P91 steam pipeline welding positioning device and welding method

Abstract

The invention relates to a P91 steam pipeline welding positioning device and a welding method, and belongs to the technical field of high-temperature and high-pressure steam pipeline welding. The device comprises a mounting frame, clamping and fixing discs are rotationally arranged on the two sides of the mounting frame, clamping and fixing pieces are evenly arranged on the inner peripheries of the clamping and fixing discs, the clamping and fixing discs are used for driving the clamping and fixing pieces to move in the radial direction, a positioning disc is fixedly arranged in the middle of the mounting frame, positioning pieces are evenly arranged on the inner periphery of the positioning disc, the positioning disc is used for driving the positioning pieces to move in the radial direction, and a driving assembly is further arranged on the mounting frame. The clamping and fixing discs are matched with the clamping and fixing pieces to clamp and fix the steam pipelines, the positioning discs are matched with the positioning pieces to position grooves of the two pipelines, so that the grooves are subjected to multi-layer bottoming electric arc welding and submerged arc welding, the pair of clamping and fixing discs and the pipelines are driven by the driving assembly to synchronously rotate, convenience is provided for groove welding, and the welding efficiency is improved. And the automation degree, the production efficiency and the welding quality consistency of pipeline welding are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature and high-pressure steam pipeline welding, and in particular relates to a P91 steam pipeline welding positioning device and a welding method. Background Art

[0002] As a high-alloy steel material, P91 steel is widely used in high-temperature and high-pressure steam pipelines and is known for its excellent high-temperature strength and oxidation resistance. Common methods for welding P91 pipes include manual metal arc welding (SMAW), tungsten inert gas welding (GTAW) and automatic submerged arc welding (SAW). Manual arc welding relies on the welder holding an electrode for welding and is suitable for small-scale production and repair work. Tungsten inert gas welding uses tungsten electrodes and inert gas (usually argon) for protection to maintain the weld quality and surface finish during the welding process. Automatic submerged arc welding uses automated equipment to form a molten pool and fill it with welding wire during the welding process, which is suitable for large-scale production and situations where high welding speeds are required.

[0003] Although P91 steam pipe welding has been used for many years, there are still the following technical challenges. First, the existing P91 steam pipe welding is not sufficiently automated. Currently, there are still few automated welding devices used in P91 pipe welding. Most welding still relies on manual operation, which limits production efficiency and the stability of welding quality. Second, it is difficult to control the welding position. During the welding process, the welding head usually needs to move circumferentially along the pipe groove, which increases the complexity and technical requirements of the operation, and also affects the improvement of welding speed and efficiency. In view of the above technical challenges, it can be seen that there is an urgent need to design a welding positioning device and a welding method in the prior art to improve the automation level, production efficiency and consistency of welding quality of P91 steam pipe welding. Summary of the invention

[0004] The purpose of the present invention is to provide a P91 steam pipe welding positioning device and a welding method in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A P91 steam pipe welding positioning device comprises a mounting frame, wherein clamping discs are rotatably provided on both sides of the mounting frame, and clamping pieces are evenly provided on the inner circumference of the clamping discs, and the clamping discs are used to drive the clamping pieces to move radially so that two groups of the clamping pieces clamp two P91 steam pipes, a positioning disc is fixedly provided in the middle of the mounting frame, and positioning pieces are evenly provided on the inner circumference of the positioning disc, and the positioning disc is used to drive the positioning pieces to move radially so that one group of the positioning pieces can position the grooves of the two P91 steam pipes, and the mounting frame is also provided with a driving assembly for driving the two clamping discs to rotate. During the welding process, the pipe body of the P91 steam pipe is clamped by the clamping disc in cooperation with the clamping piece, and the grooves of the two pipes are positioned by the positioning disc in cooperation with the positioning piece, so that the grooves of the two pipes are aligned, so as to perform multi-layer bottom arc welding and submerged arc welding on the pipe grooves. During the welding process, the two clamping discs are driven to rotate by the driving assembly, and the two clamping discs drive the two pipes to rotate synchronously through the clamping pieces.

[0007] As a further optimization solution of the present invention, two pairs of rollers are provided at one end of the positioning member facing the axis of the positioning plate.

[0008] As a further optimization scheme of the present invention, the clamping plate includes a first plate body, a second plate body detachably connected to the first plate body, a driving ring rotatably arranged on the inner side of the second plate body, a plurality of first gears and a first transmission plate evenly arranged along the circumference of the second plate body, a second transmission plate arranged on one side of the first transmission plate, a rod-shaped component penetrating the first transmission plate, and a power component for providing power to the driving ring, the first gear corresponds to the first transmission plate one by one, and the first gear is meshed and connected between the driving ring and the first transmission plate, when the first transmission plate moves along the rod-shaped component, it drives the second transmission plate to slide radially along the second plate body, and the structure of the positioning plate is the same as that of the clamping plate.

[0009] As a further optimization scheme of the present invention, the second disk body is composed of a mounting disk, a first side wall fixed to the inner edge of one side of the mounting disk, a second side wall fixed to the outer edge of one side of the mounting disk, and a connecting ring fixed to the other side of the mounting disk, the second transmission plate is slidably connected to the first side wall, and the connecting ring is rotatably arranged on the top of the mounting frame.

[0010] As a further optimization scheme of the present invention, the plurality of rod-shaped components are divided into a screw and multiple optical axes, the power component includes a first motor and a gear set arranged between the output end of the first motor and the screw, and a thread groove is provided in the first transmission plate corresponding to the screw.

[0011] As a further optimization solution of the present invention, the plurality of rod-shaped components are all optical axes, and the power component is a power source for driving the drive ring or one of the first gears to rotate.

[0012] As a further optimization scheme of the present invention, the inner side of the drive ring and the first transmission plate are both provided with convex teeth corresponding to the first gear, the first side wall is provided with a notch corresponding to the second transmission plate, the mounting plate is provided with a limiter for limiting the rotation of the first transmission plate, the first transmission plate is evenly provided with strip grooves, and the second transmission plate is provided with strip teeth corresponding one-to-one to the strip grooves.

[0013] As a further optimization scheme of the present invention, the driving assembly includes a second motor, a worm fixed at the output end of the second motor, a worm wheel meshingly connected to one side of the worm, a rotating shaft passing through the mounting frame, and second gears fixed at both ends of the rotating shaft, and the connecting rings of the two clamping plates are respectively provided with gear rings meshing with the two second gears.

[0014] As a further optimization scheme of the present invention, one of the clamping members is a pressure measuring structure, and the pressure measuring structure includes a mounting seat fixedly arranged on one side of the second transmission plate, and a pressure sensor and a pressure plate arranged at one end of the mounting seat facing the axis of the clamping disk, and the pressure sensor is fixedly arranged between the mounting seat and the pressure plate.

[0015] A P91 steam pipeline welding method comprises the following steps:

[0016] S1. Preheat the P91 steam pipe before welding to raise the temperature of the P91 steam pipe to a preheating temperature range;

[0017] S2. Position the two P91 steam pipes using the welding positioning device according to any one of claims 1 to 9, respectively pass the two P91 steam pipes through the two clamping plates, and align the grooves of the two P91 steam pipes to the inner side of the positioning plate, and the clamping plate and the positioning plate respectively drive the clamping piece and the positioning piece to abut against the P91 steam pipes;

[0018] S3, rotating the clamping plate, the clamping piece and the P91 steam pipe by the driving assembly, performing multi-layer bottom arc welding at the groove position of the P91 steam pipe, and during the welding process, the interlayer temperature is not lower than the lower limit temperature of the preheating temperature range;

[0019] S4. After the multi-layer bottom arc welding, the driving assembly continues to rotate the P91 steam pipe, and performs submerged arc welding on the groove position of the P91 steam pipe through the automatic submerged arc welding equipment;

[0020] S5. After the submerged arc welding is completed, the P91 steam pipeline is subjected to post-weld heat treatment, so that the temperature of the P91 steam pipeline is reduced to the post-weld heat treatment temperature range, and the temperature is kept until the P91 steam pipeline is transformed from austenite to martensite, and then a tempering heat treatment is performed;

[0021] S6. After the tempering heat treatment, the P91 steam pipe is subjected to weld appearance and nondestructive testing. If the test fails, the P91 steam pipe is welded and repaired, and steps S1 to S5 and weld appearance and nondestructive testing are repeated until the test passes.

[0022] The beneficial effects of the present invention are:

[0023] 1) The present invention clamps the pipe body of the P91 steam pipe by using a clamping plate in cooperation with a clamping piece, and positions the grooves of the two steam pipes by using a positioning plate in cooperation with a positioning piece, so that the grooves of the two pipes are aligned, so as to perform multi-layer bottom arc welding and automatic submerged arc welding on the grooves of the pipes. During the welding process, the two clamping plates are driven to rotate by a driving component, and the two clamping plates drive the two steam pipes to rotate synchronously through the clamping piece, which simplifies the operation of moving the welding head along the circumference of the groove during welding, provides convenience for groove welding, and improves the automation degree, production efficiency and consistency of welding quality of the P91 steam pipe welding;

[0024] 2) The present invention drives the two clamping plates and the steam pipe to rotate by means of a motor and a worm gear transmission mechanism in cooperation with a gear ring transmission mechanism. The motor and the worm gear are arranged between the two clamping plates to ensure that the torque on the two steam pipes is balanced. Two pairs of rollers are arranged on the positioning piece on the inner periphery of the positioning plate. The grooves of the two steam pipes are located between the two pairs of rollers. Under the premise of ensuring the positioning effect, the positioning piece can be prevented from interfering with the weld and the friction resistance during the rotation of the pipe can be reduced. During the welding process, the groove can be continuously positioned at multiple points to eliminate the influence of the operation of removing the positioning piece on the continuity of the welding operation.

[0025] 3) The present invention drives the driving ring to rotate through the power component, and drives the second driving plate and the clamping piece to simultaneously perform multi-point clamping along the radial direction of the steam pipe through the engagement of the gear with the driving ring and the first transmission plate. The positioning piece is also driven by the above structure to position the pipe groove, thereby improving the welding positioning accuracy, thereby improving the welding quality of the P91 steam pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the working state of the welding positioning device of the present invention;

[0027] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0028] Figure 3 yes Figure 1 The enlarged view of point B in the middle;

[0029] Figure 4 It is a schematic diagram of the overall structure of the welding positioning device of the present invention;

[0030] Figure 5 is an exploded view of the positioning disk of the present invention;

[0031] Figure 6 It is a schematic diagram of the internal structure of the positioning plate of the present invention;

[0032] Figure 7 yes Figure 6 Enlarged view of point C in the middle;

[0033] Figure 8 It is a cross-sectional view of the pressure measuring structure of the present application.

[0034] In the figure: 1, mounting frame; 2, clamping plate; 3, clamping piece; 4, positioning plate; 5, positioning piece; 6, driving assembly; 7, roller; 21, first plate body; 22, second plate body; 23, driving ring; 24, first gear; 25, first transmission plate; 26, second transmission plate; 27, rod-shaped component; 28, power component; 31, mounting seat; 32, pressure sensor; 33, pressure plate; 61, second motor; 62, worm; 63, worm wheel; 64, rotating shaft; 65, second gear; 66, gear ring; 221, mounting plate; 222, first side wall; 223, second side wall; 224, connecting ring; 225, notch; 226, limit piece; 271, screw; 272, optical axis; 281, first motor; 282, gear set. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0036] First embodiment

[0037] like Figure 1 and Figure 4As shown, this embodiment relates to a P91 steam pipe welding positioning device, including a mounting frame 1, a clamping plate 2 is rotatably provided on both sides of the mounting frame 1, and a clamping piece 3 is evenly provided on the inner circumference of the clamping plate 2, and the clamping plate 2 is used to drive the clamping piece 3 to move radially, so that two groups of clamping pieces 3 clamp two P91 steam pipes, a positioning plate 4 is fixed in the middle of the mounting frame 1, and a positioning piece 5 is evenly provided on the inner circumference of the positioning plate 4, and the positioning plate 4 is used to drive the positioning piece 5 to move radially, so that a group of positioning pieces 5 can position the grooves of the two P91 steam pipes, and the mounting frame 1 is also provided with a driving assembly 6 for driving the two clamping plates 2 to rotate. During the welding process, the preheated P91 steam pipe is placed between the clamping plate 3 and the positioning plate 4 by a mechanical arm, the pipe body of the P91 steam pipe is clamped by the clamping plate 2 in cooperation with the clamping piece 3, and the grooves of the two P91 steam pipes are positioned by the positioning plate 4 in cooperation with the positioning piece 5, so that the grooves of the two pipes are aligned, so that the grooves of the pipes can be multi-layered bottom arc welding and submerged arc welding can be performed on the grooves. During the welding process, the two clamping plates are driven to rotate by the driving assembly 6, and the two clamping plates drive the two P91 steam pipes to rotate synchronously through the clamping pieces, which simplifies the operation of moving the welding head along the circumference of the groove during welding, provides convenience for groove welding, and improves the degree of automation, production efficiency and consistency of welding quality of P91 steam pipe welding.

[0038] Specifically, see Figure 5-7 The clamping plate 2 includes a first plate body 21, a second plate body 22 detachably connected to the first plate body 21, a driving ring 23 rotatably arranged on the inner side of the second plate body 22, a plurality of first gears 24 and a first transmission plate 25 uniformly arranged along the circumference of the second plate body 22, a second transmission plate 26 arranged on one side of the first transmission plate 25, a rod-shaped component 27 penetrating the first transmission plate 25, and a power component 28 for providing power to the driving ring 23. The first gears 24 correspond to the first transmission plates 25 one by one, and the first gears 24 are meshedly connected between the driving ring 23 and the first transmission plates 25. When the first transmission plate 25 moves along the rod-shaped component 27, it drives the second transmission plate 26 to slide radially along the second plate body 22. The structure of the positioning plate 4 is the same as that of the clamping plate 2. Figure 2 As shown, two pairs of rollers 7 are provided at one end of the positioning member 5 on the inner periphery of the positioning plate 4 facing the axis of the positioning plate 4 .

[0039] During the process of clamping the P91 steam pipe, the driving ring 23 rotates under the action of the power component 28, and the driving ring 23 drives the first transmission plate 25 to move tangentially along the second disk body 22 through the first gear 24. The second transmission plate 26 slides with the second disk body 22. The first transmission plate 25 is evenly provided with strip grooves, and the strip grooves are set at a 45-degree angle to the long side of the first transmission plate 25. The second transmission plate 26 is provided with strip teeth corresponding to the strip grooves one by one. During the transverse movement of the first transmission plate 25, the second transmission plate 26 moves radially along the clamping disk 2, so that the clamping piece 3 thereon clamps the P91 steam pipe.

[0040] Furthermore, if Figure 5 As shown, the second plate body 22 is composed of a mounting plate 221, a first side wall 222 fixed to the inner edge of one side of the mounting plate 221, a second side wall 223 fixed to the outer edge of one side of the mounting plate 221, and a connecting ring 224 fixed to the other side of the mounting plate 221. The second transmission plate 26 is slidably connected to the first side wall 222, and the connecting ring 224 is rotatably arranged on the top of the mounting frame 1. Figure 7 As shown, the plurality of rod-shaped components 27 are divided into a screw rod 271 and a plurality of optical axes 272, the power component 28 comprises a first motor 281 and a gear set 282 disposed between the output end of the first motor 281 and the screw rod 271, a thread groove is disposed in the first transmission plate 25 corresponding to the screw rod 271, and the optical axis 272 is slidably connected to the corresponding first transmission plate 25. The inner side of the driving ring 23 and the first transmission plate 25 are both provided with convex teeth corresponding to the first gear 24, the first gear 24 is rotatably connected to the mounting plate 221, the first side wall 222 is provided with a notch 225 corresponding to the second transmission plate 26, and the mounting plate 221 is provided with a stopper 226 for limiting the rotation of the first transmission plate 25. In this embodiment, the power component 28 drives the screw 271 to cause one of the first transmission plates 25 to move laterally, thereby driving a corresponding first gear 24 to rotate, thereby causing the drive ring 23 to rotate, so that the drive ring 23 drives the remaining first gears 24 to rotate, and causes the remaining first transmission plates 25 to move laterally synchronously with the first transmission plate 25 outside the screw 271.

[0041] In addition, in other embodiments, the power component 28 can realize the position control of the clamping fixture 3 by driving one of the first gears 24 or driving the driving ring 23 to rotate. Specifically, the plurality of rod-shaped components 27 are all optical axes 272, and the power component 28 is a power source for driving the driving ring 23 or one of the first gears 24 to rotate. When the power component 28 drives the driving ring 23 to rotate, a gear ring is provided on the driving ring 23, and the power component 28 is a motor and a gear set provided between the output end of the motor and the gear ring. At this time, the motor can cooperate with the gear set to drive the gear ring and the driving ring 23 to rotate, and the housing of the motor is fixed to the second disk body 22. When the power component 28 drives one of the first gears 24 to rotate, the power component 28 uses a motor whose output end is fixed to one of the first gears 24, and the housing of the motor is fixed to the second disk body 22.

[0042] Further, see Figure 3 The driving assembly 6 includes a second motor 61, a worm 62 fixed at the output end of the second motor 61, a worm wheel 63 meshingly connected to one side of the worm 62, a rotating shaft 64 penetrating the mounting frame 1, and a second gear 65 fixed at both ends of the rotating shaft 64. The connecting rings 224 of the two clamping plates 2 are respectively provided with toothed rings 66 meshing with the two second gears 65. The mounting frame 1 includes a bottom plate and at least three support frames, and the three support frames all have mounting holes. The inner wall of the middle support frame mounting hole is fixed to the second plate body of the positioning plate 4, and the inner walls of the support frame mounting holes on both sides are respectively rotatably connected to the two connecting rings 224. The first motor 281 and the second motor 61 are preferably high temperature resistant motors. During the welding process, the second motor 61 drives the worm wheel 63 and the rotating shaft 64 to rotate through the worm 62, and the rotating shaft 64 drives the connecting ring 224 on the second plate body 22 of the clamping plate 2 to rotate through the second gear 65 and the toothed ring 66. Multiple support frames can also be set on both sides of the bottom plate of the mounting frame 1, and a clamping plate 2 is rotatably set on each support frame, a gear ring 66 is fixed on the connecting ring 224 of each clamping plate 2, and a second gear 65 corresponding to each gear ring 66 is set on the rotating shaft 64, thereby providing more clamping points for the P91 steam pipe to adapt to pipes of different lengths.

[0043] In the process of clamping the P91 steam pipe body, different control instructions can be input to the first motor 281 according to the outer diameter of the pipe to control the moving distance of the clamp 3; or Figure 7As shown, by detecting the pressure on the clamp 3, it is determined whether the clamp 3 is in place to control the moving distance of the clamp 3. When the scheme of controlling the first motor 281 by detecting the pressure is adopted, one of the clamps 3 is designed as a pressure measuring structure, which includes a mounting seat 31 fixed on one side of the second transmission plate 26 and a pressure sensor 32 and a pressure plate 33 arranged at one end of the mounting seat 31 facing the axis of the clamping disk 2, and the pressure sensor 32 is fixed between the mounting seat 31 and the pressure plate 33. After the first motor 281 is started, when the pressure sensor 32 detects that the pressure is greater than the pressure threshold, the first motor 281 stops working. It should be noted that the position of the pressure measuring structure is fixed at the initial moment under this scheme. In this embodiment, before the first motor 281 is started, the pressure measuring structure is located in the middle of the upper side of the clamping disk 2. In addition, if the groove alignment needs to be calibrated, the first pressure setting value and the second pressure setting value can be set. When the pressure sensor 32 detects that the pressure reaches the first pressure setting value, the first motor 281 stops working, and the clamp 3 contacts the P91 steam pipe but does not press against the pipe. At this time, the position of the two P91 steam pipes can be fine-tuned by the mechanical arm. After the groove of the steam pipe is fully aligned, the first motor 281 continues to work until the pressure sensor 32 detects that the pressure reaches the second pressure setting value. At this time, the clamp 3 presses against the pipe and the first motor 281 stops running. In addition, one of the positioning members 5 is also made of a pressure measuring structure.

[0044] Second embodiment

[0045] This embodiment relates to a P91 steam pipeline welding method, comprising the following steps:

[0046] S1. Before welding, preheat the two P91 steam pipes to be welded so that the temperature of the P91 steam pipes rises to the preheating temperature range. If tungsten inert gas welding (GTAW) is required for the P91 steam pipes, the preheating temperature range is 150℃~180℃; if tungsten inert gas welding (GTAW) is required for the P91 steam pipes, the preheating temperature range is 200℃~250℃.

[0047] S2. The preheated P91 steam pipe is passed through the clamping plate 2 by a robotic arm, and the groove of the P91 steam pipe is placed in the positioning plate 4. The two P91 steam pipes are positioned using the welding positioning device in the first embodiment. The two P91 steam pipes are passed through the two clamping plates 2 respectively, and the grooves of the two P91 steam pipes are aligned to the inner side of the positioning plate 4. The clamping plate 2 and the positioning plate 4 respectively drive the clamping piece 3 and the positioning piece 5 to abut against the P91 steam pipe.

[0048] S3, the clamping plate 2, the clamping member 3 and the P91 steam pipe are rotated by the driving assembly 6, and multi-layer bottom arc welding is performed at the groove position of the P91 steam pipe. During the welding process, the interlayer temperature is not lower than the lower limit temperature of the preheating temperature range. The bottom arc welding adopts tungsten inert gas welding (GTAW) and / or tungsten inert gas welding (GTAW), and the number of bottom layers is preferably three.

[0049] S4. After the multi-layer bottom arc welding, the driving assembly 6 continues to rotate the P91 steam pipe, and performs submerged arc welding on the groove position of the P91 steam pipe through the automatic submerged arc welding equipment.

[0050] S5. After the submerged arc welding is completed, the P91 steam pipeline is subjected to post-weld heat treatment, so that the temperature of the P91 steam pipeline is reduced to the post-weld heat treatment temperature range, and the temperature is kept until the P91 steam pipeline is transformed from austenite to martensite, and then tempering heat treatment is performed. During the post-weld heat treatment process, the P91 steam pipeline is cooled to 80℃~100℃ after welding and kept warm for 2 hours to allow all austenite to be transformed into martensite.

[0051] S6. After the tempering heat treatment, the P91 steam pipe is subjected to weld appearance and nondestructive testing. If the test fails, the P91 steam pipe is welded and repaired, and steps S1 to S5 and weld appearance and nondestructive testing are repeated until the test passes.

[0052] In addition, if some welded joints cannot be heat treated after welding in time, they should be heat treated immediately after welding at a temperature of 300℃~350℃ and a constant temperature time of 2 hours. For the post-heating of martensitic steel welded joints, the weldment should be kept at 80℃~100℃ for 2 hours after welding and after the martensitic transformation has been completed. The heating range of post-heating should not be less than the range of preheating before welding.

[0053] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A P91 steam pipe welding positioning device, comprising a mounting frame (1), characterized in that: The mounting frame (1) is provided with a clamping disk (2) rotatably on both sides, and the inner circumference of the clamping disk (2) is evenly provided with clamping pieces (3). The clamping disk (2) is used to drive the clamping pieces (3) to move radially, so that two groups of the clamping pieces (3) clamp the two P91 steam pipes. The mounting frame (1) is provided with a positioning disk (4) in the middle, and the inner circumference of the positioning disk (4) is evenly provided with positioning pieces (5). The positioning disk (4) is used to drive the positioning pieces (5) to move radially, so that one group of the positioning pieces (5) positions the grooves of the two P91 steam pipes. The mounting frame (1) is also provided with a driving assembly (6) for driving the two clamping disks (2) to rotate.

2. The welding positioning device according to claim 1, characterized in that: Two pairs of rollers (7) are provided at one end of the positioning member (5) facing the axis of the positioning plate (4).

3. The welding positioning device according to claim 1, characterized in that: The clamping plate (2) comprises a first plate body (21), a second plate body (22) detachably connected to the first plate body (21), a driving ring (23) rotatably arranged on the inner side of the second plate body (22), a plurality of first gears (24) and a first transmission plate (25) uniformly arranged along the circumference of the second plate body (22), a second transmission plate (26) arranged on one side of the first transmission plate (25), a rod-shaped component (27) penetrating the first transmission plate (25), and a power component (28) for providing power to the driving ring (23), wherein the first gears (24) correspond to the first transmission plate (25) one by one, and the first gears (24) are meshedly connected between the driving ring (23) and the first transmission plate (25), and when the first transmission plate (25) moves along the rod-shaped component (27), the second transmission plate (26) is driven to slide radially along the second plate body (22), and the structure of the positioning plate (4) is the same as that of the clamping plate (2).

4. The welding positioning device according to claim 3, characterized in that: The second disk body (22) is composed of a mounting disk (221), a first side wall (222) fixedly arranged on the inner edge of one side of the mounting disk (221), a second side wall (223) fixedly arranged on the outer edge of one side of the mounting disk (221), and a connecting ring (224) fixedly arranged on the other side of the mounting disk (221); the second transmission plate (26) is slidably connected to the first side wall (222), and the connecting ring (224) is rotatably arranged on the top of the mounting frame (1).

5. The welding positioning device according to claim 4, characterized in that: The plurality of rod-shaped components (27) are divided into a screw rod (271) and a plurality of optical axes (272); the power component (28) comprises a first motor (281) and a gear set (282) arranged between the output end of the first motor (281) and the screw rod (271); and a thread groove is arranged in the first transmission plate (25) corresponding to the screw rod (271).

6. The welding positioning device according to claim 4, characterized in that: The plurality of rod-shaped components (27) are all optical axes (272), and the power component (28) is a power source for driving the driving ring (23) or one of the first gears (24) to rotate.

7. The welding positioning device according to claim 4, characterized in that: The inner side of the driving ring (23) and the first transmission plate (25) are both provided with convex teeth corresponding to the first gear (24); the first side wall (222) is provided with a notch (225) corresponding to the second transmission plate (26); the mounting plate (221) is provided with a limiter (226) for limiting the rotation of the first transmission plate (25); the first transmission plate (25) is evenly provided with strip grooves, and the second transmission plate (26) is provided with strip teeth corresponding to the strip grooves one by one.

8. The welding positioning device according to claim 4, characterized in that: The driving assembly (6) comprises a second motor (61), a worm (62) fixedly mounted on the output end of the second motor (61), a worm wheel (63) meshingly connected to one side of the worm (62), a rotating shaft (64) penetrating the mounting frame (1), and second gears (65) fixedly mounted on both ends of the rotating shaft (64); and toothed rings (66) meshing with the two second gears (65) are respectively provided on the connecting rings (224) of the two clamping plates (2).

9. The welding positioning device according to claim 4, characterized in that: One of the clamping members (3) is a pressure measuring structure, and the pressure measuring structure comprises a mounting seat (31) fixedly arranged on one side of the second transmission plate (26), and a pressure sensor (32) and a pressure plate (33) arranged at one end of the mounting seat (31) facing the axis of the clamping disk (2), wherein the pressure sensor (32) is fixedly arranged between the mounting seat (31) and the pressure plate (33).

10. A P91 steam pipeline welding method, characterized in that: The following steps are involved: S1. Preheat the P91 steam pipe before welding to raise the temperature of the P91 steam pipe to a preheating temperature range; S2. Position the two P91 steam pipes using the welding positioning device as described in any one of claims 1 to 9, respectively pass the two P91 steam pipes through the two clamping plates (2), and align the grooves of the two P91 steam pipes to the inner side of the positioning plate (4), and the clamping plate (2) and the positioning plate (4) respectively drive the clamping piece (3) and the positioning piece (5) to abut against the P91 steam pipes; S3, rotating the clamping plate (2), the clamping member (3) and the P91 steam pipe by the driving assembly (6), and performing multi-layer bottom arc welding at the groove position of the P91 steam pipe, and during the welding process, the interlayer temperature is not lower than the lower limit temperature of the preheating temperature range; S4. After the multi-layer bottom arc welding, the driving assembly (6) continues to rotate the P91 steam pipe, and performs submerged arc welding on the groove position of the P91 steam pipe by the automatic submerged arc welding equipment; S5. After the submerged arc welding is completed, the P91 steam pipeline is subjected to post-weld heat treatment, so that the temperature of the P91 steam pipeline is reduced to the post-weld heat treatment temperature range, and the temperature is kept until the P91 steam pipeline is transformed from austenite to martensite, and then a tempering heat treatment is performed; S6. After the tempering heat treatment, the P91 steam pipe is subjected to weld appearance and nondestructive testing. If the test fails, the P91 steam pipe is welded and repaired, and steps S1 to S5 and weld appearance and nondestructive testing are repeated until the test passes.

Images