Test apparatus and method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials

Abstract

This invention discloses a test device and method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, belonging to the field of hydrogen embrittlement sensitivity evaluation technology. It includes a hollow tubular specimen, a tensile testing module, a high-pressure hydrogen environment simulation module, and an external corrosion environment simulation module. The hollow tubular specimen has connecting parts at both ends. The tensile testing module includes a drive unit and a pair of clamps, each clamp having a central through-hole, a connection port, an inlet, and an outlet valve, with the inlet and outlet valve connected to the central through-hole. The high-pressure hydrogen environment simulation module includes a hydrogen cylinder and a steel pipe, with the hydrogen cylinder connected to the inlet via the steel pipe. The external corrosion environment simulation module includes a sealable container and an electrochemical testing instrument, with the sealable container sealingly surrounding the outer wall of the hollow tubular specimen. By using a hollow tubular specimen, exposing its interior to high-pressure hydrogen and its exterior to soil corrosion media, and employing slow-strain tensile testing, the working conditions of buried high-pressure hydrogen pipelines can be realistically simulated, improving testing efficiency.

Description

Technical Field

[0001] This invention relates to the field of hydrogen embrittlement sensitivity evaluation technology, and in particular to a test apparatus and method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials. Background Technology

[0002] Hydrogen energy, as a clean energy source, is being widely used, and utilizing existing natural gas pipeline networks for hydrogen blending or pure hydrogen transportation is considered a promising solution. However, high-pressure hydrogen environments can induce hydrogen embrittlement in pipeline steel, where hydrogen atoms penetrate the metal lattice, causing a sharp decrease in the material's plasticity and toughness, leading to low-stress brittle fracture under stress. Hydrogen embrittlement poses a fatal threat to the safety of high-pressure hydrogen transmission pipelines.

[0003] Existing hydrogen embrittlement sensitivity assessment technologies suffer from problems such as difficulty in simulating actual buried hydrogen transportation environments under test conditions, complex sample preparation, and long test cycles, failing to meet the requirements for high-fidelity simulation and accurate evaluation of complex coupled environments.

[0004] 1. Distortion and oversimplification of environmental simulation: The mainstream method uses electrochemical hydrogen charging + slow tensile testing. The hydrogen charging mechanism is completely different from the hydrogen source, penetration mechanism and surface state of the actual gas-phase high-pressure hydrogen environment, leading to doubts about the correlation between experimental results and engineering practice. Some methods only conduct mechanical tests in the high-pressure hydrogen chamber, ignoring the key effects of external soil corrosion and cathodic protection, and cannot fully simulate various working conditions.

[0005] 2. Mismatch between specimen shape and stress state: Most standard tests use plate or rod-shaped solid specimens, and the dimensions of hydrogen diffusion and stress state differ greatly from those of tubular structures. While small punch tests are used, their stress state is dominated by biaxial bending, which does not match the circumferential / axial tensile principal stress state of pipelines under internal pressure. Therefore, the data obtained is difficult to directly use for evaluating and designing pipeline pressure-bearing capacity.

[0006] 3. Asynchronous and Uncoupled Testing Process: Traditional methods employ a two-step approach of "environmental exposure followed by mechanical testing," or place the sample in a static external environmental chamber for testing. These methods cannot achieve real-time synchronization of environmental factors and mechanical loads in time or their full-domain effect in space. Consequently, they cannot capture key transient processes such as hydrogen diffusion and enrichment behavior and the synergistic effect of stress corrosion during dynamic loading. The obtained test data is static and one-sided. Summary of the Invention

[0007] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a test device and method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials. It uses a hollow tubular sample, which is exposed to high-pressure hydrogen gas inside and to soil corrosion medium or cathodic protection outside. It adopts a slow strain tensile test, which can realistically simulate the working conditions of buried high-pressure hydrogen pipelines, shorten the test cycle, and improve the test efficiency.

[0008] On one hand, embodiments of the present invention provide a test apparatus for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, comprising: A hollow tubular specimen, wherein the two ends of the hollow tubular specimen are provided with connecting parts; A tensile testing module includes a drive unit and a pair of clamps. The clamps are provided with a central through hole, a connection port, an air inlet, and an air outlet valve. The connection port is adapted to the connection part at one end of the hollow tubular specimen. The air inlet and the air outlet valve are connected to the central through hole. The drive unit is used to apply a slow strain rate tensile load to the hollow tubular specimen. The clamps are provided with an annular pressure equalization cavity surrounding the central through hole. The annular pressure equalization cavity is connected to the central through hole through multiple circumferentially distributed air guide holes. The air inlet is connected to the annular pressure equalization cavity. A high-pressure hydrogen environment simulation module includes a hydrogen cylinder and a steel pipe. The hydrogen cylinder is connected to the gas inlet through the steel pipe, so that the inner cavity of the hollow tubular sample forms a sealed chamber that can withstand high-pressure hydrogen during the test. An external corrosion environment simulation module includes a sealable container and an electrochemical testing instrument. The sealable container contains a corrosive medium simulating a soil environment and is equipped with an electrochemical electrode connected to the electrochemical testing instrument. The sealable container seals and surrounds the outer wall of the hollow tubular sample. The external corrosion environment simulation module is used to apply an electrochemical environment to the hollow tubular sample. An industrial control computer is connected to the tensile testing module, the high-pressure hydrogen environment simulation module, and the external corrosion environment simulation module, respectively. The industrial control computer, after the tensile test module is started, performs the following operations synchronously to simulate the internal and external multi-field coupling of the hollow tubular specimen during dynamic tensile testing: controlling the high-pressure hydrogen environment simulation module to maintain the hydrogen pressure inside the hollow tubular specimen at a preset value; controlling the electrochemical testing instrument to continuously clamp the potential of the outer wall of the hollow tubular specimen relative to the corrosive medium within a preset target cathodic protection potential range; and controlling the driving unit to continuously apply a slow strain rate tensile load until the hollow tubular specimen fractures. Then, the hydrogen embrittlement sensitivity coefficient of the material is calculated according to the hydrogen embrittlement sensitivity coefficient calculation formula, which is: K HE = α * ( (RA0- RA H ) / RA0) + β * ( (P max0 - P maxH ) / P max0 ) ; In the formula, K HE Here, RA is the hydrogen embrittlement sensitivity coefficient, RA0 is the reduction of area under inert conditions, and RA H P represents the reduction of area under the test environment. max0 For the maximum tensile load in an inert environment, P maxH The maximum tensile load under the test environment is represented by α and β, which are weighting coefficients.

[0009] According to some embodiments of the present invention, the weighting coefficients α and β are obtained by regression analysis based on actual pipeline failure data.

[0010] According to some embodiments of the present invention, the fixture is further provided with a pressure sensor and a temperature sensor, wherein the pressure sensor is used to monitor the hydrogen pressure inside the hollow tubular sample in real time.

[0011] According to some embodiments of the present invention, the sealable container is a tank made of transparent material, and the tank is provided with a top cover with a sealing element to form a sealed space.

[0012] According to some embodiments of the present invention, the electrochemical electrode includes a platinum electrode, a reference electrode, and a Luggin capillary, wherein the platinum electrode, the reference electrode, and the Luggin capillary are all electrically connected to the hollow tubular sample.

[0013] According to some embodiments of the present invention, the external corrosion environment simulation module further includes a media circulation pump, a pH monitoring sensor, and a dissolved oxygen control unit for maintaining and regulating the chemical state of the corrosive medium.

[0014] According to some embodiments of the present invention, the industrial control computer is connected to the tensile test module, the high-pressure hydrogen environment simulation module and the external corrosion environment simulation module respectively, for synchronously controlling the tensile strain rate, internal hydrogen pressure and external electrochemical parameters, and synchronously acquiring load, displacement, pressure, potential and current data.

[0015] According to some embodiments of the present invention, the hollow tubular specimen is a welded joint specimen comprising a weld, a heat-affected zone, and a base material.

[0016] On the other hand, embodiments of the present invention provide a test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, including: The hydrogen pipeline material was prepared into a hollow tubular sample; The hollow tubular specimen is placed in a sealable container and fixed in place by a pair of clamps of the tensile testing module. Hydrogen gas is introduced into the inner cavity of the hollow tubular sample and pressurized to a preset pressure. Corrosive medium is injected into the sealable container, and preset electrochemical conditions are applied to the outer wall of the hollow tubular sample using an electrochemical testing instrument. The tensile test module is activated to stretch the hollow tubular specimen at a preset slow strain rate until the hollow tubular specimen breaks. During the tensile process, hydrogen pressure is applied inside the sample simultaneously and the external electrochemical conditions of the sample are dynamically changed. Record tensile mechanical data, pressure, temperature, and electrochemical data during the stretching process; The changes in the mechanical properties of the hollow tubular specimen under internal high-pressure hydrogen and external corrosive environments were analyzed to evaluate the hydrogen embrittlement sensitivity of the material. The mechanical properties included stress-strain relationship, yield strength and tensile strength, reduction of area and elongation after fracture.

[0017] According to some embodiments of the present invention, prior to the step of activating the tensile testing module, the following steps are included: Under the conditions of maintaining the internal and external environment of the sample, after allowing it to stand for a preset time of pre-charged hydrogen, the slow strain rate stretching is then started.

[0018] According to some embodiments of the present invention, after the step of analyzing the changes in the mechanical properties of the hollow tubular sample under internal high-pressure hydrogen gas and external corrosive environment, and evaluating the hydrogen embrittlement susceptibility of the material, the method further includes: A rapid prediction model for the hydrogen embrittlement sensitivity of materials was established based on historical experimental data.

[0019] The hydrogen embrittlement sensitivity evaluation test apparatus and method for hydrogen pipeline materials according to embodiments of the present invention have at least the following beneficial effects: The hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials provided by this invention includes a hollow tubular specimen, a tensile testing module, a high-pressure hydrogen environment simulation module, and an external corrosion environment simulation module. The geometry and radial path of hydrogen diffusion of the hollow tubular specimen are consistent with those of a real pipeline. The high-pressure gas path is integrated through a fixture, cleverly solving the problem of connecting the external high-pressure chamber with the tensile testing module, resulting in a compact structure and reliable sealing. The hollow tubular specimen directly simulates the pipeline, and the high-pressure hydrogen path is integrated through a modified tensile fixture, achieving an internal high-pressure gaseous hydrogen environment; an external electrochemical corrosion environment suitable for cathodic protection is also present, with all environmental factors and slow strain rate tensile testing conducted simultaneously. This invention achieves integrated and synchronous simulation of the "internal pressure hydrogen, external corrosive medium + cathodic protection" service environment of buried high-pressure hydrogen pipelines in the laboratory. Furthermore, the hydrogen exists in a high-pressure gaseous phase, completely consistent with reality, avoiding the discrepancy between electrochemical hydrogen charging and actual conditions, resulting in high fidelity of environmental simulation. Comprehensive performance data of the material under complex coupled environments can be obtained through a single test, avoiding the errors and inefficiencies caused by step-by-step testing. The synchronously acquired multi-dimensional data, including mechanical, pressure, and electrochemical data, provides unprecedented data support for in-depth analysis of the multi-factor interaction mechanisms. Integrated sensors and an industrial control computer enable automated, intelligent, and high-precision control of the testing process. The device boasts high integration, safety, and reliability, significantly improving operational safety and result reproducibility. Sample preparation and testing are simple and rapid, suitable for evaluating the hydrogen embrittlement sensitivity of different types of materials; it can realistically simulate the working conditions of materials in a high-pressure hydrogen environment, making the test results more practically valuable; the short testing cycle allows for rapid acquisition of test results, providing timely reference for the selection and optimization of hydrogen pipeline materials.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of the hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to an embodiment of the present invention; Figure 2 A schematic diagram of the hollow tubular sample of the hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to an embodiment of the present invention; Figure 3 This is a block diagram of the hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to an embodiment of the present invention; Figure 4 This is one of the flowcharts for the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials according to an embodiment of the present invention; Figure 5This is the second flowchart of the test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials according to an embodiment of the present invention; Figure 6 This is a schematic diagram of stress-strain curves of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention. Figure 7 This is a schematic diagram of the yield strength and tensile strength of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention. Figure 8 This is a schematic diagram of the cross-sectional shrinkage rate of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention. Figure 9 This is a schematic diagram of the elongation after fracture of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention. Figure 10 This is a schematic diagram of the macroscopic morphology of the fracture surface of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention. Figure 11 This is a schematic diagram of the fracture cross-section and inner wall morphology of samples with different hydrogen doping ratios obtained by using the hydrogen embrittlement sensitivity evaluation test method for hydrogen pipeline materials in an embodiment of the present invention.

[0022] Figure label: Hollow tubular specimen 100, connecting part 110; Tensile testing module 200, fixture 210, air vent valve 220, drive unit 230; High-pressure hydrogen environment simulation module 300, hydrogen cylinder 310, pressure reducing valve 320, steel pipe 330; External corrosion environment simulation module 400, sealable container 410, corrosive medium 420, electrochemical tester 430, industrial control computer 500. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 limiting this invention.

[0025] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, and "above," "below," "within," etc. are understood to include the stated number. If "first," "second," etc. are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0026] In the description of this invention, unless otherwise explicitly defined, the terms "setting", "installing", "connecting" and "linking" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0027] Buried high-pressure hydrogen pipelines operate in an unprecedentedly complex and harsh environment involving the coupling of multiple physical and chemical fields. First, there is the internal mechanical-chemical field: the pipeline withstands the internal pressure of high-pressure hydrogen (typically 1-20 MPa), where hydrogen exists in molecular form and diffuses through atomic layers. Second, there is the external electrochemical-corrosion field: the pipeline's outer wall is in direct contact with the soil, where the soil solution acts as an electrolyte, creating a corrosive environment. Simultaneously, to inhibit corrosion, an active cathodic protection system is applied throughout the pipeline, forming a stable electrochemical field. Third, there is the mechanical load field: the pipeline bears circumferential and axial tensile stresses generated by internal pressure, bending stresses from foundation settlement, and fatigue stresses caused by pressure fluctuations. Hydrogen, stress, and corrosion / electrochemistry do not act independently but exhibit profound interactive coupling effects. For example, overpotentials generated by cathodic protection may promote hydrogen penetration into the metal, while stress attracts hydrogen accumulation at defects, accelerating damage. Stress is the primary mechanical factor inducing cracking in hydrogen pipelines. Using slow strain rate tension as the loading method, the test results have direct guiding significance for engineering practice.

[0028] There is an urgent need for a test device and test method that can integrate and reproduce the real service environment of buried high-pressure hydrogen pipelines in a laboratory setting with high fidelity, including "internal pressure hydrogen, external corrosive medium + cathodic protection, and continuous load", and can quantitatively, accurately, and efficiently evaluate the hydrogen embrittlement sensitivity of the pipeline body and welded joint materials.

[0029] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Please see Figures 1 to 3 This embodiment discloses a hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials provided by the present invention, including a hollow tubular specimen 100, a tensile test module 200, a high-pressure hydrogen environment simulation module 300, and an external corrosion environment simulation module 400. The hollow tubular specimen 100 has connecting portions 110 at both ends; the tensile test module 200 includes a drive unit 230 and a pair of clamps 210. The clamps 210 have a central through hole, a connection port, an air inlet, and an air outlet valve. The connection port is adapted to the connecting portion 110 at one end of the hollow tubular specimen. The air inlet and the air outlet valve communicate with the central through hole. The drive unit 230 is used to apply a slow strain rate tensile load to the hollow tubular specimen; the high-pressure hydrogen environment simulation module 300 includes a hydrogen cylinder 310 and a steel pipe 330. The hydrogen cylinder 310 is connected to the steel pipe 330. The air inlet 30 is connected to form a sealed chamber capable of withstanding high-pressure hydrogen gas during the test. The external corrosion environment simulation module 400 includes a sealable container 410 and an electrochemical tester 430. The sealable container 410 is filled with a corrosive medium simulating a soil environment and is equipped with an electrochemical electrode connected to the electrochemical tester 430. The sealable container 410 seals and surrounds the outer wall of the hollow tubular sample. The external corrosion environment simulation module 400 is used to apply an electrochemical environment to the hollow tubular sample 100.

[0031] Please see Figure 1 and Figure 2 The hollow tubular specimen 100 has external threads at both ends for connection to the clamp 210. The clamp 210 of the tensile testing module 200 has internal threads for connection to the external threads at both ends of the hollow tubular specimen 100. A rubber gasket is placed at the bottom of the internal threaded hole. After the external threads at both ends of the hollow tubular specimen 100 are screwed into the internal threaded hole, the rubber gasket is squeezed, ensuring that high-pressure hydrogen exists at a certain pressure inside the hollow tubular specimen 100 during the test. The upper clamp 210 is connected to the high-pressure hydrogen environment simulation module 300 via a stainless steel double-way quick-connect coupling; the lower clamp 210 is connected to the gas outlet valve 220 via a stainless steel double-way quick-connect coupling. The material, outer diameter, wall thickness, and length of the hollow tubular specimen 100 can be designed according to specific experimental requirements.

[0032] Please see Figure 1The high-pressure hydrogen environment simulation module 300 includes a hydrogen cylinder 310, a pressure reducing valve 320, and a steel pipe 330, used to inject high-pressure hydrogen into the inner cavity of the hollow tubular specimen 100. The hydrogen cylinder 310 can hold gases of different compositions, and the pressure reducing valve 320 can display and adjust the outlet pressure of the hydrogen cylinder 310 to simulate the gas composition (such as different hydrogen specific gravities or gases containing impurities such as carbon dioxide, methane, etc.) and pressure conditions in hydrogen delivery pipelines in different practical applications, providing a pure, stable, and programmable high-pressure hydrogen environment to the specimen's inner cavity. The seamless integration of the high-pressure hydrogen environment simulation module 300 with the fixture 210 means that the high-pressure hydrogen environment is no longer an external enclosure of the tensile testing module 200. The integrated flow channel, consisting of a high-purity hydrogen gas source, a two-stage pressure reducing and stabilizing valve, a precision mass flow controller, a high-pressure solenoid valve, a safety relief device, and a through-clamp 210, can maintain the hydrogen pressure in the sample cavity at a set value (e.g., 0.1-20 MPa) with fluctuations of less than ±0.5% throughout the entire testing process (from a few minutes to hundreds of hours). It can also execute complex pressure change programs (e.g., step pressure increase, sinusoidal fluctuation) to simulate the peak-shaving operation conditions of hydrogen pipelines.

[0033] The external corrosion environment simulation module 400 includes a sealable container 410, a corrosive medium 420, an electrochemical testing instrument 430, and a rubber stopper. The sealable container 410 includes a container lid with multiple through holes into which a hollow tubular sample 100, a platinum electrode, and a Luggin capillary tube can be inserted respectively. A variable-diameter through hole is located at the center of the bottom of the sealable container 410. A rubber stopper is inserted into the variable-diameter through hole to achieve a seal, allowing the sealable container 410 to hold the corrosive medium 420 simulating a buried environment. The electrochemical testing instrument 430 is connected to a three-electrode system consisting of the hollow tubular sample 100, the platinum electrode, and a reference electrode. By setting parameters on the industrial control computer 500, cathodic protection is applied to the outer wall of the hollow tubular sample 100, and electrochemical tests are performed to simulate buried corrosion or cathodic protection environments in different practical applications.

[0034] The tensile testing module 200 is also equipped with a tie rod, which is connected to the clamp 210 via a pin. This allows for testing at a constant low strain rate (at 10...). -6 Up to 10 -4 A tensile force is applied to the hollow tubular specimen 100 within a range of / s, gradually increasing until the hollow tubular specimen 100 breaks.

[0035] Please see Figure 1The clamp 210 has an annular pressure equalization chamber surrounding a central through hole. This chamber is connected to the central through hole via multiple circumferentially distributed air guide holes, and the air inlet is also connected to the annular pressure equalization chamber. While traditional clamps 210 only handle clamping, the clamp 210 of this invention is reconstructed into an intelligent terminal that combines high-strength clamping, high-pressure dynamic sealing, uniform hydrogen introduction, and in-situ state sensing. The clamp 210 consists of two symmetrical components, each containing: a central through hole, an internal thread interface, a multi-stage composite sealing unit, and an annular pressure equalization chamber and a multi-hole flow equalization unit. The central through hole serves as a channel for high-pressure hydrogen. The internal thread interface precisely mates with the external thread of the sample, providing the main load-bearing connection. The first stage of the multi-stage composite sealing unit is a fluororubber O-ring located at the root of the thread, achieving a static seal; the second stage is a metal conical / flat sealing gasket between the end face of the clamp 210 and the end face of the sample, generating a self-tightening effect under high pressure to ensure absolute sealing under extreme pressure. Inside fixture 210, an annular cavity is machined around the central hole. High-pressure hydrogen gas first enters this annular pressure equalization cavity through a lateral inlet, and then is evenly introduced into the central hole and the inner cavity of the sample through at least eight tiny radial guide holes evenly distributed circumferentially. This completely eliminates the local airflow impact and pressure unevenness caused by single-point air intake, ensuring that the inner wall of the sample is subjected to uniform hydrogen pressure, thus achieving a revolutionary "internal pressure integration" design.

[0036] Please see Figure 1 The fixture 210 is also equipped with a pressure sensor and a temperature sensor. The pressure sensor is used to monitor the hydrogen pressure inside the hollow tubular sample 100 in real time. A sputtered thin-film pressure sensor and a fast-response platinum resistance temperature sensor are integrated and installed on the inner wall of the fixture 210, very close to the sample end face. This allows for real-time, in-situ monitoring of the hydrogen pressure and temperature inside the sample cavity, with data directly transmitted to the control system, achieving zero-distance monitoring of key environmental parameters.

[0037] In some embodiments of the present invention, the sealable container 410 is a tank made of transparent material, and the tank is provided with a top cover with a sealing element to seal the hollow tubular sample 100. In some embodiments of the present invention, the electrochemical electrode includes a platinum electrode, a reference electrode, and a Luggin capillary, all of which are electrically connected to the hollow tubular sample 100.

[0038] For example, a cylindrical sealed main tank made of plexiglass is used. The main tank cover has a central hole. A multi-layered, combined elastic dynamic sealing sleeve (e.g., an inner layer of polytetrafluoroethylene and an outer layer of fluororubber) achieves dynamic sealing with the moving sample wall, allowing axial tension while ensuring zero leakage of corrosive media. The tank is filled with simulated soil solution, and a complete three-electrode system is constructed within the tank. The working electrode is the sample wall itself; the reference electrode is a long-lasting and stable saturated calomel electrode, with its tip brought as close as possible to the sample surface via a capillary tube to accurately measure and control the interfacial potential. This three-electrode system is connected to a multi-channel electrochemical analyzer 430.

[0039] To enhance environmental realism, the external corrosion environment simulation module 400 also includes: (1) a magnetic circulation pump and heat exchanger, used to circulate the corrosive medium at a low speed to simulate the weak flow of groundwater in the soil and maintain a constant temperature; (2) an online pH meter and dissolved oxygen meter, used to monitor the chemical state of the medium in real time and can be connected to an automatic titrator for pH adjustment; (3) a gas inlet unit, used to introduce nitrogen, carbon dioxide or air mixture into the medium to precisely control dissolved oxygen and carbonate balance, simulating different soil permeability environments. Thus, the soil corrosion and cathodic protection environment is accurately reproduced on the outer wall of the sample.

[0040] In some embodiments of the present invention, the hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials further includes an industrial control computer 500. The industrial control computer 500 is connected to a tensile testing module 200, a high-pressure hydrogen environment simulation module 300, and an external corrosion environment simulation module 400, respectively, for synchronously controlling the tensile strain rate, internal hydrogen pressure, and external electrochemical parameters, and synchronously acquiring load, displacement, pressure, potential, and current data. This module is the brain and nerve center of the device, realizing multi-variable synchronous precise control, high-speed synchronous acquisition of all-dimensional data, and safety interlocking and closed-loop control. For example, when an excessive hydrogen leakage rate, abnormal internal pressure rise, or sample breakage is detected, an emergency shutdown sequence will be immediately triggered, closing the hydrogen valve, stopping the tensile test, and opening the safety pressure relief mechanism. Closed-loop control is achieved, for example, by dynamically adjusting the output current based on the real-time measured corrosion potential, precisely clamping the potential to a set protection value.

[0041] In some embodiments of the present invention, the hollow tubular specimen 100 is a welded joint specimen including the weld, heat-affected zone, and base material. Failures in hydrogen pipelines often originate from microscopically inhomogeneous areas such as the weld and heat-affected zone; however, existing general-purpose testing devices are rarely specifically optimized for welded joint specimens, leading to insufficient safety assessment of the weakest link in the engineering structure. The hollow tubular specimen 100 is a microscopic carrier simulating a real pipeline, not a simple pipe section, but designed strictly according to engineering similarity criteria. First, geometric similarity: its outer diameter to wall thickness ratio (diameter-to-thickness ratio D / t) is set between 10 and 50, covering the entire conventional range from urban gas distribution networks to main long-distance pipelines. Second, process similarity: the hollow tubular specimen 100 not only includes a homogeneous base material specimen, but more importantly, a welded joint specimen containing a full-thickness circumferential weld. The welded joint specimen strictly retains the weld reinforcement and ensures that the gauge length of the specimen includes the weld center, heat-affected zone, and base material on both sides; this is crucial for evaluating the weakest link in the engineering structure. The hollow tubular specimen 100 has standard metric or imperial external threads precisely machined at both ends, and is designed with precision grooves for installing O-ring seals.

[0042] High-pressure gaseous hydrogen is continuously supplied to the inner cavity of the hollow tubular sample via clamp 210, perfectly matching the core working medium of the hydrogen delivery pipeline. Simultaneously, a controllable simulated soil corrosion solution and cathodic protection electrochemical environment are constructed on the outer wall of the sample. This achieves full-time, synchronous dynamic coupling between slow strain rate tensile testing and the complex internal and external environments. Throughout the entire process of slow tensile testing until fracture, the internal high-pressure hydrogen environment and the external corrosion / cathodic protection environment are maintained and monitored in real time. This method can accurately capture the synergistic effects of hydrogen diffusion, enrichment, interaction with dislocations, and corrosion processes during continuous plastic deformation, revealing the dynamic mechanism of hydrogen embrittlement initiation and propagation. Its scientific validity and ability to simulate dynamic loads under actual working conditions far surpass those of static or step-by-step testing. The high-pressure hydrogen passage is highly integrated inside the clamp 210 of the tensile testing machine. This design, which uses a large, independent external high-pressure environment chamber in existing technologies, solves the problem of dynamic sealing between the moving sample and the fixed high-pressure gas source. The integrated design minimizes the high-pressure area and simplifies the piping, which not only greatly improves the operational safety and sealing reliability of the device under high pressure, but also makes the whole system more compact and efficient, achieving simplicity and robustness under complex functions.

[0043] Please see Figure 4 This embodiment also provides a test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, applied to the aforementioned test apparatus for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials. The test method includes: S101. Prepare a hollow tubular sample 100 from the hydrogen pipeline material to be tested.

[0044] S102. Install the hollow tubular specimen 100 on the tensile test module 200, and seal the sealable container 410 on the outer wall of the hollow tubular specimen 100.

[0045] S103. Hydrogen gas is introduced into the inner cavity of the hollow tubular sample 100 and pressurized to a preset pressure. Corrosive medium is injected into the sealable container 410, and preset electrochemical conditions are applied to the outer wall of the hollow tubular sample 100 through the electrochemical tester 430.

[0046] S104. Start the tensile test module 200 and stretch the hollow tubular specimen 100 at a preset slow strain rate. Under the conditions of maintaining the hydrogen pressure in the inner cavity and the electrochemical conditions of the outer wall, the tensile test continues until the hollow tubular specimen 100 breaks or reaches the failure criterion.

[0047] S105. During the stretching process, internal hydrogen pressure is applied simultaneously and external electrochemical conditions are dynamically changed.

[0048] S106. Record the tensile mechanical data, pressure, temperature, and electrochemical data during the tensile process. For example, record the load-displacement curve, the internal cavity pressure-time curve, and the external wall electrochemical parameter-time curve during the tensile process.

[0049] S107. Analyze the changes in the mechanical properties of the hollow tubular sample under internal high-pressure hydrogen gas and external corrosive environments to evaluate the material's hydrogen embrittlement susceptibility. The mechanical properties include stress-strain relationship, yield strength and tensile strength, reduction of area, and elongation after fracture. For example, calculate the material's hydrogen embrittlement susceptibility evaluation index based on the load-displacement curve.

[0050] It should be noted that the steps before starting the tensile test module 200 include: Under the conditions of maintaining the internal and external environment of the sample, after allowing it to stand for a preset time of pre-charged hydrogen, the slow strain rate stretching is then started.

[0051] In some embodiments of the present invention, the hydrogen embrittlement sensitivity evaluation index includes a comprehensive hydrogen embrittlement sensitivity coefficient, which is calculated using the following formula: K HE = α * ( (RA0- RA H ) / RA0) + β * ( (P max0 - P maxH ) / P max0 ) ; In the formula, K HE Here, RA is the hydrogen embrittlement sensitivity coefficient, RA0 is the reduction of area under inert conditions, and RA H P represents the reduction of area under the test environment. max0 For the maximum tensile load in an inert environment, P maxHThe maximum tensile load under the test environment is represented by α and β, which are weighting coefficients.

[0052] It should be noted that an inert environment refers to an environment in which the material is not sensitive to hydrogen embrittlement, typically including air, nitrogen, or helium environments. The weighting coefficients α and β are obtained through regression analysis of actual pipeline failure data. A set of preliminary weighting coefficients was determined by collecting a large amount of sample data from tests on the target pipeline steel under various simulated operating conditions (such as different hydrogen pressures and different cathodic protection potentials), combined with materials science theory (e.g., for high-strength steel, plasticity loss is often more sensitive to hydrogen embrittlement than strength loss). K will then use these weighting coefficients. HE The model is then validated using new test data or known cases. Based on the prediction accuracy, the weighting coefficients are fine-tuned and finally fixed to a set of recommended values.

[0053] Furthermore, a rapid prediction model for the hydrogen embrittlement sensitivity of materials can be established based on big data and machine learning. Using the high-quality data generated by this device, a prediction model can be trained to reduce reliance on time-consuming slow tensile tests. Five types of pipeline steel (AE) with different strength grades and microstructures were selected. For each material, a complete coupled slow tensile test was conducted under three different internal pressures (P1, P2, P3) and two different external potentials (E1, E2), and the comprehensive coefficient K was obtained. HE Simultaneously, short-term (e.g., 24-hour) hydrogen permeation tests and rapid electrochemical impedance spectroscopy were performed on each material under each of the above environmental combinations. The apparent hydrogen diffusion coefficient D was extracted from the permeation curves. app Extracting charge transfer resistance R from impedance spectrum ct Parameters such as material composition (e.g., C, Mn), strength (Rm), and apparent hydrogen diffusion coefficient D are used. app Charge transfer resistance R ct Environmental parameters (P, E) are used as input features, with the experimentally measured hydrogen embrittlement sensitivity coefficient K as the input. HE As the target value, machine learning algorithms such as random forest and gradient boosting are used to train the prediction model.

[0054] The model trained in this way can quickly and accurately predict the hydrogen embrittlement sensitivity coefficient K based on the material's fundamental properties, short-term permeation and electrochemical test results, and target environmental parameters. HE This provides an efficient and economical auxiliary tool for the rapid screening of new materials and the assessment of the material condition of in-service pipelines.

[0055] Please see Figure 5 The following is a detailed description of the test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials provided in the embodiments of the present invention: S201. Sample preparation: Prepare a hollow tubular sample 100 from the hydrogen pipeline material.

[0056] S202. Electrochemical environment construction: The corrosive medium 420 simulating the buried environment is loaded into the sealable container 410. The platinum electrode and Luggin capillary are inserted into the through hole on the container lid. The reference electrode is then inserted into the Luggin capillary. The container lid is screwed into the sealable container 410. The hollow tubular sample 100 is inserted into the sealable container 410.

[0057] S203. Construction of high-pressure hydrogen environment: Place a gasket in the threaded hole of fixture 210, connect the hollow tubular sample 100 to fixture 210 by thread, open hydrogen cylinder 310, pressure reducing valve 320 and gas outlet valve 220, flush the gas passage with hydrogen for 5 minutes and then close gas outlet valve 220, adjust pressure reducing valve 320 to keep the gas pressure in the gas passage at the required value.

[0058] S204. Electrochemical test: Connect the electrochemical tester 430 to the three-electrode system consisting of the hollow tubular sample 100, platinum electrode and reference electrode, set the parameters on the industrial control computer 500, apply cathodic protection or perform other electrochemical tests.

[0059] S205. Slow strain rate tensile test: Set the slow strain rate tensile test parameters on the industrial control computer 500, perform a slow strain rate tensile test on the hollow tubular specimen 100, and record the tensile mechanical data through the industrial control computer 500.

[0060] S206. Test Result Analysis: Based on the test results, analyze the changes in mechanical properties of the hollow tubular sample 100 under internal high-pressure hydrogen, external buried corrosion, or cathodic protection environments, such as stress-strain relationship, yield strength, tensile strength, reduction of area, and elongation after fracture, to evaluate the hydrogen embrittlement sensitivity of the hydrogen pipeline material.

[0061] Please see Figures 6 to 9 Slow strain rate tensile tests were conducted on pipeline steel under different hydrogen doping ratios and with and without cathodic protection to obtain stress-strain curves under open-circuit potential / cathode protection in 0%, 10%, and 50% H2 environments. It is evident that a higher hydrogen doping ratio results in a lower fracture strain; the fracture strain of the cathodic protection specimen is smaller than that under open-circuit potential. Hydrogen doping and cathodic protection do not affect the yield strength and tensile strength of the material. A higher hydrogen doping ratio results in a lower reduction of area; the reduction of area of ​​the cathodic protection specimen is smaller than that under open-circuit potential. The effects of hydrogen doping ratio and cathodic protection on elongation after fracture are consistent with their effects on reduction of area.

[0062] Specifically designed for the actual working conditions of buried high-pressure hydrogen pipelines, the hollow tubular specimen 100 has a diameter-to-thickness ratio (D / t) set between 10 and 50, covering the conventional range from urban gas distribution networks to main long-distance pipelines. This specimen includes not only the base material but also the welded joint with a full-wall-thickness circumferential weld. Its gauge length includes the weld center, heat-affected zone, and base material on both sides, which is crucial for evaluating the weakest point of the engineering structure. The annular pressure equalization chamber and circumferential air guide hole structure inside the fixture 210 ensure that high-pressure hydrogen is uniformly introduced into the specimen cavity in a shower-like manner, eliminating local airflow impact and pressure unevenness caused by single-point air intake, realistically simulating the mechanical boundary conditions of the pipeline inner wall under uniform internal pressure. The external corrosion environment simulation module is equipped with a magnetic circulation pump, online pH meter, dissolved oxygen meter, and gas inlet unit, which can accurately simulate groundwater flow, pH buffering, and dissolved oxygen changes in the soil, making the laboratory testing conditions highly consistent with the on-site buried environment.

[0063] Based on the results of slow strain rate tensile tests, the hydrogen embrittlement sensitivity index of the materials under different hydrogen doping ratios and cathodic protection conditions was calculated, as shown in Table 1.

[0064] Table 1 Hydrogen embrittlement susceptibility index of materials under different hydrogen doping ratios and cathodic protection conditions It is evident that as the hydrogen doping ratio increases, the hydrogen embrittlement sensitivity index of the material increases, and cathodic protection also significantly increases the hydrogen embrittlement sensitivity index of the material.

[0065] Figure 10 The macroscopic morphology of the fracture surfaces of the samples under open-circuit potential conditions of 0% H2 and 50% H2 is shown. It can be seen that under 0% H2 conditions, the fracture surface is a typical cup-cone shape, which is ductile fracture; while under 50% H2 conditions, the fracture surface is shear-shaped, showing embrittlement characteristics.

[0066] Figure 11 The fracture surface profile and inner wall morphology are shown. It can be seen that under the condition of 0% H2+ open circuit, the outer and inner walls of the fracture surface of the sample are relatively smooth. However, under the condition of 50% H2+ open circuit, the inner wall of the fracture surface is affected by hydrogen embrittlement and circumferential cracks appear, while the outer wall remains smooth. Under the condition of 0% H2+ cathodic protection, secondary cracks appear on the outer wall, while the inner wall remains smooth. Under the condition of 50% H2+ cathodic protection, secondary cracks appear on both the inner and outer walls.

[0067] The results above demonstrate that the hydrogen embrittlement sensitivity evaluation test device and method for hydrogen pipeline materials provided in this invention fully replicates all core service environment elements of buried high-pressure hydrogen pipelines on a laboratory scale: the internal environment is real high-pressure gaseous hydrogen (1~20MPa, non-alternative electrochemical hydrogen charging), while the external environment is a dynamically controllable soil corrosion medium and a precisely adjustable cathodic protection electrochemical field. Simultaneously, the sample is subjected to slow strain rate tensile loads, accurately simulating the stress-induced hydrogen-induced cracking process. By highly integrating the high-pressure hydrogen passage within the tensile fixture, the engineering challenges of dynamic sealing, alignment difficulties, and high safety risks associated with traditional external high-pressure chambers and moving samples are solved. This results in a compact and reliable device that can be directly used for pipeline integrity assessment, residual strength calculation, and maintenance decision support, demonstrating high engineering practical value. It can effectively analyze the influence of hydrogen on the inner wall of pipeline steel samples and the cathodic protection conditions on the material's mechanical properties and fracture behavior. The test yielded material performance data obtained under a high-fidelity coupling environment, which has immeasurable engineering practical value for accurately evaluating the hydrogen embrittlement sensitivity of pipeline steel and welded joints, determining the safe operating window, guiding the research and development of new materials, and assessing the safety of hydrogen-incorporated retrofitting of existing pipelines.

[0068] The embodiments of the present invention have the following significant beneficial effects: 1. Achieving ultimate fidelity in service environment simulation: On a laboratory scale, all core service environment elements of buried high-pressure hydrogen pipelines are completely and synchronously reproduced. The interior is real high-pressure gaseous hydrogen, with non-alternative electrolytic hydrogen filling; the exterior is a dynamically controllable soil corrosion medium and a precisely adjustable cathodic protection / corrosion electrochemical field; at the same time, the sample is subjected to slow strain rate tensile loads, accurately simulating the stress-induced hydrogen-induced cracking process, achieving high full-coupled simulation accuracy.

[0069] 2. Overcoming the industry challenge of a severe disconnect between testing principles and engineering practice: Hollow tubular welded joint specimens are used, ensuring high consistency with real pipeline components in all key aspects, including geometry, microstructure (including the weld), the radial one-dimensional path of hydrogen diffusion, and the stress state primarily under tension. The resulting data eliminates the significant extrapolation uncertainties associated with transitioning from plate specimens to tubular components and from laboratory media to real-world environments. The results can be directly used for pipeline integrity assessment, residual strength calculation, and maintenance decision support, demonstrating high engineering guidance value.

[0070] 3. Enhanced Capability for Simultaneous Massive Data Acquisition: Data from over ten channels, including mechanical, pressure, temperature, electrochemical, acoustic, and optical systems, can be simultaneously acquired in a single experiment, with all data possessing a unified timescale. This provides a panoramic experimental observation window for in-depth research into the microscopic mechanisms of hydrogen embrittlement, such as the interaction between hydrogen traps and dislocations, the competitive mechanism of stress corrosion cracking, and the impact of cathodic protection on hydrogen penetration. The comprehensive hydrogen embrittlement sensitivity coefficient constructed based on this data has propelled evaluation methods from single-indicator, empirical judgment to multi-parameter, model-based, and quantitative approaches.

[0071] 4. Highly integrated, intelligent, safe, and highly scalable: By integrating the high-pressure gas circuit inside the fixture, a series of engineering challenges associated with external high-pressure chambers, such as difficulty in alignment, sealing, and high risks associated with movable connections, are solved, resulting in a compact structure and extremely high reliability. Intelligent collaborative control achieves full automation of testing, greatly improving operational safety and result reproducibility. Furthermore, it possesses strong scalability; by changing the fixtures and tanks, it can adapt to samples of different diameters; and by modifying the control software, it can achieve testing coupled with environmental conditions, such as fatigue and creep tests.

[0072] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A test device for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, characterized in that, include: A hollow tubular specimen, wherein the hollow tubular specimen has connecting portions at both ends; the hollow tubular specimen is a welded joint specimen including a weld, a heat-affected zone and a base material; the diameter-to-thickness ratio of the hollow tubular specimen is set between 10 and 50. A tensile testing module includes a drive unit and a pair of clamps. Each clamp has a central through-hole, a connection port, an air inlet, and an air outlet valve. The connection port is adapted to the connection portion at one end of the hollow tubular specimen. The air inlet and the air outlet valve communicate with the central through-hole. The drive unit applies a slow strain rate tensile load to the hollow tubular specimen. An annular pressure equalization chamber surrounding the central through-hole is provided inside the clamps. The annular pressure equalization chamber communicates with the central through-hole through multiple circumferentially distributed air guide holes. The air inlet communicates with the annular pressure equalization chamber. The clamps consist of two symmetrical components, each with a central through-hole, an internal thread interface, and a multi-stage composite sealing unit. The first stage of the multi-stage composite sealing unit is a fluororubber O-ring located at the root of the thread, and the second stage is a metal conical / flat sealing gasket located between the clamp end face and the specimen end face. A high-pressure hydrogen environment simulation module includes a hydrogen cylinder and a steel pipe. The hydrogen cylinder is connected to the gas inlet through the steel pipe, so that the inner cavity of the hollow tubular sample forms a sealed chamber that can withstand high-pressure hydrogen during the test. An external corrosion environment simulation module includes a sealable container and an electrochemical testing instrument. The sealable container contains a corrosive medium simulating a soil environment and is equipped with an electrochemical electrode connected to the electrochemical testing instrument. The sealable container seals and surrounds the outer wall of the hollow tubular sample. The external corrosion environment simulation module is used to apply an electrochemical environment to the hollow tubular sample. The external corrosion environment simulation module also includes a medium circulation pump, a pH monitoring sensor, and a dissolved oxygen control unit for adjusting the chemical state of the corrosive medium. An industrial control computer is connected to the tensile testing module, the high-pressure hydrogen environment simulation module, and the external corrosion environment simulation module. The industrial control computer is used to synchronously control the tensile strain rate, the internal hydrogen pressure of the sample, and the external electrochemical parameters of the sample, and to synchronously collect load, displacement, pressure, potential, and current data. The industrial control computer is also used to trigger an emergency shutdown sequence when the hydrogen leakage rate exceeds the standard, the internal pressure rises abnormally, or the sample breaks. And dynamically adjust the output current based on the real-time measured corrosion potential to precisely clamp the potential at the set protection value; The industrial control computer, after the tensile test module is started, performs the following operations synchronously to simulate the internal and external multi-field coupling of the hollow tubular specimen during dynamic tensile testing: controlling the high-pressure hydrogen environment simulation module to maintain the hydrogen pressure inside the hollow tubular specimen at a preset value; controlling the electrochemical testing instrument to continuously clamp the potential of the outer wall of the hollow tubular specimen relative to the corrosive medium within a preset target cathodic protection potential range; and controlling the driving unit to continuously apply a slow strain rate tensile load until the hollow tubular specimen fractures. Then, the hydrogen embrittlement sensitivity coefficient of the material is calculated according to the hydrogen embrittlement sensitivity coefficient calculation formula, which is: K HE = α * ( (RA0 - RA H ) / RA0 ) + β * ( (P max0 - P maxH ) / P max0 ); In the formula, K HE Here, RA is the hydrogen embrittlement sensitivity coefficient, RA0 is the reduction of area under inert conditions, and RA H P represents the reduction of area under the test environment. max0 For the maximum tensile load in an inert environment, P maxH The maximum tensile load under the test environment is represented by α and β, which are weighting coefficients. The weighting coefficients α and β are obtained by regression analysis based on actual pipeline failure data.

2. The hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to claim 1, characterized in that, The fixture is also equipped with a pressure sensor and a temperature sensor. The pressure sensor is used to monitor the hydrogen pressure inside the hollow tubular sample in real time.

3. The hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to claim 1, characterized in that, The sealable container is a tank made of transparent material, and the tank is provided with a top cover with a seal to form a sealed space.

4. The hydrogen embrittlement sensitivity evaluation test device for hydrogen pipeline materials according to claim 3, characterized in that, The electrochemical electrode includes a platinum electrode, a reference electrode, and a Luggin capillary, all of which are electrically connected to the hollow tubular sample.

5. A test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials, characterized in that, The test method, applied to the hydrogen embrittlement sensitivity evaluation test apparatus for hydrogen pipeline materials as described in any one of claims 1 to 4, comprises: The hydrogen pipeline material was prepared into a hollow tubular sample; The hollow tubular specimen is placed in a sealable container and fixed in place by a pair of clamps of the tensile testing module. Hydrogen gas is introduced into the inner cavity of the hollow tubular sample and pressurized to a preset pressure. Corrosive medium is injected into the sealable container, and preset electrochemical conditions are applied to the outer wall of the hollow tubular sample using an electrochemical testing instrument. The tensile test module is activated to stretch the hollow tubular specimen at a preset slow strain rate until the hollow tubular specimen breaks. During the tensile process, hydrogen pressure is applied inside the sample simultaneously and the external electrochemical conditions of the sample are dynamically changed. Record tensile mechanical data, pressure, temperature, and electrochemical data during the stretching process; The changes in the mechanical properties of the hollow tubular specimen under internal high-pressure hydrogen and external corrosive environments were analyzed to evaluate the hydrogen embrittlement sensitivity of the material. The mechanical properties included stress-strain relationship, yield strength and tensile strength, reduction of area and elongation after fracture.

6. The test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials according to claim 5, characterized in that, Prior to starting the tensile testing module, the following steps are included: Under the conditions of maintaining the internal and external environment of the sample, after allowing it to stand for a preset time of pre-charged hydrogen, the slow strain rate stretching is then started.

7. The test method for evaluating the hydrogen embrittlement sensitivity of hydrogen pipeline materials according to claim 5, characterized in that, After analyzing the changes in the mechanical properties of the hollow tubular sample under internal high-pressure hydrogen gas and external corrosive environments, and evaluating the material's hydrogen embrittlement susceptibility, the following steps are included: A rapid prediction model for the hydrogen embrittlement sensitivity of materials was established based on historical experimental data.

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