Metal material hydrogen compatibility simulation test method based on hydrogen content

Abstract

The invention discloses a metal material hydrogen compatibility simulation test method based on hydrogen content. The method comprises the following steps: S1, sample preparation; s2, charging hydrogen in a high-pressure hydrogen environment; s3, diffusible hydrogen is measured; s4, preparing an electrochemical hydrogen charging solution; s5, carrying out hydrogen charging by using an electrochemical hydrogen charging solution; s6, storing the sample; s7, drawing a hydrogen concentration change curve; s8, electrogalvanizing process parameters are set; s9, performing hydrogen charging in a simulated high-pressure hydrogen environment; s10, the sample is galvanized; s11, carrying out a slow tensile test and a fracture toughness test on the sample; and S12, evaluating the high-pressure hydrogen embrittlement of the sample based on the results of the slow tensile test and the fracture toughness test. According to the method, the hydrogen embrittlement performance of the material under different hydrogen pressure environments can be obtained, and the influence of the influence factors on the high-pressure hydrogen embrittlement performance of the steel can be analyzed in combination with the process, alloy components and stress states of the steel.

Description

Technical Field

[0001] The present invention relates to a method for testing the delayed fracture of metal materials in a high-pressure hydrogen environment, and more specifically, to a method for simulating the hydrogen compatibility of metal materials based on hydrogen content. Background Art

[0002] As a clean energy source, hydrogen energy has a wide range of sources and has the advantages of high energy conversion rate, pollution-free, zero emissions, storable, and renewable. It is an important direction for energy transformation and upgrading and an important path to achieve carbon peak and carbon neutrality, with huge market potential. The whole life cycle of the hydrogen energy system includes links such as hydrogen production, storage, transportation, and utilization. Among them, hydrogen storage, transportation, and pipelines connect the upstream production and downstream end-users, which is a key intermediate link. Hydrogen storage, transportation, and pipeline containers and pipelines work in a high-pressure and high-purity hydrogen environment for a long time, which is likely to cause local plastic reduction, accelerated crack propagation speed, and decreased durability, resulting in problems such as hydrogen-induced cracking, hydrogen embrittlement, or fatigue damage. Solving the problem of high-pressure hydrogen embrittlement of materials is a prerequisite for the safe use of high-pressure hydrogen storage containers. In principle, various conventional material mechanics performance methods can be used for hydrogen embrittlement tests, but the more common test methods are the following, which are also the test methods required by relevant standards or specifications (Table 1).

[0003] Table 1 Test Methods Required by Standards

[0004]

[0005] The hydrogen embrittlement test methods of metal materials can be roughly divided into two categories: one is used for the preliminary screening of materials to quickly evaluate whether the materials can be used to manufacture hydrogen-containing parts, such as disk tests, hydrogen-induced cracking stress intensity factor threshold value tests, etc.; the other is used for in-situ testing of material mechanics properties to provide performance data for the design of hydrogen-containing parts or the evaluation of material applicability, such as slow strain rate tensile tests, fatigue crack propagation rate tests, fatigue life tests, etc. The test environment in the above standards is a high-pressure hydrogen environment, and the test is difficult. Since hydrogen atoms are small and the explosion limit range is wide, the test risk is relatively large, especially the test risk in a high-pressure and ultra-high-pressure hydrogen environment is very high. This is also an important reason restricting the application of hydrogen storage and transportation metal materials. It is urgent to develop a test hydrogen embrittlement evaluation method with low risk that can replace the high-pressure hydrogen environment. Summary of the Invention

[0006] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a method for simulating the hydrogen compatibility of metal materials based on hydrogen content, which can obtain the hydrogen embrittlement performance of materials under different hydrogen pressure environments and can analyze the influence of these influencing factors on the high-pressure hydrogen embrittlement performance of steel in combination with the process, alloy composition, and stress state of the steel.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A method for simulating the hydrogen compatibility of metal materials based on hydrogen content, comprising the following steps:

[0009] S1, sample preparation;

[0010] S2, hydrogen charging under a high-pressure hydrogen environment;

[0011] S3, measuring diffusible hydrogen;

[0012] S4, preparing an electrochemical hydrogen charging solution;

[0013] S5, hydrogen charging with the electrochemical hydrogen charging solution;

[0014] S6, sample preservation;

[0015] S7, plotting the hydrogen concentration change curve;

[0016] S8, setting the electro-galvanizing process parameters;

[0017] S9, simulating hydrogen charging under a high-pressure hydrogen environment;

[0018] S10, galvanizing the sample;

[0019] S11, performing slow tensile tests and fracture toughness tests on the sample;

[0020] S12, evaluating the high-pressure hydrogen embrittlement of the sample based on the results of the slow tensile test and the fracture toughness test.

[0021] Preferably, the sample includes a hydrogen-charged sample, a slow tensile sample, and a CT sample.

[0022] Preferably, the hydrogen-charged sample is a sheet sample with dimensions of 100mm * 20mm * 2mm;

[0023] The dimensions of the slow tensile sample are manufactured according to the ASTM G142 standard.

[0024] Preferably, in step S2, the hydrogen charging under a high-pressure hydrogen environment specifically includes:

[0025] According to the ASME B31.12 standard, place the hydrogen-charged sample in a hydrogen-containing high-pressure hydrogen storage container for 1000 h. The number of hydrogen-charged samples is at least 3. After the test, measure the diffusible hydrogen to obtain the hydrogen content Cg of the hydrogen-charged sample under the high-pressure hydrogen environment.

[0026] Preferably, in step S3, the measurement of diffusible hydrogen specifically includes:

[0027] Use a hydrogen analyzer to heat the hydrogen-charged sample at 400 °C for 20 min to 1 h using the thermal desorption method to obtain the diffusible hydrogen content.

[0028] Preferably, in the step S4, the electrochemically hydrogen-charged solution is a solution of 0.5 mol / L H2SO4 + 0.3 g / L thiourea, and it is stored at room temperature for 24 h.

[0029] Preferably, in the step S5, the specific process of hydrogen charging the electrochemically hydrogen-charged solution includes:

[0030] Charging the hydrogen-charged sample in the electrochemically hydrogen-charged solution for different durations by using the electrochemical constant current mode;

[0031] The hydrogen charging current is 0.01 - 10 mA / cm 2 ;

[0032] The hydrogen charging time is 1 min - 10 h.

[0033] Preferably, in the step S6, the specific process of sample preservation includes:

[0034] Placing the hydrogen-charged sample after hydrogen charging in liquid nitrogen for preservation.

[0035] Preferably, in the step S7, the specific process of plotting the hydrogen concentration change curve includes:

[0036] Measuring the hydrogen content of the hydrogen-charged sample one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1 ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged sample. Meanwhile, record the relationship between the hydrogen charging concentration and time to establish a hydrogen concentration change curve.

[0037] Preferably, in the step S8, the electroplated zinc solution uses an alkaline zinc plating solution.

[0038] Preferably, in the alkaline zinc plating solution, the concentration of sodium hydroxide is 100 - 120 g / L, the concentration of zinc oxide is 8 - 12 g / L, and the concentration of triethanolamine is 20 - 30 ml / L;

[0039] During electroplating, the temperature is 10 - 40 °C, and the current density is 5 - 20 mA / cm 2 。

[0040] Preferably, in the step S9, the specific process of hydrogen charging under the simulated high-pressure hydrogen environment includes:

[0041] Preparing the slow tensile sample and the CT sample by using the electrochemically hydrogen-charging process, and controlling the ratio range of the hydrogen content Cgm of the slow tensile sample and the CT sample to the hydrogen content Cg of the hydrogen-charged sample to be between 0.8 and 1.1.

[0042] Preferably, the number of the slow tensile samples and the CT samples is at least 5.

[0043] Preferably, in the step S10, electrogalvanizing process is adopted to galvanize the slow-stretching sample and the CT sample.

[0044] Preferably, in the step S11, the slow-stretching test specifically includes:

[0045] Perform a slow-stretching test on the slow-stretching sample at a slow-stretching rate of 5*10 -7 ~1*10 -5 , and record the data;

[0046] The fracture toughness test specifically includes:

[0047] Adopt the displacement-increasing method to perform a fracture toughness test on the CT sample at a displacement rate of 0.04 mm / min, and record the fracture toughness K IH .

[0048] Preferably, in the step S12, the high-pressure hydrogen embrittlement evaluation based on the slow-stretching test results is specifically as follows:

[0049] Compare the slow-stretching test results after hydrogen charging with the test results in an inert gas environment, compare the ratio changes. If the ratio reaches more than 0.9, the slow-stretching sample has no hydrogen embrittlement in a high-pressure environment; 0.75 - 0.9 indicates mild hydrogen embrittlement; 0.5 - 0.75 indicates moderate hydrogen embrittlement; less than 0.5 indicates severe hydrogen embrittlement;

[0050] The sorting of the above three data ratios is as follows:

[0051] The reduction of area ratio has the highest priority, the tensile strength ratio ranks second, and the elongation ratio ranks third. When there are conflicts in the ratios, the reduction of area ratio shall prevail;

[0052] The high-pressure hydrogen embrittlement evaluation based on the fracture toughness is specifically as follows:

[0053] Compare the fracture toughness K IH under different hydrogen content conditions. According to the ASTM B31.12 standard, if K IH ≥55 MPa*m 1 / 2 , it indicates that the CT sample passes the anti-hydrogen embrittlement performance test in this environment, and thus it can be determined whether the anti-hydrogen performance of the material under the corresponding simulated high-pressure environment is qualified.

[0054] A method for simulating the hydrogen compatibility of metal materials based on hydrogen content provided by the present invention starts from the damage mechanism of hydrogen to materials and designs a method for simulating high-pressure hydrogen embrittlement test from the perspective of hydrogen content. This method is combined with the existing high-pressure hydrogen embrittlement evaluation methods and standards to enhance the accuracy and rationality of the test. Using the present invention, different high-pressure hydrogen environments can be simulated under normal temperature and pressure conditions, the hydrogen embrittlement performance of metal materials in a high-pressure hydrogen environment can be evaluated, and the hydrogen embrittlement risk of metal materials in a high-pressure hydrogen embrittlement environment can be clarified. Using the present invention, the hydrogen embrittlement resistance of steel under different hydrogen pressure conditions can be simulated, the applicability and hydrogen embrittlement risk of steel under different hydrogen pressure conditions can be clarified, and at the same time, it can provide guidance and direction for the improvement of the hydrogen embrittlement resistance of steel and its safe use. Brief Description of the Drawings

[0055] Figure 1 is a schematic flow chart of the method for simulating the hydrogen compatibility of metal materials of the present invention;

[0056] Figure 2 is a schematic diagram of the sample in the method for simulating the hydrogen compatibility of metal materials of the present invention, (a) is a slow tensile sample, and (b) is a CT sample. Detailed Embodiments

[0057] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0058] Combined with Figure 1 as shown, a method for simulating the hydrogen compatibility of metal materials based on hydrogen content provided by the present invention includes the following steps:

[0059] S1, sample preparation:

[0060] The samples are divided into 3 types. The first type is the hydrogen-charged sample, which is a sheet sample with a size of 100mm * 20mm * 2mm; the second type is the slow tensile sample. To ensure the accuracy of the test, the size of the slow tensile sample is manufactured with reference to the ASTM G142 standard, specifically as shown in Figure 2 (a) of Figure 2 (b) of

[0061] S2, hydrogen charging under high-pressure hydrogen environment:

[0062] Referring to the ASME B31.12 standard, the hydrogen-charged samples are placed in a hydrogen-containing high-pressure hydrogen storage container for 1000h. The number of hydrogen-charged samples is at least 3. After the test, the measurement of diffusible hydrogen is carried out to obtain the hydrogen content Cg of the hydrogen-charged samples under the high-pressure hydrogen environment;

[0063] S3, measurement of diffusible hydrogen:

[0064] Using a hydrogen analyzer, the hydrogen-charged sample is heated at 400 °C for 20 min to 1 h by thermal desorption method to obtain the diffusible hydrogen content;

[0065] S4, Prepare an electrochemical hydrogen charging solution:

[0066] Prepare a solution of 0.5 mol / L H2SO4 + 0.3 g / L thiourea as the hydrogen charging solution and store it at room temperature for 24 h for use;

[0067] S5, Perform hydrogen charging with the electrochemical hydrogen charging solution:

[0068] Use the electrochemical constant current mode to perform hydrogen charging on the hydrogen-charged sample in the electrochemical hydrogen charging solution for different durations;

[0069] The hydrogen charging current is 0.01 - 10 mA / cm 2 ;

[0070] The hydrogen charging time varies from 1 min to 10 h;

[0071] S6, Sample storage:

[0072] Place the hydrogen-charged sample after hydrogen charging in liquid nitrogen for storage and standby;

[0073] S7, Plot the hydrogen concentration change curve:

[0074] Measure the hydrogen content of the hydrogen-charged sample one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1 ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged sample. At the same time, record the relationship between the hydrogen charging concentration and time and establish a hydrogen concentration change curve;

[0075] S8, Set the electrogalvanizing process parameters:

[0076] To avoid hydrogen absorption caused by the reaction of the material with the acidic solution, an alkaline zinc plating solution is used for electrogalvanizing;

[0077] In the alkaline zinc plating solution, the concentration of sodium hydroxide is 100 - 120 g / L, the concentration of zinc oxide is 8 - 12 g / L, and the concentration of triethanolamine is 20 - 30 ml / L;

[0078] During electroplating, the temperature is 10 - 40 °C and the current density is 5 - 20 mA / cm 2 ;

[0079] S9, Simulate hydrogen charging under a high-pressure hydrogen environment:

[0080] According to the hydrogen concentration change curve in step S7 and the hydrogen content Cg in the high-pressure hydrogen environment obtained in step S2, and then using the electrochemical hydrogen charging process in step S5 to prepare slow-tensile samples and CT samples, so that the ratio range between the hydrogen content Cgm of the slow-tensile samples and CT samples and the hydrogen content Cg of the hydrogen-charged samples is controlled between 0.8 and 1.1. In this way, samples similar to those after hydrogen charging in the high-pressure hydrogen environment can be obtained, with similar internal hydrogen damage. The obtained samples can then be used to carry out simulated high-pressure hydrogen environment tests;

[0081] The number of slow-tensile samples and CT samples is at least 5;

[0082] S10, galvanize the samples:

[0083] Use the electro-galvanizing process in step S8 to galvanize the slow-tensile samples and CT samples to prevent the escape of diffusible hydrogen. Then place the slow-tensile samples and CT samples in liquid nitrogen for standby;

[0084] S11, conduct slow-tensile tests and fracture toughness tests on the samples:

[0085] Refer to ASTM G129 to conduct slow-tensile tests on the slow-tensile samples, with a slow-tensile rate of 5*10 -7 ~1*10 -5 , record the reduction of area, elongation, and tensile strength, etc. Before the test, take the samples out of liquid nitrogen and place them in alcohol until they reach room temperature before conducting the test. Then conduct slow-tensile tests on the samples under inert gas and record the data;

[0086] Refer to GB / T21143-2014 and use the increased displacement method to conduct fracture toughness tests on the CT samples, with a displacement rate of 0.04 mm / min, and record the fracture toughness K IH .

[0087] S12, evaluate the high-pressure hydrogen embrittlement of the samples based on the results of slow-tensile tests and fracture toughness tests:

[0088] Compare the results of slow-tensile tests after hydrogen charging with those of tests in an inert gas environment, and compare the ratio changes. If the ratio reaches more than 0.9, then the slow-tensile samples have no hydrogen embrittlement in the high-pressure environment, 0.75 - 0.9 is mild hydrogen embrittlement, 0.5 - 0.75 is moderate hydrogen embrittlement, and below 0.5 is severe hydrogen embrittlement;

[0089] The sorting of the above three data ratios is as follows:

[0090] The priority of the reduction of area ratio is the first, the ratio of tensile strength is the second, and the ratio of elongation is the third. When there are conflicts in the ratios, the ratio of the reduction of area shall prevail;

[0091] The specific evaluation of high-pressure hydrogen embrittlement based on fracture toughness is as follows:

[0092] Compare the fracture toughness K under different hydrogen content conditions IH According to the standard of ASTM B31.12, for K IH ≥55MPa*m 1 / 2 it indicates that the CT sample passes the hydrogen embrittlement resistance test in this environment, and thus the hydrogen resistance of the material under the corresponding simulated high-pressure environment can be obtained whether it is qualified or not.

[0093] Example 1

[0094] In this Example 1, 4130X is used as the test sample, and the specific steps are as follows:

[0095] S1. Sample preparation: There are 3 types of test samples. The first type is the hydrogen-charged sample, which is a sheet sample of 100mm * 20mm * 2mm; the second type is the slow-stretching sample. To ensure the accuracy of the test, the size of the slow-stretching sample is manufactured with reference to the ASTM G142 standard, specifically as shown in Figure 2 (a) of Figure 2 (b) of

[0096] S2. Hydrogen charging in a high-pressure hydrogen environment: Referring to the ASME B31.12 standard, the hydrogen-charged samples are placed in a high-pressure hydrogen storage container with a hydrogen pressure of 50MPa for 1000h. There are 4 samples. After the test, the diffusible hydrogen is measured to obtain the hydrogen content Cg of the hydrogen-charged samples in the high-pressure hydrogen environment;

[0097] S3. Diffusible hydrogen measurement method: Using a hydrogen analyzer, the hydrogen-charged samples are heated at 400°C for 30min by the thermal desorption method to obtain the diffusible hydrogen content;

[0098] S4. Electrochemical hydrogen charging solution: Prepare a 0.5mol / L H2SO4 + 0.3g / L thiourea solution as the hydrogen charging solution and store it at room temperature for 24h for use;

[0099] S5. Electrochemical hydrogen charging: Using the electrochemical constant current mode, hydrogen charging is carried out on the hydrogen-charged samples in the electrochemical hydrogen charging solution with a hydrogen charging current of 1mA / cm 2 for different durations. The hydrogen charging time ranges from 1min to 6h;

[0100] S6. Sample storage: The hydrogen-charged samples after hydrogen charging are stored in liquid nitrogen for standby;

[0101] S7. Drawing the hydrogen concentration change curve: The hydrogen-charged samples after hydrogen charging are measured for hydrogen one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged samples. At the same time, record the relationship between the hydrogen charging concentration and time to establish a hydrogen concentration change curve;

[0102] S8, Electro-galvanizing process: To avoid hydrogen absorption caused by the reaction of materials with acidic solutions, in this Example 1, an alkaline zinc plating solution is used, and its formula is 100 - 120 g / L of sodium hydroxide, 8 - 12 g / L of zinc oxide, and 20 - 30 ml / L of triethanolamine. During electroplating, the temperature is 25 °C, and the current density is 8 mA / cm 2 ;

[0103] S9, Simulating hydrogen charging in a high-pressure hydrogen environment: Based on the hydrogen concentration change curve in step S7 and the hydrogen content Cg in the high-pressure hydrogen environment obtained in step S2, slow tensile samples and CT samples with a hydrogen content equivalent to Cg are prepared using the electrochemical hydrogen charging process in step S5. There are at least 5 samples of each type, and the ratio range of their hydrogen content Cgm to Cg is controlled within 0.8 - 1.1. In this way, samples similar to those after hydrogen charging in a high-pressure hydrogen environment can be obtained, with similar internal hydrogen damage. Subsequently, the obtained samples can be used to conduct a simulation test of the high-pressure hydrogen environment;

[0104] S10, Galvanizing the samples: Immediately after step S9 is completed, the slow tensile samples and CT samples are galvanized using the galvanizing process in step S8 to prevent the escape of diffusible hydrogen. Subsequently, the samples are placed in liquid nitrogen for standby;

[0105] S11, Slow tensile test: Referring to ASTM G129, a slow tensile test is carried out on the slow tensile samples in step S10. The slow tensile rate is 3*10. Before the test, the samples are taken out of liquid nitrogen and placed in alcohol until they reach room temperature before the test. Subsequently, a slow tensile test of the samples is carried out under an inert gas, and the data is recorded;

[0106] S12, Fracture toughness test: Referring to GB / T21143 - 2014, the CT samples in step S10 are subjected to a fracture toughness test using the increased displacement method, and the displacement rate is 0.04 mm / min to obtain the fracture toughness K IH ;

[0107] S13, Evaluation of high-pressure hydrogen embrittlement based on the slow tensile test results: Comparing the slow tensile test results after hydrogen charging with the test results in an inert gas environment, the test results show that all ratios reach above 0.9, and the samples have no hydrogen embrittlement under this high-pressure environment;

[0108] S14, Evaluation of high-pressure hydrogen embrittlement based on fracture toughness: The obtained fracture toughnesses are all K IH ≥55 MPa*m 1 / 2 The test materials are qualified for hydrogen embrittlement resistance under a 50 MPa hydrogen environment.

[0109] Cg / ppm Cgm / ppm Ratio of reduction of area Ratio of tensile strength Ratio of elongation <![CDATA[K IH / MPa*m 1 / 2 > 0.13 0.1 0.957 1.024 0.962 82 0.11 0.106 0.981 1.021 0.92 88 0.08 0.13 0.972 1.01 0.931 92 0.102 0.12 0.935 1.003 0.922 81

[0110] Example 2

[0111] In this Example 2, 4130X is used as the test sample, and the specific steps are as follows:

[0112] S1, Sample Preparation: There are 3 types of test specimens. The first type is the hydrogen-charged sample, which is a sheet sample with dimensions of 100 mm * 20 mm * 2 mm. The second type is the slow-tensile sample. To ensure the accuracy of the test, the dimensions of the slow-tensile sample are manufactured with reference to ASTM G142 standard, as shown in (a) of Figure 2 ; The third type is the CT sample, as shown in (b) of Figure 2 ;

[0113] S2, Hydrogen Charging in High-Pressure Hydrogen Environment: Referring to ASME B31.12 standard, the hydrogen-charged samples are placed in a high-pressure hydrogen storage container with a hydrogen pressure of 102 MPa for 1000 h. The number of samples is 3. After the test, the diffusible hydrogen is measured, and the hydrogen content of the samples in the high-pressure hydrogen environment is obtained as Cg;

[0114] S3, Method for Measuring Diffusible Hydrogen: Using a hydrogen analyzer, the samples are heated at 400 °C for 30 min by thermal desorption method to obtain the diffusible hydrogen content;

[0115] S4, Electrochemical Hydrogen Charging Solution: Prepare a 0.5 mol / L H2SO4 + 0.3 g / L thiourea solution as the hydrogen charging solution and store it at room temperature for 24 h for use;

[0116] S5, Electrochemical Hydrogen Charging: Using the electrochemical constant current mode, a hydrogen charging current of 2 mA / cm 2 is used to charge the hydrogen-charged samples in the electrochemical hydrogen charging solution for different durations. The hydrogen charging time ranges from 1 min to 4 h;

[0117] S6, Sample Preservation: The hydrogen-charged samples after hydrogen charging are placed in liquid nitrogen for storage and standby;

[0118] S7, Plotting the Hydrogen Concentration Change Curve: The hydrogen-charged samples after hydrogen charging are measured for hydrogen one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1 ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged samples. At the same time, record the relationship between the hydrogen charging concentration and time to establish the hydrogen concentration change curve;

[0119] S8, Electrogalvanizing Process: To avoid hydrogen absorption caused by the reaction of the material with the acidic solution, in this Example 2, an alkaline zinc plating solution is used. Its formula is 100 - 120 g / L of sodium hydroxide, 8 - 12 g / L of zinc oxide, and 20 - 30 ml / L of triethanolamine. During electroplating, the temperature is 25 °C and the current density is 10 mA / cm 2 ;

[0120] S9, Hydrogen charging under simulated high-pressure hydrogen environment: According to the hydrogen concentration change curve in step S7 and the hydrogen content Cg under the high-pressure hydrogen environment obtained in step S2, slow tensile samples and CT samples with hydrogen content equivalent to Cg are prepared by the electrochemical hydrogen charging process in step S5. There are at least 5 samples of each type, and the ratio range of their hydrogen content Cgm to Cg is controlled within 0.8 - 1.1. In this way, samples similar to those after hydrogen charging under the high-pressure hydrogen environment can be obtained, with similar internal hydrogen damage. The obtained samples can then be used to conduct simulated high-pressure hydrogen environment tests;

[0121] S10, Galvanizing the samples: Immediately after step S9 is completed, the slow tensile samples and CT samples are galvanized using the galvanizing process in step S8 to prevent the escape of diffusible hydrogen. Then, the samples are placed in liquid nitrogen for standby;

[0122] S11, Slow tensile test: The slow tensile test is carried out on the slow tensile samples in step S10 with reference to ASTM G129. The slow tensile rate is 6*10 -6 , Record the reduction of area, elongation, tensile strength, etc. Before the test, take the sample out of the liquid nitrogen and place it in alcohol until it reaches room temperature before conducting the test. Then, conduct the slow tensile test of the sample under an inert gas environment and record the data;

[0123] S12, Fracture toughness test: The CT samples in step S10 are subjected to a fracture toughness test using the increasing displacement method with reference to GB / T21143 - 2014. The displacement rate is 0.05 mm / min to obtain the fracture toughness K IH ;

[0124] S13, Evaluation of high-pressure hydrogen embrittlement based on slow tensile test results: Compare the slow tensile test results after hydrogen charging with the test results in the inert gas environment. The test results show that all ratios do not reach above 0.9, and the samples have a risk of mild hydrogen embrittlement under this high-pressure environment;

[0125] S14, Evaluation of high-pressure hydrogen embrittlement based on fracture toughness: The obtained fracture toughnesses are all K IH <55MPa*m 1 / 2 , The hydrogen embrittlement resistance of the test material is unqualified under the 102 MPa hydrogen environment.

[0126] Cg / ppm Cgm / ppm Ratio of reduction of area Ratio of tensile strength Ratio of elongation <![CDATA[K IH / MPa*m 1 / 2 > 0.27 0.3 0.828 0.897 0.83 52 0.19 0.23 0.879 0.864 0.862 42 0.26 0.23 0.846 0.832 0.818 46

[0127] Example 3

[0128] In this Example 3, X100 pipeline steel is used as the test sample, and the specific steps are as follows:

[0129] S1, Sample preparation: There are 3 types of test samples. The first type is the hydrogen-charged sample, which is a 100 mm * 20 mm * 2 mm sheet sample; the second type is the slow tensile sample. To ensure the accuracy of the test, the size of the slow tensile sample is manufactured with reference to the ASTM G142 standard. Specifically,Figure 2 as shown in (a) of; The third type is the CT sample, specifically as Figure 2 shown in (b) of;

[0130] S2, Hydrogen charging in high-pressure hydrogen environment: Referring to the ASME B31.12 standard, place the hydrogen-charged sample in a high-pressure hydrogen storage container with a hydrogen pressure of 27.6 MPa for 1000 h. The number of samples is 3. After the test, measure the diffusible hydrogen to obtain the hydrogen content Cg of the hydrogen-charged sample in the high-pressure hydrogen environment;

[0131] S3, Method for measuring diffusible hydrogen: Use a hydrogen analyzer and heat desorb the hydrogen-charged sample at 400 °C for 30 min to obtain the diffusible hydrogen content;

[0132] S4, Electrochemical hydrogen charging solution: Prepare a 0.5 mol / L H2SO4 + 0.3 g / L thiourea solution as the hydrogen charging solution and store it at room temperature for 24 h for use;

[0133] S5, Electrochemical hydrogen charging: Use the electrochemical constant current mode to charge the hydrogen-charged sample in the electrochemical hydrogen charging solution with a hydrogen charging current of 4 mA / cm 2 for different durations with a hydrogen charging current of this magnitude. The hydrogen charging time ranges from 1 min to 4 h;

[0134] S6, Sample storage: Store the hydrogen-charged sample in liquid nitrogen for later use;

[0135] S7, Plotting the hydrogen concentration change curve: Measure the hydrogen content of the hydrogen-charged sample one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1 ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged sample. At the same time, record the relationship between the hydrogen charging concentration and time to establish a hydrogen concentration change curve;

[0136] S8, Electrogalvanizing process: To avoid hydrogen absorption caused by the reaction of the material with the acidic solution, in this Example 3, an alkaline zinc plating solution is used with a formula of 100 - 120 g / L of sodium hydroxide, 8 - 12 g / L of zinc oxide, and 20 - 30 ml / L of triethanolamine. During electroplating, the temperature is 25 °C and the current density is 5 mA / cm 2 ;

[0137] S9, Simulating hydrogen charging in high-pressure hydrogen environment: Based on the hydrogen concentration change curve in step S7 and the hydrogen content Cg in the high-pressure hydrogen environment obtained in step S2, use the electrochemical hydrogen charging process in step S5 to prepare slow tensile samples and CT samples with a hydrogen content equivalent to Cg. There are at least 5 samples of each type, and the ratio range of the hydrogen content Cgm to Cg is controlled within 0.8 - 1.1. In this way, samples similar to those after hydrogen charging in the high-pressure hydrogen environment can be obtained, with similar internal hydrogen damage. The obtained samples can then be used to conduct a simulation of the high-pressure hydrogen environment test;

[0138] S10, Sample galvanization: Immediately after step S9 is completed, the slow tensile samples and CT samples are galvanized using the galvanization process in step S8 to prevent the escape of diffusible hydrogen. Subsequently, the samples are placed in liquid nitrogen for standby;

[0139] S11, Slow tensile test: The slow tensile test is carried out on the slow tensile samples in step S10 with reference to ASTM G129. The slow tensile rate is 7*10 -6 , and the reduction of area, elongation, and tensile strength are recorded. Before the test, the samples are taken out of the liquid nitrogen and placed in alcohol until they reach room temperature before the test is carried out. Subsequently, the slow tensile test of the samples is carried out under an inert gas atmosphere, and the data are recorded;

[0140] S12, Fracture toughness test: The fracture toughness test is carried out on the CT samples in step S10 by the increasing displacement method with reference to GB / T21143-2014. The displacement rate is 0.04 mm / min to obtain the fracture toughness K IH ;

[0141] S13, High-pressure hydrogen embrittlement evaluation based on slow tensile test results: Compare the slow tensile test results after hydrogen charging with the test results in an inert gas environment. The test results show that all partial ratios reach more than 90%, but the reduction of area ratios are all below 0.5. The samples have a serious risk of hydrogen embrittlement under this high-pressure environment;

[0142] S14, High-pressure hydrogen embrittlement evaluation based on fracture toughness: All the fracture toughnesses K obtained from the tests IH <55MPa*m 1 / 2 , and the hydrogen embrittlement resistance of the test materials is unqualified under a 27.6 MPa hydrogen environment.

[0143] Cg / ppm Cgm / ppm Ratio of reduction of area Ratio of tensile strength Ratio of elongation <![CDATA[K IH / MPa*m 1 / 2 > 0.33 0.41 0.373 0.998 0.409 24 0.29 0.32 0.28 1.04 0.5 31 0.35 0.37 0.267 1.05 0.545 27

[0144] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as it is within the scope of the essential spirit of the present invention, changes and modifications to the above-described embodiments will fall within the scope of the claims of the present invention.

Claims

1. A simulation test method for the hydrogen compatibility of metal materials based on hydrogen content, characterized in that, It includes the following steps: S1, Sample preparation; S2, Hydrogen charging under high-pressure hydrogen environment; S3, Measuring diffusible hydrogen; S4, Preparing an electrochemical hydrogen charging solution; S5, Charging hydrogen with the electrochemical hydrogen charging solution; S6, Sample preservation; S7, Plotting the hydrogen concentration change curve; S8, Setting electrogalvanizing process parameters; S9, Simulating hydrogen charging under high-pressure hydrogen environment; S10, Galvanizing the sample; S11, Conducting slow tensile tests and fracture toughness tests on the sample; S12, Evaluating the high-pressure hydrogen embrittlement of the sample based on the results of the slow tensile tests and fracture toughness tests.

2. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 1, characterized in that: The sample includes a hydrogen-charged sample, a slow tensile sample, and a CT sample.

3. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 2, characterized in that: The hydrogen-charged sample is a sheet sample with dimensions of 100mm * 20mm * 2mm; The dimensions of the slow tensile sample are manufactured according to ASTM G142 standard.

4. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 2, characterized in that, In step S2, the hydrogen charging under high-pressure hydrogen environment specifically includes: According to ASME B31.12 standard, the hydrogen-charged sample is placed in a hydrogen-containing high-pressure hydrogen storage container for 1000h. The number of hydrogen-charged samples is at least 3. After the test, diffusible hydrogen is measured to obtain the hydrogen content Cg of the hydrogen-charged sample under high-pressure hydrogen environment.

5. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 4, characterized in that, In step S3, the measurement of diffusible hydrogen specifically includes: Using a hydrogen analyzer, the hydrogen-charged sample is heated to 400°C and placed for 20min - 1h by the thermal desorption method to obtain the diffusible hydrogen content.

6. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 5, characterized in that: In step S4, the electrochemical hydrogen charging solution is a 0.5mol / L H2SO4 + 0.3g / L thiourea solution and is stored at room temperature for 24h.

7. The method for simulating the hydrogen compatibility of a metal material based on the hydrogen content according to claim 6, wherein, In step S5, the hydrogen charging with the electrochemical hydrogen charging solution specifically includes: Charging the hydrogen-charged sample in the electrochemical hydrogen charging solution for different durations using the electrochemical constant current mode; The hydrogen charging current is 0.01 to 10 mA / cm 2 ; The charging time is 1min - 10h.

8. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 7, characterized in that, In step S6, the sample preservation specifically includes: The hydrogen-charged sample after hydrogen charging is placed in liquid nitrogen for preservation.

9. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 8, wherein In step S7, the plotting of the hydrogen concentration change curve specifically includes: The hydrogen-charged sample after hydrogen charging is measured for hydrogen one by one according to the hydrogen charging duration until the difference between the hydrogen contents is less than 0.1ppm. At this time, the hydrogen content is the saturated hydrogen concentration Cm of the hydrogen-charged sample. Meanwhile, the relationship between the hydrogen charging concentration and time is recorded to establish a hydrogen concentration change curve.

10. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 9, characterized in that, In step S8, an alkaline electrogalvanizing solution is used for the electrogalvanizing solution.

11. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 10, characterized in that: In the alkaline electrogalvanizing solution, the concentration of sodium hydroxide is 100 - 120g / L, the concentration of zinc oxide is 8 - 12g / L, and the concentration of triethanolamine is 20 - 30ml / L; During electroplating, the temperature is 10 to 40 °C and the current density is 5 to 20 mA / cm 2 .

12. The method for simulating the hydrogen compatibility of a metallic material based on hydrogen content according to claim 10, characterized in that, In step S9, the simulation of hydrogen charging under high-pressure hydrogen environment specifically includes: Using the electrochemical hydrogen charging process to prepare the slow tensile sample and the CT sample, and controlling the ratio range of the hydrogen content Cgm of the slow tensile sample and the CT sample to the hydrogen content Cg of the hydrogen-charged sample between 0.8 and 1.

1.

13. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 12, characterized in that: The number of the slow tensile samples and the CT samples is at least 5.

14. The method for simulating the hydrogen compatibility of a metallic material based on hydrogen content according to claim 12, characterized in that: In step S10, the slow tensile sample and the CT sample are galvanized using the electrogalvanizing process.

15. The method for simulating the hydrogen compatibility of a metallic material based on the hydrogen content according to claim 14, characterized in that, In step S11, the slow tensile test specifically includes: Perform a slow tensile test on the slow tensile sample at a slow tensile rate of 5*10 -7 ~1*10 -5 , and record the data; The fracture toughness test specifically includes: The fracture toughness test of the CT sample is carried out by the incremental displacement method, and the displacement rate is 0.04 mm / min, and the fracture toughness K is recorded IH .

16. The method for simulating the hydrogen compatibility of a metallic material based on hydrogen content according to claim 15, characterized in that, In the step S12, the high-pressure hydrogen embrittlement evaluation based on the slow tensile test results is specifically as follows: Compare the slow tensile test results after hydrogen charging with the test results in an inert gas environment, and compare the ratio changes. If the ratio reaches more than 0.9, the slow tensile sample has no hydrogen embrittlement in a high-pressure environment; 0.75 - 0.9 indicates mild hydrogen embrittlement; 0.5 - 0.75 indicates moderate hydrogen embrittlement; and less than 0.5 indicates severe hydrogen embrittlement. The sorting of the above three data ratios is as follows: The reduction of area ratio has the first priority, the tensile strength ratio has the second priority, and the elongation ratio has the third priority. When there are conflicts in the ratios, the reduction of area ratio shall prevail. The high-pressure hydrogen embrittlement evaluation based on fracture toughness is specifically as follows: Compare the fracture toughness K under different hydrogen content conditions IH , according to K in ASTM B31.12 standard IH ≥55MPa*m 1 / 2 , it means that the CT sample passes the hydrogen embrittlement resistance test in this environment, and then it can be determined whether the hydrogen resistance of the material under the corresponding simulated high-pressure environment is qualified.

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