Nondestructive testing tool and method for butt weld of dissimilar steel pipe joint
By designing the non-destructive testing tool for butt welds of different steel pipe joints, forming a pipe column structure and combining the communication connection between the X-ray transillumination system and the digital imaging processing system, the problem of short length of different steel pipe joints is solved, and efficient and low-cost non-destructive testing is achieved.
Patent Information
- Application Number
- CN202411386022.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, due to the short length of the different steel pipe joints, it is impossible to conduct non-destructive testing in an automatic X-ray transillumination system, resulting in manual filming, which is time-consuming, labor-intensive and costly.
A non-destructive testing tool for butt welds of different steel pipe joints is designed, and the workpiece is connected through several different steel pipe joints is coaxially distributed and connected through pipe joints to form a pipe column structure, which is mounted on the roller transmission rod and moved to the transillumination position of the X-ray transillumination system. Combined with the communication connection between the X-ray transillumination system and the digital imaging processing system, the non-destructive testing of the butt welds is realized.
By forming a pipe column structure, the different steel pipe joints can be effectively penetrated in the X-ray transillumination system, which improves the efficiency of non-destructive testing of butt welds, reduces the detection cost, and solves the shortcomings of manual testing.
Smart Images
Figure CN119985552A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of product nondestructive testing, and specifically relates to a nondestructive testing tool and method for a butt weld of a dissimilar steel pipe joint. Background Art
[0002] During the production process of boiler equipment header components, it is often necessary to weld dissimilar steel pipe joints on the header, most of which are dissimilar steel pipe joints that are butt-jointed with T92 and austenitic stainless steel. According to the standard requirements, the length of dissimilar steel butt joints is generally not less than 100mm, and the length of the pipes at both ends of the pipe joint butt weld is not less than 50mm; the manufacturer generally designs the pipe joint length to be within 150mm. In view that the length of the pipe to be inspected by the automatic X-ray radiography system is generally at least 1 meter, the dissimilar steel pipe joints on the header cannot be automatically imaged by X-ray digital imaging due to their short length, and only manual filming can be used for non-destructive testing of the butt welds. Manual testing is time-consuming, labor-intensive and costly. Summary of the invention
[0003] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a tool and method for non-destructive testing of butt welds of dissimilar steel pipe joints, so as to solve the technical problem of how to uniformly perform non-destructive testing of butt welds of dissimilar steel pipe joints of several short sections in the prior art.
[0004] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a nondestructive testing tool for butt welds of dissimilar steel pipe joints, including a plurality of dissimilar steel pipe joints, a roller transmission rod, an X-ray transillumination system, and a digital imaging processing system; A plurality of heterogeneous steel pipe joints are coaxially distributed, and adjacent heterogeneous steel pipe joints are connected by pipe joint connecting tools to form a pipe column structure; The pipe column structure is mounted on the roller transmission rod and is moved to the transillumination position of the X-ray transillumination system through the roller transmission rod; the X-ray transillumination system is communicatively connected with the digital imaging processing system.
[0005] Preferably, the pipe joint connection tool comprises a connection pipe; Both ends of the connecting pipe are coaxially and fixedly connected with access pipes; Adjacent heterogeneous steel pipe joints are respectively sleeved on the access pipes and located on both sides of the connecting pipe.
[0006] Furthermore, the outer wall of the access pipe is provided with anti-slip grooves; the heterogeneous steel pipe joint is sleeved on the access pipe, and the inner wall of the heterogeneous steel pipe joint contacts the anti-slip grooves on the outer wall of the access pipe.
[0007] Furthermore, a diameter expansion device is provided in the connecting pipe; The two ends of the diameter expansion device extend to the inner hole of the access pipe respectively, and are used to expand the inner hole of the access pipe to tighten the access pipe into the heterogeneous steel pipe joint.
[0008] Furthermore, the two ends of the inner hole of the access pipe are a first port and a second port; the first port is larger than the second port; the first port is the end of the access pipe close to the connecting pipe, and the second port is the end of the access pipe away from the connecting pipe; the pipe between the first port and the second port has a constricted structure.
[0009] Furthermore, the diameter expansion device includes a bolt and two sets of diameter expansion rods; Two groups of expansion rods are coaxially arranged in the connecting pipe and are respectively aligned with the inner holes of the access pipe; One end of the bolt penetrates into the connecting pipe, and the end is pressed between the ends of the two groups of expansion rods, so as to drive the two groups of expansion rods to advance along the inner hole of the access pipe after the bolt is inserted into the connecting pipe.
[0010] Furthermore, the rod body of the bolt is in a conical structure, wherein the diameter of the rod body is arranged to decrease along the direction of extending into the connecting pipe.
[0011] Furthermore, the diameter of the expansion rod corresponds to the inner diameter of the first port connected to the inner hole of the pipe.
[0012] Preferably, a controller is provided in the digital imaging processing system, the input end of the controller is connected to the signal input module, and the output end of the controller is connected to the processor and the human-computer interaction module; The input end of the signal input module is connected to the X-ray transillumination system.
[0013] In a second aspect, the present invention further provides a method for nondestructive testing of butt welds of dissimilar steel pipe joints, based on the above-mentioned nondestructive testing tool for butt welds of dissimilar steel pipe joints, comprising the following process: Distribute a number of different steel pipe joints coaxially and connect them in sequence through pipe joint connection tools to form a pipe column structure; The pipe column structure is mounted on the roller transmission rod and is moved to the irradiation position of the X-ray irradiation system through the roller transmission rod; The X-ray transillumination system transilluminates the butt welds on the pipe string structure, and generates digital negatives from the transillumination data through the digital imaging processing system.
[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a nondestructive testing tool for butt welds of dissimilar steel pipe joints. A plurality of dissimilar steel pipe joints are coaxially distributed and adjacent dissimilar steel pipe joints are respectively connected by pipe joint connecting tooling to form a pipe column structure, so that the dissimilar steel pipe joints form a pipe column body with a certain length, which is convenient for an X-ray transillumination system to perform transillumination. The pipe column structure is erected on the roller transmission rod and is moved to the transillumination position of the X-ray transillumination system through the roller transmission rod; the X-ray transillumination system is communicatively connected with a digital imaging processing system, and the transillumination data is fed back to the digital imaging processing system through the X-ray transillumination system, thereby improving the nondestructive testing efficiency of butt welds.
[0015] Furthermore, the pipe fitting connection tooling includes a connecting pipe; both ends of the connecting pipe are coaxially fixedly connected with access pipes; adjacent dissimilar steel pipe joints are respectively sleeved on the access pipes and located on both sides of the connecting pipe, and the access pipes coaxially fixedly connected at both ends of the connecting pipe ensure the stability and consistency of the dissimilar steel pipe joints during the connection process, avoid misalignment and offset between the joints, and improve the stability of the overall structure.
[0016] Furthermore, the outer wall of the access pipe is provided with anti-slip grooves; the dissimilar steel pipe joint is sleeved on the access pipe, and the inner wall of the dissimilar steel pipe joint contacts the anti-slip grooves on the outer wall of the access pipe, thereby ensuring the stability of the assembly of the dissimilar steel pipe joint and the access pipe.
[0017] Furthermore, a diameter expansion device is provided in the connecting pipe; the two ends of the diameter expansion device extend to the inner hole of the access pipe respectively, and are used to expand the inner hole of the access pipe to tighten the access pipe into the heterogeneous steel pipe joint, wherein the diameter expansion device expands the inner hole of the access pipe so that it fits more closely with the inner wall of the heterogeneous steel pipe joint. This close fit enhances the stability of the connection; the function of the diameter expansion device is not limited to increasing the contact area, but also firmly fixes the access pipe into the heterogeneous steel pipe joint by physical means. This mechanical locking effect significantly improves the strength and durability of the connection.
[0018] Furthermore, the two ends of the inner hole of the access pipe are a first port and a second port; the first port is larger than the second port; the first port is the end of the access pipe close to the connecting pipe, and the second port is the end of the access pipe away from the connecting pipe; the pipeline between the first port and the second port is a necking structure, so that the two ends of the expansion device can be abutted against the inside of the necking during the process of pushing into the inner hole, so that the inner diameter of the access pipe is expanded, thereby improving the stability of the abutment between the access pipe and the heterogeneous steel pipe joint; the design of the necking structure enables the expansion device to generate a greater locking force during the expansion process, firmly locking the access pipe in the heterogeneous steel pipe joint, thereby improving the stability and reliability of the connection.
[0019] Furthermore, the expansion device includes a bolt and two groups of expansion rods; the two groups of expansion rods are coaxially arranged in the connecting tube and are respectively aligned with the inner hole of the access tube; one end of the bolt penetrates into the connecting tube, and the end is pressed between the ends of the two groups of expansion rods, which is used to insert the bolt into the connecting tube and drive the two groups of expansion rods to advance along the inner hole of the access tube. The two groups of expansion rods are coaxially arranged in the connecting tube to ensure that they can maintain linear motion during the advancement process to avoid uneven expansion caused by offset or tilt. The expansion rods are respectively aligned with the inner hole of the access tube, so that the expansion force can directly act on the inner wall of the access tube to achieve accurate and efficient expansion effect. The two groups of expansion rods act simultaneously, so that the inner hole of the access tube can be expanded evenly, avoiding stress concentration and local deformation caused by a single expansion point.
[0020] Furthermore, the rod body of the bolt has a conical structure, wherein the diameter of the rod body is arranged to decrease along the direction of inserting into the connecting pipe, and the insertion of the bolt can effectively push the two sets of expanding rods along the inner hole of the access pipe.
[0021] The present invention also provides a method for nondestructive testing of butt welds of dissimilar steel pipe joints, wherein a plurality of dissimilar steel pipe joints are connected together by a pipe joint connecting tool to form a pipe column structure, and the pipe column structure is sent to an existing X-ray industrial television system for nondestructive testing of the butt welds of the dissimilar steels. The present invention solves the problem that the butt welds of short-connected dissimilar steel pipe joints can only be subjected to manual X-ray filming due to their short size and cannot be subjected to nondestructive testing in the existing X-ray transillumination system, thereby greatly improving the testing efficiency, reducing the testing cost, and having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is an overall schematic diagram of a non-destructive testing tool for butt welds of dissimilar steel pipe joints in an embodiment of the present invention; Figure 2 This is a schematic structural diagram of a pipe joint connection tool in an embodiment of the present invention; Figure 3 It is a structural schematic diagram of another pipe joint connection tooling in an embodiment of the present invention; Figure 4 for Figure 3 Sectional view of part A; In the figure: 1-dissimilar steel pipe joint; 2-pipe joint connecting tooling; 3-roller transmission rod; 4-X-ray transillumination system; 5-digital imaging processing system; 6-expansion device; 7-support rod; 21-connecting pipe; 22-access pipe; 61-bolt; 62-expansion rod. DETAILED DESCRIPTION
[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0024] The present invention is further described in detail below in conjunction with the accompanying drawings: The purpose of the present invention is to provide a non-destructive testing tool and method for butt welds of dissimilar steel pipe joints, so as to solve the technical problem of how to uniformly perform non-destructive testing on butt welds of dissimilar steel pipe joints of several short sections in the prior art.
[0025] Example 1 See also Figure 1 In one embodiment of the present invention, a nondestructive testing tool for butt welds of dissimilar steel pipe joints is provided, comprising a plurality of dissimilar steel pipe joints 1, a roller transmission rod 3, an X-ray transillumination system 4 and a digital imaging processing system 5; A plurality of heterogeneous steel pipe joints 1 are coaxially distributed and arranged, and adjacent heterogeneous steel pipe joints 1 are connected by pipe joint connecting tools 2 to form a pipe column structure; The pipe column structure is mounted on the roller transmission rod 3 and is moved to the transillumination position of the X-ray transillumination system 4 through the roller transmission rod 3; the X-ray transillumination system 4 is communicatively connected with the digital imaging processing system 5.
[0026] Specifically, the pipe joint connecting tool 2 includes a connecting pipe 21 ; both ends of the connecting pipe 21 are coaxially fixedly connected with access pipes 22 ; adjacent heterogeneous steel pipe joints 1 are respectively sleeved on the access pipes 22 and located on both sides of the connecting pipe 21 .
[0027] Specifically, the outer wall of the access pipe 22 is provided with anti-slip grooves; the heterogeneous steel pipe joint 1 is sleeved on the access pipe 22, and the inner wall of the heterogeneous steel pipe joint 1 contacts the anti-slip grooves on the outer wall of the access pipe 22, such as Figure 2 shown.
[0028] In this embodiment, several heterogeneous steel pipe joints are coaxially distributed to ensure that the butt welds of all joints can be uniformly X-rayed during the inspection process. The pipe joint connection tool 2 includes a connecting pipe 21 and an access pipe 22. The connecting pipe serves as an intermediate bridge, and the two ends of the connecting pipe are coaxially fixedly connected with the access pipe. The design of the access pipe allows adjacent heterogeneous steel pipe joints to be respectively sleeved thereon and located on both sides of the connecting pipe, thereby forming a stable pipe column structure.
[0029] Example 2 See also Figure 1 In one embodiment of the present invention, a nondestructive testing tool for butt welds of dissimilar steel pipe joints is provided, comprising a plurality of dissimilar steel pipe joints 1, a roller transmission rod 3, an X-ray transillumination system 4 and a digital imaging processing system 5; A plurality of heterogeneous steel pipe joints 1 are coaxially distributed and arranged, and adjacent heterogeneous steel pipe joints 1 are connected by pipe joint connecting tools 2 to form a pipe column structure; The pipe column structure is mounted on the roller transmission rod 3 and is moved to the transillumination position of the X-ray transillumination system 4 through the roller transmission rod 3; the X-ray transillumination system 4 is communicatively connected with the digital imaging processing system 5.
[0030] Specifically, the pipe joint connecting tool 2 includes a connecting pipe 21 ; both ends of the connecting pipe 21 are coaxially fixedly connected with access pipes 22 ; adjacent heterogeneous steel pipe joints 1 are respectively sleeved on the access pipes 22 and located on both sides of the connecting pipe 21 .
[0031] Specifically, according to Figure 3 As shown, a diameter expansion device 6 is provided in the connecting pipe 21; both ends of the diameter expansion device 6 extend to the inner hole of the access pipe 22 respectively, and are used to expand the inner hole of the access pipe 22 to tighten the access pipe 22 in the heterogeneous steel pipe joint 1.
[0032] Specifically, the two ends of the inner hole of the access pipe 22 are a first port and a second port; the first port is larger than the second port; the first port is the end of the access pipe 22 close to the connecting pipe 21, and the second port is the end of the access pipe 22 away from the connecting pipe 21; the pipeline between the first port and the second port is a constricted structure.
[0033] Among them, the expansion device 6 includes a bolt 61 and two sets of expansion rods 62; the two sets of expansion rods 62 are coaxially arranged in the connecting tube 21 and are respectively aligned with the inner holes of the access tube 22; one end of the bolt 61 penetrates into the connecting tube 21, and the end is pressed between the ends of the two sets of expansion rods 62, which is used to extend the bolt 61 into the connecting tube 21 and drive the two sets of expansion rods 62 to advance along the inner hole of the access tube 22.
[0034] Specifically, according to Figure 4 As shown, the rod body of the bolt 61 is of a conical structure, wherein the diameter of the rod body is gradually reduced along the direction of extending into the connecting pipe 21 .
[0035] The diameter of the expansion rod 62 corresponds to the inner diameter of the first port of the inner hole of the access pipe 22 .
[0036] In this embodiment, the expansion device 6 is located in the connecting tube 21, and includes a bolt 61 and two groups of expansion rods 62. The rod body of the bolt 61 is a conical structure, and the diameter decreases along the insertion direction, so as to gradually increase the thrust on the expansion rod 62 during the insertion process. The rod diameter of the expansion rod 62 corresponds to the inner diameter of the first port of the inner hole of the access tube 22. When the bolt 61 is inserted into the connecting tube 21, its end is pressed between the ends of the two groups of expansion rods 62. As the bolt 61 continues to be inserted, its conical structure gradually increases the thrust on the expansion rod 62, driving the two groups of expansion rods 62 to advance along the inner hole of the access tube 22. Since the two ends of the inner hole of the access tube 22 are the first port and the second port, and the first port is larger than the second port, a shrinking structure is formed. The expansion rod 62 will expand the inner hole of the access tube 22 during the advancement process, so that it fits tightly with the inner wall of the heterogeneous steel pipe joint 1 to achieve a tightening effect. In this embodiment, the access pipe 22 is a discontinuous petal-shaped structure with a variable outer diameter, and is made of a wear-resistant alloy; the bolt 61 can be operated manually, pneumatically or electrically to meet the requirements of different working conditions.
[0037] In Examples 1 and 2, a controller is provided in the digital imaging processing system 5 , the input end of the controller is connected to the signal input module, and the output end of the controller is connected to the processor and the human-computer interaction module; the input end of the signal input module is connected to the X-ray transillumination system 4 .
[0038] Wherein, both Example 1 and Example 2 also include a support rod 7, and the support rod 7 is arranged at a position corresponding to the roller transmission rod 3, so that one end of the pipe column structure formed by several heterogeneous steel pipe joints 1 connected by the pipe joint connecting tooling 2 is mounted on the support rod 7, and the other end is mounted on the roller transmission rod 3.
[0039] To summarize, Example 1 and Example 2 are structural embodiments, which provide a nondestructive testing tool for butt welds of dissimilar steel pipe joints. A number of dissimilar steel pipe joints are coaxially distributed, and adjacent dissimilar steel pipe joints are respectively connected by pipe joint connecting tooling to form a pipe column structure, so that the dissimilar steel pipe joints form a pipe column body with a certain length, which is convenient for the X-ray transillumination system to perform transillumination. The pipe column structure is erected on the roller transmission rod and is moved to the transillumination position of the X-ray transillumination system through the roller transmission rod; the X-ray transillumination system is communicatively connected to the digital imaging processing system, and the transillumination data is fed back to the digital imaging processing system through the X-ray transillumination system, thereby improving the efficiency of nondestructive testing of butt welds.
[0040] Example 3 This embodiment provides a method for nondestructive testing of butt welds of dissimilar steel pipe joints, based on the above-mentioned nondestructive testing tool for butt welds of dissimilar steel pipe joints, including the following process: A plurality of heterogeneous steel pipe joints 1 are coaxially distributed and connected in sequence through pipe joint connecting tools 2 to form a pipe column structure; the pipe column structure is mounted on a roller transmission rod 3 and is moved to an irradiation position of an X-ray irradiation system 4 through the roller transmission rod 3; the X-ray irradiation system 4 irradiates the butt welds on the pipe column structure and generates a digital negative film from the irradiation data through a digital imaging processing system 5.
[0041] Among them, one structure of the pipe joint connecting tool 2 includes a connecting pipe 21; both ends of the connecting pipe 21 are coaxially fixedly connected with access pipes 22; adjacent heterogeneous steel pipe joints 1 are respectively sleeved on the access pipes 22 and located on both sides of the connecting pipe 21.
[0042] Among them, another structure of the pipe joint connection tooling 2 includes a connecting pipe 21; the two ends of the connecting pipe 21 are respectively coaxially fixedly connected with an access pipe 22; the adjacent heterogeneous steel pipe joints 1 are respectively sleeved on the access pipe 22 and located on both sides of the connecting pipe 21; wherein, a diameter expansion device 6 is provided in the connecting pipe 21; the two ends of the diameter expansion device 6 respectively extend to the inner hole of the access pipe 22, and are used to expand the inner hole of the access pipe 22 to tighten the access pipe 22 in the heterogeneous steel pipe joint 1; Among them, the expansion device 6 includes a bolt 61 and two groups of expansion rods 62; the two groups of expansion rods 62 are coaxially arranged in the connecting tube 21 and are respectively aligned with the inner hole of the access tube 22; one end of the bolt 61 is inserted into the connecting tube 21, and the end is pressed between the ends of the two groups of expansion rods 62, which is used to extend the bolt 61 into the connecting tube 21 and drive the two groups of expansion rods 62 to advance along the inner hole of the access tube 22. The two groups of expansion rods 62 are coaxially arranged in the connecting tube 21 to ensure that they can maintain linear motion during the advancement process to avoid uneven expansion caused by offset or tilt. The expansion rods 62 are respectively aligned with the inner hole of the access tube, so that the expansion force can directly act on the inner wall of the access tube to achieve accurate and efficient expansion effect.
[0043] In summary, the present embodiment provides a method for connecting a plurality of heterogeneous steel pipe joints together through a pipe joint connecting tool to form a pipe column structure, and sending the pipe column structure to an existing X-ray industrial television system for non-destructive testing of the heterogeneous steel butt welds. The present invention solves the problem that the butt welds of short-connected heterogeneous steel pipe joints can only be subjected to manual X-ray filming due to their short size, but cannot be subjected to non-destructive testing in the existing X-ray transillumination system, greatly improves the detection efficiency, reduces the detection cost, and has good application prospects.
[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A non-destructive testing tool for butt welds of dissimilar steel pipe joints, characterized in that: It comprises a plurality of heterogeneous steel pipe joints (1), a roller transmission rod (3), an X-ray transillumination system (4) and a digital imaging processing system (5); A plurality of heterogeneous steel pipe joints (1) are coaxially distributed, and adjacent heterogeneous steel pipe joints (1) are connected via pipe joint connecting tools (2) to form a pipe column structure; The pipe column structure is mounted on the roller transmission rod (3) and is moved to the transillumination position of the X-ray transillumination system (4) through the roller transmission rod (3); the X-ray transillumination system (4) is communicatively connected with the digital imaging processing system (5).
2. The non-destructive testing tool for butt welds of heterogeneous steel pipe joints according to claim 1 is characterized in that: The pipe joint connecting tool (2) comprises a connecting pipe (21); Both ends of the connecting pipe (21) are coaxially and fixedly connected to access pipes (22); Adjacent heterogeneous steel pipe joints (1) are respectively sleeved on the access pipes (22) and located on both sides of the connecting pipe (21).
3. The non-destructive testing tool for butt welds of heterogeneous steel pipe joints according to claim 2, characterized in that: The outer wall of the access pipe (22) is provided with anti-slip grooves; the heterogeneous steel pipe joint (1) is sleeved on the access pipe (22), and the inner wall of the heterogeneous steel pipe joint (1) is in contact with the anti-slip grooves on the outer wall of the access pipe (22).
4. The non-destructive testing tool for butt welds of heterogeneous steel pipe joints according to claim 2 is characterized in that: The connecting pipe (21) is provided with a diameter expansion device (6); Both ends of the diameter expansion device (6) extend to the inner hole of the access pipe (22) respectively, and are used to expand the inner hole of the access pipe (22) to tighten the access pipe (22) into the heterogeneous steel pipe joint (1).
5. The non-destructive testing tool for butt welds of dissimilar steel pipe joints according to claim 4 is characterized in that: The two ends of the inner hole of the access pipe (22) are a first port and a second port; the first port is larger than the second port; the first port is an end of the access pipe (22) close to the connecting pipe (21), and the second port is an end of the access pipe (22) away from the connecting pipe (21); the pipe between the first port and the second port is a constricted structure.
6. The non-destructive testing tool for butt welds of dissimilar steel pipe joints according to claim 4 is characterized in that: The diameter expansion device (6) comprises a bolt (61) and two sets of diameter expansion rods (62); Two groups of diameter-expanding rods (62) are coaxially arranged in the connecting tube (21) and are respectively aligned with the inner holes of the access tube (22); One end of the bolt (61) is inserted into the connecting tube (21), and the end is pressed between the ends of the two sets of expansion rods (62), so that the bolt (61) is inserted into the connecting tube (21) and drives the two sets of expansion rods (62) to be pushed along the inner hole of the access tube (22).
7. The non-destructive testing tool for butt welds of dissimilar steel pipe joints according to claim 6, characterized in that: The rod body of the bolt (61) is in a conical structure, wherein the diameter of the rod body is arranged to decrease along the direction in which the rod body extends into the connecting pipe (21).
8. The non-destructive testing tool for butt welds of dissimilar steel pipe joints according to claim 6 is characterized in that: The diameter of the expansion rod (62) corresponds to the inner diameter of the first port of the inner hole of the access pipe (22).
9. The non-destructive testing tool for butt welds of heterogeneous steel pipe joints according to claim 1 is characterized in that: The digital imaging processing system (5) is provided with a controller, the input end of the controller is connected to the signal input module, and the output end of the controller is connected to the processor and the human-computer interaction module; The input end of the signal input module is connected to the X-ray transillumination system (4).
10. A nondestructive testing method for butt welds of dissimilar steel pipe joints, characterized in that: A non-destructive testing tool for butt welds of dissimilar steel pipe joints according to claim 1, comprising the following process: Distributing a plurality of different types of steel pipe joints (1) coaxially and connecting them in sequence through pipe joint connecting tools (2) to form a pipe column structure; The pipe column structure is mounted on a roller transmission rod (3) and is moved to an irradiation position of an X-ray irradiation system (4) via the roller transmission rod (3); The X-ray transillumination system (4) transilluminates the butt weld on the pipe column structure, and generates a digital negative film using the transillumination data through the digital imaging processing system (5).