantly, resulting in the loss of ODS strengthening mechanism. The presence of high-temperature resistant oxide film requires higher laser power for welding Fe-Cr-Al alloy. Higher energy input leads to the growth of crystalline structure and oxide phase. At the same time, the presence of oxide film will increase the probability of pores and liquefaction cracks, reducing the performance of laser welded joints.

[0003] Laser shock peening (LSP) is a new surface modification technology that uses laser-induced plasma shock waves to improve the fatigue life of materials. This technology uses short-pulse, high-peak power density lasers to act on the surface of the workpiece to form high-pressure plasma shock waves, which causes plastic deformation of the material surface and produces a residual compressive stress layer, thereby improving the material's wear resistance, stress corrosion resistance and fatigue resistance. For Fe-Cr-Al alloys under the ODS strengthening mechanism, laser shock peening technology can introduce residual compressive stress on the surface of the ODS alloy, improve the microstructure, and thus improve its performance. Laser shock peening technology has almost no thermal effect on the material, so it can avoid the grain growth and oxidation phase growth caused by heat. It is an effective means to compensate for the reduced performance of Fe-Cr-Al alloy laser welding welds. At present, laser shock is used in production as a post-processing method, but due to the need for frequent equipment replacement and other reasons, it seriously affects production efficiency. Therefore, it is urgent to propose an in-situ laser welding device and method for improving the performance of alloy laser welding heads by high-efficiency shock. Summary of the invention

[0004] In view of the shortcomings of the background technology, the purpose of the present invention is to provide an in-situ laser welding device and method for improving the performance of alloy laser welding joints by laser shock, which solves the problems of low performance of laser welding joints, frequent replacement of laser shock equipment and low production efficiency in the prior art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] According to one aspect of the present application, an in-situ laser welding device for improving the performance of alloy laser welding heads by laser shock is disclosed, comprising: a PC control terminal, a control system, a laser galvanometer, a fixture and a workbench;

[0007] The PC control terminal is used to set welding process parameters, impact process parameters and control programs and transmit them to the control system;

[0008] The control system is located between the PC control end and the laser galvanometer, and the control system includes an industrial controller, a fiber laser, a beam-combining optical fiber, a robot control end and a mechanical arm; the industrial controller receives instructions from the PC control end to control the fiber laser to output laser, the fiber laser includes a welding fiber laser and an impact fiber laser, and the lasers output by the welding fiber laser and the impact fiber laser are combined by the beam-combining optical fiber and incident on the laser galvanometer, the robot control end is located between the fiber laser and the mechanical arm, and the mechanical arm is connected to the laser galvanometer;

[0009] The clamp is arranged on the workbench.

[0010] According to another aspect of the present application, an in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock is also disclosed, comprising:

[0011] Obtaining the size information corresponding to the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded;

[0012] butting a first Fe-Cr-Al alloy base material to be welded and a second Fe-Cr-Al alloy base material to be welded, wherein a welding gap exists between the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded after butting, and performing a pretreatment operation on the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded;

[0013] Arranging a laser galvanometer along a welding path direction, wherein the welding path direction is the length direction of the welding gap formed after the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are butt-jointed;

[0014] The control system controls the laser galvanometer to perform spot welding and fix the two ends of the welding gap;

[0015] Based on the size information corresponding to the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded, respectively, the welding process parameters are determined, wherein the welding process parameters include the welding laser power output by the laser galvanometer being 3000W to 5000W, the welding speed being 2.0m / min to 2.6m / min, and the laser defocus amount of the welding laser being 0;

[0016] The control system controls the laser galvanometer to output a welding laser so that the laser galvanometer welds the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded along the welding path direction to obtain a welded plate;

[0017] Determine the impact process parameters, wherein the impact process parameters include the pulse energy of the laser galvanometer is 10-15J, the pulse width is 16ns-20ns, the impact laser frequency is 6kHz-8kHz, the impact beam moving speed is 1.5m / min-2m / min, and the impact laser defocus is 0;

[0018] The control system controls the laser galvanometer to output impact laser, so that the laser galvanometer performs laser impact on the welded plate along the impact path direction, and the impact path is consistent with the welding path.

[0019] In some embodiments, the first Fe-Cr-Al alloy base material to be welded and the second Fe-Cr-Al alloy base material to be welded are butted together by a clamp, and heat conducting plates are respectively provided on the clamping surfaces of the clamp, and the width of the clamped Fe-Cr-Al alloy base material not covered by the heat conducting plates is 3 to 10 mm.

[0020] In some embodiments, the thermally conductive sheet is a copper plate or an aluminum plate.

[0021] In some embodiments, the Fe-Cr-Al alloy base material has a thickness of 1 mm to 3 mm.

[0022] In some embodiments, a shielding gas is used during the welding and impacting process, the shielding gas is 99.99% pure argon, and the shielding gas flow rate is 10 L / min;

[0023] In some embodiments, the welding laser is a solid circular spot with a diameter of 1 mm to 3 mm; the impact laser is a linear spot with a diameter of 3 mm to 10 mm; the impact laser is perpendicular to the welding gap, and the linear oscillation frequency of the impact laser spot is 100 to 150 Hz.

[0024] In some embodiments, the pretreatment operations include cleaning, grinding, plate preheating and beveling.

[0025] In some embodiments, the welding fiber laser is a continuous fiber laser or a pulsed fiber laser, and the shock fiber laser is a pulsed fiber laser.

[0026] The present invention includes but is not limited to the following beneficial effects: (1) laser shock is performed after welding to form a high-pressure plasma shock wave, causing plastic deformation of the material surface and generating a residual compressive stress layer, thereby improving the performance of the alloy laser welding head; (2) the present invention integrates laser welding and laser shock on one device, eliminating the need for frequent equipment replacement and greatly improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0028] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

[0029] Figure 2 is a welding process flow chart of an embodiment of the present invention;

[0030] Figure 3 is an exemplary diagram of a fixture structure according to an embodiment of the present invention;

[0031] Figure 4 is a schematic diagram of a welding process according to an embodiment of the present invention;

[0032] Figure 5 is a schematic diagram of an impact process of an embodiment of the present invention;

[0033] In the figure, 1-PC control end, 2-control system, 21-industrial controller, 22-fiber laser, 23-beam combining fiber, 24-robot control end, 25-mechanical arm, 22a-welding fiber laser, 22b-impact fiber laser; 3-laser galvanometer, 4-clamp, 41-heat conducting plate, 41a-first heat conducting plate, 41b-second heat conducting plate, 41c-third heat conducting plate, 41d-fourth heat conducting plate; 5-workbench, 6-first Fe-Cr-Al alloy base material to be welded, 7-second Fe-Cr-Al alloy base material to be welded, 8-welding laser, 9-impact laser. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0035] The present invention discloses an in-situ laser welding device for improving the performance of alloy laser welding heads by laser shock. Figure 1 , including: PC control terminal 1, control system 2, laser galvanometer 3, fixture 4 and workbench 5;

[0036] The PC control terminal 1 is used to set welding process parameters, impact process parameters, welding and impact positions, welding-impact paths and control programs and transmit them to the control system 2;

[0037] The control system 2 is located between the PC control terminal 1 and the laser galvanometer 3. The control system 2 includes an industrial controller 21, a fiber laser 22, a beam combining fiber 23, a robot control terminal 24 and a mechanical arm 25. The industrial controller 21 adjusts the switch and time of the electrical signal according to the control program received from the PC control terminal 1 and sends it to the fiber laser 22. The industrial controller 21 controls the fiber laser 22 to output laser. The fiber laser 22 includes a welding fiber laser 22a and an impact fiber laser 22b. The lasers output by the welding fiber laser 22a and the impact fiber laser 22b are combined by the beam combining fiber 23 and incident on the laser galvanometer 3. The robot control terminal 24 is located between the fiber laser 22 and the mechanical arm 25. The mechanical arm 25 is connected to the laser galvanometer 3. The robot control terminal 24 controls the mechanical arm 25 to drive the laser galvanometer 3 to weld and impact the base material to be welded according to the set welding and impact paths. The fixture 4 is arranged on the workbench 5.

[0038] This solution also discloses an in-situ laser welding method for improving the performance of alloy laser welding joints by laser shock. Figure 2 , the method comprises the following steps:

[0039] S100, obtaining the size information corresponding to the first Fe-Cr-Al alloy base material 6 and the second Fe-Cr-Al alloy base material 7 to be welded.

[0040] Among them, the size information refers to the length, width and height of the Fe-Cr-Al alloy base materials to be welded (the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded). It can be understood that the length dimension or width dimension refers to the edge length to be welded.

[0041] S101, butt-joining the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded, whereby a welding gap exists between the first Fe-Cr-Al alloy base material 6 and the second Fe-Cr-Al alloy base material 7 to be welded.

[0042] In some preferred embodiments, the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are butt-jointed by a clamp 4, and heat conducting plates 41 are respectively provided on the clamping surfaces of the clamp 4, and the parts of the clamped Fe-Cr-Al alloy base material that need to be impacted are not covered by the heat conducting plates 41, and the width not covered by the heat conducting plates 41 is 3 to 10 mm; the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are both pretreated; the pretreatment operation in the present embodiment includes cleaning, grinding, preheating the plate and beveling the alloy base material to be welded.

[0043] S102, arranging the laser galvanometer 3 along the welding path direction, wherein the welding path direction is the length direction of the welding gap formed after the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are butt-jointed.

[0044] In this embodiment, the welding path direction is Figure 3 The direction of the arrow.

[0045] S103, the control system 2 controls the laser galvanometer 3 to perform spot welding to fix the two ends of the welding gap.

[0046] By spot welding the two ends of the welding gap, displacement of the first Fe-Cr-Al alloy base material 6 and the second Fe-Cr-Al alloy base material 7 during welding can be avoided, thereby improving welding quality.

[0047] S104 , determining welding process parameters based on the size information corresponding to the first Fe—Cr—Al alloy base material 6 and the second Fe—Cr—Al alloy base material 7 .

[0048] The welding process parameters include that the power of the welding laser 8 output by the laser galvanometer 3 is 3000W to 5000W, the welding speed is 2.0m / min to 2.6m / min, and the laser defocus of the welding laser 8 is 0;

[0049] S105, the control system 2 controls the laser galvanometer 3 to output the welding laser 8, so that the laser galvanometer 3 welds the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded along the welding path direction to obtain the welded welded plate.

[0050] S106, determining impact process parameters.

[0051] Among them, the impact process parameters include the pulse energy of the laser galvanometer 3 is 10-15J, the pulse width is 16ns-20ns, the impact laser frequency is 6kHz-8kHz, the impact beam moving speed is 1.5m / min-2m / min, and the defocus amount of the impact laser 9 is 0.

[0052] S107 , the control system 2 controls the laser galvanometer 3 to output the impact laser 9 , so that the laser galvanometer 3 performs laser impact on the welded plate along the impact path direction.

[0053] The direction of the impact path is consistent with the direction of the welding path. Figure 4 The direction of the arrow.

[0054] In some embodiments, the heat conductive sheet 41 is a copper plate or an aluminum plate, preferably a pure copper plate with a thickness of 1 to 2 mm. The heat conductive sheet is provided to quickly conduct away excess welding heat, thereby preventing the welding heat from providing excessive growth driving force for the grains in the unmelted parts, thereby keeping the grains and the oxidized phases in a small state, which is beneficial to reducing the scope that needs to be involved in subsequent laser shock.

[0055] In some embodiments, the thickness of the Fe-Cr-Al alloy parent material is 1 mm to 3 mm.

[0056] In some embodiments, a shielding gas is used during welding and impacting, the shielding gas is 99.99% pure argon, and the shielding gas flow rate is 10 L / min.

[0057] In some embodiments, the welding laser 8 is a solid circular spot with a spot diameter of 1 mm to 3 mm; the impact laser 9 is a linear spot with a spot diameter of 3 mm to 10 mm; the impact laser 9 is perpendicular to the welding gap, and the linear oscillation frequency of the impact laser 9 spot is 100 to 150 Hz.

[0058] In some embodiments, the welding fiber laser 22a is a continuous fiber laser or a pulse fiber laser, and the impact fiber laser 22b is a pulse fiber laser.

[0059] The welding process of this scheme is specifically described below in conjunction with specific embodiments:

[0060] In one example, the thickness of the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are both selected to be 2 mm, and the chemical composition mass percentages are 22% Cr, 6.8% Al and the remainder Fe, respectively. The first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are pretreated, and the surfaces of the first and second Fe-Cr-Al alloy base materials to be welded are polished with 500# SiC sandpaper, and cleaned with acetone, and placed in a constant temperature drying oven at 25°C for 25 minutes, and the first Fe-Cr-Al alloy base material 6 to be welded and the second Fe-Cr-Al alloy base material 7 to be welded are clamped with a clamp 4. It is placed on the workbench 5, and the first heat conducting plate 41a, the second heat conducting plate 41b, the third heat conducting plate 41c and the fourth heat conducting plate 41d are respectively arranged on the clamping surface of the clamp 4, the first Fe-Cr-Al alloy base material 6 to be welded is located between the first heat conducting plate 41a and the second heat conducting plate 41b, and the second Fe-Cr-Al alloy base material 7 to be welded is located between the third heat conducting plate 41c and the fourth heat conducting plate 41d. The two alloy base materials to be welded are butt-jointed. After butt-jointing, there is a welding gap between the two base materials to be welded. The welding gap here can be the length dimension of the alloy base material to be welded or the width dimension of the base material to be welded. After butt-jointing, the spacing between the first heat conducting plate 41a and the third heat conducting plate 41c is 6mm.

[0061] The welding process parameters are set as follows: the welding power of the laser galvanometer 3 is 4800W, the welding speed is 2.4m / min, the laser defocus of the welding laser 8 is 0mm, the shielding gas is 99.99% pure argon, and the shielding gas flow rate is 10L / min. The welding fiber laser 22a in the control system 2 outputs the laser beam through the beam combining fiber 23 and then incident on the laser galvanometer 3. The laser galvanometer 3 outputs a solid circular spot with a diameter of 3mm. The robot arm 25 controls the laser galvanometer 3 to move along the beam combining fiber 23. Figure 3 Move in the direction of the middle arrow to weld the welding gap.

[0062] The impact process parameters are set as follows: the pulse energy of the laser galvanometer 3 is 10J, the pulse width is 20ns, the frequency of the impact laser 9 is 6kHz, the speed of the light beam moving to the end point is 1.7m / min, the laser defocus of the impact laser 9 is 0mm, the protective gas is 99.99% pure argon, the flow rate of the protector is 10L / min, the spot is a straight line with a diameter of 6mm, the impact fiber laser 22b in the control system 2 outputs the laser after passing through the beam combining optical fiber and is incident on the laser galvanometer 3, the laser galvanometer 3 outputs a straight line spot, and the laser galvanometer 3 is controlled by the robot arm 25 along Figure 5 The weld seam that has been welded is impacted by moving in the direction of the middle arrow, and the oscillation frequency of the impact laser 9 spot is 150 Hz during the impact.

[0063] Laser shock peening technology can introduce residual compressive stress on the surface of Fe-Cr-Al alloy welds, improve the microstructure, bring oxygen atoms deep into the impact surface and redistribute them, which helps to compensate for the performance degradation of oxide dispersion strengthened alloy welds caused by the loss of a large number of oxygen atoms and mismatch. At the same time, laser shock peening has almost no thermal effect on the material, avoiding the grain growth and oxidation phase growth caused by heat, and improving the performance of the welded joint.

[0064] The welding laser and impact laser optical paths are combined by using a beam-combined optical fiber and then integrated into a laser galvanometer, avoiding frequent equipment replacement and greatly improving production efficiency.

[0065] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. An in-situ laser welding device for improving the performance of alloy laser welding joints by laser shock, characterized in that: include: PC control terminal (1), control system (2), laser galvanometer (3), fixture (4) and workbench (5); The PC control terminal (1) is used to set welding process parameters, impact process parameters and control programs and transmit them to the control system (2); The control system is located between the PC control end (1) and the laser galvanometer (3); the control system (2) comprises an industrial controller (21), a fiber laser (22), a beam combining optical fiber (23), a robot control end (24) and a mechanical arm (25); the industrial controller (21) receives instructions from the PC control end (1) to control the fiber laser (22) to output laser light; the fiber laser (22) comprises a welding fiber laser (22a) and an impact fiber laser (22b); the laser light output by the welding fiber laser (22a) and the impact fiber laser (22b) is combined by the beam combining optical fiber (23) and then incident on the laser galvanometer (3); the robot control end (24) is located between the fiber laser (22) and the mechanical arm (25); the mechanical arm (25) is connected to the laser galvanometer (3); The clamp (4) is arranged on the workbench (5).

2. An in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock, characterized in that: include: Obtaining the size information corresponding to the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded; The first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are butt-jointed, and after butt-jointing, a welding gap exists between the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded, and the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are both subjected to pretreatment operations; A laser galvanometer (3) is arranged along a welding path direction, wherein the welding path direction is the length direction of the welding gap formed after the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are butt-jointed; The control system (2) controls the laser galvanometer (3) to perform spot welding and fixation on both ends of the welding gap; Based on the size information corresponding to the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded, welding process parameters are determined, wherein the welding process parameters include that the welding laser power output by the laser galvanometer (3) is 3000W to 5000W, the welding speed is 2.0m / min to 2.6m / min, and the laser defocus amount of the welding laser is 0; The control system (2) controls the laser galvanometer (3) to output a welding laser (8), so that the laser galvanometer (3) welds the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded along the welding path direction, so as to obtain a welded plate; Determining impact process parameters, wherein the impact process parameters include that the pulse energy of the laser galvanometer (3) is 10-15 J, the pulse width is 16 ns-20 ns, the impact laser frequency is 6 kHz-8 kHz, the impact beam moving speed is 1.5 m / min-2 m / min, and the impact laser defocus is 0; The control system (2) controls the laser galvanometer (3) to output impact laser (9), so that the laser galvanometer (3) performs laser impact on the welded plate along the impact path, and the impact path is consistent with the welding path.

3. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 2, characterized in that: The first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are butt-jointed by a clamp (4), and heat conducting plates (41) are respectively provided on the clamping surfaces of the clamp (4), and the width of the clamped Fe-Cr-Al alloy base material not covered by the heat conducting plates is 3 to 10 mm.

4. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 3 is characterized in that: The heat conducting sheet (41) is a copper plate or an aluminum plate.

5. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 2, characterized in that: The thickness of the first Fe-Cr-Al alloy base material (6) to be welded and the second Fe-Cr-Al alloy base material (7) to be welded are both in the range of 1 mm to 3 mm.

6. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 2, characterized in that: A shielding gas is used during the welding and impacting process. The shielding gas is 99.99% pure argon gas, and the shielding gas flow rate is 10 L / min.

7. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 2, characterized in that: The welding laser (8) is a solid circular spot, and the spot diameter of the welding laser (8) is 1 mm to 3 mm; the shock laser (9) is a linear spot, and the spot diameter of the shock laser (9) is 3 mm to 10 mm; the shock laser (9) is perpendicular to the welding gap, and the linear oscillation frequency of the shock laser (9) spot is 100 to 150 Hz.

8. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 2, characterized in that: The pretreatment operations include cleaning, grinding, plate preheating and beveling.

9. The in-situ laser welding method for improving the performance of alloy laser welded joints by laser shock according to claim 1, characterized in that: The welding fiber laser (22a) is a continuous fiber laser or a pulse fiber laser, and the impact fiber laser (22b) is a pulse fiber laser.

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