A method for testing hydrogen embrittlement sensitivity of a material in different hydrogen-doped environments

Abstract

The application provides a material hydrogen embrittlement sensitivity test method which can realize different hydrogen-doped environments. The method comprises the following steps: processing a material to be tested into a test piece; preparing an electrolyte; placing the test piece in a high-pressure reaction kettle, injecting hydrogen and other gases into the high-pressure reaction kettle to charge the test piece with hydrogen, simulating the hydrogen-doped environment pressure by controlling the gas pressure, simulating the hydrogen-doped ratio by controlling the hydrogen concentration through the partial pressure method, and setting the hydrogen charging time; calculating the hydrogen charging time required for the test piece to complete the hydrogen charging in the electrolyte, placing the test piece in the electrolyte to complete the hydrogen charging of the test piece, and obtaining the test piece after hydrogen charging; and performing slow tensile test on the test piece after hydrogen charging to obtain the hydrogen embrittlement sensitivity of the material. The method can realize the mechanical property test of the material in different hydrogen-doped environments, obtain the hydrogen embrittlement sensitivity of the material in different hydrogen-doped environments, reduce the danger of the experiment, has high quantitative precision, and can complete the experiment under the condition that the interval of the hydrogen-doped ratio is small.

Description

Technical Field

[0001] The invention relates to a method for testing hydrogen embrittlement sensitivity of materials in different hydrogen-doped environments, and belongs to the technical field of energy transportation. Background Art

[0002] Hydrogen is a highly efficient, clean energy source with enormous development prospects. Its role in industry and daily life is expected to grow. While China has been gradually increasing its development and utilization of hydrogen energy, this has also placed significant pressure on its transportation. Currently, pipelines are perhaps the most economical and widespread mode of transport for gas. Rebuilding hydrogen pipelines still incurs significant economic costs. Transporting hydrogen or a hydrogen-natural gas blend through existing natural gas pipelines could effectively address this challenge. However, compared to natural gas, hydrogen atoms have a smaller diameter and are more likely to penetrate pipeline materials under high-pressure conditions, causing hydrogen embrittlement and posing a significant risk to pipeline safety. Therefore, experimental testing of pipeline hydrogen embrittlement susceptibility is essential. This paper proposes a material mechanical property testing method simulating hydrogen-doped environments. This method can effectively investigate the hydrogen embrittlement mechanism of materials in different hydrogen-doped environments, providing effective guidance for accident prevention and control in hydrogen-doped pipelines. This method has significant technical and economic value in the field of energy transportation technology.

[0003] Hydrogen embrittlement can be divided into two categories, depending on the source of the hydrogen. The first is internal hydrogen embrittlement, caused by excessive hydrogen absorption during smelting, forging, welding, electroplating, or pickling. The second type, environmental hydrogen embrittlement, is a brittle fracture caused by the combined effects of stress and hydrogen or other hydrogen-containing media. For hydrogen-blended natural gas pipeline transportation, environmental hydrogen embrittlement is the primary factor affecting pipeline safety and is a key research focus.

[0004] In most current studies on hydrogen embrittlement mechanisms, material testing is traditional static hydrogen charging testing or dynamic hydrogen charging testing. For static hydrogen charging testing, the metal material generally needs to be placed in an electrolyte first, and hydrogen is continuously generated at the metal end through electrochemical means. After the hydrogen is fully in contact with the metal material for a period of time, the material can be hydrogenated; or the metal material is placed in a high-pressure hydrogen environment for a period of time to complete the hydrogen charging of the material. The testing process of metal materials can be completed in a normal pressure environment. For dynamic hydrogen charging testing, the metal material is placed in a high-pressure reactor, and a regulating valve is used to simulate a variety of hydrogen-doped environments. The metal material is always in a high-pressure hydrogen environment during the process of testing mechanical properties.

[0005] In general, static hydrogen charging experiments are relatively simple and cannot effectively simulate different hydrogen doping environments. Dynamic hydrogen charging experiments, on the other hand, are more dangerous, with difficulty in accurately controlling the hydrogen doping ratio and unable to precisely test experimental conditions with small hydrogen doping ratio intervals. Therefore, it is necessary to design a method for testing the hydrogen embrittlement susceptibility of materials that can be tested in different hydrogen doping environments. Summary of the Invention

[0006] To solve the above technical problems, the present invention aims to provide a method for testing the hydrogen embrittlement sensitivity of materials in different hydrogen-doped environments. The method of the present invention can test the mechanical properties of materials in different hydrogen-doped environments and thereby determine the hydrogen embrittlement sensitivity of materials in different hydrogen-doped environments.

[0007] In order to achieve the above object, the present invention provides a method for testing the hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments, which comprises the following steps:

[0008] (1) Processing the material to be tested into a test piece;

[0009] (2) preparing electrolyte;

[0010] (3) placing the test piece obtained in step (1) in a high-pressure reactor, injecting hydrogen and other gases into the high-pressure reactor to charge the test piece with hydrogen, simulating the set hydrogen doping environment pressure by controlling the gas pressure, and controlling the hydrogen concentration by the partial pressure method to simulate the set hydrogen doping ratio, and setting the hydrogen charging time;

[0011] (4) The hydrogen charging time required for the specimen to be fully charged in the electrolyte is calculated according to formula (1):

[0012]

[0013] In formula (I), t is the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte, s; t' is the hydrogen charging time in step (3), s; n is the concentration of the electrolyte, mol / L; l is the set hydrogen doping ratio, %; I is the set current density; P is the set hydrogen doping environment pressure, MPa;

[0014] The test piece obtained in step (1) is placed in the electrolyte obtained in step (2), and after the hydrogen charging time calculated according to formula (I) is reached, the test piece is hydrogenated to obtain a hydrogenated test piece;

[0015] (5) performing a slow tensile test on the hydrogen-filled specimen obtained in step (4) to obtain the hydrogen embrittlement sensitivity of the material to be tested under the hydrogen doping ratio and the hydrogen doping environment pressure.

[0016] In the above method, preferably, step (1) specifically includes: designing the size of the test piece according to the mechanical property test standard of the material and the requirements of the mechanical property test platform, and completing the processing of the test piece. Specifically, the mechanical property test standard is standard GB228. The mechanical property test platform is the platform for the slow tensile test in step (5). The processing of the test piece can adopt conventional processing methods in the field, such as wire cutting and polishing.

[0017] In the above method, preferably, in step (2), the electrolyte comprises a sulfuric acid solution containing thiourea, the concentration of sulfuric acid in the electrolyte is 0.2 to 0.6 mol / L, and the concentration of thiourea is 0.02 to 0.04 g / L, wherein thiourea is used as a poisoning agent.

[0018] In the above method, preferably, in step (3), the other gas includes natural gas.

[0019] In the above method, preferably, in step (3), the hydrogen charging time is set to 345600s to 604800s.

[0020] In the above method, preferably, in step (4), the hydrogen doping ratio l in formula (I) is controlled in the range of 10% to 40%.

[0021] In the above method, preferably, in step (4), the current density I in formula (I) is controlled in the range of 10 to 20 mA / cm 2 .

[0022] In the above method, preferably, in step (4), the hydrogen doping environment pressure P in formula (I) is controlled in the range of 2 to 6 MPa.

[0023] In the above method, preferably, step (5) specifically includes:

[0024] The hydrogen-charged specimen obtained in step (4) is subjected to a slow tensile test, and the load-displacement data of the hydrogen-charged specimen is recorded; a non-hydrogen-charged specimen is set as a control group, and a slow tensile test is performed on the non-hydrogen-charged specimen in a nitrogen environment, and the load-displacement data of the non-hydrogen-charged specimen is recorded; the tensile strength of the hydrogen-charged specimen and the tensile strength of the non-hydrogen-charged specimen in a nitrogen environment are obtained based on the load-displacement data, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II):

[0025]

[0026] In formula (II), RNS is the hydrogen embrittlement sensitivity characterized by relative tensile strength, %; is the tensile strength of the non-hydrogen-filled specimen in a nitrogen environment; is the tensile strength of the specimen after hydrogen charging.

[0027] In the method, preferably, in step (5), the slow tensile test is performed by using a slow stress strain tensile testing machine.

[0028] In the method, preferably, in step (5), the slow tensile test is performed at a tensile rate of 10 -8 - 6 mm / min. The tensile rate can be adjusted steplessly in the range.

[0029] In the method, preferably, step (5) further comprises: drawing a load-displacement curve by using the load displacement data, and obtaining the tensile strength of the hydrogen-charged specimen and the tensile strength of the non-hydrogen-charged specimen in the nitrogen environment according to the load-displacement curve.

[0030] According to the specific embodiment of the present application, preferably, the method further comprises step (6): setting a hydrogen-doped environment with different hydrogen-doped environment pressures and different hydrogen-doped ratios, obtaining the hydrogen embrittlement sensitivity of the material to be tested in the hydrogen-doped environment, and analyzing the change rule of the hydrogen embrittlement sensitivity of the material to be tested in the hydrogen-doped environment.

[0031] In the method, preferably, in step (6), the analysis of the change rule of the hydrogen embrittlement sensitivity of the material to be tested in the hydrogen-doped environment specifically comprises: if RNS < 5%, the material to be tested has no hydrogen embrittlement risk in the hydrogen-doped environment with the set hydrogen-doped environment pressure and hydrogen-doped ratio; if 5%≤RNS < 15%, the material to be tested has low hydrogen embrittlement risk in the hydrogen-doped environment with the set hydrogen-doped environment pressure and hydrogen-doped ratio; if 15%≤RNS < 30%, the material to be tested has medium hydrogen embrittlement risk in the hydrogen-doped environment with the set hydrogen-doped environment pressure and hydrogen-doped ratio; and if RNS≥30%, the material to be tested has high hydrogen embrittlement risk in the hydrogen-doped environment with the set hydrogen-doped environment pressure and hydrogen-doped ratio. When the material reaches low hydrogen embrittlement risk, the safety management of the pipeline and equipment of the material needs extra attention during service; and when the material reaches medium or high hydrogen embrittlement risk, it indicates that the pipeline and equipment of the material are not suitable for the hydrogen-doped environment (i.e., hydrogen transportation condition) with the hydrogen-doped ratio and hydrogen-doped environment pressure.

[0032] The hydrogen embrittlement of the pipe material is an important factor affecting the safety of natural gas pipeline hydrogen transportation. By testing and exploring the pipe material embrittlement mechanism in the hydrogen-doped environment, effective guidance can be provided for the accident prevention and control of the hydrogen-doped pipeline. However, in the current testing method, the electrochemical hydrogen charging experiment condition is relatively single, which cannot effectively simulate different hydrogen-doped environments. The high-pressure environment hydrogen charging experiment is relatively dangerous, and the control precision of the hydrogen-doped ratio is difficult to guarantee, which cannot precisely test the experimental conditions with small hydrogen-doped ratio intervals.

[0033] Compared with the prior art, the technical scheme of the present application has at least the following beneficial effects:​

[0034] The method of the present invention designs a correction scheme (i.e., formula (I)) for the relationship between hydrogen charging time, hydrogen charging current density, and hydrogen doping ratio, thereby completing the hydrogen charging of the material under different hydrogen doping environments. Afterwards, a tensile test is performed on the material after hydrogen charging is completed by a mechanical testing machine (i.e., a slow stress strain tensile testing machine). Finally, the load-displacement curve of the material under different hydrogen doping environments is used to obtain the hydrogen embrittlement sensitivity of the material under different hydrogen doping environments, and the variation law of the hydrogen embrittlement sensitivity of the material under different hydrogen doping environments is analyzed. The method of the present invention can realize the mechanical property testing of materials under different hydrogen doping environments, and then obtain the hydrogen embrittlement sensitivity of materials under different hydrogen doping environments. This method effectively reduces the risk of the experiment, and has high quantitative accuracy, and can complete experimental conditions with a small hydrogen doping ratio interval. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural diagram of a test piece in a specific embodiment of the present invention.

[0036] Figure 2 Dimensional drawings of the test pieces in Examples 1 to 3.

[0037] Figure 3 It is a structural schematic diagram of a device used for charging a test piece with hydrogen in an electrolyte in a specific embodiment of the present invention.

[0038] Figure 4 The load-displacement curves of the hydrogen-charged specimen, the non-hydrogen-charged specimen, and the hydrogen-charged specimen obtained by the conventional high-pressure method in Example 1 are shown.

[0039] Figure 5 The load-displacement curves of the hydrogen-charged specimen of Example 2, the non-hydrogen-charged specimen, and the hydrogen-charged specimen obtained by the conventional high-pressure method.

[0040] Figure 6 These are the load-displacement curves of the hydrogen-charged specimen of Example 3, the non-hydrogen-charged specimen, and the hydrogen-charged specimen obtained by the conventional high-pressure method.

[0041] Explanation of the accompanying symbols: d0: inner diameter of the specimen; r: circumferential diameter; L0: original gauge length; L c : parallel length; L t : total length; S0: original cross-sectional area of ​​parallel length. DETAILED DESCRIPTION

[0042] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0043] Example 1

[0044] This embodiment provides a method for testing the hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments, which includes the following steps:

[0045] (1) Processing the material to be tested into a test piece: For natural gas pipelines, the commonly used pipeline steel grades cover a wide range. In this embodiment, No. 20 steel is used as the research object. According to the mechanical property test standard GB228 of the material and the requirements of the mechanical property test platform, the size of the test piece is designed, and the test piece is processed by processes such as wire cutting and polishing. The structure of the processed test piece is as follows: Figure 1 The size of the specimen is shown in Table 1:

[0046] Table 1

[0047]

[0048] like Figure 2 As shown, the dimensions of the test piece tested in this embodiment are: d0 is 5 mm, r is 8.5 mm, L0 is 25 mm, L c 28mm;

[0049] (2) Preparation of electrolyte: The electrolyte used was a sulfuric acid solution containing thiourea. 2 g / L of thiourea solution was added to the sulfuric acid solution as a poisoning agent. The volume ratio of the sulfuric acid solution to the thiourea solution was 50:1. The electrolyte was obtained, wherein the concentration of sulfuric acid was 0.6 mol / L and the concentration of thiourea was 0.04 g / L.

[0050] (3) Hydrogenated test piece obtained by dynamic hydrogenation using a conventional high-pressure method: Referring to the method described in CN114383945A, the test piece obtained in step (1) is placed in a high-pressure reactor, and hydrogen and natural gas are injected into the high-pressure reactor to charge the test piece with hydrogen. The set hydrogenation environment pressure is simulated by controlling the gas pressure, and the set hydrogenation ratio is simulated by controlling the hydrogen concentration by the partial pressure method, and the hydrogenation time is set at the same time. In this embodiment, the hydrogenation environment pressure set is 2 MPa, the hydrogenation ratio is 30%, and the hydrogenation time is one week, i.e., 604800 s.

[0051] (4) This example studies the hydrogen embrittlement sensitivity of materials in a hydrogen-doped environment with a pressure of 2 MPa and a hydrogen doping ratio of 30%. The relationship between the hydrogen charging time, current density, and hydrogen doping ratio is controlled by formula (I). The hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte is calculated according to formula (I):

[0052]

[0053] In formula (I), t is the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte, s; t' is the hydrogen charging time in step (3), s; n is the concentration of the electrolyte (i.e., the concentration of sulfuric acid), mol / L; l is the set hydrogen doping ratio, %; I is the set current density; P is the hydrogen doping environment pressure in step (3), MPa;

[0054] It is known that the hydrogen doping environment pressure is 2MPa, the hydrogen doping ratio is 30%, and the current density is set to 15mA / cm 2 , the hydrogen charging time in step (3) is 604800s, the concentration of sulfuric acid is 0.6mol / L, and the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte is calculated according to formula (I) to be 26327s, which is about 7.3h;

[0055] The test piece obtained in step (1) is placed in the electrolyte obtained in step (2). After 7.3 hours, the test piece is charged with hydrogen to obtain a hydrogen-charged test piece. The structure of the device used for charging the test piece with hydrogen in the electrolyte is as follows: Figure 3 As shown;

[0056] (5) A slow stress strain tensile testing machine was used to perform a slow tensile test on the hydrogen-charged specimen obtained in step (4), with a tensile rate of 10 -6 mm / min, the load-displacement data of the specimen after hydrogen filling were recorded through the data port, and the load-displacement curve was drawn; the specimen without hydrogen filling was set as the control group, and the slow stress-strain tensile testing machine was used to conduct a slow tensile test on the specimen without hydrogen filling in a nitrogen environment, with a tensile rate of 10 -6 mm / min, and record the load-displacement data of the non-hydrogen-charged specimen through the data port to draw the load-displacement curve; the tensile strength of the hydrogen-charged specimen and the tensile strength of the non-hydrogen-charged specimen in a nitrogen environment are obtained based on the load-displacement curve, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II):

[0057]

[0058] In formula (II), RNS is the hydrogen embrittlement sensitivity characterized by relative tensile strength, %; is the tensile strength of the non-hydrogen-filled specimen in a nitrogen environment; is the tensile strength of the specimen after hydrogen charging;

[0059] The hydrogen embrittlement sensitivity of No. 20 steel calculated in this example is:

[0060]

[0061] 5%≤RNS<15%, then the material tested in this embodiment has a low hydrogen embrittlement risk under a hydrogen-doped environment with a set hydrogen-doped ambient pressure and hydrogen-doped ratio (2 MPa, 30%).

[0062] For comparison, the hydrogen-charged specimen obtained by dynamic hydrogen charging using a conventional high-pressure method in step (3) was subjected to a slow tensile test in the manner of step (5) to obtain load-displacement data and draw a load-displacement curve. The hydrogen embrittlement sensitivity of the material was calculated according to formula (II).

[0063] The load-displacement curves of the hydrogen-charged specimen, the non-hydrogen-charged specimen, and the hydrogen-charged specimen obtained by dynamic hydrogen charging using a conventional high-pressure method are shown in FIG. Figure 4 shown.

[0064] The calculation results of hydrogen embrittlement sensitivity of the hydrogen-charged specimen obtained by conventional high-pressure method are as follows:

[0065]

[0066] It can be seen from this that the error between the test results of the method of this embodiment and the test results of the conventional high-pressure method is only 1.09%.

[0067] Example 2

[0068] This embodiment provides a method for testing the hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments, which includes the following steps:

[0069] (1) Processing the material to be tested into a test piece: For natural gas pipelines, the station is an important transportation place for hydrogen-blended natural gas. In this embodiment, the valve body of the valve is used as the research object; according to the mechanical property test standard GB228 of the material and the requirements of the mechanical property test platform, the size of the test piece is designed, and the test piece is processed by processes such as wire cutting and polishing. The structure of the processed test piece is as follows: Figure 1 As shown; Figure 2 As shown, the dimensions of the test piece tested in this embodiment are: d0 is 5 mm, r is 8.5 mm, L0 is 25 mm, L c 28mm;

[0070] (2) Preparation of electrolyte: The electrolyte used was a sulfuric acid solution containing thiourea. 2 g / L of thiourea solution was added to the sulfuric acid solution as a poisoning agent. The volume ratio of the sulfuric acid solution to the thiourea solution was 50:1. The electrolyte was obtained, wherein the concentration of sulfuric acid was 0.4 mol / L and the concentration of thiourea was 0.04 g / L.

[0071] (3) Hydrogenated test piece obtained by dynamic hydrogenation using a conventional high-pressure method: Referring to the method described in CN114383945A, the test piece obtained in step (1) is placed in a high-pressure reactor, and hydrogen and natural gas are injected into the high-pressure reactor to charge the test piece with hydrogen. The set hydrogenation environment pressure is simulated by controlling the gas pressure, and the hydrogen concentration is controlled by the partial pressure method to set different hydrogenation ratios, and the hydrogenation time is set at the same time; the hydrogenation environment pressure set in this embodiment is 4 MPa, the hydrogenation ratio is 20%, and the hydrogenation time is 4 days, i.e., 345600 s;

[0072] (4) This example studies the hydrogen embrittlement sensitivity of materials in a hydrogen-doped environment with a pressure of 4 MPa and a hydrogen doping ratio of 20%. The relationship between the hydrogen charging time, current density, and hydrogen doping ratio is controlled by formula (I). The hydrogen charging time required for the specimen to be completely charged in the electrolyte is calculated according to formula (I):

[0073]

[0074] In formula (I), t is the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte, s; t' is the hydrogen charging time in step (3), s; n is the concentration of the electrolyte (i.e., the concentration of sulfuric acid), mol / L; l is the set hydrogen doping ratio, %; I is the set current density; P is the hydrogen doping environment pressure in step (3), MPa;

[0075] It is known that the hydrogen doping environment pressure is 4MPa, the hydrogen doping ratio is 20%, and the current density is set to 15mA / cm 2 , the hydrogen charging time in step (3) is 345600s, the concentration of sulfuric acid is 0.4mol / L, and the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte is calculated according to formula (I) to be 16828s, which is about 4.7h;

[0076] The test piece obtained in step (1) is placed in the electrolyte obtained in step (2). After 4.7 hours, the test piece is charged with hydrogen to obtain a hydrogen-charged test piece. The structure of the device used for charging the test piece with hydrogen in the electrolyte is as follows: Figure 3 As shown;

[0077] (5) A slow stress strain tensile tester was used to perform a slow tensile test on the hydrogen-charged specimen obtained in step (4), with a tensile rate of 2×10 -7 mm / min, and the load-displacement data of the specimen after hydrogenation were recorded through the data port, and the load-displacement curve was drawn; the specimen without hydrogenation was set as the control group, and a slow stress-strain tensile testing machine was used to perform a slow tensile test on the specimen without hydrogenation in a nitrogen environment, with a tensile rate of 2×10 -7mm / min, record the load displacement data of the unhydrogenated specimen through the data port, and draw the load-displacement curve; according to the load-displacement curve, the tensile strength of the hydrogen-charged specimen and the tensile strength of the unhydrogenated specimen in the nitrogen environment are obtained, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II):

[0078]

[0079] In formula (II), RNS is the hydrogen embrittlement sensitivity represented by the relative tensile strength, %; is the tensile strength of the unhydrogenated specimen in the nitrogen environment; is the tensile strength of the hydrogen-charged specimen;

[0080] The hydrogen embrittlement sensitivity of the valve is calculated as follows:

[0081]

[0082] 5%≤RNS<15%, the material tested in this example has a low hydrogen embrittlement risk in the hydrogen-doped environment with the set hydrogen-doping environment pressure and hydrogen-doping ratio (4 MPa, 20%).

[0083] As a comparison, the hydrogen-charged specimen obtained by dynamic hydrogen charging by the conventional high-pressure method in step (3) is subjected to slow tensile test in the manner of step (5), load displacement data are obtained and a load-displacement curve is drawn, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II).

[0084] The load-displacement curves of the hydrogen-charged specimen of this example, the unhydrogenated specimen, and the hydrogen-charged specimen obtained by dynamic hydrogen charging by the conventional high-pressure method are shown in Figure 5 .

[0085] The hydrogen embrittlement sensitivity of the hydrogen-charged specimen obtained by the conventional high-pressure method is calculated as follows:

[0086]

[0087] It can be seen that the error between the test results of the method of this example and the test results of the conventional high-pressure method is only 0.96%.

[0088] Example 3

[0089] The example provides a material hydrogen embrittlement sensitivity test method which can realize different hydrogen-doped environments, which comprises the following steps:

[0090] (1) Processing the material to be tested into a test piece: For natural gas pipelines, the station is an important place for transporting hydrogen-blended natural gas. In this embodiment, the shell of the filter separator is used as the research object; according to the mechanical property test standard GB228 of the material and the requirements of the mechanical property test platform, the size of the test piece is designed, and the test piece is processed by processes such as wire cutting and polishing. The structure of the processed test piece is as follows: Figure 1 As shown; Figure 2 As shown, the dimensions of the test piece tested in this embodiment are: d0 is 5 mm, r is 8.5 mm, L0 is 25 mm, L c 28mm;

[0091] (2) Preparation of electrolyte: The electrolyte used was a sulfuric acid solution containing thiourea. 2 g / L of thiourea solution was added to the sulfuric acid solution as a poisoning agent. The volume ratio of the sulfuric acid solution to the thiourea solution was 50:1. The electrolyte was obtained, wherein the concentration of sulfuric acid was 0.2 mol / L and the concentration of thiourea was 0.04 g / L.

[0092] (3) Hydrogenated test piece obtained by dynamic hydrogenation using a conventional high-pressure method: Referring to the method described in CN114383945A, the test piece obtained in step (1) is placed in a high-pressure reactor, and hydrogen and natural gas are injected into the high-pressure reactor to charge the test piece with hydrogen. The set hydrogenation environment pressure is simulated by controlling the gas pressure, and the set hydrogenation ratio is simulated by controlling the hydrogen concentration by the partial pressure method, and the hydrogenation time is set at the same time. In this embodiment, the hydrogenation environment pressure set is 6 MPa, the hydrogenation ratio is 25%, and the hydrogenation time is 5 days, i.e., 432,000 s.

[0093] (4) This example studies the hydrogen embrittlement sensitivity of materials in a hydrogen-doped environment with a pressure of 6 MPa and a hydrogen doping ratio of 25%. The relationship between the hydrogen charging time, current density, and hydrogen doping ratio is controlled by formula (I). The hydrogen charging time required for the specimen to be completely charged in the electrolyte is calculated according to formula (I):

[0094]

[0095] In formula (I), t is the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte, s; t' is the hydrogen charging time in step (3), s; n is the concentration of the electrolyte (i.e., the concentration of sulfuric acid), mol / L; l is the set hydrogen doping ratio, %; I is the set current density; P is the hydrogen doping environment pressure in step (3), MPa;

[0096] It is known that the hydrogen doping environment pressure is 6MPa, the hydrogen doping ratio is 25%, and the current density is set to 20mA / cm 2, the hydrogen charging time in step (3) is 432000s, the concentration of sulfuric acid is 0.2mol / L, and the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte is calculated according to formula (I) to be 17619s, which is about 4.9h;

[0097] The test piece obtained in step (1) is placed in the electrolyte obtained in step (2). After 4.9 hours, the test piece is charged with hydrogen to obtain a hydrogen-charged test piece. The structure of the device used for charging the test piece with hydrogen in the electrolyte is as follows: Figure 3 As shown;

[0098] (5) A slow stress strain tensile testing machine was used to perform a slow tensile test on the hydrogen-charged specimen obtained in step (4). The tensile rate was 4×10 -7 mm / min, and the load-displacement data of the hydrogen-charged specimens were recorded through the data port to draw the load-displacement curve; the non-hydrogen-charged specimens were set as the control group, and the slow stress-strain tensile testing machine was used to perform slow tensile testing on the non-hydrogen-charged specimens in a nitrogen environment at a tensile rate of 4×10 -7 mm / min, and record the load-displacement data of the non-hydrogen-charged specimen through the data port to draw the load-displacement curve; the tensile strength of the hydrogen-charged specimen and the tensile strength of the non-hydrogen-charged specimen in a nitrogen environment are obtained based on the load-displacement curve, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II):

[0099]

[0100] In formula (II), RNS is the hydrogen embrittlement sensitivity characterized by relative tensile strength, %; is the tensile strength of the non-hydrogen-filled specimen in a nitrogen environment; is the tensile strength of the specimen after hydrogen charging;

[0101] The calculation results of the hydrogen embrittlement sensitivity of the valve in this embodiment are:

[0102]

[0103] 5%≤RNS<15%, then the material tested in this embodiment has a low hydrogen embrittlement risk under a hydrogen-doped environment with a set hydrogen-doped ambient pressure and hydrogen-doped ratio (6 MPa, 25%).

[0104] For comparison, the hydrogen-charged specimen obtained by dynamic hydrogen charging using a conventional high-pressure method in step (3) was subjected to a slow tensile test in the manner of step (5) to obtain load-displacement data and draw a load-displacement curve. The hydrogen embrittlement sensitivity of the material was calculated according to formula (II).

[0105] The load-displacement curves of the hydrogen-charged specimen, the non-hydrogen-charged specimen, and the hydrogen-charged specimen obtained by dynamic hydrogen charging using a conventional high-pressure method are shown in FIG. Figure 6 shown.

[0106] The calculation results of hydrogen embrittlement sensitivity of the hydrogen-charged specimen obtained by conventional high-pressure method are as follows:

[0107]

[0108] It can be seen that the error between the test results of the method of this embodiment and the test results of the conventional high-pressure method is only 0.69%.

[0109] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for testing the hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments, comprising the following steps: (1) Processing the material to be tested into a test piece; (2) preparing electrolyte; (3) placing the test piece obtained in step (1) in a high-pressure reactor, injecting hydrogen and other gases into the high-pressure reactor to charge the test piece with hydrogen, simulating the set hydrogen doping environment pressure by controlling the gas pressure, and controlling the hydrogen concentration by the partial pressure method to simulate the set hydrogen doping ratio, and setting the hydrogen charging time; (4) The hydrogen charging time required for the specimen to be fully charged in the electrolyte is calculated according to formula (1): In formula (I), t is the hydrogen charging time required for the specimen to complete hydrogen charging in the electrolyte, s; t' is the hydrogen charging time in step (3), s; n is the concentration of the electrolyte, mol / L; l is the set hydrogen doping ratio, %; I is the set current density; P is the set hydrogen doping environment pressure, MPa; The test piece obtained in step (1) is placed in the electrolyte obtained in step (2), and after the hydrogen charging time calculated according to formula (I) is reached, the test piece is hydrogenated to obtain a hydrogenated test piece; (5) performing a slow tensile test on the hydrogen-filled specimen obtained in step (4) to obtain the hydrogen embrittlement sensitivity of the material to be tested under the hydrogen doping ratio and the hydrogen doping environment pressure.

2. The method for testing hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments according to claim 1, wherein: Step (1) specifically includes: designing the size of the test piece according to the mechanical property test standard of the material and the requirements of the mechanical property test platform, and completing the processing of the test piece.

3. The method for testing hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments according to claim 1, wherein: In step (2), the electrolyte comprises a sulfuric acid solution containing thiourea, the concentration of sulfuric acid in the electrolyte is 0.2 to 0.6 mol / L, and the concentration of thiourea is 0.02 to 0.04 g / L.

4. The method for testing hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments according to claim 1, wherein: In step (3), the other gas includes natural gas.

5. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 1, wherein: In step (3), the hydrogen charging time is set to 345600s to 604800s.

6. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 1, wherein: In step (4), the hydrogen doping ratio l in formula (I) is controlled in the range of 10% to 40%.

7. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 1, wherein: In step (4), the current density I in formula (I) is controlled in the range of 10-20 mA / cm 2 .

8. The method for testing hydrogen embrittlement sensitivity of materials in different hydrogen-doping environments according to claim 1, wherein: In step (4), the hydrogen doping environment pressure P in formula (I) is controlled in the range of 2 to 6 MPa.

9. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 1, wherein: Step (5) specifically includes: The hydrogen-charged specimen obtained in step (4) is subjected to a slow tensile test, and the load-displacement data of the hydrogen-charged specimen is recorded; a non-hydrogen-charged specimen is set as a control group, and a slow tensile test is performed on the non-hydrogen-charged specimen in a nitrogen environment, and the load-displacement data of the non-hydrogen-charged specimen is recorded; the tensile strength of the hydrogen-charged specimen and the tensile strength of the non-hydrogen-charged specimen in a nitrogen environment are obtained based on the load-displacement data, and the hydrogen embrittlement sensitivity of the material is calculated according to formula (II): In formula (II), RNS is the hydrogen embrittlement sensitivity characterized by relative tensile strength, %; is the tensile strength of the non-hydrogen-filled specimen in a nitrogen environment; is the tensile strength of the specimen after hydrogen charging.

10. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 9, wherein: In step (5), the slow tensile test is performed using a slow stress-strain tensile testing machine.

11. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 9, wherein: In step (5), the stretching rate of the slow stretching test is 10 -8 ~10 -6 mm / min.

12. The method for testing hydrogen embrittlement sensitivity of materials capable of achieving different hydrogen doping environments according to claim 1, wherein: The method further includes step (6): setting hydrogen-doped environments with different hydrogen-doped environment pressures and different hydrogen-doped ratios, obtaining the hydrogen embrittlement sensitivity of the material to be tested under different hydrogen-doped environments, and analyzing the variation pattern of the hydrogen embrittlement sensitivity of the material to be tested under different hydrogen-doped environments.

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