Titanium alloy medium plate powder feeding device and welding method

Abstract

The invention belongs to the technical field of material processing engineering, and discloses a titanium alloy medium plate powder feeding device and a welding method, a back gas protection device of the titanium alloy medium plate powder feeding device is supported at the lower end of a to-be-welded workpiece, and a tail gas protection cover is arranged at the upper end of the tail of the to-be-welded workpiece; the K-TIG welding guns are all electrically connected with the computer control system, the K-TIG welding guns are installed on the movement mechanism, and the front powder feeding device is connected with the K-TIG welding guns through the connecting mechanism. The front powder feeding device and the rear powder feeding device are arranged on the two sides of the K-TIG welding gun correspondingly, and the rear powder feeding device is located between the K-TIG welding gun and the tail gas protection cover. The welding method comprises the following steps: 1) performing groove processing on a workpiece to be welded; (2) a rear powder feeding device, a K-TIG welding gun and a front powder feeding device are arranged above a welding seam of the workpiece to be welded in series in the welding direction; 3) adjusting the position of a nozzle of a front powder feeding device; 4) setting welding parameters; and 5) starting welding. The welding efficiency is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of material processing engineering, and in particular relates to a powder feeding device and a welding method for a titanium alloy medium and thick plate. Background Art

[0002] At present, welding structures are developing towards large-scale, high-parameter, and precise dimensions. High-efficiency and high-performance welding technologies have greatly promoted the rapid development of my country's construction technology and metal industry. In the field of 5-50mm thick plate welding, welding heat is not easy to diffuse, the welded joints have coarse grains, and there are a large number of columnar crystals, which seriously affect the mechanical properties of the welded joints. This problem is more obvious in the welding of metals with low thermal conductivity such as titanium alloys.

[0003] In order to solve the problem of excessive grain size in medium and thick plate welding, relevant researchers generally consider reducing heat input, changing the solidification conditions of the molten pool or introducing grain refinement elements. Although the method of using special welding wires, such as flux-cored welding wires, has been proven to be able to refine grains to a certain extent, its manufacturing cost is too high. It is generally used for thin plate welding or high-precision component welding. The demand for filler materials (welding materials) is too large when welding medium and thick plates, and the cost performance is not high. Therefore, in the welding of medium and thick plates, new welding equipment such as double tungsten electrode narrow gap TIG welding guns and rotary welding guns are generally derived from reducing heat input or changing the solidification conditions of the molten pool, and then new welding methods such as pulse welding, laser-MIG composite welding, or various auxiliary devices are derived. However, these improved methods all have problems such as complex equipment, difficult to control welding accuracy, and high welding cost. For medium and thick plate welding, although the powder feeding fusion welding technology is not mature, the introduction of alloying elements by powder feeding is still a cost-effective solution worthy of consideration.

[0004] Powder feeding fusion welding is mainly concentrated in metal arc welding and laser welding. Among them, metal arc welding (such as MIG welding) has the best effect, but it has high requirements on the reliability of the equipment. At present, such equipment is expensive, and it is very sensitive to any instability of the arc during welding, and the position of the welding wire (i.e. centering) must be very accurate; powder feeding laser welding has a small molten pool, and the powder is easy to be sent off-center and not fully melted, resulting in an increase in the frequency of powder recovery, and the energy behind the molten pool is not fully utilized and wasted. In addition, the biggest difficulty in tungsten inert gas welding powder feeding is that the alloy powder has a large burnout rate and mostly exists in the upper part of the molten pool, and cannot be effectively fed into the weld to improve the welding quality.

[0005] In view of the above problems, patent CN113231740A discloses a post-powder feeding welding method based on scanning laser. The patent adopts the post-powder feeding method to obtain a fine-grained area on the weld surface, but the method is only applicable to thin plate welding without groove or small groove, and cannot solve the problem of insufficient front-end filling during high-speed welding of large groove; patent CN110170723B discloses a dual-heat source synchronous wire feeding and powder feeding welding method, which adopts the dual-heat source synchronous wire feeding and powder feeding welding method to improve the flowability of the molten pool metal generated by the main welding heat source at the end of solidification, and promote the shrinkage of the small gap caused by the shrinkage of the molten pool metal liquid at the end of solidification, but the single-side dual heat source welding method increases the heat input of the welding process, especially for materials with low thermal conductivity such as titanium alloys, which are easy to coarse grains, which puts high requirements on the welding accuracy of dual heat source wire feeding and powder feeding. And all current powder feeding welding methods do not involve how to improve the utilization rate of alloy powder and the uniform distribution of alloy powder in the molten pool.

[0006] In summary, it is necessary to develop a new welding technology to improve the utilization rate of alloy powder and solve the problem of uneven distribution of alloy elements in the molten pool, so as to effectively improve the filling capacity of liquid metal in the weld pool at the end of solidification, and improve the stress distribution of the weld, prevent the warping and thermal cracking of the plate, and obtain a well-formed and excellent performance welded joint. Summary of the invention

[0007] The purpose of the present invention is to provide a powder feeding device and a welding method for titanium alloy medium and thick plates, so as to solve the above problems existing in the prior art.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A powder feeding device for titanium alloy medium and thick plates, comprising a motion mechanism, an integrated front powder feeding welding gun, a molten pool morphology and temperature monitoring system, a computer control system, a ventilation protection system and a rear powder feeding device, wherein the computer control system is electrically connected to the motion mechanism, the integrated front powder feeding welding gun, the molten pool morphology and temperature monitoring system and the rear powder feeding device, the molten pool morphology and temperature monitoring system comprises an infrared imager and a signal processor, the infrared imager is used to monitor in real time the temperature field change and the molten pool surface morphology of the molten pool surface in the groove of the workpiece to be welded, and the signal processor is electrically connected to the infrared imager and the computer control system;

[0010] The ventilation protection system comprises a back gas protection device and a rear gas protection cover, wherein the back gas protection device is supported at the lower end of the workpiece to be welded, and the rear gas protection cover is arranged at the upper end of the rear of the workpiece to be welded, and a groove located below the molten pool is arranged in the middle of the back gas protection device, and a plurality of ventilation holes are densely distributed in the groove;

[0011] The integrated front powder feeding welding gun includes a K-TIG welding gun, a front powder feeding device and a connecting mechanism. The K-TIG welding gun is electrically connected to a computer control system. The K-TIG welding gun is installed on a motion mechanism. The front powder feeding device is connected to the K-TIG welding gun through a connecting mechanism. The front powder feeding device and the rear powder feeding device are respectively arranged on both sides of the K-TIG welding gun, and the rear powder feeding device is located between the K-TIG welding gun and the rear gas protection cover.

[0012] As a preferred technical solution in the present invention, the post-powder feeding device includes an outer tube and a powder feeding mechanism and a powder mixing mechanism arranged in sequence from top to bottom in the outer tube, the powder feeding mechanism includes an alloy powder feeding tube and a wetting agent spray tube, an external powder conveying tube and an air supply tube arranged in sequence from near to far on both sides of the alloy powder feeding tube, and the distances between the alloy powder feeding tube outlet, the wetting agent spray tube outlet, the external powder conveying tube outlet and the air supply tube outlet and the powder mixing mechanism are arranged in sequence from far to near; the powder mixing mechanism includes a high-speed powder mixer and a rotating mechanism for rotating the high-speed powder mixer in the outer tube, and the rotating mechanism is electrically connected to the computer control system ; The alloy powder feeding tube conveys alloy powder, the wet agent spray tube conveys wetting agent, the external powder feeding tube conveys high melting point powder, the air feeding tube conveys inert gas, the gas flow rate when the alloy powder feeding tube feeds powder is higher than the gas flow rate when the external powder feeding tube feeds powder, the alloy powder is sprayed out at high speed through the alloy powder feeding tube, and after being wetted by the wetting agent, the high melting point powder is adhered to the surface to form a shell-like structure and enters the powder mixing mechanism for further mixing and drying; the wetting agent is composed of 20-40wt.% sodium chloride and 60-80wt.% quartz glass fiber, and the gas flow rate is 70L / min.

[0013] As a preferred technical solution in the present invention, the high-speed powder mixer includes a barrel and a fixing mechanism, the upper end of the barrel is connected to the rotating mechanism, and at least one fixing mechanism is arranged below the rotating mechanism; three annular inner grooves evenly distributed along its axial direction are opened outside the barrel below the rotating mechanism, and a fixing mechanism is arranged between each annular inner groove and the outer tube; the fixing mechanism includes three evenly distributed fixing rods, one end of the fixing rod is fixedly connected to the inner wall of the outer tube, and the other end of the fixing rod is connected to a rotating ball, and the end of the rotating ball away from the fixing rod is arranged in the annular inner groove.

[0014] As a preferred technical solution in the present invention, the rotating mechanism includes a plurality of pneumatic structures evenly distributed around the cylinder, the pneumatic structure including a cylinder, a connecting rod, a support rod and a driving ball, the cylinder is mounted on the inner wall of the outer tube, the connecting rod is vertically arranged, and the upper end of the connecting rod is rotatably connected to the piston rod of the cylinder through a first one-way bearing, the support rod is horizontally arranged, one end of the support rod is rotatably connected to the lower end of the connecting rod through a second one-way bearing, and the rotation direction of the first one-way bearing is the same as the rotation direction of the second one-way bearing; the driving ball is mounted on the other end of the support rod; an annular limit groove is provided on the outer wall of the upper end of the cylinder, and the driving ball matches and abuts against the annular limit groove.

[0015] As a preferred technical solution in the present invention, the alloy powder feeding pipe, the wetting agent spray pipe, the external powder conveying pipe and the air supply pipe are all connected to the rear conveyor, and the rear conveyor is electrically connected to the computer control system.

[0016] As a preferred technical solution in the present invention, the high melting point powder is a base material powder, the powder particle size of the base material powder is 500 mesh, the powder feeding speed is 30 g / min, and the gas flow rate is 30 L / min.

[0017] As a preferred technical solution in the present invention, the alloy powder is composed of 40-50wt.% nickel powder, 20-30wt.% boron powder and 30wt.% copper powder, the powder particle size of the alloy powder is 200 mesh, the powder feeding speed is 15g / min, and the gas flow rate is 60L / min.

[0018] As a preferred technical solution in the present invention, the front powder feeding device is externally connected to a front powder feeder, which is electrically connected to a computer control system. The nozzle of the front powder feeder is a 2mm circular narrow mouth structure from which the powder is ejected in a jet shape.

[0019] As a preferred technical solution in the present invention, the front powder feeding device is a single powder feeding tube, and the powder transported in the single powder feeding tube is composed of 91-100wt.% titanium powder, 0-6wt.% aluminum powder and 0-3wt.% vanadium powder, the powder particle size is 300 mesh, the powder feeding speed is 50g / min, and the gas flow rate is 30L / min.

[0020] A method for welding titanium alloy medium and thick plates using the titanium alloy medium and thick plate powder feeding device described in any one of the above items comprises the following steps:

[0021] 1〉Perform groove processing on the workpiece to be welded, grind the processed welding surface to be flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the back gas protection device;

[0022] 2〉 Arrange the rear powder feeding device, K-TIG welding gun and front powder feeding device in series above the weld of the workpiece to be welded along the welding direction, and install a ventilation protection system close to the rear powder feeding device, wherein the ventilation protection system includes an external ventilation protection cover and an internal ventilation pipe;

[0023] 3〉Adjust the nozzle position of the front powder feeding device so that the powder beam sent by the front powder feeding device is focused to the edge of the welding arc of the K-TIG welding gun, and the angle between the axis of the nozzle of the front powder feeding device and the axis of the K-TIG welding gun is 30-60°; adjust the nozzle position of the rear powder feeding device so that the powder beam sent by the rear powder feeding device is focused to the center of the rear molten pool, and the angle between the axis of the nozzle of the rear powder feeding device and the axis of the K-TIG welding gun is 10-30°;

[0024] 4〉Set welding parameters: select corresponding filling powder according to the material type of the workpiece to be welded, select the nozzle diameter of the rear powder feeding device, the tungsten electrode diameter of the K-TIG welding gun, the nozzle diameter of the front powder feeding device and the powder feeding gas flow rate according to the thickness and groove of the workpiece to be welded;

[0025] 5〉Start welding, make the front powder feeding device, K-TIG welding gun, rear powder feeding device and ventilation protection system work simultaneously, and implement single heat source, front and rear differential speed synchronous powder feeding welding method to weld the workpiece.

[0026] Beneficial effects: Compared with flux-cored wire filling welding, the device of the present invention directly feeds alloy powder into the molten pool by synchronous front and rear powder feeding welding, which greatly reduces welding costs, improves the welding quality of titanium alloy medium and thick plates, and reduces the deformation and residual stress of welded joints. Based on the coordinated control of the computer control system, the device has multiple working modes and can also be used for local repair of welded joints. It has strong welding adaptability. When welding with the device, the powder feeding rate of the front and rear devices can be adjusted in real time to obtain high-quality welds without secondary repair, and the welding efficiency is greatly improved.

[0027] During welding, the present invention allows the post-powder to enter the molten pool in the form of a shell-like structure in which the original repair powder covers the alloy powder through the unique post-powder feeding device and the wetting agent, which greatly improves the utilization rate of the alloy powder, solves the problem of uneven distribution of the alloy powder in the molten pool, and effectively improves the mechanical properties of the joint. The shell-like structure under the action of the wetting agent is explosively stirred inside the molten pool, which enhances the fluidity of the molten pool and makes the distribution of alloy elements more uniform, so that a high-quality welding joint can be obtained.

[0028] In summary, the welding method based on the powder feeding device of titanium alloy medium and thick plates can effectively solve the problems of low alloy powder utilization and uneven distribution in the molten pool in powder feeding welding, and at the same time avoid the occurrence of welding defects, which has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the post-powder feeding device in the present invention;

[0031] Figure 3 It is a structural schematic diagram of the powder mixing mechanism in the present invention. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0033] Example:

[0034] like Figure 1-Figure 3 As shown, this embodiment provides a powder feeding device for titanium alloy medium and thick plates, including a motion mechanism 1, an integrated front powder feeding welding gun 2, a molten pool morphology and temperature monitoring system 3, a computer control system 4, a ventilation protection system 5 and a rear powder feeding device 6. The computer control system 4 is electrically connected to the motion mechanism 1, the integrated front powder feeding welding gun 2, the molten pool morphology and temperature monitoring system 3 and the rear powder feeding device 6, and is used to control the operation of each part and the selection of welding parameters, and at the same time monitor the powder feeding welding quality under the groove in real time. The molten pool morphology and temperature monitoring system 3 includes an infrared imager 7 and a signal processor 8. The signal processor 8 is electrically connected to the infrared imager 7 and the computer control system 4. The infrared imager 7 is used to monitor the temperature field changes and the molten pool surface morphology of the molten pool in the groove of the workpiece 13 to be welded in real time, and transmit them to the computer control system 4 after the signal processor 8.

[0035] The ventilation protection system 5 includes a back gas protection device 9 and a rear gas protection cover 10. The back gas protection device 9 is supported at the lower end of the workpiece 13 to be welded, and the rear gas protection cover 10 is arranged at the upper end of the rear of the workpiece 13 to be welded. A groove located below the molten pool is arranged in the middle of the back gas protection device 9, and a plurality of ventilation holes 11 are densely distributed in the groove to ensure the gas environment on the back of the joint. The protective gas used is an inert gas, and the inert gas is argon, helium or xenon.

[0036] The integrated front powder feeding welding gun 2 includes a K-TIG welding gun 12, a front powder feeding device 14 and a connecting mechanism 15. The connecting mechanism 15 can be a simple mechanical arm. The front powder feeding device 14 can swing left and right with the K-TIG welding gun 12 through the connecting mechanism 15, and can swing along the direction of the K-TIG welding gun 12 through the connecting mechanism 15. The swing amplitude is 0-20°. The K-TIG welding gun 12 is electrically connected to the computer control system 4. The K-TIG welding gun 12 is installed on the motion mechanism 1. The front powder feeding device 14 is connected to the computer control system 4. The connecting mechanism 15 is connected to the K-TIG welding gun 12; the front powder feeding device 14 and the rear powder feeding device 6 are respectively arranged on both sides of the K-TIG welding gun 12, and the rear powder feeding device 6 is located between the K-TIG welding gun 12 and the tail gas protection cover 10. During welding, the K-TIG welding gun 12 swings left and right with the moving mechanism 1, and the front powder feeding device 14 swings synchronously with the K-TIG welding gun 12, and can be adjusted to a certain extent in the up and down directions through the connecting mechanism 15. The moving mechanism 1 can use an existing manipulator.

[0037] Compared with flux-cored wire filling welding, the device of the present invention directly feeds alloy powder into the molten pool by synchronous front and rear powder feeding welding, which greatly reduces welding costs, improves the welding quality of titanium alloy medium and thick plates, and reduces the deformation and residual stress of welded joints. Based on the coordinated control of the computer control system, the device has multiple working modes and can also be used for local repair of welded joints. It has strong welding adaptability. When welding with the device, the powder feeding rate of the front and rear devices can be adjusted in real time to obtain high-quality welds without secondary repair, and the welding efficiency is greatly improved.

[0038] As a preferred implementation scheme in this embodiment, it needs to be further explained that the post-powder feeding device 6 includes an outer tube and a powder feeding mechanism and a powder mixing mechanism arranged in sequence from top to bottom in the outer tube, the powder feeding mechanism includes an alloy powder feeding tube 20 and a wetting agent spray tube 21, an external powder conveying tube 22 and an air supply tube 23 arranged in sequence from near to far on both sides of the alloy powder feeding tube 20, and the distances between the outlet of the alloy powder feeding tube 20, the outlet of the wetting agent spray tube 21, the outlet of the external powder conveying tube 22 and the outlet of the air supply tube 23 and the powder mixing mechanism are arranged in sequence from far to near, and the overall arrangement is gradient, so as to ensure the smoothness of the powder feeding process and the stability of the powder feeding quality; and the outlet of the external powder conveying tube 22 is closer to the powder mixing mechanism than the outlet of the wetting agent spray tube 21, so as to prevent a large amount of external powder from contacting the wetting agent and adhering to each other; The powder mixing mechanism includes a high-speed powder mixer 24 and a rotating mechanism 26 for rotating the high-speed powder mixer 24 in an outer tube, and the rotating mechanism 26 is electrically connected to the computer control system 4; the alloy powder feeding tube 20 conveys alloy powder, the wetting agent spray tube 21 conveys wetting agent, the external powder conveying tube 22 conveys high melting point powder, and the air supply tube 23 conveys inert gas. The gas flow rate when the alloy powder feeding tube 20 delivers powder is higher than the gas flow rate when the external powder conveying tube 22 delivers powder. The alloy powder is sprayed out at a high speed through the alloy powder feeding tube 20, and after being wetted by the wetting agent, the high melting point powder is adhered to the surface to form a shell-like structure and enters the powder mixing mechanism for further mixing and drying, and the air supply tube 23 can provide power for the formed shell-like structure, so that it can enter the powder mixing mechanism more smoothly and at a high speed.

[0039] The wetting agent is composed of 20-40wt.% sodium chloride and 60-80wt.% quartz glass fiber, and the gas flow rate is 70L / min. The working principle of the wetting agent is as follows: after being wetted by the wetting agent, the powder sprayed out from the rear powder feeding device is the shell structure of the base material repair powder coating the alloy powder. After the shell structure enters the molten pool, the surface metal powder melts and quickly transfers the heat to the inside. The low-boiling point sodium chloride is quickly heated and gasified, forming an internal and external pressure difference so that the shell structure explodes in a small range in the molten pool, stirring the molten pool while uniformly sending the alloy powder to the inside of the molten pool to enhance the performance of the weld. Further, the quartz glass fiber is decomposed into silicon and oxygen at high temperature. Silicon can further improve the fluidity of the molten pool, which is beneficial to the formation of the weld. At the same time, the generated oxygen is fully discharged from the molten pool under the impact force generated by the atmospheric airflow of the powder feeding device and the explosion of the shell structure, which ultimately helps to improve the distribution of alloy elements in the molten pool and optimize the weld formability by enhancing the fluidity of the molten pool. It should be noted that the titanium alloy medium and thick plate powder feeding device also includes a power supply 16 for power supply.

[0040] The rear powder feeding device 6 can be independent of the integrated front powder feeding welding gun 2, and can adjust the powder feeding in real time by swinging left and right. Its swing range is determined by the temperature field of the molten pool. After real-time temperature monitoring, the powder is accurately sent to the rear molten pool 17 at 2000℃-3000℃ behind the heat source; its powder feeding rate is determined by the surface morphology of the molten pool. Before welding the next weld, if the previous weld is detected to have unfused or poor weld quality, the powder feeding rate near this place will be appropriately adjusted to ensure the welding quality. The actual powder feeding adopts the differential powder feeding method. The spray pipes on both sides of the outlet of the alloy powder feeding tube 20 spray the wetting agent at the same time. The wetting agent is composed of sodium chloride and quartz glass fiber. The alloy powder is sprayed out at high speed through the alloy powder feeding tube 20. After wetting, the high melting point powder is bonded to the surface to form a shell-like structure and enter the powder mixing mechanism for further mixing and drying. Finally, it is spirally sprayed into the molten pool to ensure that the alloy powder can effectively enter the molten pool and be evenly distributed in the molten pool, which plays a role in micro-alloying of the welding joint.

[0041] As a preferred implementation scheme in this embodiment, it is necessary to further explain that the high-speed powder mixer 24 includes a barrel 25 and a fixing mechanism 30. The upper end of the barrel 25 is connected to the rotating mechanism 26 so that the barrel 25 is driven to rotate by the rotating mechanism 26, thereby further mixing and drying the shell-like structure entering the powder mixing mechanism. At least one fixing mechanism 30 is arranged below the rotating mechanism 26. The barrel 25 below the rotating mechanism 26 is provided with three annular inner grooves 32 evenly distributed along its axial direction, and each annular inner groove 32 is provided with a plurality of annular grooves 32. 2 and the outer tube are provided with a fixing mechanism 30; the fixing mechanism 30 comprises three evenly distributed fixing rods 31, one end of the fixing rod 31 is fixedly connected to the inner wall of the outer tube, and the other end of the fixing rod 31 is connected to a rotating ball 29, preferably the rotating ball 29 is movably connected to the other end of the fixing rod 31 in an embedded manner, and the end of the rotating ball 29 away from the fixing rod 31 is arranged in an annular inner groove 32 to provide stable support and limit, thereby maintaining the stability of the cylinder 25 through the fixing mechanism 30, and reducing the friction when the cylinder 25 rotates.

[0042] As a preferred implementation scheme in this embodiment, it needs to be further explained that the rotating mechanism 26 includes a plurality of pneumatic structures 27 evenly distributed around the cylinder 25, the pneumatic structure 27 includes a cylinder 33, a connecting rod 34, a support rod 35 and a driving ball 36, the cylinder 33 is installed on the inner wall of the outer tube, the connecting rod 34 is vertically arranged, and the upper end of the connecting rod 34 is rotatably connected to the piston rod 28 of the cylinder 33 through a first one-way bearing, the support rod 35 is horizontally arranged, and one end of the support rod 35 is rotatably connected to the lower end of the connecting rod 34 through a second one-way bearing, and the rotation direction of the first one-way bearing is the same as the rotation direction of the second one-way bearing; the driving ball 36 The ball 36 is installed at the other end of the support rod 35; an annular limiting groove is provided on the outer wall of the upper end of the cylinder 25, and the driving ball 36 is matched and abutted with the annular limiting groove. In practice, the cylinder 33 drives the piston rod to extend and retract. When the piston rod slides outward, the supporting rod 35 is driven to rotate through the connecting rod 34, and the supporting rod 35 drives the driving ball 36 to rotate. When the driving ball 36 contacts the annular limiting groove, the cylinder 25 can be driven by friction. Multiple air pressure structures 27 work alternately to ensure that the cylinder 25 can rotate continuously as needed, and the air supply and exhaust of the cylinder 33 are controlled by the computer control system 4 to ensure the high-speed and stable rotation of the cylinder 25. In addition, the computer control system 4 optimizes the powder feeding rate during the welding process according to the real-time monitoring data of the infrared imager, realizes the real-time adjustment of the powder feeding process during the welding process, and ensures the welding quality. The powder feeding system of the post-powder feeding device can realize the combination of synchronous powder feeding and shell-like structure, and the powder mixing mechanism can further ensure the density of the powder on the surface of the shell-like structure, and at the same time play a drying role.

[0043] As a preferred implementation scheme in this embodiment, it needs to be further explained that the alloy powder feeding pipe 20, the wetting agent spray pipe 21, the external powder conveying pipe 22 and the air supply pipe 23 are all connected to the rear conveyor 19, and the rear conveyor 19 is electrically connected to the computer control system 4 to facilitate the control of the working conditions of each pipeline.

[0044] As a preferred implementation scheme in this embodiment, it is necessary to further explain that the high melting point powder is a base material powder, the present invention is a titanium alloy powder, which is the same material as the workpiece to be welded, the powder particle size of the base material powder is 500 mesh, the powder feeding speed is 30g / min, and the gas flow rate is 30L / min; the alloy powder is composed of 40-50wt.% nickel powder, 20-30wt.% boron powder and 30wt.% copper powder, the powder particle size of the alloy powder is 200 mesh, the powder feeding speed is 15g / min, and the gas flow rate is 60L / min, boron mainly plays the role of grain refinement, nickel and copper can play the role of improving corrosion resistance, in addition, nickel can improve weld plasticity, copper can improve weld strength, and the specific addition amount is determined by the base material composition. Preferably, for pure titanium plate, the alloy powder uses 40wt.% nickel powder, 30wt.% boron powder and 30wt.% copper powder, and the powder particle size is 200 mesh. For TC4 plate, the alloy powder uses 50wt.% nickel powder, 20wt.% boron powder, and 30wt.% copper powder.

[0045] As a preferred implementation scheme in this embodiment, it needs to be further explained that the front powder feeding device 14 is externally connected to a front powder feeder 18, and the front powder feeder 18 is electrically connected to the computer control system 4. The nozzle of the front powder feeder 18 is a 2mm circular narrow mouth structure from which the ejected powder is ejected in a jet shape. The swing amplitude is determined by the arc morphology. After the infrared imager monitors the arc morphology in real time and feeds back to the computer control system 4, the swing amplitude is adjusted to feed the powder from the edge of the arc.

[0046] As a preferred implementation scheme in this embodiment, it is necessary to further explain that the front powder feeding device 14 is a single powder feeding tube, with a large powder feeding amount and a small gas flow rate, which ensures the powder feeding efficiency and does not affect the heat source. The powder transported in the single powder feeding tube is composed of 91-100wt.% titanium powder, 0-6wt.% aluminum powder and 0-3wt.% vanadium powder, the powder particle size is 300 mesh, the powder feeding speed is 50g / min, and the gas flow rate is 30L / min. The front powder feeding device 14 mainly plays the role of replenishing the molten pool. According to the difference of the welded parent material, the filling powder content is different. The aluminum content can be based on the nominal composition ratio of the parent material, and the vanadium content is 1wt.% less than the nominal composition ratio of the parent material. Preferably, for pure titanium plate, 100% titanium powder is the best, and for TC4 plate, 91% titanium powder, 6% aluminum powder and 3% vanadium powder are the best.

[0047] The present invention also provides a welding method for welding titanium alloy medium and thick plates using the titanium alloy medium and thick plate powder feeding device, comprising the following steps:

[0048] 1〉Perform groove processing on the workpiece 13 to be welded, grind the welded surface to be smooth, clean the surface oxides and oil stains, and finally install the workpiece 13 to be welded on the back gas protection device 9;

[0049] 2〉arrange the rear powder feeding device 6, the K-TIG welding gun 12 and the front powder feeding device 14 in series above the weld of the workpiece 13 to be welded along the welding direction, and install the ventilation protection system 5 near the rear powder feeding device 6, wherein the ventilation protection system 5 includes an external ventilation protection cover and an internal ventilation pipe;

[0050] 3〉Adjust the nozzle position of the front powder feeding device 14 so that the powder beam sent by the front powder feeding device 14 is focused to the edge of the welding arc of the K-TIG welding gun 12, and the angle between the axis of the nozzle of the front powder feeding device 14 and the axis of the K-TIG welding gun 12 is 30-60°; adjust the nozzle position of the rear powder feeding device 3 so that the powder beam sent by the rear powder feeding device 6 is focused to the center of the rear molten pool 17, and the angle between the axis of the nozzle of the rear powder feeding device 6 and the axis of the K-TIG welding gun 12 is 10-30°;

[0051] 4〉Set welding parameters: select corresponding filling powder according to the material type of the workpiece 13 to be welded, and select the nozzle diameter of the rear powder feeding device 6, the nozzle diameter of the K-TIG welding gun 12, the nozzle diameter of the front powder feeding device 14 and the powder feeding gas flow rate according to the thickness and groove of the workpiece 13 to be welded;

[0052] 5> Start welding, make the front powder feeding device 14, K-TIG welding gun 12, rear powder feeding device 6 and ventilation protection system 5 work simultaneously, and implement single heat source, front and rear differential synchronous powder feeding welding method to weld the workpiece 13 to be welded.

[0053] During welding, the present invention allows the post-powder to enter the molten pool in the form of a shell-like structure in which the original repair powder covers the alloy powder through the unique post-powder feeding device and the wetting agent, which greatly improves the utilization rate of the alloy powder, solves the problem of uneven distribution of the alloy powder in the molten pool, and effectively improves the mechanical properties of the joint. The shell-like structure under the action of the wetting agent is explosively stirred inside the molten pool, which enhances the fluidity of the molten pool and makes the distribution of alloy elements more uniform, so that a high-quality welding joint can be obtained.

[0054] Below, pure argon is used as a specific protective gas, and the present invention will be further described according to Example 1 and Example 2.

[0055] Experimental Example 1:

[0056] In this experimental example, a TC4 thick plate with a thickness of 20 mm is selected as the workpiece to be welded. The K-TIG welding gun 12 is used for welding under argon protection. The gas flow rate of the ventilation protection device is 25 L / min. The specific welding steps are as follows:

[0057] 1〉Perform V-shaped groove processing on the workpiece to be welded, with a groove angle of 60° and a groove depth of 8mm, and grind the processed welding surface to be flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the welding tooling;

[0058] 2〉Use visual inspection method to inspect the required welding parts, and adjust the positions of the integrated front powder feeding welding gun and the rear swing powder feeding device with the help of the motion mechanism, adjust the nozzle position of the front powder feeding device so that the powder beam sent by the front powder feeding device is focused on the edge of the arc, and the angle between the axis of the nozzle and the axis of the welding gun is 60°; adjust the position of the nozzle of the rear powder feeding device so that the powder beam sent by the rear powder feeding device is focused on the center of the rear molten pool, and the angle between the axis of the nozzle and the axis of the welding gun is 10°;

[0059] 3〉Weigh the required filling powder according to the proportion, mix and dry it through the powder mixing mechanism, and then put it into the corresponding powder sprayer device, and prepare the required wetting agent at the same time. The mesh number of the powder filled in the front powder feeding device is 300 mesh, and the powder ratio is: 91wt.% titanium powder, 6wt.% aluminum powder, 3wt.% vanadium powder, which ensures the strength of the weld and increases the plasticity to a certain extent; the upper and lower tubes in the rear powder feeding device are filled with powder with a nominal composition of Ti-6Al-4V, with a mesh number of 500 mesh, and the middle powder feeding tube is filled with powder with a mesh number of 200 mesh, and the powder ratio is: 50wt.% nickel powder, 20wt.% boron powder, 30wt.% copper powder, which can make the welding effect better. The wetting agent is composed of 30wt.% NaCl solution and 70wt.% quartz glass fiber.

[0060] 4〉According to the intelligent welding expert database, the optimal welding process and parameters are obtained, and the base welding current is set to 500A, the base welding speed is set to 200mm / min, and the filling welding current is set to 200A. Under this current, both the welding efficiency and the powder feeding efficiency can be guaranteed. The filling welding speed is 120mm / min; the powder feeding speed of the front powder feeding device is 40g / min, and the gas flow rate is 20L / min; the upper and lower powder feeding pipes of the rear powder feeding device are set to have a powder feeding speed of 25g / min and a gas flow rate of 40L / min, and the powder feeding speed of the middle powder feeding pipe is set to 10g / min and the gas flow rate is 60L / min;

[0061] 5> Start the computer control system 4. In practice, the computer control system 4 is used to control each device, so that the equipment operation is more accurate, and the front powder feeding device, heat source, rear powder feeding device and ventilation protection device work at the same time, and start welding;

[0062] 6〉Based on the weld quality and groove size under groove conditions, the welding parameters are selected based on the intelligent welding expert library system, and the welding parameters, powder feeding speed and device swing speed are adjusted in real time to ensure the quality and stability of the weld;

[0063] 7〉Before welding the next weld, monitor the previous weld for any lack of fusion or poor weld quality, and appropriately adjust the powder feeding rate near that location to ensure welding quality.

[0064] Comparative Example 1:

[0065] In this comparative example, a TC4 thick plate with a thickness of 20 mm is selected as the workpiece to be welded, and a K-TIG welding gun 12 is used for welding under argon protection, with a gas flow rate of 25 L / min. The specific welding steps are as follows:

[0066] 1〉Perform V-shaped groove processing on the workpiece to be welded, with a groove angle of 60° and a groove depth of 8mm, and grind the processed welding surface to be flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the welding tooling;

[0067] 2〉Use visual inspection method to inspect the required welding parts, and adjust the positions of the integrated front powder feeding welding gun and the rear swing powder feeding device with the help of the motion mechanism, adjust the nozzle position of the front powder feeding device so that the powder beam sent by the front powder feeding device is focused to the edge of the arc, and the angle between the axis of the nozzle and the axis of the welding gun is 60°; adjust the position of the nozzle of the rear powder feeding device so that the powder beam sent by the rear powder feeding device is focused to the center of the rear molten pool, and the angle between the axis of the nozzle and the axis of the welding gun is 10°;

[0068] 3〉Weigh the required filling powder according to the proportion, mix and dry it through the powder mixing mechanism, and then put it into the corresponding powder sprayer device. No wetting agent is added during the powder feeding process. The mesh number of the powder filled in the front powder feeding device is 300 mesh, and the powder ratio is: 91wt.% titanium powder, 6wt.% aluminum powder, 3wt.% vanadium powder; the powder filled in the upper and lower tubes of the rear powder feeding device is a powder with a nominal composition of Ti-6Al-4V, with a mesh number of 500 mesh, and the powder filled in the middle powder feeding tube has a mesh number of 200 mesh, and the powder ratio is: 50wt.% nickel powder, 20wt.% boron powder, 30wt.% copper powder,

[0069] 4〉According to the intelligent welding expert database, the optimal welding process and parameters are obtained, and the base welding current is set to 500A, the base welding speed is set to 200mm / min, the filling welding current is set to 200A, and the filling welding speed is set to 120mm / min; the powder feeding speed of the front powder feeding device is set to 40g / min, and the gas flow rate is set to 20L / min; the upper and lower powder feeding pipes of the rear powder feeding device are set to have a powder feeding speed of 25g / min and a gas flow rate of 40L / min, and the powder feeding speed of the middle powder feeding pipe is set to 10g / min and the gas flow rate is set to 60L / min;

[0070] 5> Start the computer control system 4. In practice, the computer control system 4 is used to control each device, so that the equipment operation is more accurate, and the front powder feeding device, heat source, rear powder feeding device and ventilation protection device work at the same time to start welding.

[0071] 6〉Based on the weld quality and groove size under groove conditions, the welding parameters are selected based on the intelligent welding expert library system, and the welding parameters, powder feeding speed and device swing speed are adjusted in real time to ensure the quality and stability of the weld.

[0072] 7〉Before welding the next weld, monitor the previous weld for any lack of fusion or poor weld quality, and appropriately adjust the powder feeding rate near that location to ensure welding quality.

[0073] Comparative Example 2:

[0074] In this comparative example, a TC4 thick plate with a thickness of 20 mm is selected as the workpiece to be welded, and a K-TIG welding gun 12 is used for welding under argon protection, with a gas flow rate of 25 L / min. The specific welding steps are as follows:

[0075] 1〉Perform V-shaped groove processing on the workpiece to be welded, with a groove angle of 60° and a groove depth of 8mm, and grind the processed welding surface to be flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the welding tooling;

[0076] 2〉Arrange the welding gun and wire feeding device in series above the weld along the welding direction, install the ventilation protection device close to the welding gun, and perform welding ventilation protection in real time.

[0077] 3〉Adjust the gun head position of the wire feeding device, the included angle between the axis of the gun head and the axis of the welding gun is 60°, so that the tip of the welding wire sent by the wire feeding device is coupled with the center of the welding gun;

[0078] 4〉Set welding parameters, the base welding current is 510A, the base welding speed is 200mm / min, the filling welding current is 230A, and the filling welding speed is 120mm / min; the welding wire used is Ti-6Al-3V welding wire with a diameter of 1.2mm, and the wire feeding speed is 4000mm / min;

[0079] 5〉Start wire feeding and filling welding.

[0080] Experimental Example 2:

[0081] In this experimental example, a TA2 medium-thick plate with a thickness of 12 mm was selected as the workpiece to be welded. A K-TIG welding torch 12 was used for flat plate surfacing under argon protection. The gas flow rate of the ventilation protection device was 25 L / min. The specific welding steps were as follows:

[0082] 1〉Grind the welding surface until it is flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the welding tool;

[0083] 2〉Use visual inspection method to inspect the required welding parts, and adjust the positions of the integrated front powder feeding welding gun and the rear swing powder feeding device with the help of the motion mechanism, adjust the nozzle position of the front powder feeding device so that the powder beam sent by the front powder feeding device is focused to the edge of the arc, and the angle between the axis of the nozzle and the axis of the welding gun is 60°; adjust the position of the nozzle of the rear powder feeding device so that the powder beam sent by the rear powder feeding device is focused to the center of the rear molten pool, and the angle between the axis of the nozzle and the axis of the welding gun is 10°;

[0084] 3〉Weigh the required filling powder according to the proportion, mix and dry it through the powder mixing mechanism, and then put it into the corresponding powder sprayer device, and prepare the required wetting agent at the same time. The filling powder in the front powder feeding device is pure titanium powder with a mesh size of 300 mesh; the filling powder in the upper and lower tubes of the rear powder feeding device is pure titanium powder with a nominal composition of 500 mesh, and the filling powder in the middle powder feeding tube has a mesh size of 200 mesh. The powder ratio is: 40wt.% nickel powder, 30wt.% boron powder and 30wt.% copper powder, and the wetting agent is composed of 30wt.% NaCl solution and 70wt.% quartz glass fiber.

[0085] 4〉According to the intelligent welding expert database, the best welding process and parameters are obtained, and the welding current is set to 580A and the welding speed is set to 300mm / min; the powder feeding speed of the front powder feeding device is set to 40g / min and the gas flow rate is set to 20L / min; the powder feeding speed of the upper and lower powder feeding pipes of the rear powder feeding device is set to 25g / min and the gas flow rate is set to 40L / min, and the powder feeding speed of the middle powder feeding pipe is set to 10g / min and the gas flow rate is set to 60L / min;

[0086] 5> Start the computer control system 4. In practice, the computer control system 4 is used to control each device, so that the equipment operation is more accurate, and the front powder feeding device, heat source, rear powder feeding device and ventilation protection device work at the same time to start welding.

[0087] Comparative Example 3:

[0088] In this comparative example, a TA2 medium-thick plate with a thickness of 12 mm is selected as the workpiece to be welded, and a K-TIG welding gun 12 is used for flat plate surfacing under argon protection, with a gas flow rate of 25 L / min. The specific welding steps are as follows:

[0089] 1〉Grind the welding surface until it is flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the welding tool;

[0090] 2〉Arrange the welding gun and wire feeding device in series above the weld along the welding direction, install the ventilation protection device close to the welding gun, and perform welding ventilation protection in real time.

[0091] 3〉Adjust the gun head position of the wire feeding device, the included angle between the axis of the gun head and the axis of the welding gun is 60°, so that the tip of the welding wire sent by the wire feeding device is coupled with the center of the welding gun;

[0092] 4〉Set welding parameters, welding current is 620A, welding speed is 300mm / min; the welding wire used is Ti-6Al-3V welding wire with a diameter of 1.2mm, and the wire feeding speed is 4000mm / min;

[0093] 5〉Start wire feeding and filling welding.

[0094] The macroscopic morphology and mechanical properties of the welded joints of the embodiment and the comparative example are shown in Table 1 and Table 2, respectively. It can be seen from the table that the welding method based on the titanium alloy medium and thick plate powder feeding welding device of the present invention can effectively reduce the excess height of the surface and back of the welded joint while ensuring the excellent performance of the welded joint, and accurately control it within 1 mm. In addition, the overall performance of the welded joint obtained by this method is better than that of the welded joint obtained by wire feeding welding under the same process.

[0095] Table 1: Comparison of macroscopic morphology of welded joints

[0096]

[0097]

[0098] Table 2: Comparison of welding joint performance

[0099]

[0100] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A powder feeding device for titanium alloy medium and thick plates, characterized in that: It includes a motion mechanism, an integrated front powder feeding welding gun, a molten pool morphology and temperature monitoring system, a computer control system, a ventilation protection system and a rear powder feeding device. The computer control system is electrically connected to the motion mechanism, the integrated front powder feeding welding gun, the molten pool morphology and temperature monitoring system and the rear powder feeding device. The molten pool morphology and temperature monitoring system includes an infrared imager and a signal processor. The infrared imager is used to monitor the temperature field change and the molten pool surface morphology of the molten pool in the groove of the workpiece to be welded in real time. The signal processor is electrically connected to the infrared imager and the computer control system. The ventilation protection system comprises a back gas protection device and a rear gas protection cover, wherein the back gas protection device is supported at the lower end of the workpiece to be welded, and the rear gas protection cover is arranged at the upper end of the rear of the workpiece to be welded, and a groove located below the molten pool is arranged in the middle of the back gas protection device, and a plurality of ventilation holes are densely distributed in the groove; The integrated front powder feeding welding gun includes a K-TIG welding gun, a front powder feeding device and a connecting mechanism. The K-TIG welding gun is electrically connected to a computer control system. The K-TIG welding gun is installed on a motion mechanism. The front powder feeding device is connected to the K-TIG welding gun through a connecting mechanism. The front powder feeding device and the rear powder feeding device are respectively arranged on both sides of the K-TIG welding gun, and the rear powder feeding device is located between the K-TIG welding gun and the rear gas protection cover.

2. The titanium alloy medium and thick plate powder feeding device according to claim 1, characterized in that: The post-powder feeding device comprises an outer tube and a powder feeding mechanism and a powder mixing mechanism arranged in sequence from top to bottom in the outer tube, the powder feeding mechanism comprises an alloy powder feeding tube and a wetting agent spray tube, an external powder conveying tube and an air supply tube arranged in sequence from near to far on both sides of the alloy powder feeding tube, and the distances between the alloy powder feeding tube outlet, the wetting agent spray tube outlet, the external powder conveying tube outlet and the air supply tube outlet and the powder mixing mechanism are arranged in sequence from far to near; the powder mixing mechanism comprises a high-speed powder mixer and a rotating mechanism for rotating the high-speed powder mixer in the outer tube, and the rotating mechanism is electrically connected to a computer control system; the alloy powder feeding tube Alloy powder is transported in the powder tube, wetting agent is transported in the wet agent spray tube, high melting point powder is transported in the external powder transport tube, inert gas is transported in the air delivery tube, the gas flow rate of the alloy powder delivery tube when delivering powder is higher than the gas flow rate of the external powder delivery tube when delivering powder, the alloy powder is sprayed out at high speed through the alloy powder delivery tube, and after being wetted by the wetting agent, the high melting point powder is adhered to the surface to form a shell-like structure and enter the powder mixing mechanism for further mixing and drying; the wetting agent is composed of 20-40wt.% of sodium chloride and 60-80wt.% of quartz glass fiber, and the gas flow rate is 70L / min.

3. The titanium alloy medium and thick plate powder feeding device according to claim 2, characterized in that: The high-speed powder mixer comprises a barrel and a fixing mechanism, wherein the upper end of the barrel is connected to the rotating mechanism, and at least one fixing mechanism is arranged below the rotating mechanism; three annular inner grooves evenly distributed along the axial direction are opened outside the barrel below the rotating mechanism, and a fixing mechanism is arranged between each annular inner groove and the outer tube; the fixing mechanism comprises three evenly distributed fixing rods, one end of the fixing rod is fixedly connected to the inner wall of the outer tube, and the other end of the fixing rod is connected to a rotating ball, and the end of the rotating ball away from the fixing rod is arranged in the annular inner groove.

4. The titanium alloy medium and thick plate powder feeding device according to claim 2 or 3, characterized in that: The rotating mechanism includes a plurality of pneumatic structures evenly distributed around the cylinder, the pneumatic structure includes a cylinder, a connecting rod, a support rod and a driving ball. The cylinder is mounted on the inner wall of the outer tube, the connecting rod is vertically arranged, and the upper end of the connecting rod is rotatably connected to the piston rod of the cylinder through a first one-way bearing, the support rod is horizontally arranged, one end of the support rod is rotatably connected to the lower end of the connecting rod through a second one-way bearing, and the rotation direction of the first one-way bearing is the same as that of the second one-way bearing; the driving ball is mounted on the other end of the support rod; an annular limit groove is provided on the outer wall of the upper end of the cylinder, and the driving ball matches and abuts against the annular limit groove.

5. The titanium alloy medium and thick plate powder feeding device according to claim 2, characterized in that: The alloy powder feeding pipe, the wetting agent spray pipe, the external powder conveying pipe and the air supply pipe are all connected with the rear conveyor, and the rear conveyor is electrically connected with the computer control system.

6. The titanium alloy medium and thick plate powder feeding device according to claim 2, characterized in that: The high melting point powder is a base material powder, the powder particle size of the base material powder is 500 mesh, the powder feeding speed is 30 g / min, and the gas flow rate is 30 L / min.

7. The titanium alloy medium and thick plate powder feeding device according to claim 6, characterized in that: The alloy powder consists of 40-50wt.% nickel powder, 20-30wt.% boron powder and 30wt.% copper powder. The alloy powder has a particle size of 200 meshes, a powder feeding speed of 15g / min, and a gas flow rate of 60L / min.

8. The titanium alloy medium and thick plate powder feeding device according to claim 1, characterized in that: The front powder feeding device is externally connected to a front powder feeder, which is electrically connected to a computer control system. The nozzle of the front powder feeder is a 2mm round narrow mouth structure from which the ejected powder is ejected in a jet shape.

9. The titanium alloy medium and thick plate powder feeding device according to claim 1 or 8, characterized in that: The front powder feeding device is a single powder feeding tube. The powder transported in the single powder feeding tube consists of 91-100wt.% titanium powder, 0-6wt.% aluminum powder and 0-3wt.% vanadium powder. The powder particle size is 300 mesh, the powder feeding speed is 50g / min, and the gas flow rate is 30L / min.

10. A method for welding titanium alloy medium and thick plates using the titanium alloy medium and thick plate powder feeding device according to claim 2, 3, 5, 6 or 7, characterized in that: The steps include: 1〉Perform groove processing on the workpiece to be welded, grind the processed welding surface to be flat and smooth, clean the surface oxides and oil stains, and finally install the workpiece to be welded on the back gas protection device; 2〉 Arrange the rear powder feeding device, K-TIG welding gun and front powder feeding device in series above the weld of the workpiece to be welded along the welding direction, and install a ventilation protection system close to the rear powder feeding device, wherein the ventilation protection system includes an external ventilation protection cover and an internal ventilation pipe; 3〉Adjust the nozzle position of the front powder feeding device so that the powder beam sent by the front powder feeding device is focused to the edge of the welding arc of the K-TIG welding gun, and the angle between the axis of the nozzle of the front powder feeding device and the axis of the K-TIG welding gun is 30-60°; adjust the nozzle position of the rear powder feeding device so that the powder beam sent by the rear powder feeding device is focused to the center of the rear molten pool, and the angle between the axis of the nozzle of the rear powder feeding device and the axis of the K-TIG welding gun is 10-30°; 4〉Set welding parameters: select corresponding filling powder according to the material type of the workpiece to be welded, select the nozzle diameter of the rear powder feeding device, the tungsten electrode diameter of the K-TIG welding gun, the nozzle diameter of the front powder feeding device and the powder feeding gas flow rate according to the thickness and groove of the workpiece to be welded; 5〉Start welding, make the front powder feeding device, K-TIG welding gun, rear powder feeding device and ventilation protection system work simultaneously, and implement single heat source, front and rear differential speed synchronous powder feeding welding method to weld the workpiece.

Images