Method and system for synergistically testing and evaluating fatigue and fracture of metal material in hydrogen environment

Abstract

The invention relates to a hydrogen environment metal material fatigue and fracture cooperative test and evaluation method and system, and belongs to the field of metal material hydrogen environment compatibility. The method comprises the following steps: performing a fatigue crack propagation test and a fracture toughness test on a fatigue and fracture synergistic test sample in a hydrogen environment with preset pressure and preset temperature; based on the obtained fatigue crack propagation curve and the obtained crack propagation resistance curve, obtaining a fatigue crack propagation fitting curve and a fracture toughness characteristic value in the hydrogen environment with the preset pressure and the preset temperature; and based on the fatigue crack propagation fitting curve and the fracture toughness characteristic value in the hydrogen environment with the preset pressure and the preset temperature, safety evaluation of the metal material simulated hydrogen conveying pipeline under the fatigue load working condition is completed. The fatigue crack test is replaced by the fracture toughness test according to the defect length, the fatigue and fracture cooperative test is realized, the sample replacement is not needed, the test material is saved, the test preparation time for the sample replacement and cooling process is reduced, and the test efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen-environment compatibility of metallic materials, and specifically relates to a method and system for synergistic testing and evaluation of fatigue and fracture of metallic materials in hydrogen environments. Background Technology

[0002] Long-distance pipeline hydrogen transportation is an economically feasible way to achieve large-scale and efficient hydrogen energy transportation. It not only helps to utilize industrial by-product hydrogen and hydrogen production from renewable energy sources, but also reduces storage and transportation costs under large-scale transportation conditions, thereby reducing the end-use price of hydrogen energy and promoting the healthy development of the hydrogen energy industry.

[0003] The pipeline hydrogen transportation technology is still immature. Because hydrogen molecules can be adsorbed onto the surface of pipeline materials and then decompose into adsorbed hydrogen atoms, which then enter the material interior through desorption, there is a risk of hydrogen embrittlement failure during pipeline operation. Therefore, a systematic study of the hydrogen environment compatibility of pipeline materials is necessary. High-pressure hydrogen environments have a significant impact on the fatigue and fracture properties of materials; therefore, the testing and characterization of fatigue and fracture properties of materials in high-pressure hydrogen environments have become a key focus of metallic material compatibility research. In particular, the synergistic effect of hydrogen and ambient temperature on materials in low-temperature environments, and the underlying mechanisms, are still unclear.

[0004] Because the process of hydrogen entering the interior of metallic materials is significantly related to the material's strain rate, fatigue and fracture tests in high-pressure hydrogen environments are typically conducted using slow strain rates, with single-specimen tests exceeding five hours. Considering the cooling process in low-temperature environments, the test time is even longer, resulting in low efficiency and failing to meet the needs of basic research and engineering applications. For example, existing methods for evaluating the compatibility of materials with high-pressure hydrogen based on constant displacement loading use compact tensile specimens (CT specimens) and bolt-loaded compact tensile specimens (WOL specimens). This test method can measure the hydrogen-induced cracking susceptibility of the specimen material under constant displacement loading and the critical stress intensity factor K of bolt-loaded compact tensile specimens in a high-pressure hydrogen environment. IH It can be seen that this method used two different single samples to conduct high-pressure hydrogen compatibility evaluation tests, which took a long time and could not reflect the actual performance changes of the hydrogen pipeline under fatigue load conditions. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for the coordinated testing and evaluation of fatigue and fracture properties of metallic materials in a hydrogen environment. Specifically designed for fatigue and fracture testing in high-pressure, low-temperature hydrogen environments, it proposes using compact tensile specimens with pre-existing defects to conduct fatigue crack propagation tests. After obtaining the fatigue crack propagation rate curve, fracture toughness tests are then performed to obtain the crack propagation resistance curve. This method saves on test materials, reduces test preparation time such as specimen replacement and cooling processes, improves testing efficiency, and solves the problem of coordinated testing and evaluation of fatigue and fracture performance in high-pressure, low-temperature hydrogen environments.

[0006] The first objective of this invention is to provide a method for the synergistic testing and evaluation of fatigue and fracture of metallic materials in a hydrogen environment, comprising:

[0007] Fatigue crack propagation test and fracture toughness test were performed on the fatigue and fracture synergistic test specimens under a hydrogen environment with preset pressure and temperature.

[0008] Based on the fatigue crack propagation curve obtained from the fatigue crack propagation test and the crack propagation resistance curve obtained from the fracture toughness test, the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and preset temperature are obtained.

[0009] Based on the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and temperature, a safety evaluation of a simulated hydrogen transport pipeline made of metallic materials under fatigue load conditions was completed.

[0010] In a specific embodiment of the present invention, the fatigue crack propagation test and fracture toughness test of the fatigue and fracture synergistic test specimen under a preset pressure and preset temperature hydrogen environment include:

[0011] The fatigue and fracture synergistic test specimens were subjected to fatigue crack propagation tests in a hydrogen environment with preset pressure and temperature, and the changes in notch opening displacement were recorded during the test.

[0012] When the real-time defect length reaches the first preset length, the fatigue load is stopped, and a fracture toughness test is conducted under a preset pressure and temperature hydrogen environment. The change in notch opening displacement during the test is recorded.

[0013] The fracture toughness test is stopped when the real-time defect length reaches the second preset length.

[0014] In a specific embodiment of the present invention, the fatigue crack propagation test is conducted at a frequency of 0.1 to 1 Hz.

[0015] In a specific embodiment of the present invention, when the length of the pre-fabricated defect on the fatigue and fracture synergistic test specimen is 0.2W, the first preset length is 0.45 to 0.5W, and the second preset length is 0.6 to 0.7W, wherein W is the longest distance between the center of the pin hole and the edge of the specimen in the fatigue and fracture synergistic test specimen.

[0016] In a specific embodiment of the present invention, the fatigue crack propagation test includes the following calculations:

[0017] Calculate the real-time defect length based on the notch opening displacement variation of fatigue crack propagation test;

[0018] Based on the real-time defect length, a curve showing the relationship between the number of cycles and the crack length is obtained;

[0019] When the real-time defect length reaches the first preset length, calculate the stress intensity factor and the crack propagation amount for each loading cycle;

[0020] Based on the stress intensity factor and the crack propagation amount per loading cycle, the Delauc crack propagation curve is obtained.

[0021] In a specific embodiment of the present invention, the formula for calculating the stress intensity factor is as follows:

[0022]

[0023] Where K is the stress intensity factor, F is the test load, a is the real-time defect length of the fatigue and fracture synergistic test specimen, W is the longest distance from the center of the pin hole to the edge of the specimen in the fatigue and fracture synergistic test specimen, and B is the specimen thickness. N The net thickness of the sample after machining the side grooves along the crack propagation direction is given. If the side grooves are not machined, B N The answer is B.

[0024] In a specific embodiment of the present invention, the loading rate during the fracture toughness test is 0.01 to 0.1 mm / min.

[0025] In a specific embodiment of the present invention, the fracture toughness test includes the following calculations:

[0026] Based on the notch opening displacement variation of the fracture toughness test, the load opening displacement variation curve of the fracture toughness test is obtained.

[0027] Based on the notch opening displacement variation of fracture toughness test, the crack propagation amount is calculated in real time.

[0028] When the real-time defect length reaches the second preset length, the fracture toughness is calculated based on the real-time crack propagation amount.

[0029] Based on the crack propagation amount and the fracture toughness of the material, the crack propagation resistance curve is obtained.

[0030] In a specific embodiment of the present invention, the formula for calculating the fracture toughness is as follows:

[0031]

[0032] Where δ is the fracture toughness, F is the test load, a is the real-time defect length of the fatigue and fracture synergistic test specimen, W is the longest distance from the center of the pin hole to the edge of the specimen in the fatigue and fracture synergistic test specimen, and B is the specimen thickness. N The net thickness of the sample after machining the side grooves along the crack propagation direction is given. If the side grooves are not machined, B N Let B be the radius of rotation, R be the radius of rotation, v be Poisson's ratio, E be the elastic modulus, and z be the distance from the extensometer mounting position to the sample surface. p0.2 For yield strength, V p g2(a / W) represents the plastic component during the experimental loading process, and g2(a / W) is the stress intensity factor coefficient.

[0033] In a specific embodiment of the present invention, the preset pressure and preset temperature hydrogen environment is a hydrogen environment of 0-12 MPa and -40-25°C.

[0034] The second objective of this invention is to provide a system for the coordinated testing and evaluation of fatigue and fracture of metallic materials in a hydrogen environment, comprising:

[0035] The test module is used to perform fatigue crack propagation tests and fracture toughness tests on fatigue and fracture synergistic test specimens under preset pressure and temperature hydrogen environment.

[0036] The calculation module is used to obtain the fatigue crack propagation curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and preset temperature based on the fatigue crack propagation curve obtained from the fatigue crack propagation test and the crack propagation resistance curve obtained from the fracture toughness test.

[0037] The evaluation module is used to complete the safety evaluation of the simulated hydrogen transport pipeline under fatigue load conditions based on the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and temperature.

[0038] A third objective of this invention is to provide an electronic device comprising: a processor coupled to a memory;

[0039] The memory is used to store computer programs;

[0040] The processor is configured to execute the computer program stored in the memory, so that the electronic device performs the method described above.

[0041] A fourth objective of this invention is to provide a computer-readable storage medium storing a program or instructions that, when executed on a computer, cause the computer to perform the method described above.

[0042] The beneficial effects of this invention are:

[0043] This invention provides a method for the combined testing and evaluation of fatigue and fracture of metallic materials in a hydrogen environment. The method utilizes fatigue and fracture test specimens for combined fatigue and fracture testing and determines the connection method in the specific combined testing process (replacing fatigue crack testing with fracture toughness testing based on defect length). This eliminates the need for specimen replacement, saving test materials, reducing test preparation time such as specimen replacement and cooling processes, and improving test efficiency. Furthermore, it more realistically simulates the performance changes of hydrogen pipelines under fatigue load conditions, thereby solving the problem of combined testing and evaluation of fatigue and fracture performance in high-pressure, low-temperature hydrogen environments.

[0044] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the 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 based on these drawings without creative effort.

[0046] Figure 1 A flowchart of a method for synergistic testing and evaluation of fatigue and fracture of metallic materials in a hydrogen environment according to an embodiment of the present invention is shown;

[0047] Figure 2 A schematic diagram of a fatigue and fracture synergistic test specimen according to an embodiment of the present invention is shown;

[0048] Figure 3 A schematic diagram of the crack length in a fatigue and fracture synergy test specimen according to an embodiment of the present invention is shown.

[0049] Figure 4 The graph shows the crack length versus cycle number in a fatigue crack propagation test according to an embodiment of the present invention.

[0050] Figure 5 A fatigue crack propagation curve diagram according to an embodiment of the present invention is shown;

[0051] Figure 6 The fracture toughness test load-displacement curve according to an embodiment of the present invention is shown.

[0052] Figure 7 The fracture toughness test crack propagation resistance curve according to an embodiment of the present invention is shown;

[0053] Figure 8 A distribution diagram of evaluation points and evaluation curves for materials based on fatigue and fracture synergy tests according to an embodiment of the present invention is shown;

[0054] Figure 9 A framework diagram of a hydrogen environment fatigue and fracture synergistic testing and evaluation system for metallic materials according to an embodiment of the present invention is shown.

[0055] Figure 10 A frame diagram of an electronic device according to an embodiment of the present invention is shown;

[0056] In the diagram: Experimental module 1; Calculation module 2; Evaluation module 3; Electronic device 300; Processor 301; Memory 302. Detailed Implementation

[0057] 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] like Figure 1 As shown, the method for synergistic testing and evaluation of fatigue and fracture of metallic materials in a hydrogen environment according to an embodiment of the present invention includes:

[0059] Step S1: Conduct fatigue crack propagation test and fracture toughness test on the fatigue and fracture synergistic test specimen under a preset pressure and temperature hydrogen environment.

[0060] Step S2: Based on the fatigue crack propagation curve obtained from the fatigue crack propagation test and the crack propagation resistance curve obtained from the fracture toughness test, obtain the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and preset temperature.

[0061] Step S3: Based on the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and temperature, complete the safety evaluation of the simulated hydrogen transport pipeline of metallic materials under fatigue load conditions.

[0062] In this embodiment of the invention, the fatigue and fracture synergistic test specimen is a compact tensile specimen. One edge of the specimen has an opening, the shape of which matches the extensometer used in the fatigue and fracture synergistic test. Pin holes are symmetrically arranged along both sides of the opening. A pre-fabricated defect (i.e., an initial defect with a depth a0) is provided at the top of the opening. A schematic diagram of the fatigue and fracture synergistic test specimen is shown below. Figure 2 As shown, its dimensions are as follows: Figure 2 mark;

[0063] Where W is the longest distance from the center of the pin hole to the edge of the specimen in the fatigue and fracture synergistic test specimen;

[0064] a0 represents the initial defect length of the fatigue and fracture synergistic test specimen.

[0065] Meanwhile, the thickness of the fatigue and fracture synergistic test specimen should not be less than 85% of the steel pipe wall thickness (simulated hydrogen transport pipeline).

[0066] Before proceeding to step S1, prepare the test equipment:

[0067] (1) Testing machine and sensor

[0068] The testing machine should be an electro-hydraulic servo testing machine equipped with a high-pressure hydrogen environment test chamber; the hydrogen environment test chamber should be equipped with at least one pressure sensor that can accurately display the test pressure, with an accuracy of not less than 0.5 grade; the hydrogen environment test chamber should include a sensor that can accurately display the test temperature, with a resolution of not less than 0.1℃; the hydrogen environment test chamber should be able to house extensometers for fatigue and fracture tests.

[0069] (2) Experimental preparation

[0070] i. Sample mounting and installation of extensometers for fatigue and fracture testing;

[0071] ii. Replace the hydrogen environmental test chamber and pipelines with nitrogen, and then replace them with hydrogen.

[0072] iii. The gas inside the test chamber is pressurized to the preset pressure, and the pressure fluctuation does not exceed 5%;

[0073] iv. The gas inside the test chamber is cooled down to the preset temperature, and the gas pressure is dynamically adjusted during the cooling process.

[0074] v. After the gas temperature and pressure in the test chamber reach the set value, let it stand for no less than 1 hour until the load value of the test machine stabilizes.

[0075] The preset pressure is 0-12 MPa and the preset temperature is -40-25℃ to simulate the fatigue load conditions of hydrogen pipelines under high pressure and low temperature.

[0076] In an embodiment of the present invention, for example, the preset pressure is 4 MPa and the preset temperature is -10°C.

[0077] Once the above preparations are completed, step S1 is performed, which involves conducting fatigue crack propagation tests and fracture toughness tests on the fatigue and fracture synergistic test specimens under a preset pressure and temperature hydrogen environment. Specifically:

[0078] i. The fatigue and fracture synergistic test specimens were subjected to fatigue crack propagation tests in a hydrogen environment with preset pressure and temperature, and the changes in notch opening displacement were recorded during the test. The test frequency was 0.1 to 1 Hz during the test.

[0079] ii. When the real-time defect length reaches the first preset length, stop applying fatigue load, conduct a fracture toughness test in a hydrogen environment with preset pressure and preset temperature, and record the notch opening displacement change during the test. The loading rate during the test is 0.01 to 0.1 mm / min, and the first preset length is 0.45 to 0.5 W.

[0080] iii. When the real-time defect length reaches the second preset length, the fracture toughness test is stopped. The second preset length is 0.6 to 0.7 W.

[0081] Based on the process of step S1 above, the fatigue and fracture performance of the same pre-fabricated defect specimen were tested in a coordinated manner, as shown in the schematic diagram. Figure 3 As shown.

[0082] For example, in step S1 of the embodiment of the present invention, the pre-fabrication defect a0 of the fatigue and fracture synergistic test specimen is 0.2W, the test frequency in the fatigue crack propagation test is 1Hz, the loading rate in the fracture toughness test is 0.05mm / min, the first preset length is 0.5W, and the second preset length is 0.6W;

[0083] The following calculations are included in step S1, subdivided into step i, of the fatigue crack propagation test:

[0084] a. Calculate the real-time defect length based on the notch opening displacement variation of fatigue crack propagation tests;

[0085] b. Based on the real-time defect length, obtain the curve showing the relationship between the number of cycles and the crack length; such as... Figure 4 As shown;

[0086] c. When the real-time defect length reaches the first preset length, calculate the stress intensity factor and the crack propagation amount for each loading cycle. The formula for calculating the stress intensity factor is shown in equation (1):

[0087]

[0088] In equation (1), K is the stress intensity factor, F is the test load, a is the real-time defect length of the fatigue and fracture synergistic test specimen, W is the longest distance from the center of the pin hole to the edge of the specimen in the fatigue and fracture synergistic test specimen, and B is the specimen thickness. N The net thickness of the sample after machining the side grooves along the crack propagation direction is given. If the side grooves are not machined, B N The answer is B.

[0089] d. Based on the stress intensity factor and the crack propagation amount per loading cycle, the crack propagation curve is obtained, as shown below. Figure 5 As shown.

[0090] The following calculations are included in step S1, subdivided into step ii, the fracture toughness test:

[0091] a. Based on the notch opening displacement variation in the fracture toughness test, the load opening displacement variation curve of the fracture toughness test is obtained, as follows: Figure 6 As shown;

[0092] b. Calculate crack propagation in real time based on notch opening displacement changes from fracture toughness tests;

[0093] c. When the real-time defect length reaches the second preset length, the fracture toughness is calculated based on the real-time crack propagation amount. The formula for calculating the fracture toughness is as follows:

[0094]

[0095] In equation (1), δ is the fracture toughness, F is the test load, a is the real-time defect length of the fatigue and fracture synergistic test specimen, W is the longest distance from the center of the pin hole to the edge of the specimen in the fatigue and fracture synergistic test specimen, and B is the specimen thickness. N The net thickness of the sample after machining the side grooves along the crack propagation direction is given. If the side grooves are not machined, B N Let B be the radius of rotation, R be the radius of rotation, v be Poisson's ratio, E be the elastic modulus, and z be the distance from the extensometer mounting position to the sample surface. p0.2 For yield strength, V p g2(a / W) represents the plastic component during the experimental loading process, and g2(a / W) is the stress intensity factor coefficient.

[0096] d. Based on the crack propagation amount and the material fracture toughness, the crack propagation resistance curve is obtained, such as... Figure 7 As shown.

[0097] In step S2, based on the fatigue crack propagation curve obtained from the fatigue crack propagation test and the crack propagation resistance curve obtained from the fracture toughness test, the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment at a preset pressure and temperature are obtained, specifically:

[0098] based on Figure 5 The fatigue crack propagation curve was fitted to obtain the following formula for fatigue crack propagation of the material in a high-pressure hydrogen environment at 4 MPa and -10℃: da / dN = 1.07 × 10⁻⁶. -7 ΔK 2.417 .

[0099] based on Figure 7 The crack propagation resistance curve obtained from the fracture toughness test showed that the characteristic value of the fracture toughness of the material in a high-pressure hydrogen environment of 4 MPa and -10℃ was 0.31 mm.

[0100] After completing step S2, proceed to step S3, which involves completing a safety evaluation of the simulated hydrogen transport pipeline under fatigue load conditions based on the fatigue crack propagation fitting curve and fracture toughness characteristic values ​​in a hydrogen environment with preset pressure and temperature. Specifically:

[0101] Based on the slow strain rate tensile stress-strain curve of the test material in a simulated hydrogen environment, and Equation (3), the evaluation curve f(Lr) is obtained.

[0102]

[0103] In equation (3), E is the elastic modulus, ε ref For reference strain, σ Y For yield strength, L r This is the ratio of reference stress to yield strength.

[0104] Based on the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and temperature, the stress intensity factor K and its corresponding stress ratio Lr in the crack propagation process are calculated. Then, the ratio of stress intensity factor K to material fracture toughness is calculated to obtain a series of evaluation points.

[0105] The distribution of specific evaluation points and evaluation curves is as follows: Figure 8 As shown, from Figure 8 (The horizontal axis is Lr, the vertical axis is Kr, and Kr is the ratio of stress intensity factor K to material fracture toughness) It can be seen from the evaluation point that it is located below the evaluation curve. This indicates that the hydrogen pipeline made of the same material as the fatigue and fracture synergistic test specimen in this embodiment is safe to operate under fatigue load conditions in a high-pressure hydrogen environment of 4MPa and -10℃.

[0106] like Figure 9 As shown, the hydrogen environment fatigue and fracture synergistic testing and evaluation system for metallic materials according to an embodiment of the present invention includes:

[0107] Test module 1 is used to conduct fatigue crack propagation tests and fracture toughness tests on fatigue and fracture synergistic test specimens under preset pressure and temperature hydrogen environment.

[0108] Calculation module 2 is used to obtain the fatigue crack propagation curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and preset temperature based on the fatigue crack propagation curve obtained from the fatigue crack propagation test and the crack propagation resistance curve obtained from the fracture toughness test.

[0109] Evaluation module 3 is used to complete the safety evaluation of the simulated hydrogen transport pipeline under fatigue load conditions based on the fatigue crack propagation fitting curve and fracture toughness characteristic value in a hydrogen environment with preset pressure and temperature.

[0110] like Figure 10 As shown, in some embodiments of the present invention, an electronic device is provided, the electronic device 300 including: a processor 301 coupled to a memory 302;

[0111] The memory 302 is used to store computer programs;

[0112] The processor 301 is configured to execute the computer program stored in the memory 302, so that the electronic device performs the method described in the above embodiments.

[0113] In some embodiments of the present invention, a computer-readable storage medium is provided that stores a program or instructions that, when executed on a computer, cause the computer to perform the methods described in the above embodiments.

[0114] According to embodiments of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, electronic device, or apparatus.

[0115] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for hydrogen environment metal material fatigue and fracture collaborative test and evaluation, characterized in that, The application relates to a method for evaluating safety of a hydrogen pipeline under fatigue load, and belongs to the field of hydrogen pipeline safety evaluation. The method comprises the following steps: a fatigue crack propagation test and a fracture toughness test are carried out on a fatigue and fracture cooperative test sample under a preset pressure and a preset temperature hydrogen environment; a fatigue crack propagation fitting curve and a fracture toughness characteristic value in the preset pressure and preset temperature hydrogen environment are obtained based on the fatigue crack propagation curve obtained in the fatigue crack propagation test and the crack propagation resistance curve obtained in the fracture toughness test; 2. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 1, characterized by, safety evaluation of a metal material simulation hydrogen pipeline under a fatigue load condition is completed based on the fatigue crack propagation fitting curve and the fracture toughness characteristic value in the preset pressure and preset temperature hydrogen environment. The fatigue crack propagation test and the fracture toughness test carried out on the fatigue and fracture cooperative test sample under the preset pressure and preset temperature hydrogen environment comprise the following steps: the fatigue crack propagation test is carried out on the fatigue and fracture cooperative test sample under the preset pressure and preset temperature hydrogen environment, and the notch opening displacement change in the test process is recorded; when the real-time defect length reaches a first preset length, the fatigue load is stopped, the fracture toughness test under the preset pressure and preset temperature hydrogen environment is carried out, and the notch opening displacement change in the test process is recorded; 3. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 2, characterized by, when the real-time defect length reaches a second preset length, the fracture toughness test is stopped.

4. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 2, characterized by, During the fatigue crack propagation test, the test frequency is 0.1-1 Hz.

5. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 2, characterized by, When the pre-prepared defect length on the fatigue and fracture cooperative test sample is 0.2W, the first preset length is 0.45-0.5W, and the second preset length is 0.6-0.7W, wherein W is the longest length of the hole center distance from the sample edge in the pin hole of the fatigue and fracture cooperative test sample. During the fatigue crack propagation test, the following calculation is carried out: the real-time defect length is calculated based on the notch opening displacement change in the fatigue crack propagation test; a cycle number-crack length relationship curve is obtained based on the real-time defect length; when the real-time defect length reaches the first preset length, the stress intensity factor and the crack propagation amount of each loading cycle are calculated; 6. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 5, characterized by, a fatigue crack propagation curve is obtained based on the stress intensity factor and the crack propagation amount of each loading cycle. wherein K is a stress intensity factor, F is a test load, a is a real-time defect length of the fatigue and fracture collaborative test sample, W is a length of a pin hole center distance from the sample edge in the fatigue and fracture collaborative test sample, B is a sample thickness, B N is a net thickness of the sample after machining a side groove in the crack propagation direction, and if the side groove is not machined, B N is B.

7. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 2, characterized by, The calculation formula of the stress intensity factor is as follows:

8. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 2, characterized by, During the fracture toughness test, the loading rate is 0.01-0.1 mm / min. During the fracture toughness test, the following calculation is carried out: a fracture toughness test load opening displacement change curve is obtained based on the notch opening displacement change in the fracture toughness test; the crack propagation amount is calculated in real time based on the notch opening displacement change in the fracture toughness test; when the real-time defect length reaches the second preset length, the fracture toughness is calculated based on the real-time crack propagation amount; 9. The hydrogen environment metal material fatigue and fracture collaborative test and evaluation method according to claim 8, characterized by, a crack propagation resistance curve is obtained based on the crack propagation amount and the material fracture toughness. wherein δ is the fracture toughness, F is the test load, a is the real-time flaw length of the fatigue and fracture collaborative test sample, W is the longest length from the hole center of the pin hole in the fatigue and fracture collaborative test sample to the sample edge, B is the sample thickness, B N is the net thickness of the sample after machining the side groove in the crack propagation direction, and B N is B, R is the radius of rotation, v is the Poisson's ratio, E is the elastic modulus, z is the distance from the sample surface to the clamping position of the extensometer, R p0.2 is the yield strength, V p is the plastic component in the test loading process, and g2(a / W) is the stress intensity factor coefficient.

10. The hydrogen environment metal material fatigue and fracture collaborative testing and evaluation method according to any one of claims 1 to 9, characterized by, The calculation formula of the fracture toughness is as follows:

11. A hydrogen environment metal material fatigue and fracture collaborative test and evaluation system, characterized by, The preset pressure and preset temperature hydrogen environment is a hydrogen environment with a pressure of 0-12 MPa and a temperature of-40-25 DEG C. The application further provides a safety evaluation device for a hydrogen pipeline under a fatigue load. The test module is used for carrying out the fatigue crack propagation test and the fracture toughness test on the fatigue and fracture cooperative test sample under the preset pressure and preset temperature hydrogen environment; the calculation module is used for obtaining the fatigue crack propagation fitting curve and the fracture toughness characteristic value in the preset pressure and preset temperature hydrogen environment based on the fatigue crack propagation curve obtained in the fatigue crack propagation test and the crack propagation resistance curve obtained in the fracture toughness test; and the safety evaluation device comprises the test module and the calculation module. The evaluation module is used for fitting a curve of fatigue crack propagation and a characteristic value of fracture toughness in a hydrogen environment with preset pressure and preset temperature, and completing safety evaluation of a metal material simulation hydrogen pipeline under a fatigue load working condition.

12. An electronic device, comprising: Comprise: A processor coupled with a memory; The memory is used for storing a computer program; The processor is used for executing the computer program stored in the memory, so that the electronic device executes the method as claimed in any one of claims 1 to 10.

13. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a program or instruction, which makes the computer execute the method as claimed in any one of claims 1 to 10 when the program or instruction runs on the computer.

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