Seal welding prefabrication process for hydrogen blocking coating and stainless steel intersection area of inner wall port of hydrogen conveying pipeline and prefabricated pipeline

Abstract

The invention relates to the technical field of hydrogen energy transportation pipeline welding, in particular to a hydrogen transportation pipeline inner wall port hydrogen resistance coating and stainless steel intersection area seal welding prefabrication process and a prefabrication pipeline. The process comprises the steps that a carbon steel pipe is prepared, a nickel base alloy part extends into the carbon steel pipe and is subjected to annular seal welding to form a gentle slope seal welding part, and then the pipe end is welded and sealed; and finally, a hydrogen-resistant coating is sprayed to the middle of the seal welding part, the edge of the coating is fundamentally prevented from being damaged by machinery and air flow through the process of welding firstly, coating secondly and stopping the coating on a gentle slope, a high-strength and hydrogen embrittlement-resistant standard connecting end is prefabricated in a factory, and the sealing reliability, the construction efficiency and the long-term operation safety of the pipeline are remarkably improved.

Description

Technical Field

[0001] This invention relates to the technical field of welding hydrogen transport pipelines, and in particular to a prefabrication process and prefabricated pipeline for sealing the junction area between hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen transport pipeline. Background Technology

[0002] A prefabrication process and prefabricated pipeline for sealing the junction area between hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen pipeline. High-pressure hydrogen pipelines are pipeline systems specifically designed for large-scale, long-distance hydrogen transportation. They transport hydrogen under high pressure, delivering it to downstream users in an economical and efficient manner. Traditional hydrogen pipelines are mostly made of stainless steel or nickel-based alloys, which are costly; some use hydrogen-resistant carbon steel pipelines, but these are prone to hydrogen embrittlement, permeation, and corrosion under high pressure and high-purity hydrogen environments, posing significant risks in long-term operation.

[0003] In recent years, a new hydrogen pipeline structure has emerged, using low-cost carbon steel as the base support pipe. Its inner wall is coated with a hydrogen permeation-resistant coating through spraying or plating, and nickel-based alloy material is applied to the pipe ends to achieve a combination of corrosion resistance and structural strength. During pipeline installation, multiple prefabricated pipe sections need to be welded together as a whole.

[0004] However, the brittle functional coating on the inner wall of existing precast pipelines extends to the pipe end face, and the edges are easily peeled off or damaged during subsequent pipeline construction (such as pigging and pipe cleaning) and long-term operation (high-speed airflow scouring). Summary of the Invention

[0005] The purpose of this invention is to provide a prefabrication process and prefabricated pipeline for sealing the intersection area of ​​hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen pipeline, in order to solve the technical problem in the prior art where the brittle functional coating on the inner wall of the prefabricated pipeline extends to the pipe end face, and the edge is easily peeled off or damaged during subsequent pipeline construction (such as pigging and pipe cleaning) and long-term operation (high-speed airflow scouring).

[0006] In a first aspect, the present invention provides a prefabrication process for sealing the junction area between a hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen transport pipeline, comprising the following steps: S1. Prepare carbon steel base material pipe; S2. Roll the nickel-based alloy plate into a cylindrical shape and insert it into the carbon steel substrate tube as a nickel-based alloy part. Then, circumferentially seal the end of the nickel-based alloy part away from the end face of the carbon steel substrate tube to the carbon steel substrate tube to form a sealing part. S3. Weld one end of the nickel-based alloy component near the port of the carbon steel substrate tube to the end face of the carbon steel substrate tube. S4. Spray an anti-hydrogen coating onto the inner surface of the carbon steel substrate tube, so that the anti-hydrogen coating extends to the middle of the sealing weld.

[0007] Furthermore, S2 includes; The nickel-based alloy plate is rolled into a cylindrical shape, inserted into the carbon steel base tube, and then the nickel-based alloy part is welded into a complete cylinder along the joint seam of the cylinder, and the nickel-based alloy part is welded and fixed to the carbon steel base tube.

[0008] Furthermore, during circumferential sealing welding, by controlling the energy distribution of the welding heat source and / or the location of the filler metal addition, the amount of filler metal deposited on the outer side of the formed sealing part on the cross-section is greater than that on the inner side, thereby naturally forming a gentle slope that smoothly transitions from the inner surface of the nickel-based alloy part to the inner surface of the carbon steel substrate tube.

[0009] Furthermore, when welding one end of the nickel-based alloy component near the port of the carbon steel substrate tube to the end face of the carbon steel substrate tube; The nickel-based alloy component is attached to the inner wall at a predetermined distance from the end face of the carbon steel substrate tube. Welding is performed on the end face area of ​​the port until the surface of the weld metal formed by the weld is flush with the inner surface of the nickel-based alloy part and the outer surface of the carbon steel base tube, forming a flush transition surface. Subsequently, based on the flush transition surface, cladding welding is performed from the outer wall side of the carbon steel substrate tube so that the weld metal completely covers the end area of ​​the nickel-based alloy part.

[0010] Furthermore, when preparing the carbon steel substrate tube; A bevel is machined on the outer wall of the end of the carbon steel base tube, and the bevel is set at an angle of 20° to 45° with the axial direction of the carbon steel base tube.

[0011] Furthermore, the prefabrication process for sealing the junction area between the hydrogen barrier coating and the stainless steel at the inner wall port of the hydrogen pipeline also includes; S4. Perform X-ray flaw detection on the prefabricated pipeline after welding.

[0012] Secondly, the present invention also provides a prefabricated hydrogen transport pipeline, which is prepared by the aforementioned prefabrication process of sealing the junction area between the hydrogen barrier coating on the inner wall of the hydrogen transport pipeline and stainless steel, comprising: Carbon steel base material pipe; Two nickel-based alloy parts are respectively disposed at both ends of the carbon steel substrate tube. The nickel-based alloy parts extend into the carbon steel substrate tube such that the end of the nickel-based alloy part near the port of the carbon steel substrate tube is at a set distance from the port of the carbon steel substrate tube. A weld overlay is provided between the nickel-based alloy part and the port of the carbon steel substrate tube. A hydrogen-resistant coating is provided on the inner wall of the carbon steel substrate tube, and the hydrogen-resistant coating extends to the middle of the sealing weld portion.

[0013] Furthermore, the outer surface of the carbon steel substrate tube at the port is provided with a slope, and the slope is set at an angle of 20° to 45° with the axial direction of the carbon steel substrate tube.

[0014] Thirdly, the present invention also provides a prefabricated hydrogen transport pipeline, which is prepared by the aforementioned prefabrication process of sealing the junction area between the hydrogen barrier coating on the inner wall of the hydrogen transport pipeline and stainless steel, comprising: Carbon steel base material pipe; Two nickel-based alloy components are respectively disposed at both ends of the carbon steel substrate tube. The nickel-based alloy components extend into the carbon steel substrate tube so that the end of the nickel-based alloy component near the port of the carbon steel substrate tube is flush with the port of the carbon steel substrate tube. A hydrogen-resistant coating is provided on the inner wall of the carbon steel substrate tube, and the hydrogen-resistant coating extends to the middle of the sealing weld portion.

[0015] Furthermore, the outer surface of the carbon steel substrate tube at the port is provided with a slope, and the slope is set at an angle of 20° to 45° with the axial direction of the carbon steel substrate tube.

[0016] Compared with the prior art, the present invention provides a prefabrication process for sealing the junction area between the hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen pipeline, comprising the following steps: S1. Prepare carbon steel base material pipe; S2. Roll the nickel-based alloy plate into a cylindrical shape and insert it into the carbon steel substrate tube to form a nickel-based alloy part. Then, circumferentially seal the end of the nickel-based alloy part away from the end face of the carbon steel substrate tube to the carbon steel substrate tube to form a sealing part. S3. Weld the end of the nickel-based alloy part near the port of the carbon steel base tube to the end face of the carbon steel base tube. S4. Spray an anti-hydrogen coating onto the inner surface of the carbon steel substrate pipe, extending the anti-hydrogen coating to the middle of the sealing weld. By optimizing the process sequence, the hydrogen-resistant coating is applied after the core welding, and the coating is precisely controlled to terminate at the middle of the gentle slope naturally formed by the sealing welding process. This places the functional coating in a protected area with mechanical shielding and stress dispersion, fundamentally preventing edge peeling caused by mechanical impact or airflow erosion during construction and operation, significantly improving the long-term reliability of the pipeline. Simultaneously, a three-dimensional metallurgical seal from the inner wall to the end face between the nickel-based alloy components and the carbon steel base pipe is pre-completed in a factory environment, forming a high-strength, hydrogen-embrittle-resistant standardized connection end. This greatly simplifies the complexity of on-site butt welding, improving overall construction efficiency and joint safety. The clear process chain design enables efficient and controllable factory prefabrication, ensuring the consistency and stability of prefabricated pipeline quality, providing key technical support for the large-scale, safe construction of high-pressure hydrogen pipelines. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the prefabrication process of sealing the intersection area between the hydrogen barrier coating and stainless steel at the inner wall port of a hydrogen pipeline, as provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the prefabricated pipeline structure for hydrogen transportation provided in Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the prefabricated pipeline structure for hydrogen transportation provided in Embodiment 3 of the present invention.

[0019] Figure label: 100. Carbon steel base material pipe; 110. Sloping surface; 200. Nickel-based alloy parts; 300. Hydrogen-resistant coating; 400. Sealing and welding section; 500. Welding section. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] Example 1 This embodiment provides a method for preparing prefabricated hydrogen transportation pipelines, such as... Figure 1 As shown. This method aims to systematically solve the key technical problem mentioned in the background art—that the functional coating on the inner wall of prefabricated pipes is easily peeled off or damaged because it extends to the pipe ends—through optimized process steps, while simultaneously achieving highly reliable sealing at the connection ends and efficient factory prefabrication. The method includes the following steps: S1. Prepare carbon steel base material pipe.

[0028] Carbon steel pipes meeting strength requirements are selected as the base structure. In a preferred embodiment, a bevel 110 can be pre-machined on the outer wall of the end of the carbon steel base pipe 100 to facilitate subsequent welding operations and accommodate weld metal. The angle between the bevel 110 and the axial direction of the carbon steel base pipe 100 is preferably set between 20° and 45° (e.g., 30°), and the bevel depth can be determined according to the pipe diameter and wall thickness.

[0029] S2, nickel-based alloy parts are installed and sealed.

[0030] First, a prefabricated nickel-based alloy plate (such as Inconel 625) is rolled into a cylindrical shape, serving as the nickel-based alloy component 200, and inserted into a designated position at the end of the carbon steel base tube 100. To ensure the structural integrity of the nickel-based alloy component 200, it is welded along the longitudinal joint of its cylinder to form a complete annular lining, which is then initially fixed to the carbon steel base tube 100. Subsequently, a crucial annular sealing weld operation is performed: at the end of the nickel-based alloy component 200 furthest from the end face of the carbon steel base tube (i.e., the part extending deeper into the pipe), it is circumferentially sealed to the inner wall of the carbon steel base tube 100. This weld constitutes the sealing section 400.

[0031] To achieve the special protective function of the weld seal 400, during circumferential welding, the energy distribution of the welding heat source (such as laser or TIG) and / or the position of the filler metal addition are consciously controlled (e.g., the welding torch is offset outwards, or the wire feed point is biased outwards). This results in the weld seal 400 exhibiting a greater filler thickness on the outer side than on the inner side in cross-section. This "long outer, short inner" welding strategy allows the molten metal to naturally form a gentle slope that smoothly transitions from the inner surface of the nickel-based alloy part 200 to the inner surface of the carbon steel substrate tube 100. This gentle slope structure forms the basis for the ideal termination position of the subsequent hydrogen-resistant coating.

[0032] S3. Pipe end welding seal.

[0033] This step is the second step in completing the three-dimensional sealing of the prefabricated pipe end. Its goal is to reliably connect the end of the nickel-based alloy component 200 near the port to the end face of the carbon steel base pipe 100, and completely seal the interface between the carbon steel and the nickel-based alloy.

[0034] Method 1 (as in Example 2): The end of the nickel-based alloy part 200 is directly welded to the end face of the carbon steel substrate tube 100.

[0035] Method 2 (corresponding to the structure of Embodiment 3): First, the nickel-based alloy part 200 is attached to the inner wall at a predetermined distance (e.g., 1-3 mm) from the end face of the pipe. Then, welding is performed on the end face area until the weld metal surface is flush with the inner surface of the nickel-based alloy part 200 and the outer surface of the carbon steel base tube 100, forming a flush transition surface (i.e., weld overlay 500). Finally, based on this flush transition surface, cladding welding is performed from the outer wall side of the carbon steel base tube 100, so that the weld metal completely covers the end area of ​​the nickel-based alloy part 200.

[0036] S4, Hydrogen-resistant coating applied.

[0037] After all high-temperature welding steps (S2, S3) are completed and pass inspection, an anti-hydrogen permeation functional coating, namely the anti-hydrogen coating 300, is sprayed onto the inner surface of the carbon steel base pipe 100 (including the welded gentle slope area). The coating boundary of the anti-hydrogen coating 300 is strictly controlled so that it extends precisely to the middle of the gentle slope formed by the welded section 400. In this way, the coating terminates in a mechanically shielded area with no sharp edges and a gentle stress distribution, rather than at the vulnerable pipe end or weld edge, thus structurally avoiding coating edge peeling caused by subsequent pigging, airflow erosion, etc.

[0038] S5. Post-weld inspection and repair.

[0039] After all welding steps are completed, the prefabricated pipeline undergoes rigorous non-destructive testing, preferably using X-ray inspection, to confirm the absence of defects such as incomplete fusion, porosity, and slag inclusions inside the weld. If necessary, minor pipe end deformations caused by welding can be trimmed.

[0040] The preparation method provided in this embodiment, through the process of "first constructing a metal sealing structure, then implementing a functional coating, and precisely controlling the coating boundary", not only perfectly solves the coating protection problem, but also prefabricates standardized connection ends with high integrity and resistance to hydrogen embrittlement in a factory environment, laying a solid foundation for the efficient and reliable on-site connection and laying of high-pressure hydrogen pipelines.

[0041] Example 2 This embodiment provides a prefabricated hydrogen transport pipeline prepared by the preparation method of Embodiment 1 (especially using Method 1 in S3), the structure of which is as follows. Figure 2 As shown.

[0042] The prefabricated pipeline includes: carbon steel base pipe 100, nickel-based alloy component 200, hydrogen-resistant coating 300, sealing weld 400, and optional outer wall slope 110.

[0043] Two nickel-based alloy components 200 are respectively disposed at both ends of the carbon steel substrate tube 100. The nickel-based alloy components 200 extend into the tube, with one end near the port extending to approximately flush with the port of the carbon steel substrate tube 100 before being welded to the end face. At the port, a reliable end face seal is formed by welding. The outer surface of the port of the carbon steel substrate tube 100 may have a bevel 110. A sealing weld 400 is located at the end of the nickel-based alloy component 200 extending into the tube, forming a gentle slope through a specific welding process. A hydrogen-resistant coating 300 is applied to the inner wall of the carbon steel substrate tube and terminates precisely at the middle of the gentle slope of the sealing weld 400.

[0044] This structure achieves safe and reliable connections through direct welding sealing at the end faces and coating protection on the internal gentle slope.

[0045] Example 3 This embodiment provides another prefabricated hydrogen transport pipeline prepared by the preparation method of Embodiment 1 (especially using Method 2 in S3), the structure of which is as follows. Figure 3 As shown.

[0046] The prefabricated pipeline also includes a carbon steel base pipe 100, a nickel-based alloy component 200, a hydrogen-resistant coating 300, a sealing weld 400, and an optional slope 110. Its distinguishing feature from Embodiment 2 is that, after the nickel-based alloy component 200 extends into the carbon steel base pipe 100, its end near the port does not extend to the pipe opening, but terminates at a certain distance (a predetermined distance) from the end face of the pipe port on the inner wall. In the annular region between the port of the carbon steel base pipe 100 and the end of the nickel-based alloy component 200, a weld overlay 500 is formed by welding. The metal surface of this weld overlay 500 is flush with the inner surface of the nickel-based alloy component 200 and the outer surface of the carbon steel base pipe 100, forming a flush transition surface. The final seal of the port is achieved by covering this area with a cladding weld on the outer wall. The hydrogen-resistant coating 300 also extends to the middle of the sealing weld 400.

[0047] The prefabricated pipeline and its preparation method provided by this invention effectively overcome the challenges of sealing and coating protection at the pipe ends of high-pressure hydrogen transmission pipelines through structural innovation and process optimization, and have high industrial application value.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pre-process for welding the intersection area between the hydrogen blocking coating on the inner wall of a hydrogen pipeline and stainless steel, characterized in that, It comprises the following steps: S1, preparing a carbon steel base material pipe; S2, rolling a nickel-based alloy plate into a cylindrical shape and extending into the carbon steel base material pipe as a nickel-based alloy piece, annularly sealing one end of the nickel-based alloy piece away from the end face of the carbon steel base material pipe and the carbon steel base material pipe to form a sealing portion; S3, welding one end of the nickel-based alloy piece close to the port of the carbon steel base material pipe to the end face of the carbon steel base material pipe; S4, spraying a hydrogen-resistant coating on the inner surface of the carbon steel base material pipe, and extending the hydrogen-resistant coating to the middle of the sealing portion.

2. The process for the prefabrication of the intersection area between the hydrogen permeation tube inner wall port hydrogen barrier coating and the stainless steel, according to claim 1, characterized in that, In the S2, it comprises; After rolling the nickel-based alloy plate into a cylindrical shape and extending into the carbon steel base material pipe, the nickel-based alloy piece is welded along the joint of the cylinder to form a complete cylinder, and the nickel-based alloy piece is welded and fixed with the carbon steel base material pipe.

3. The process for the prefabrication of the intersection area between the hydrogen permeation tube inner wall port hydrogen barrier coating and the stainless steel by welding, according to claim 2, characterized in that, During annular sealing, by controlling the energy distribution of the welding heat source and / or the addition position of the filler metal, the sealing portion formed has a larger outside deposition amount than the inside deposition amount in cross section, thereby naturally forming a gentle slope smoothly transitioning from the inner surface of the nickel-based alloy piece to the inner surface of the carbon steel base material pipe.

4. The process for the pre-fabrication of the intersection area between the hydrogen permeation tube inner wall port hydrogen barrier coating and the stainless steel by welding according to claim 1, characterized in that, When welding one end of the nickel-based alloy piece close to the port of the carbon steel base material pipe to the end face of the carbon steel base material pipe; The nickel-based alloy piece is attached to the inner wall position at a certain distance from the port end face of the carbon steel base material pipe; Surfacing is performed in the port end face area until the weld metal surface formed by surfacing is flush with the inner surface of the nickel-based alloy piece and the outer surface of the carbon steel base material pipe, respectively, to form a flush transition surface; Subsequently, based on the flush transition surface, cladding welding is performed from the outer wall side of the carbon steel base material pipe, so that the weld metal completely wraps the end region of the nickel-based alloy piece.

5. The process for the prefabrication of the intersection area between the hydrogen permeation tube wall port hydrogen barrier coating and the stainless steel according to any one of claims 1 to 4, characterized in that, When preparing the carbon steel base material pipe; A slope is machined on the outer wall of the pipe end of the carbon steel base material pipe, and the slope is arranged at an angle of 20° to 45° with respect to the axial direction of the carbon steel base material pipe.

6. The process for the prefabrication of the intersection area between the hydrogen permeation tube wall port hydrogen barrier coating and the stainless steel according to any one of claims 1 to 4, characterized in that, The hydrogen-resistant coating of the hydrogen inlet port of the hydrogen pipeline also comprises the following steps: S4, X-ray detection is performed on the prefabricated pipeline after welding.

7. A hydrogen pipeline pre-fabricated pipeline prepared by a pre-fabrication process of sealing welding the intersection area of the hydrogen pipeline inner wall port hydrogen barrier coating and stainless steel according to any one of claims 1-6, characterized in that, It comprises: A carbon steel base material pipe; Two nickel-based alloy pieces are arranged at the two ends of the carbon steel base material pipe respectively, the nickel-based alloy pieces extend into the carbon steel base material pipe, so that one end of the nickel-based alloy piece close to the port of the carbon steel base material pipe is at a certain distance from the port of the carbon steel base material pipe, and a surfacing portion is arranged between the nickel-based alloy piece and the port of the carbon steel base material pipe; A hydrogen-resistant coating is arranged on the inner wall of the carbon steel base material pipe, and the hydrogen-resistant coating extends to the middle of the sealing portion.

8. The hydrogen-carrying pipe preform of claim 7, wherein, The outer surface of the port of the carbon steel base material pipe is provided with a slope, and the slope is arranged at an angle of 20° to 45° with respect to the axial direction of the carbon steel base material pipe.

9. A hydrogen transport pipeline pre-fabricated pipe prepared by a pre-fabrication process of sealing welding the intersection area of the hydrogen transport pipeline inner wall port hydrogen barrier coating and stainless steel according to any one of claims 1-6, characterized in that, It comprises: A carbon steel base material pipe; Two nickel-based alloy pieces are arranged at the two ends of the carbon steel base material pipe respectively, the nickel-based alloy pieces extend into the carbon steel base material pipe, so that one end of the nickel-based alloy piece close to the port of the carbon steel base material pipe is flush with the port of the carbon steel base material pipe; A hydrogen-resistant coating is provided on the inner wall of the carbon steel substrate pipe, and the hydrogen-resistant coating extends to the middle of the sealing part.

10. The hydrogen-carrying pipe preform of claim 9, wherein, An outer surface at a port of the carbon steel substrate pipe is provided with a slope surface, and the slope surface is arranged at an angle of 20° to 45° with respect to the axial direction of the carbon steel substrate pipe.

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