Method for evaluating hydrogen embrittlement of metal material by replacing high-pressure hydrogen environment with alkaline environment

Abstract

The invention discloses a method for evaluating hydrogen embrittlement of a metal material by replacing a high-pressure hydrogen environment with an alkaline environment, which comprises the following steps of: obtaining the percentage reduction of area, the elongation percentage, the tensile strength and the fracture toughness of a sample through a slow tensile test and a fracture toughness test in the high-pressure hydrogen environment and an inert gas environment; an alkaline environment system is used for replacing a high-pressure hydrogen environment, a high-pressure slow tensile test and a high-pressure fracture toughness test are simulated, and the high-pressure hydrogen embrittlement risk of the metal material is evaluated according to test results.

Description

Technical Field

[0001] This invention relates to the field of high-pressure hydrogen embrittlement technology, and more specifically, to a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment instead of a high-pressure hydrogen environment. Background Technology

[0002] Hydrogen energy, as a clean energy source, is widely available and boasts advantages such as high energy conversion efficiency, zero pollution, zero emissions, storability, and renewability. It is an important direction for energy transformation and upgrading, and a crucial pathway to achieving carbon neutrality and peak carbon emissions, with enormous market potential. The entire lifecycle of a hydrogen energy system includes hydrogen production, storage, transportation, and utilization. Among these, hydrogen storage and transportation connect upstream production and downstream end-users, forming a critical link. Hydrogen storage, transportation, and transportation containers and pipelines operate under high pressure and high-purity hydrogen environments for extended periods, which can easily lead to reduced local plasticity, accelerated crack propagation, decreased durability, and problems such as hydrogen-induced cracking, hydrogen embrittlement, or fatigue damage. Solving the problem of high-pressure hydrogen embrittlement in materials is a prerequisite for the safe use of high-pressure hydrogen storage containers. While various conventional material mechanical property methods can generally be used for hydrogen embrittlement testing, the test methods required by the relevant standards or specifications in Table 1 are more commonly used.

[0003] Table 1 Test methods required by relevant standards or specifications

[0004]

[0005] Currently, hydrogen embrittlement testing methods for metallic materials can be broadly categorized into two types: one type is used for preliminary material screening to quickly evaluate whether a material can be used to manufacture hydrogen-exposed components, such as disc tests and hydrogen-induced cracking stress intensity factor threshold tests; the other type is used for in-situ testing of material mechanical properties to provide performance data for the design of hydrogen-exposed components or the assessment of material suitability, such as slow strain rate tensile tests, fatigue crack propagation rate tests, and fatigue life tests. All the above standards describe high-pressure hydrogen environments, which are challenging due to the small size of hydrogen atoms and their wide explosive limits, posing significant testing risks, especially in high-pressure and ultra-high-pressure hydrogen environments. This is a major reason limiting the application of metallic materials for hydrogen storage and transportation, necessitating the development of low-risk hydrogen embrittlement evaluation methods that can replace high-pressure hydrogen environments. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment to replace the high-pressure hydrogen environment. By using an alkaline solution system to replace the high-pressure hydrogen environment, different high-pressure hydrogen environments are simulated at room temperature and pressure, thereby enabling the assessment of the risk of hydrogen embrittlement of metallic materials under high pressure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for evaluating hydrogen embrittlement of metallic materials by utilizing an alkaline environment instead of a high-pressure hydrogen environment includes the following steps:

[0009] S1, Sample preparation;

[0010] S2, Conduct a high-pressure gas-phase hydrogen permeation test to obtain the steady-state hydrogen permeation current I of the sample. H and surface adsorbed hydrogen concentration C H ;

[0011] S3, slow tensile tests and fracture toughness tests were carried out in high-pressure hydrogen environment and inert gas environment respectively to obtain the reduction of area, elongation, tensile strength and fracture toughness of the specimens.

[0012] S4, prepare the liquid phase hydrogen permeation solution;

[0013] S5, Conduct a liquid-phase hydrogen permeation test to obtain the steady-state hydrogen permeation current I of the sample. s and surface adsorbed hydrogen concentration C s ;

[0014] S6. Under alkaline liquid phase environment, simulate high pressure slow tensile test and high pressure fracture toughness test to obtain the cross-sectional reduction rate, elongation, tensile strength and fracture toughness of the sample, and verify the effectiveness of the simulation test method.

[0015] S7, based on the results of slow tensile tests and fracture toughness tests, evaluates the hydrogen embrittlement properties of metallic materials in high-pressure hydrogen environments.

[0016] Preferably, in step S1, the specimen includes a slow-tension specimen, a hydrogen-permeable specimen, and a fracture toughness specimen.

[0017] Preferably, the process of step S2 is as follows:

[0018] Hydrogen permeation experiments were conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell contained high-pressure hydrogen gas at a pressure of P. H The hydrogen electrolysis cell contained NaOH solution. After the background current decreased to 0.1 μA, hydrogen gas was added. After the experiment, the steady-state hydrogen permeation current I of the sample was obtained. H and surface adsorbed hydrogen concentration C H .

[0019] Preferably, step S3 includes the following process:

[0020] Slow tensile test in a high-pressure hydrogen environment: A slow tensile test is performed in a high-pressure hydrogen environment with a hydrogen pressure of P. H The slow stretching rate is 5*10 -7 / s~1*10 -5 / s, and after the test, the reduction of area, elongation and tensile strength of the specimen are obtained;

[0021] Fracture toughness tests were conducted in a high-pressure hydrogen environment using the displacement method under a hydrogen pressure of P. H The displacement rate was 0.01 mm / min to 0.1 mm / min, and the fracture toughness of the specimen was obtained after the test.

[0022] The slow tensile test in an inert gas environment is conducted under the same conditions as the slow tensile test in a high-pressure hydrogen environment. After the test, the reduction of area, elongation, and tensile strength of the specimen are obtained.

[0023] The fracture toughness test in an inert gas environment was conducted using the displacement method under the same conditions as the fracture toughness test in a high-pressure hydrogen environment. The fracture toughness of the specimen was obtained after the test.

[0024] Preferably, in step S4, the liquid-phase hydrogen permeation solution is a NaOH solution with a concentration of 0.01 mol / L to 10 mol / L and a solution temperature of 20 to 30°C.

[0025] Preferably, the process of step S5 is as follows:

[0026] Hydrogen permeation experiments were conducted in an alkaline liquid-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell contained a liquid-phase hydrogen permeation solution, while the hydrogen measurement electrolysis cell contained a NaOH solution. After the background current decreased to 0.1 μA, the liquid-phase hydrogen permeation solution was added. Subsequently, a cathode current I was applied to the hydrogen permeation electrolysis cell side. t After the experiment, the steady-state hydrogen permeation current I of the sample was obtained. s and surface adsorbed hydrogen concentration C s Repeatedly adjust the cathode current I t until I s with I H Record the cathode current I when the ratio reaches 0.85 to 1.2. t .

[0027] Preferably, step S6 includes the following process:

[0028] A simulated high-pressure slow tensile test was conducted in an alkaline liquid environment using a dynamic hydrogen-filled slow tensile test. The test solution was the liquid-phase hydrogen permeation solution from step S4. The slow tensile rate was consistent with that of the high-pressure hydrogen environment slow tensile test, and the hydrogen filling current was the same as the cathode current I of the liquid-phase hydrogen permeation test. t After the test, the reduction of area, elongation and tensile strength of the sample were obtained.

[0029] A simulated high-pressure fracture toughness test was conducted using a displacement method in an alkaline liquid environment with dynamic hydrogen-filled fracture toughness testing. The liquid hydrogen permeation solution from step S4 was selected, and the displacement rate was consistent with that of the high-pressure hydrogen environment fracture toughness test. The hydrogen current was the same as the cathodic current I in the liquid hydrogen permeation test. t The fracture toughness of the specimen was obtained after the test.

[0030] The effectiveness of the simulation method was verified when the ratio of the reduction of area, elongation, tensile strength, and fracture toughness of the specimen in the simulation test to the corresponding reduction of area, elongation, tensile strength, and fracture toughness in the high-pressure hydrogen environment was between 0.8 and 1.25.

[0031] Preferably, in step S7, the evaluation method based on the slow tensile test results is as follows:

[0032] By comparing the results of the simulated high-pressure slow tensile test with the results of the inert gas environment test, the ratios of the corresponding reduction of area, elongation, and tensile strength were obtained.

[0033] When the ratio is ≥0.9, the sample has no risk of hydrogen embrittlement under this high-pressure environment;

[0034] When 0.75 ≤ ratio < 0.9, the sample is at slight risk of hydrogen embrittlement under this high-pressure environment;

[0035] When 0.5 ≤ ratio < 0.75, the sample has a moderate risk of hydrogen embrittlement under this high-pressure environment;

[0036] When the ratio is less than 0.5, the sample is at high risk of hydrogen embrittlement under this high-pressure environment;

[0037] Among the ratios of reduction of area, elongation, and tensile strength, the ratio of reduction of area has the highest priority, followed by the ratio of tensile strength, and then the ratio of elongation. If there is a conflict between the ratios, the ratio of reduction of area shall prevail.

[0038] Preferably, in step S7, the evaluation method based on the fracture toughness test results is as follows:

[0039] When the fracture toughness K of the simulated high-pressure fracture toughness test results IM ≥55MPa*m 1 / 2 If the sample is within a certain range, then the sample is qualified for resistance to hydrogen embrittlement under high pressure.

[0040] The present invention provides a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment instead of a high-pressure hydrogen environment, which has the following advantages:

[0041] 1. This invention utilizes an alkaline solution system to replace the high-pressure hydrogen environment, enabling high-pressure hydrogen embrittlement evaluation tests to be conducted in a solution system. This invention can be combined with the steel's processing technology, alloy composition, and stress state to analyze the influence of these factors on the high-pressure hydrogen embrittlement performance of the steel. This invention can provide guidance for the hydrogen embrittlement evaluation of steels serving in high-pressure hydrogen environments.

[0042] 2. This invention starts from the perspective of hydrogen diffusion in metallic materials and combines the characteristics of alkaline solutions. It designs a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment instead of a high-pressure hydrogen environment through hydrogen permeation. This invention, combined with existing high-pressure hydrogen embrittlement evaluation methods and standards, enhances the accuracy and rationality of the test.

[0043] 3. This invention can simulate different high-pressure hydrogen environments under normal temperature and pressure conditions, enabling the evaluation of the hydrogen embrittlement performance of metallic materials under high-pressure hydrogen environments and clarifying the hydrogen embrittlement risk of metallic materials under high-pressure hydrogen embrittlement environments; this invention can also simulate the hydrogen embrittlement resistance of steel under different hydrogen pressure conditions, clarifying the applicability of steel under different hydrogen pressure conditions and the hydrogen embrittlement risk, and at the same time providing guidance and direction for improving the hydrogen embrittlement resistance of steel and its safe use.

[0044] 4. This invention is mainly aimed at metal materials such as hydrogen pipelines and hydrogen storage tanks that operate under high-pressure hydrogen environments, but it is also applicable to other metal materials operating under high-pressure hydrogen environments. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the hydrogen embrittlement evaluation method for metallic materials that utilizes an alkaline environment instead of a high-pressure hydrogen environment, as described in this invention.

[0046] Figure 2 This is a schematic diagram of the slow-tension specimen of the present invention;

[0047] Figure 3 This is a schematic diagram of the hydrogen permeation sample of the present invention;

[0048] Figure 4 This is a schematic diagram of the fracture toughness CT specimen of the present invention. (a) is the front view of the fracture toughness CT specimen, and (b) is the side view of (a).

[0049] Figure 5 This is a schematic diagram of the high-pressure gas-phase hydrogen permeation of the present invention. (a) is a dual electrolytic cell used for high-pressure gas-phase hydrogen permeation; (b) is an enlarged view of point A in (a).

[0050] Figure 6 This is a schematic diagram of the liquid-phase electrochemical hydrogen permeation of the present invention; Detailed Implementation

[0051] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0052] For metallic materials operating under high-pressure hydrogen environments (such as high-pressure hydrogen pipeline steel and hydrogen storage tanks), from the perspective of the high-pressure hydrogen embrittlement mechanism, the main factor causing hydrogen embrittlement is the diffusible hydrogen dissolved in the material. Therefore, this invention develops a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment instead of a high-pressure hydrogen environment, based on the perspective of hydrogen permeation and combined with mechanical property tests.

[0053] Combination Figure 1 As shown, the present invention provides a method for evaluating hydrogen embrittlement of metallic materials by using an alkaline environment instead of a high-pressure hydrogen environment, comprising the following steps:

[0054] S1, Sample preparation;

[0055] This invention relates to three types of specimens, including a slow-tension specimen, a hydrogen permeation specimen, and a fracture toughness specimen. Slow-tension specimen: To ensure testing accuracy, the dimensions of the slow-tension specimen are manufactured according to ASTM G142 standard (see [reference needed]). Figure 2 (As shown). See also the dimensions of the hydrogen permeation sample. Figure 3 As shown. The dimensions of the fracture toughness specimen are shown in [reference needed]. Figure 4 As shown. Before the test, remove surface oil and dirt with alcohol to keep the surface clean;

[0056] S2, Conduct a high-pressure gas-phase hydrogen permeation test to obtain the steady-state hydrogen permeation current I of the sample. H and surface adsorbed hydrogen concentration C H ;

[0057] High-pressure gas-phase hydrogen permeation: combination Figure 5 As shown, a hydrogen permeation experiment was conducted in a gas-phase environment using a dual electrolytic cell. The hydrogen permeation electrolytic cell contained high-pressure hydrogen gas at a pressure of P. H The hydrogen electrolysis cell contained a NaOH solution (concentration could be 0.1 mol). The hydrogen voltage was measured as 0.2 V vs SCE. After the background current decreased to 0.1 μA, hydrogen gas was added. The steady-state hydrogen permeation current I of the sample was obtained after the experiment. H and surface adsorbed hydrogen concentration C H .

[0058] S3, slow tensile tests and fracture toughness tests were carried out in high-pressure hydrogen environment and inert gas environment respectively to obtain the reduction of area, elongation, tensile strength and fracture toughness of the specimens.

[0059] Slow tensile testing in a high-pressure hydrogen environment, referring to ASTM G129, involves performing a slow tensile test on the specimen under high-pressure hydrogen pressure (P). H The slow stretching rate is 5*10 -7 / s~1*10 -5 / s, before the test, the slow tensile specimen can be left to stand in a high-pressure hydrogen environment for 24 hours. After the test, the reduction of area RA of the specimen is obtained. H Elongation EL H Tensile strength σ H Equal mechanical properties;

[0060] Fracture toughness test in a high-pressure hydrogen environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was carried out in a high-pressure hydrogen environment using the displacement method, with a hydrogen pressure of P. H The displacement rate was 0.01 mm / min to 0.1 mm / min. After the test, the fracture toughness K of the specimen was obtained. IH ;

[0061] The slow tensile test in an inert gas environment is conducted according to ASTM G129. The test conditions are the same as those for the slow tensile test in a high-pressure hydrogen environment (i.e., pressure P). H The slow stretching rate is 5*10 -7 / s~1*10 -5 / s), and after the test, the mechanical properties of the specimen, such as the reduction of area RA, elongation EL, and tensile strength σ, are obtained;

[0062] Fracture toughness test in inert gas environment: Referring to GB / T21143-2014, the fracture toughness specimen was tested in an inert gas environment using the displacement method. The test conditions were the same as those for the high-pressure hydrogen environment fracture toughness test (i.e., gas pressure P). H The displacement rate was 0.01 mm / min to 0.1 mm / min. After the test, the fracture toughness K of the specimen was obtained. IC .

[0063] S4, prepare the liquid phase hydrogen permeation solution;

[0064] The liquid phase hydrogen permeation solution is a NaOH solution with a concentration of 0.01 mol / L to 10 mol / L, and the solution temperature is 20 to 30℃.

[0065] S5, Conduct a liquid-phase hydrogen permeation test to obtain the steady-state hydrogen permeation current I of the sample. s and surface adsorbed hydrogen concentration C s ;

[0066] Combination Figure 6 As shown, a hydrogen permeation experiment was conducted in an alkaline liquid phase environment using a dual electrolytic cell. The hydrogen permeation electrolytic cell contained a liquid phase hydrogen permeation solution, while the hydrogen measurement electrolytic cell contained a NaOH solution. The hydrogen voltage was measured as 0.2 V vs SCE. After the background current decreased to 0.1 μA, the liquid phase hydrogen permeation solution was added. Subsequently, a cathode current I was applied to the hydrogen permeation electrolytic cell side. tAfter the experiment, the steady-state hydrogen permeation current I of the sample was obtained. s and surface adsorbed hydrogen concentration C s Repeatedly adjust the cathode current I t until I s with I H Record the cathode current I when the ratio reaches 0.85 to 1.2. t .

[0067] Combination Figure 6 As shown, the dual electrolytic cell includes a constant current source 1, an electrochemical workstation 2, a hydrogen-filled electrolytic cell 3, and a hydrogen-releasing electrolytic cell 4. The positive electrode of the constant current source 1 is connected to the Pt electrode in the hydrogen-filled electrolytic cell 3, the negative electrode of the constant current source 1 is connected to the W terminal of the electrochemical workstation 2, the R terminal of the electrochemical workstation 2 is connected to the reference electrode of the hydrogen-releasing electrolytic cell 4, and the C terminal of the electrochemical workstation 2 is connected to the Pt electrode of the hydrogen-releasing electrolytic cell 4.

[0068] S6. Under alkaline liquid phase environment, simulate high pressure slow tensile test and high pressure fracture toughness test to obtain the cross-sectional reduction rate, elongation, tensile strength and fracture toughness of the sample, and verify the effectiveness of the simulation test method.

[0069] A simulated high-pressure slow tensile test was conducted, referring to ASTM G129. A dynamic hydrogen-filled slow tensile test was performed on the slow-tension specimen in an alkaline liquid phase environment. The test solution used was the liquid-phase hydrogen permeation solution from step S4. The slow tensile rate was consistent with the slow tensile rate set for the high-pressure hydrogen environment test, and the hydrogen filling current was the cathodic current I of the liquid-phase hydrogen permeation test. t The reduction of area RA of the specimen was obtained after the experiment. M Elongation EL M Tensile strength σ M Equal mechanical properties;

[0070] A simulated high-pressure fracture toughness test was conducted, referring to GB / T21143-2014. The dynamic hydrogen-filled fracture toughness test was performed on the fracture toughness specimens in an alkaline liquid environment using the displacement method. The liquid hydrogen permeation solution from step S4 was selected. The displacement rate was consistent with the slow tensile rate set for the high-pressure hydrogen fracture toughness test. The hydrogen current was the cathodic current I of the liquid hydrogen permeation test. t The fracture toughness K of the specimen was obtained after the test. IM ;

[0071] Validation of the simulation method: Limiting the reduction of area (RA) of the specimen in the simulation test. M Elongation EL M Tensile strength σ M and fracture toughness K IM The corresponding reduction of area RA in a high-pressure hydrogen environment H Elongation ELH 、Tensile strength σ H and fracture toughness K IH are in the ratio of 0.8 to 1.25, then the simulation test method is determined to be effective.

[0072] S7. Based on the slow tensile test results and fracture toughness test results, evaluate the hydrogen embrittlement performance of metallic materials in a high-pressure hydrogen environment.

[0073] The evaluation method based on the slow tensile test results is as follows: Compare the results of the simulated high-pressure slow tensile test with the test results in an inert gas environment to obtain the ratios of the corresponding reduction of area, elongation, and tensile strength between the two; Compare the ratio changes: When the ratios of the relevant indicators (reduction of area, elongation, tensile strength) in a high-pressure hydrogen environment to the corresponding indicators in an inert gas environment are ≥ 0.9, the specimen has no hydrogen embrittlement risk in this high-pressure environment; When 0.75 ≤ ratio < 0.9, the specimen has a mild hydrogen embrittlement risk in this high-pressure environment; When 0.5 ≤ ratio < 0.75, the specimen has a moderate hydrogen embrittlement risk in this high-pressure environment; When the ratio < 0.5, the specimen has a severe hydrogen embrittlement risk in this high-pressure environment; Among the ratios of reduction of area, elongation, and tensile strength, the ratio of reduction of area has the highest priority, the ratio of tensile strength is the second, and the ratio of elongation is the third. If there are conflicts in the ratios, the ratio of reduction of area shall prevail.

[0074] The evaluation method based on the fracture toughness test results is as follows: Compare the fracture toughness K IM of the simulated high-pressure fracture toughness test with K IH in ASTM B31.12 standard. When the fracture toughness K IM of the simulated high-pressure fracture toughness test result is ≥ 55 MPa*m 1 / 2 , then the specimen is qualified for hydrogen embrittlement resistance in this high-pressure environment, otherwise it is unqualified; Through this method, it can be obtained whether the hydrogen resistance performance of the material in the corresponding simulated high-pressure environment is qualified.

[0075] Example 1

[0076] In this example, X65 is used as the test specimen. The specific operation of the hydrogen embrittlement evaluation method of metallic materials using an alkaline environment to replace a high-pressure hydrogen environment is as follows:

[0077] 1. Specimen preparation: There are 3 types of specimens involved: One is a slow tensile specimen. To ensure the accuracy of the test, the size of the slow tensile specimen is manufactured according to ASTM G142 standard, as Figure 2 shown; Another is a hydrogen permeation specimen, the size of which is as Figure 3 shown, and the third is a fracture toughness specimen, the test size of which is as Figure 4 shown. Before the test, the specimens are cleaned with alcohol to remove the surface oil stains and keep the surface clean;

[0078] 2. High-Pressure Gas-Phase Hydrogen Permeation: Hydrogen permeation experiments were conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used high-pressure hydrogen gas at a pressure of 6 MPa. The hydrogen measurement cell used a 0.1 mol NaOH solution, and the hydrogen voltage was measured at 0.2 V vs. SCE. Hydrogen gas was added after the background current decreased to 0.1 μA. The steady-state hydrogen permeation current I was obtained from the experiment. H Surface adsorbed hydrogen concentration C H ;

[0079] 3. High-Pressure Hydrogen Environment Slow Tensile Test: Referring to ASTM G129, a slow tensile test is performed on the specimens in a hydrogen environment with a hydrogen pressure of 6 MPa and a slow tensile rate of 1*10. -5 / s, before the test, the sample was placed in a high-pressure hydrogen environment for 24 hours. After the test, the reduction of area RA was recorded. H Elongation EL H and tensile strength σ H wait;

[0080] 4. Fracture toughness test under high pressure hydrogen environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was carried out under high pressure hydrogen environment using the displacement method. The hydrogen pressure was 6 MPa, the displacement rate was 0.05 mm / min, and the fracture toughness K was recorded. IH ;

[0081] 5. Slow tensile test in inert gas environment: Refer to ASTM G129, conduct a slow tensile test on the specimen in an inert gas environment, with a pressure of 6 MPa and a slow tensile rate the same as in step 3. After the test, record the reduction of area RA, elongation EL, and tensile strength σ, etc.

[0082] 6. Fracture toughness test in an inert gas environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen is carried out in an inert gas environment using the displacement method. The gas pressure is PH, and the displacement rate is the same as in step 4. Record the fracture toughness K. IC ;

[0083] 7. Liquid-phase hydrogen permeation solution: The liquid-phase hydrogen permeation solution is a 0.1 mol / L NaOH solution, and the temperature of the test solution is maintained at 23℃;

[0084] 8. Liquid-phase hydrogen permeation test: A hydrogen permeation test was conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used the hydrogen permeation solution from step 7, while the hydrogen measurement electrolysis cell used a 0.1 mol NaOH solution. The hydrogen voltage was measured at 0.2 V vs SCE. After the background current decreased to 0.1 μA, the hydrogen permeation solution was added, and then a cathode current I was applied to the hydrogen permeation side. t The steady-state hydrogen permeation current I was obtained from the experiment. s Surface adsorbed hydrogen concentration C sRepeatedly adjust I t until I s Compared with step 2, I H Record the cathode current I when the ratio reaches 0.85 to 1.2. t ;

[0085] 9. Simulated High-Pressure Slow Tension Test: Referring to ASTM G129, a dynamic hydrogen-filled slow tensile test was performed on the slow tensile specimen in a solution environment. The test solution was the hydrogen-permeable solution from step 7. The slow tensile rate was the same as in step 3, and the hydrogen filling current was It. After the test, the reduction of area RA was recorded. M Elongation EL M and tensile strength σ M wait;

[0086] 10. Simulated High-Pressure Fracture Toughness: Referring to GB / T21143-2014, the fracture toughness specimens were subjected to dynamic hydrogen-filled fracture toughness tests in a solution environment using the displacement method. The test solution was the hydrogen-permeable solution from step 5, and the hydrogen filling current was I. t The displacement rate was 0.05 mm / min, and the fracture toughness K was recorded. IM ;

[0087] 11. Validation of the simulation method: Surface shrinkage rate RA in the simulated environment. M Elongation EL M and fracture toughness K IM Equivalent to the section reduction ratio RA in a high-pressure hydrogen environment H Elongation EL H and fracture toughness K IM The effectiveness of this simulation test method is determined if the ratios are all between 0.8 and 1.25.

[0088] 12. Evaluation of high-pressure hydrogen embrittlement based on slow tensile test results: According to Table 2, the results of simulated high-pressure slow tensile test and inert gas environment test were compared and the ratio changes were compared. The test results showed that the reduction of area, elongation and fracture ratio were between 0.75 and 0.9, indicating that X65 has a slight risk of hydrogen embrittlement under 6MPa hydrogen pressure.

[0089] 13. Evaluation of fracture toughness under high pressure hydrogen embrittlement: As shown in Table 2, the fracture toughness obtained from the experiment is KIM≥55MPa*m. 1 / 2 The test material passed the test in a 6MPa hydrogen atmosphere to resist hydrogen embrittlement.

[0090] Table 2

[0091]

[0092]

[0093] Example 2

[0094] This embodiment uses X60 as the test sample and the specific operation of the evaluation method for hydrogen embrittlement of metallic materials using an alkaline environment instead of a high-pressure hydrogen environment is as follows:

[0095] 1. Specimen Preparation: This embodiment involves three types of specimens: one is a slow-tension specimen. To ensure test accuracy, the dimensions of the slow-tension specimen are manufactured according to ASTM G142 standard, such as... Figure 2 As shown; another type is a hydrogen permeation sample, with dimensions as shown. Figure 3 As shown; the third type is the fracture toughness specimen, with test dimensions as shown. Figure 4 As shown. Before the test, the sample was cleaned with alcohol to remove surface oil and keep the surface clean;

[0096] 2. High-Pressure Gas-Phase Hydrogen Permeation: Hydrogen permeation experiments were conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used high-pressure hydrogen gas at a pressure of 10.3 MPa. The hydrogen measurement cell used 0.1 mol NaOH solution, and the hydrogen voltage was measured as 0.2 V vs. SCE. Hydrogen gas was added after the background current decreased to 0.1 μA. The steady-state hydrogen permeation current I was obtained from the experiment. H Surface adsorbed hydrogen concentration C H ;

[0097] 3. High-Pressure Hydrogen Environment Slow Tensile Test: Referring to ASTM G129, a slow tensile test is performed on the specimens in a hydrogen environment with a hydrogen pressure of 10.3 MPa and a slow tensile rate of 1*10. -5 / s, before the test, the sample was placed in a high-pressure hydrogen environment for 24 hours. After the test, the reduction of area RA was recorded. H Elongation EL H and tensile strength σ H wait;

[0098] 4. Fracture toughness test under high pressure hydrogen environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was carried out under high pressure hydrogen environment using the displacement method. The hydrogen pressure was 10.3 MPa, the displacement rate was 0.03 mm / min, and the fracture toughness K was recorded. IH ;

[0099] 5. Slow tensile test in inert gas environment: Refer to ASTM G129, conduct a slow tensile test on the specimen in an inert gas environment, with a pressure of 10.3 MPa and a slow tensile rate the same as in step 3. After the test, record the reduction of area RA, elongation EL, and tensile strength σ, etc.

[0100] 6. Fracture toughness test in an inert gas environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was carried out in an inert gas environment using the displacement method. The gas pressure was 10.3 MPa, and the displacement rate was the same as in step 4. The fracture toughness K was recorded. IC ;

[0101] 7. Liquid-phase hydrogen permeation solution: The liquid-phase hydrogen permeation solution is a 0.5 mol / L NaOH solution, and the temperature of the test solution is maintained at 25℃;

[0102] 8. Liquid-phase hydrogen permeation test: A hydrogen permeation test was conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used the hydrogen permeation solution from step 7, while the hydrogen measurement electrolysis cell used a 0.1 mol NaOH solution. The hydrogen voltage was measured at 0.2 V vs SCE. After the background current decreased to 0.1 μA, the hydrogen permeation solution was added, and then a cathode current I was applied to the hydrogen permeation side. t The steady-state hydrogen permeation current I was obtained from the experiment. s Surface adsorbed hydrogen concentration C s Repeatedly adjust I t until I s Compared with step 2, I H Record the cathode current I when the ratio reaches 0.85 to 1.2. t ;

[0103] 9. Simulated High-Pressure Slow Tension Test: Referring to ASTM G129, a dynamic hydrogen-filled slow tension test was performed on the slow-tension specimen in a solution environment. The test solution was the hydrogen-permeable solution from step 7, the slow tension rate was the same as in step 3, and the hydrogen filling current was I. t After the experiment, the reduction of area RA was recorded. M Elongation EL M and tensile strength σ M wait;

[0104] 10. Simulated High-Pressure Fracture Toughness: Referring to GB / T21143-2014, the fracture toughness specimens were subjected to dynamic hydrogen-filled fracture toughness tests in a solution environment using the displacement method. The test solution was the hydrogen-permeable solution from step 5, and the hydrogen filling current was I. t The displacement rate was 0.03 mm / min, and the fracture toughness K was recorded. IM ;

[0105] 11. Validation of the simulation method: Surface shrinkage rate RA in the simulated environment. M Elongation EL M and fracture toughness KI M Equivalent to the section reduction ratio RA in a high-pressure hydrogen environment H Elongation EL H and fracture toughness K IMThe effectiveness of this simulation test method is determined if the ratios are all between 0.8 and 1.25.

[0106] 12. Evaluation of high-pressure hydrogen embrittlement based on slow tensile test results: According to Table 3, the results of simulated high-pressure slow tensile test and inert gas environment test were compared and the ratio changes were compared. The test results showed that the reduction of area, elongation and fracture ratio were between 0.75 and 0.9, indicating that X60 has a slight risk of hydrogen embrittlement under 6MPa hydrogen pressure.

[0107] 13. Evaluation of fracture toughness under high pressure hydrogen embrittlement: As shown in Table 3, the fracture toughness obtained from the experiment is K IM ≥55MPa*m 1 / 2 The test material passed the test in a 10.3 MPa hydrogen atmosphere with good resistance to hydrogen embrittlement.

[0108] Table 3

[0109]

[0110] Example 3

[0111] This embodiment uses X52 as the test sample and the specific operation of the method for evaluating hydrogen embrittlement of metallic materials using an alkaline environment instead of a high-pressure hydrogen environment is as follows:

[0112] 1. Specimen Preparation: This embodiment involves three types of specimens: one is a slow-tension specimen. To ensure test accuracy, the dimensions of the slow-tension specimen are manufactured according to ASTM G142 standard, such as... Figure 2 As shown; another type is hydrogen permeation sample size as shown. Figure 3 As shown; the third type is the fracture toughness specimen, with test dimensions as shown. Figure 4 As shown. Before the test, the sample was cleaned with alcohol to remove surface oil and keep the surface clean;

[0113] 2. High-Pressure Gas-Phase Hydrogen Permeation: Hydrogen permeation experiments were conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used high-pressure hydrogen gas at a pressure of 10.3 MPa. The hydrogen measurement cell used 0.1 mol NaOH solution, and the hydrogen voltage was measured as 0.2 V vs. SCE. Hydrogen gas was added after the background current decreased to 0.1 μA. The steady-state hydrogen permeation current I was obtained from the experiment. H Surface adsorbed hydrogen concentration C H ;

[0114] 3. High-Pressure Hydrogen Environment Slow Tensile Test: Referring to ASTM G129, a slow tensile test is performed on the specimens in a hydrogen environment with a hydrogen pressure of 10.3 MPa and a slow tensile rate of 1*10. -5 / s, before the test, the sample was placed in a high-pressure hydrogen environment for 24 hours. After the test, the reduction of area RA was recorded. H Elongation EL H and tensile strength σH wait;

[0115] 4. Fracture toughness test under high pressure hydrogen environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was conducted under high pressure hydrogen environment using the displacement method. The hydrogen pressure was 10.3 MPa, the displacement rate was 0.03 mm / min, and the fracture toughness K was recorded. IH ;

[0116] 5. Slow tensile test in inert gas environment: Refer to ASTM G129, conduct a slow tensile test on the specimen in an inert gas environment, with a pressure of 10.3 MPa and a slow tensile rate the same as in step 3. After the test, record the reduction of area RA, elongation EL, and tensile strength σ, etc.

[0117] 6. Fracture toughness test in an inert gas environment: Referring to GB / T21143-2014, the fracture toughness test of the specimen was carried out in an inert gas environment using the displacement method. The gas pressure was 10.3 MPa, and the displacement rate was the same as in step 4. The fracture toughness K was recorded. IC ;

[0118] 7. Liquid-phase hydrogen permeation solution: The liquid-phase hydrogen permeation solution is a 0.5 mol / L NaOH solution, and the temperature of the test solution is maintained at 25℃;

[0119] 8. Liquid-phase hydrogen permeation test: A hydrogen permeation test was conducted in a gas-phase environment using a dual-electrolysis cell. The hydrogen permeation electrolysis cell used the hydrogen permeation solution from step 7, while the hydrogen measurement electrolysis cell used a 0.1 mol NaOH solution. The hydrogen voltage was measured at 0.2 V vs SCE. After the background current decreased to 0.1 μA, the hydrogen permeation solution was added, and then a cathode current I was applied to the hydrogen permeation side. t The steady-state hydrogen permeation current I was obtained from the experiment. s Surface adsorbed hydrogen concentration C s Repeatedly adjust I t until I s Compared with step 2, I H Record the cathode current I when the ratio reaches 0.85 to 1.2. t ;

[0120] 9. Simulated High-Pressure Slow Tension Test: Referring to ASTM G129, a dynamic hydrogen-filled slow tensile test was performed on the slow tensile specimen in a solution environment. The test solution was the hydrogen-permeable solution from step 7. The slow tensile rate was the same as in step 3, and the hydrogen filling current was It. After the test, the reduction of area RA was recorded. M Elongation EL M and tensile strength σ M wait;

[0121] 10. Simulated High-Pressure Fracture Toughness: Referring to GB / T21143-2014, the fracture toughness specimens were subjected to dynamic hydrogen-filled fracture toughness tests in a solution environment using the displacement method. The test solution was the hydrogen-permeable solution from step 5, and the hydrogen filling current was I. t The displacement rate was 0.03 mm / min, and the fracture toughness K was recorded. IM ;

[0122] 11. Validation of the simulation method: Surface shrinkage rate RA in the simulated environment. M Elongation EL M and fracture toughness KI M Equivalent to the section reduction ratio RA in a high-pressure hydrogen environment H Elongation EL H and fracture toughness K IM The effectiveness of this simulation test method is determined if the ratios are all between 0.8 and 1.25.

[0123] 12. Evaluation of high-pressure hydrogen embrittlement based on slow tensile test results: By comparing the results of the simulated high-pressure slow tensile test and the inert gas environment test as shown in Table 4, and comparing the changes in ratios, the test results show that the reduction of area, elongation and fracture ratio are between 0.75 and 0.9, indicating that X60 has a slight risk of hydrogen embrittlement under 10.3 MPa hydrogen pressure.

[0124] 13. Evaluation of fracture toughness under high pressure hydrogen embrittlement: As shown in Table 4, the fracture toughness obtained from the experiment is K IM The test material passed the test under a hydrogen embrittlement resistance test at 10.3 MPa with a pressure of ≥55 MPa * m1 / 2.

[0125] Table 4

[0126]

[0127] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment, characterized by, The method comprises the following steps: S1, preparing samples; S2, carry out high-pressure gas-phase hydrogen permeation test to obtain steady-state hydrogen permeation current I of the sample H and surface adsorbed hydrogen concentration C H ; S3, conducting slow tension test and fracture toughness test in high-pressure hydrogen environment and inert gas environment respectively, and obtaining the sample's reduction of area, elongation, tensile strength and fracture toughness; S4, configuring liquid-phase hydrogen permeation solution; S5, carry out basic liquid phase hydrogen permeation test to obtain the cathode current I of the sample t , steady-state hydrogen permeation current I s and surface adsorbed hydrogen concentration C s ; S6, simulating high-pressure slow tension test and high-pressure fracture toughness test in alkaline liquid-phase environment, obtaining the sample's reduction of area, elongation, tensile strength and fracture toughness, and verifying the effectiveness of the simulation test method; S7, evaluating the hydrogen embrittlement performance of the metal material in high-pressure hydrogen environment based on the results of slow tension test and fracture toughness test.

2. The metal material hydrogen embrittlement evaluation method using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized by: In the step S1, the samples include slow tension samples, hydrogen permeation samples and fracture toughness samples.

3. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized by: The process of the step S2 is as follows: Hydrogen permeation test in gas phase was carried out by using double electrolytic cells, high pressure hydrogen was in the hydrogen permeation cell, and the hydrogen pressure was P H , NaOH solution was in the hydrogen measurement cell, hydrogen was injected after the background current was reduced to 0.1 μA, and the steady-state hydrogen permeation current I H and the surface adsorbed hydrogen concentration C H of the sample were obtained after the test.

4. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized by: The step S3 comprises the following processes: High-pressure hydrogen environment slow stretching test, a slow stretching test is carried out under a high-pressure hydrogen environment, the hydrogen pressure is P H , the slow stretching rate is 5*10 -7 / s~1*10 -5 / s, and the sample section shrinkage rate, elongation rate and tensile strength are obtained after the test is completed; The high-pressure hydrogen environment fracture toughness test is carried out by using the displacement method in the high-pressure hydrogen environment, the hydrogen pressure is P H , the displacement rate is 0.01mm / min~0.1mm / min, and the fracture toughness of the sample is obtained after the test. Inert gas environment slow tension test, slow tension test is conducted in inert gas environment, the test conditions are consistent with those of high-pressure hydrogen environment slow tension test, and the sample's reduction of area, elongation and tensile strength are obtained after the test; Inert gas environment fracture toughness test, displacement increment method is used to conduct fracture toughness test in inert gas environment, the test conditions are consistent with those of high-pressure hydrogen environment fracture toughness test, and the sample's fracture toughness is obtained after the test.

5. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized in that: In the step S4, the liquid-phase hydrogen permeation solution is selected from 0.01 mol / L-10 mol / L NaOH solution, and the solution temperature is 20-30℃.

6. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized in that, The process of the step S5 is as follows: Hydrogen permeation test in alkaline solution is carried out by using double electrolytic cell, the solution in hydrogen permeation cell is hydrogen permeation solution, the solution in hydrogen detection cell is NaOH solution, after the background current is reduced to 0.1uA, hydrogen permeation solution is added, then cathode current I t is applied to hydrogen permeation cell s After the test, steady-state hydrogen permeation current I s and surface adsorbed hydrogen concentration C t are obtained, cathode current I s is adjusted repeatedly until the ratio of I H to I t is 0.85-1.2, then the cathode current I t is recorded.

7. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized by, The step S6 comprises the following processes: The dynamic hydrogen charging slow stretching test is carried out in the alkaline liquid phase environment, the test solution is selected from the liquid phase hydrogen permeation solution in step S4, the slow stretching rate is consistent with that of the high-pressure hydrogen environment slow stretching test, and the hydrogen charging current is the cathode current I of the liquid phase hydrogen permeation test t After the test, the cross-section shrinkage rate, elongation rate and tensile strength of the sample are obtained. The high pressure fracture toughness test is simulated, and the dynamic hydrogen charging fracture toughness test is carried out in the alkaline liquid phase environment by using the displacement method. The liquid phase hydrogen permeation solution of step S4 is selected, the displacement rate is consistent with the displacement rate of the high pressure hydrogen environment fracture toughness test, and the hydrogen current is the cathode current I of the liquid phase hydrogen permeation test t , and the fracture toughness of the sample is obtained after the test. Verification of the effectiveness of the simulation method, when the ratio of the sample's reduction of area, elongation, tensile strength and fracture toughness in the simulation test to the corresponding values in high-pressure hydrogen environment is 0.8-1.25, the simulation test method is effective.

8. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized by, In the step S7, the evaluation method based on the results of slow tension test is as follows: Comparing the results of simulated high-pressure slow tension test with those of inert gas environment test, and obtaining the ratio of the corresponding reduction of area, elongation and tensile strength; When the ratio is greater than or equal to 0.9, the sample has no hydrogen embrittlement risk in the high-pressure environment; When the ratio is 0.75-0.9, the sample has slight hydrogen embrittlement risk in the high-pressure environment; When the ratio is 0.5-0.75, the sample has moderate hydrogen embrittlement risk in the high-pressure environment; When the ratio is less than 0.5, the sample has severe hydrogen embrittlement risk in the high-pressure environment; Among the ratios of reduction of area, elongation and tensile strength, the priority of the reduction of area ratio is the first, the priority of the tensile strength ratio is the second, and the priority of the elongation ratio is the third, and if there is a conflict in the ratios, the reduction of area ratio is used as the reference.

9. The method for evaluating hydrogen embrittlement of a metal material using an alkaline environment instead of a high-pressure hydrogen environment according to claim 1, characterized in that, In the step S7, the evaluation method based on the results of fracture toughness test is as follows: When the fracture toughness K IM ≥ 55 MPa*m 1 / 2 of the simulated high pressure fracture toughness test results is greater than or equal to 55 MPa*m, then the test sample is qualified for resistance to hydrogen embrittlement under the high pressure environment.

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