Pipe welding method and compensation ring for pipe welding

Abstract

The application discloses a pipe welding method and a compensation ring applied to pipe welding. The pipe welding method comprises the following steps: butting end-to-end the base material pipe to be welded, wherein an outer circumferential ring at the butt joint of the base material pipe is provided with a compensation ring; vacuum electron beam welding is performed at the butt joint of the base material pipe, and the compensation ring is melted at the same time, so as to form a weld at the butt joint of the base material pipe, wherein the compensation ring is used to make the lowest part of the outer surface of the weld higher than or flush with the outer circumferential surface of the base material pipe. In the foregoing manner, the application can reduce the risk of incomplete weld, and the weld is formed by one-time welding, which is beneficial to guarantee the quality of the weld.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding, in particular to a pipe welding method and a compensation ring applied to pipe welding. BACKGROUND

[0002] As a widely used welding method, vacuum electron beam welding has the characteristics of small line energy, small welding deformation, pure weld, and no oxidation, and is suitable for welding materials such as stainless steel and alloy steel. However, when vacuum electron beam welding is applied to welding small pipe joints with small diameter and large wall thickness, due to the small and thick pipe joint, the heat dissipation is slow during welding, and the weld solidification speed is slow, resulting in more low-melting compounds seeping out from the back of the weld during the welding process, which causes the weld surface to be prone to incomplete welding. Therefore, it is often necessary to repair it by argon arc welding, but the quality of the repaired weld is difficult to guarantee. SUMMARY

[0003] The present application provides a pipe welding method and a compensation ring applied to pipe welding, which can reduce the risk of incomplete welding of the weld and form the weld in one welding, thereby facilitating the guarantee of the quality of the weld.

[0004] The present application provides a pipe welding method, comprising: end-to-end butt joining the base material pipe joint to be welded, wherein a compensation ring is arranged on the outer periphery of the butt joint of the base material pipe joint; vacuum electron beam welding is performed on the butt joint of the base material pipe joint, and the compensation ring is melted at the same time, so as to form a weld on the butt joint of the base material pipe joint, wherein the compensation ring is used to make the lowest part of the outer surface of the weld higher than or flush with the outer periphery of the base material pipe joint.

[0005] In an embodiment of the present application, the compensation ring comprises: a ring body; and a clamping portion arranged on the ring body; wherein the ring body is arranged on the outer periphery of the butt joint of the base material pipe joint to be welded after end-to-end butt joining, and the clamping portion is used to clamp the butt joint of the base material pipe joint; the outer diameter of the ring body is D1, the inner diameter of the ring body is D2, and the maximum compensation amount of the weld is Tmax, wherein D1≥D2+2Tmax.

[0006] In an embodiment of the present application, the compensation ring comprises: a ring body; and a clamping portion arranged on the ring body; wherein the ring body is arranged on the outer periphery of the butt joint of the base material pipe joint to be welded after end-to-end butt joining, and the clamping portion is used to clamp the butt joint of the base material pipe joint; the inner diameter of the ring body is D2, and the outer diameter of the base material pipe joint is D3; wherein D2≥D3.

[0007] In an embodiment of the present application, the width of the compensation ring is d1, and the width of the weld is d2; wherein d1≥d2.

[0008] In an embodiment of the present application, the compensation ring comprises at least two compensation bodies, each of which is arranged along the circumference of the compensation ring; the step of butt-jointing the base material pipe fittings to be welded comprises: sequentially mounting each compensation body to the outer periphery of the butt-jointed base material pipe fittings; and spot welding the butt-jointed adjacent compensation bodies.

[0009] In an embodiment of the present application, the step of vacuum electron beam welding the butt-jointed base material pipe fittings comprises: uniformly spot welding the compensation ring along the circumference of the compensation ring by controlling the electron beam gun head; aligning the relative position between the electron beam gun head and the base material pipe fittings by the spot welding track, so that the electron beam gun head is aligned with the center of the compensation ring; and continuously welding the compensation ring along the circumference of the compensation ring by controlling the electron beam gun head; aligning the relative position between the electron beam gun head and the base material pipe fittings by the continuous welding track, so that the electron beam gun head is aligned with the center of the compensation ring.

[0010] In an embodiment of the present application, the step of vacuum electron beam welding the butt-jointed base material pipe fittings comprises: vacuum electron beam welding the butt-jointed base material pipe fittings by using preset welding parameters, wherein the preset welding parameters match the sum of the thickness of the base material pipe fitting and the ring thickness of the compensation ring.

[0011] In an embodiment of the present application, the step of butt-jointing the base material pipe fittings to be welded comprises: machining a bevel at the end of the base material pipe fitting, so that the bevels of the adjacent base material pipe fittings form a limiting groove after the base material pipe fittings are butt-jointed; and wherein the compensation ring comprises a ring body and a clamping portion, the clamping portion is protruded on the inner side of the ring body, and the clamping portion is used to be clamped in the limiting groove after the ring body is arranged on the outer periphery of the butt-jointed base material pipe fittings.

[0012] In an embodiment of the present application, the step of butt-jointing the base material pipe fittings to be welded comprises: butt-jointing the base material pipe fittings and spot welding the butt-jointed base material pipe fittings; and wherein the assembly gap between the adjacent base material pipe fittings is less than or equal to 0.05 mm.

[0013] Correspondingly, the present application also provides a compensation ring applied to pipe fitting welding. The compensation ring comprises: a ring body; and a clamping portion arranged on the ring body; wherein the ring body is used to be arranged on the outer periphery of the butt-jointed base material pipe fittings to be welded, and the clamping portion is used to be clamped on the butt-jointed base material pipe fittings; and when vacuum electron beam welding the butt-jointed base material pipe fittings, the compensation ring is melted together to form a weld joint on the butt-jointed base material pipe fittings, wherein the compensation ring is used to make the lowest part of the outer surface of the weld joint higher than or flush with the outer peripheral surface of the base material pipe fittings.

[0014] The beneficial effects of the present application are: different from the prior art, the present application provides a pipe welding method and a compensation ring applied to pipe welding. The base material pipe to be welded is butt jointed end to end, and the outer periphery ring at the butt joint of the base material pipe is provided with a compensation ring. Vacuum electron beam welding is performed at the butt joint of the base material pipe, and the compensation ring is melted at the same time, so as to form a weld at the butt joint of the base material pipe. Wherein, the compensation ring makes the lowest part of the outer surface of the weld higher than the outer periphery surface of the base material pipe or flush with the outer periphery surface of the base material pipe, that is, the compensation ring can effectively solve the problem of incomplete weld, so as to reduce the risk of incomplete weld. Moreover, the compensation ring is melted at the same time in the welding process, that is, the weld is formed by one-time welding, which is beneficial to ensure the quality of the weld. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0016] Figure 1 is a structure schematic diagram of the pipe after being welded by vacuum electron beam welding in the prior art;

[0017] Figure 2 is a cross-sectional structure schematic diagram of an embodiment of the base material pipe and the compensation ring thereon of the present application;

[0018] Figure 3 is a structure schematic diagram of an embodiment of the compensation ring of the present application;

[0019] Figure 4 is Figure 2 a structure schematic diagram of the base material pipe without the compensation ring shown in the above;

[0020] Figure 5 is Figure 4 a structure schematic diagram of the area A of the base material pipe shown in the above;

[0021] Figure 6 is Figure 3 a cross-sectional structure schematic diagram of the compensation ring in the direction B-B shown in the above;

[0022] Figure 7 is Figure 2 a structure schematic diagram of the area C of the base material pipe and the compensation ring thereon shown in the above;

[0023] Figure 8 is a flow schematic diagram of an embodiment of the pipe welding method of the present application;

[0024] Figure 9 is a flow schematic diagram of another embodiment of the pipe welding method of the present application.

[0025] Explanation of reference signs:

[0026] 10 base pipe; 11 bevel; 12 limiting groove; 20 compensating ring; 21 compensating body; 22 ring main body; 23 clamping portion. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation words such as "upper", "lower", "left", "right" generally refer to the upper, lower, left and right of the device in the actual use or working state, and specifically refer to the direction of the drawing surface in the drawings.

[0028] In the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "stacked" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The present application provides a pipe welding method and a compensating ring applied to pipe welding, which are described in detail below. It should be noted that the description order of the following embodiments is not limited as the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0030] Vacuum electron beam welding as a widely used welding method has the characteristics of small line energy, small welding deformation, pure weld and no oxidation, and is suitable for welding stainless steel, alloy steel and other materials. The nickel-based alloy (such as NS1402, NS3105, etc.) described in the application is commonly used in the manufacture of air coolers, ceramic furnaces and other products. The air cooler, ceramic furnace and other structures are complex, among which the small pipe fittings such as the feed pipe and the measuring pipe need to be welded by vacuum electron beam welding (design document requirements). Such pipe fittings are often long and straight pipes, elbow structures, and have the characteristics of small caliber (φ10-35mm), large wall thickness (3-10mm) and small processing allowance. The butt weld of the pipe requires full penetration, and the radiographic testing is qualified. The weld quality is required to be high, and it is impossible to use the pre-welding bevel allowance method for welding. Because the nickel-based alloy has high thermal crack sensitivity, the use of traditional fusion welding can easily produce oxides with a large linear expansion coefficient, increasing the risk of thermal cracking. The use of vacuum electron beam welding can avoid the above-mentioned thermal cracking.

[0031] However, when welding small pipe fittings with small caliber (φ10-35mm) and large wall thickness (3-10mm), the pipe fittings are small and thick, the heat dissipation is slow during welding, and the weld solidification speed is slow, resulting in more low-melting compounds seeping out from the back of the weld during the welding process, which causes the weld surface to be prone to incomplete welding. Figure 1 It is shown that the pipe fitting 31 and the pipe fitting 32 are welded by traditional vacuum electron beam welding, and the weld 33 has the defect of incomplete welding. The deepest depth of the incomplete welding defect of the weld 33 is T, that is, the compensation amount of the weld is T.

[0032] It is often necessary to repair by argon arc welding, but the quality of the repaired weld is difficult to guarantee.

[0033] For the above-mentioned incomplete welding problem, in theory, the method of built-in gasket can also be used to reduce the seepage of compounds from the back of the weld, thereby reducing the incomplete welding defect of the weld. However, in actual application, because the pipe fittings to be welded are mostly long and curved structures, the built-in gasket is difficult to remove after welding.

[0034] Based on the above problems, the application adopts the method of external compensation ring to weld small pipe fittings by vacuum electron beam welding, which not only solves the problem of easy incomplete welding of the weld, but also reduces the risk of incomplete welding of the weld. The weld is formed by one-time welding, the radiographic testing is qualified, and there are no defects such as thermal cracking, which is beneficial to guarantee the quality of the weld.

[0035] Please refer to Figure 2 , Figure 2 is a cross-sectional structure schematic diagram of an embodiment of the parent pipe fitting and the compensation ring thereon.

[0036] In one embodiment, a compensation ring 20 is provided for use in welding a pipe. The base material pipes 10 to be welded are butted end to end, and the outer periphery of the butted portion of the base material pipes 10 is provided with the compensation ring 20. The butted portion of the base material pipes 10 is vacuum electron beam welded, and the compensation ring 20 is melted together to form a weld at the butted portion of the base material pipes 10. The compensation ring 20 is used to make the lowest point of the outer surface of the weld higher than or flush with the outer periphery of the base material pipes 10.

[0037] After the welding is completed, the weld is in the shape of a ring as a whole. The lowest point of the outer surface of the weld is understood to be the position of the outer surface of the weld closest to the center of the ring. The lowest point of the outer surface of the weld being higher than the outer periphery of the base material pipes 10 is understood to mean that the lowest point of the outer surface of the weld is farther away from the center line of the base material pipes 10 relative to the outer periphery of the base material pipes 10, i.e., the weld has a reinforcement. When the lowest point of the outer surface of the weld is flush with the outer periphery of the base material pipes 10, it can be understood that the reinforcement of the weld is zero.

[0038] In the above manner, the compensation ring 20 makes the lowest point of the outer surface of the weld higher than or flush with the outer periphery of the base material pipes 10, i.e., the compensation ring 20 can effectively solve the problem of incomplete penetration of the weld, and thus can reduce the risk of incomplete penetration of the weld. Moreover, the compensation ring 20 is melted together during the welding process, i.e., the weld is formed by one-time welding, which is advantageous for ensuring the quality of the weld. The compensation ring 20 of the present embodiment is particularly suitable for small pipes with a small welding diameter (φ10-35 mm) and a large wall thickness (3-10 mm).

[0039] Please also refer to Figure 3 , Figure 3 which is a structural schematic diagram of one embodiment of the compensation ring of the present application.

[0040] In one embodiment, the compensation ring 20 comprises a ring body 22 and a clamping portion 23. The clamping portion 23 is arranged on the ring body 22. The ring body 22 is arranged on the outer periphery of the butted portion of the base material pipes 10 after the base material pipes 10 to be welded are butted end to end, and the clamping portion 23 is used to clamp the butted portion of the base material pipes 10.

[0041] Specifically, please refer to Figure 4 and Figure 5 , the end portion of the base material pipe 10 is processed with a bevel 11. After the base material pipes 10 are butted, the bevels 11 of the adjacent base material pipes 10 cooperate to form a limiting groove 12. For example, the bevel 11 of the end portion of the base material pipe 10 is a chamfer with an inclination angle of 45°, and the width of the bevel 11 in the axial direction of the base material pipe 10 is 1 mm. After the base material pipes 10 are butted, the bevels 11 of the adjacent base material pipes 10 cooperate to form a V-shaped limiting groove 12, and the center of the limiting groove 12 is the center of the weld. The cross-sectional shape of the limiting groove 12 is an isosceles right triangle, and the length of the hypotenuse is 2 mm.

[0042] Please refer to Figure 6 and Figure 7 , the shape of the clamping portion 23 of the compensation ring 20 matches the shape of the limiting groove 12. The cross-sectional shape of the limiting groove 12 is V-shaped, and the cross-sectional shape of the clamping portion 23 is also V-shaped. For example, the cross-sectional shape of the clamping portion 23 is also an isosceles right triangle, and the length of the hypotenuse is also 2mm. After the compensation ring 20 is installed on the base pipe 10, the clamping portion 23 is clamped in the limiting groove 12 of the base pipe 10, achieving the purpose of limiting and centering the compensation ring 20, fixing the position of the compensation ring 20 on the base pipe 10, and ensuring that the compensation ring 20 can compensate the weld to reduce the risk of incomplete weld.

[0043] Please continue to refer to Figure 3 In an embodiment, the compensation ring 20 includes at least two compensation bodies 21, and each compensation body 21 is sequentially distributed along the circumference of the compensation ring 20. Specifically, the above-mentioned ring body 22 and the clamping portion 23 are divided into at least two parts, and each compensation body 21 is composed of a corresponding ring body 22 and clamping portion 23.

[0044] In the above manner, the compensation ring 20 of the present embodiment is divided into at least two compensation bodies 21, so as to facilitate the installation of the compensation ring 20 to the butt joint of the base pipe 10, specifically, sequentially installing each compensation body 21 to the outer circumference of the butt joint of the base pipe 10, and then assembling the complete compensation ring 20. The design of dividing the compensation ring 20 of the present embodiment into at least two compensation bodies 21 has wide application range and can be applied to the butt welding of straight pipes, elbow pipes and the like.

[0045] For example, the compensation ring 20 of the present embodiment is divided into two compensation bodies 21, each of which is a half-ring structure, and after the two compensation bodies 21 are respectively installed to the butt joint of the base pipe 10, the two compensation bodies 21 are assembled into a complete compensation ring 20.

[0046] In an embodiment, the outer diameter of the ring body 22 is D1, the inner diameter of the ring body 22 is D2, and the maximum compensation amount of the weld is Tmax. Wherein, D1≥D2+2Tmax. In this way, it can be ensured that the compensation ring 20 is sufficient to compensate for the incomplete weld defect, further reducing the risk of incomplete weld.

[0047] It should be noted that the maximum compensation amount of the weld should be understood as the depth of the deepest part of the incomplete weld defect when the compensation ring 20 is not set, and the maximum compensation amount of the weld is obtained according to a large number of welding tests in the early stage.

[0048] In an embodiment, the outer diameter of the base pipe 10 is D3, such as Figure 4As shown. Where D2≥D3. In this way, it is ensured that the compensation ring 20 can be properly fitted onto the outer circumference of the mating joint of the base pipe fitting 10. The inner diameter D2 of the ring body 22 is equal to the outer diameter D3 of the base pipe fitting 10, and the inner diameter D2 of the ring body 22 should have a positive tolerance of 0mm to 0.1mm.

[0049] In one embodiment, the width of the compensation ring 20 is d1 (e.g., Figure 5 As shown in the diagram, the width of the weld is d2. Where d1 ≥ d2. The width d1 of the compensation ring 20 should be understood as the length of the compensation ring 20 in the axial direction of the base pipe fitting 10. Similarly, the width d2 of the weld should also be understood as the length of the weld in the axial direction of the base pipe fitting 10. The width d2 of the weld is obtained based on measurements from previous welding tests, for example, by selecting the average width of welds obtained from a large number of previous welding tests. In this way, the compensation ring 20 can cover the weld in the axial direction of the base pipe fitting 10, further ensuring that the compensation ring 20 can compensate for the weld and reduce the risk of incomplete weld.

[0050] It should be noted that the dimensional parameters of the compensation ring 20 in this embodiment are all obtained based on the base material pipe fitting 10 and welding test measurements. In practical applications, they can be flexibly adjusted according to actual needs, providing good flexibility.

[0051] Please refer to the following: Figure 8 , Figure 8 This is a schematic flowchart of an embodiment of the pipe fitting welding method of this application. The pipe fitting welding method described in this embodiment is based on the compensation ring described in the above embodiment, and will not be repeated here.

[0052] S101: The base material pipe fittings to be welded are connected end to end, wherein the outer circumference of the connection point of the base material pipe fittings is provided with a compensation ring.

[0053] In this embodiment, the base material pipe fittings to be welded are butted end-to-end, and then welded and fixed by vacuum electron beam welding. A compensation ring is provided on the outer periphery of the butt joint of the base material pipe fittings. The compensation ring is used to compensate for the weld seam and reduce the risk of incomplete weld seam.

[0054] S102: Vacuum electron beam welding is performed at the joint of the base material pipe fittings, and the compensation ring is melted at the same time to form a weld at the joint of the base material pipe fittings, wherein the compensation ring is used to make the lowest point of the outer surface of the weld higher than or flush with the outer circumferential surface of the base material pipe fittings.

[0055] In the embodiment, the compensation ring is installed to the butt joint of the base material pipe, then vacuum electron beam welding is performed on the butt joint of the base material pipe, and the compensation ring is melted at the same time to form a weld on the butt joint of the base material pipe. The compensation ring makes the lowest point of the outer surface of the weld higher than or flush with the outer circumferential surface of the base material pipe, that is, the compensation ring can effectively solve the problem of incomplete weld, thereby reducing the risk of incomplete weld. Moreover, the compensation ring is melted at the same time in the welding process, that is, the weld is formed by one-time welding, which is beneficial to guarantee the quality of the weld.

[0056] Please also refer to Figure 9 , Figure 9 is a flowchart of another embodiment of the pipe welding method of the present application. The pipe welding method described in the embodiment is based on the compensation ring described in the above embodiment, which will not be described here.

[0057] S201: cleaning the base material pipe.

[0058] In the embodiment, the base material pipe is a nickel-based alloy pipe, and the specific grade combination can be NS1402 / NS1402, NS3105 / NS3105, NS1402 / NS3105, or other similar material grade combinations. A groove is processed at the end of the base material pipe to form a limiting groove between the grooves of the adjacent base material pipes after the butt joint of the base material pipes. The compensation ring includes a ring body and a clamping portion protruding from the inner side of the ring body. The clamping portion is used to clamp the limiting groove after the ring body is arranged on the outer circumference of the butt joint of the base material pipe. In the embodiment, acetone or the like can be used to clean the base material pipe. Specifically, acetone or the like is used to wipe and clean the base material pipe and the groove thereon, and then dried.

[0059] S202: end-to-end butt joint of the base material pipe to be welded.

[0060] In the embodiment, the base material pipes are end-to-end butt jointed and point welded and assembled at the butt joint of the base material pipes. The assembly gap between the adjacent base material pipes is less than or equal to 0.05 mm. Specifically, the base material pipes can be point welded and assembled by using argon arc welding. After the point welding is completed, the welds can be polished to be smooth.

[0061] S203: installing the compensation ring to the butt joint of the base material pipe.

[0062] In the embodiment, the compensation ring is installed to the butt joint of the base material pipe after the point welding and assembly of the base material pipe to be welded. The compensation ring includes at least two compensation bodies. In the embodiment, the compensation bodies are sequentially installed to the outer circumference of the butt joint of the base material pipe, and then point welded and fixed at the butt joint of the adjacent compensation bodies.

[0063] Specifically, the material grade of the compensation ring is consistent with that of the base pipe as much as possible. The compensation ring in the embodiment is divided into two compensation bodies, each of which is a half-ring structure, and each compensation body is provided with a clamping portion on the inner wall. The compensation ring structure in the embodiment is easy to process and realize. One of the compensation bodies is first embedded into the limiting groove along the radial direction of the base pipe from the outside to the inside for installation, and then the other compensation body is embedded into the limiting groove along the radial direction of the base pipe from the outside to the inside for installation, so that the compensation body installed later and the compensation body installed earlier form a complete compensation ring. The compensation bodies are locked by spot welding with argon arc, specifically, 1 to 2 welding spots are spot welded at each butt joint of the two compensation bodies, and the locking is realized. After the spot welding is completed, the welding spots can be polished to be smooth.

[0064] S204: The base pipe provided with the compensation ring is sent into a welding chamber, and the welding chamber is vacuumized.

[0065] In the embodiment, after the compensation ring is installed at the butt joint of the base pipe, the base pipe provided with the compensation ring is sent into a welding chamber, and the welding chamber is vacuumized, so as to carry out subsequent vacuum electron beam welding work.

[0066] S205: The electron beam gun head is positioned.

[0067] In the embodiment, the positioning of the electron beam gun head is specifically as follows: the electron beam gun head is controlled to uniformly spot weld the compensation ring along the circumferential direction of the compensation ring, the relative position of the electron beam gun head and the base pipe is calibrated through the spot welding track, so that the electron beam gun head is aligned with the center of the compensation ring, so as to play a role of positioning and centering for the electron beam gun head; then, the electron beam gun head is controlled to continuously weld the compensation ring along the circumferential direction of the compensation ring, the relative position of the electron beam gun head and the base pipe is calibrated through the continuous welding track, so that the electron beam gun head is aligned with the center of the compensation ring, that is, the electron beam gun head pre-travels a welding track, so as to ensure that the electron beam gun head is centered correctly.

[0068] S206: The vacuum electron beam welding is carried out at the butt joint of the base pipe.

[0069] In the embodiment, the vacuum electron beam welding is carried out at the butt joint of the base pipe, and the compensation ring is also melted, so as to form a weld at the butt joint of the base pipe. The compensation ring makes the lowest part of the outer surface of the weld higher than or flush with the outer circumferential surface of the base pipe, that is, the compensation ring can effectively solve the problem of incomplete weld, so as to reduce the risk of incomplete weld. Moreover, the compensation ring is also melted during the welding process, that is, the weld is formed by one-time welding, which is beneficial to guarantee the quality of the weld.

[0070] Specifically, the butt joint of the base pipe is welded by vacuum electron beam welding with preset welding parameters. The preset welding parameters match the sum of the thickness of the base pipe and the ring thickness of the compensation ring to ensure the base pipe and the compensation ring to be penetrated. The preset welding parameters are measured according to the previous welding test, for example, the mean value of a large number of welding parameters measured by the previous welding test can be selected. The welding parameters depend on the welding equipment, the grade of the base pipe, the size of the base pipe and other factors. The welding parameters can specifically include electron beam current, electron beam gun voltage, welding speed, focusing current and the like.

[0071] It should be noted that after the vacuum electron beam welding is completed, it is selected whether to perform finish welding according to the weld surface forming condition. If the weld is well formed, the finish welding can be omitted.

[0072] S207: After the welding is completed, the welding chamber is exhausted, and the welded base pipe is taken out.

[0073] In this embodiment, after the welding is completed, the welding chamber is exhausted, and the welded base pipe is taken out. The excess height of the weld on the base pipe can be polished or processed according to actual needs.

[0074] The technical solutions provided by the embodiments of the present application will be described below in combination with specific application scenarios.

[0075] Embodiment 1:

[0076] Taking the vacuum electron beam welding of the feed pipe head in the ceramic electric furnace project as an example, the grade of the base pipe is NS3105 / NS3105, the groove specification of the base pipe is φ26.9mm*φ3.2mm / φ26.9mm*φ3.2mm, and the welding process is as follows:

[0077] Firstly, the base pipe groove is cleaned by wiping with acetone and dried.

[0078] Secondly, the base pipe is assembled by argon arc welding spot welding, and the assembly gap is ≤0.05mm.

[0079] Thirdly, the compensation ring is installed to the assembled base pipe. The size of the compensation ring is as follows: the outer diameter D1 of the compensation ring is 29.9mm, the inner diameter D2 of the compensation ring is 26.9(0-0.1)mm, the width d1 of the compensation ring is 5mm, and the clamping part of the compensation ring is an isosceles right triangle with a bevel of 2mm (which cooperates with the limiting groove formed after the base pipe is assembled).

[0080] Fourthly, the base pipe with the installed compensation ring is sent into the welding chamber, and the welding chamber is vacuumized to the air pressure of the welding chamber ≤5x10 -4 Mpa.

[0081] In the fifth step, the electron beam gun head is positioned by spot welding three welding spots. The electron beam current of the electron beam gun head is 10 mA, the electron beam gun head voltage is 45 KV, and the focusing current is 1.70 A.

[0082] In the sixth step, vacuum electron beam welding is performed at the butt joint of the base material pipe. According to the results of the previous welding test, the preset welding parameters are used for vacuum electron beam welding. The preset welding parameters specifically include an electron beam current of 45 mA, an electron beam gun head voltage of 45 KV, a welding speed of 65 cm / min, and a focusing current of 1.70 A.

[0083] In the seventh step, after the welding is completed, the welding chamber is exhausted, and the welded base material pipe is taken out.

[0084] In the eighth step, the weld reinforcement is ground or machined.

[0085] In the ninth step, the weld surface is subjected to liquid penetrant inspection. According to the standard NB47013.5-15, the acceptance is in accordance with the 1st level weld standard, and the liquid penetrant inspection is qualified.

[0086] In the tenth step, the weld is subjected to radiographic testing. According to the standard NB47013.5-15, the acceptance is in accordance with the 1st level weld standard, and the weld radiographic testing is qualified.

[0087] Notes for Example 1:

[0088] In the third step, the compensation ring size is determined as follows: the inner diameter D2 of the compensation ring is determined according to the actual outer diameter D3 of the base material pipe, D2=D3=26.9(0-0.1) mm; the outer diameter D1 of the compensation ring is calculated according to the maximum depth of the incomplete weld defect Tmax, which requires D1≥D2+2Tmax=26.9+2x1.5=29.9 mm, and note that Tmax=1.5 mm is obtained from the previous welding test; the width d1 of the compensation ring is determined according to the weld width d2 obtained from the previous welding test, d1≥d2, d2=5 mm, and note that d2=5 mm is obtained from the previous welding test. The welding parameters in the fifth and sixth steps are different for different vacuum electron beam welding equipment.

[0089] Summary of Example 1:

[0090] The pipe welding method provided in Example 1 has the following advantages: 1. The weld of the feed pipe head is full, which not only solves the problem of incomplete weld, but also leaves a suitable machining allowance after welding; 2. The weld passes the liquid penetrant inspection and radiographic testing, and the weld is well formed and free of defects such as hot cracks; 3. The external compensation ring releases welding stress and reduces welding deformation, and the welded base material pipe does not need to be straightened.

[0091] In summary, the application provides a pipe welding method and a compensation ring applied to pipe welding. The base material pipes to be welded are butt-jointed end-to-end, and a compensation ring is arranged on the outer periphery of the butt joint of the base material pipes. The butt joint of the base material pipes is vacuum electron beam welded, and the compensation ring is melted at the same time to form a weld at the butt joint of the base material pipes. The compensation ring makes the lowest point of the outer surface of the weld higher than or flush with the outer periphery of the base material pipes, that is, the compensation ring can effectively solve the problem of incomplete weld, thereby reducing the risk of incomplete weld. Moreover, the compensation ring is melted during welding, that is, the weld is formed by one-time welding, which is beneficial to ensuring the quality of the weld.

[0092] The application has the following advantages:

[0093] 1. The welding method of the application adopts an external compensation ring in cooperation with vacuum electron beam welding for the first time, which is used to solve the problem of incomplete weld of nickel-based alloy (such as NS1402, NS3105, etc.) pipe butt joint. For the problem of incomplete weld of nickel-based alloy pipe butt joint, the current method of using argon arc welding for repair cannot guarantee the quality of the weld.

[0094] 2. The welding method of the application adopts an external compensation ring in cooperation with vacuum electron beam welding for the first time, which successfully realizes the butt joint of nickel-based alloy (such as NS1402, NS3105, etc.) pipes, and the butt joint weld is well formed without defects such as hot cracks. For nickel-based alloy materials, traditional fusion welding methods such as argon arc welding are used for welding. Due to the poor weldability of the materials, the weld is prone to defects such as hot cracks. The use of vacuum electron beam welding helps to avoid the generation of hot cracks.

[0095] 3. The application adopts two half-ring forms of compensation bodies to form a complete compensation ring for the first time in vacuum electron beam welding. The compensation bodies are spot-welded to form a complete compensation ring. The compensation ring is convenient to lock at the butt joint of the base material pipes, and can realize the butt joint of straight pipes, the butt joint of straight pipes and bent pipes, and the butt joint of bent pipes. Compared with the integral compensation ring, the compensation ring of the application has a wide range of applications.

[0096] 4. The application adopts a compensation ring with a V-shaped structure for the first time in vacuum electron beam welding.

[0097] 5. The installation of the compensation ring is unique. The V-shaped structure of the clamping part cooperates with the limiting groove reserved in the base material pipe to achieve the purpose of limiting and centering.

[0098] 6. The structure of the compensation ring is unique. The cross-sectional shape of the compensation ring is a combination of a rectangle and an isosceles right triangle with a hypotenuse of 2 mm. The compensation ring structure is simple and easy to process.

[0099] 7. The compensation ring has the advantages of originality of function, not only leaving a suitable process allowance after welding, but also helping to release stress and reduce welding deformation during the welding process, and the pipe does not need to be straightened after welding.

[0100] 8. The method for determining the size of the compensation ring is original, and the outer diameter D1, the inner diameter D2 and the width d1 of the compensation ring are measured according to the size of the base material pipe and the welding test, and has certain flexibility in actual use.

[0101] 9. The pipe welding method provided by the present application is innovative.

[0102] 10. Compared with the welding method of the built-in gasket, the compensation ring provided by the present application does not have the problem that the built-in gasket is difficult to take out after welding, and the fusion excess height of the compensation ring after welding can be removed by grinding or machining.

[0103] The pipe welding method provided by the present application and the compensation ring applied to the pipe welding are described in detail above, and specific examples are applied to explain the principles and implementation modes of the present application. The above description of the examples is only used to help understand the method and the core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and the application range will be changed, and the above description should not be understood as a limitation of the present application.

Claims

1. A method of welding a pipe, characterized by, The method comprises the following steps: butting the base material pipe to be welded end to end, wherein a compensation ring is arranged on the outer periphery of the butt joint of the base material pipe; the compensation ring comprises a ring body and a clamping portion, and the clamping portion is arranged on the ring body; the ring body is arranged on the outer periphery of the butt joint of the base material pipe after the base material pipe to be welded is butted end to end, and the clamping portion is used to clamp the butt joint of the base material pipe; the outer diameter of the ring body is D1, the inner diameter of the ring body is D2, the outer diameter of the base material pipe is D3, and the maximum compensation amount of the weld is Tmax, wherein D1≥D2+2Tmax, and D2≥D3; vacuum electron beam welding is performed on the butt joint of the base material pipe, and the compensation ring is melted at the same time, so as to form a weld on the butt joint of the base material pipe, wherein the compensation ring is used to make the lowest part of the outer surface of the weld higher than or flush with the outer peripheral surface of the base material pipe.

2. The pipe welding method according to claim 1, wherein the width of the compensation ring is d1, and the width of the weld is d2; and d1≥d2.

3. The pipe welding method according to claim 1 or 2, wherein the compensation ring comprises at least two compensation bodies, and each compensation body is sequentially arranged along the circumferential direction of the compensation ring; and after the step of butting the base material pipe to be welded end to end, the method further comprises the following steps: sequentially arranging each compensation body on the outer periphery of the butt joint of the base material pipe; and point welding and fixing the butt joints of adjacent compensation bodies.

4. The pipe welding method according to claim 1 or 2, wherein before the step of performing vacuum electron beam welding on the butt joint of the base material pipe, the method further comprises the following steps: controlling the electron beam gun head to uniformly point weld the compensation ring along the circumferential direction of the compensation ring; aligning the relative position between the electron beam gun head and the base material pipe through a point welding track, so that the electron beam gun head is aligned with the center of the compensation ring; controlling the electron beam gun head to continuously weld the compensation ring along the circumferential direction of the compensation ring; aligning the relative position between the electron beam gun head and the base material pipe through a continuous welding track, so that the electron beam gun head is aligned with the center of the compensation ring.

5. The pipe welding method according to claim 1 or 2, wherein the step of performing vacuum electron beam welding on the butt joint of the base material pipe comprises the following step: performing vacuum electron beam welding on the butt joint of the base material pipe by using preset welding parameters, wherein the preset welding parameters match the sum of the thickness of the base material pipe wall and the ring thickness of the compensation ring.

6. The pipe welding method according to claim 1, wherein before the step of butting the base material pipe to be welded end to end, the method further comprises the following step: machining a bevel on the end of the base material pipe, so that the bevels of adjacent base material pipes form a limiting groove after the base material pipes are butted; and the compensation ring comprises a ring body and a clamping portion, the clamping portion is protruded on the inner side of the ring body, and the clamping portion is used to be clamped in the limiting groove after the ring body is arranged on the outer periphery of the butt joint of the base material pipe.

7. The pipe welding method according to claim 1 or 2, wherein The step of butt-jointing the base material pipe fittings end to end includes: Butt-jointing the base material pipe fittings end to end and spot-welding the base material pipe fittings at the butt-jointed part; wherein the assembly gap between adjacent base material pipe fittings is less than or equal to 0.05 mm.

8. A compensating ring for use in the welding of pipe, characterized by, The compensation ring includes: a ring body; and a clamping part provided on the ring body; wherein the ring body is used to be arranged around the outer periphery of the butt-jointed part of the base material pipe fittings after butt-jointing the base material pipe fittings end to end, and the clamping part is used to be clamped on the butt-jointed part of the base material pipe fittings; the outer diameter of the ring body is D1, the inner diameter of the ring body is D2, the outer diameter of the base material pipe fittings is D3, and the maximum compensation amount of the weld is Tmax, wherein D1≥D2+2Tmax, and D2≥D3; when vacuum electron beam welding is performed on the butt-jointed part of the base material pipe fittings, the compensation ring is melted together to form a weld on the butt-jointed part of the base material pipe fittings, and the compensation ring is used to make the lowest part of the outer surface of the weld higher than or flush with the outer peripheral surface of the base material pipe fittings.

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