A method for non-destructive prediction of hydrogen damage in a shock tube

Abstract

The present application belongs to the technical field of hypersonic test equipment, and discloses a method for nondestructive prediction of hydrogen damage of a shock tube. The method comprises the following steps: setting two monitoring sections; respectively performing original control group detection on the two monitoring sections; installing the two monitoring sections; performing influence detection of a shock tunnel test; performing comparative analysis; making a decision; and performing comprehensive inspection of the shock tube. The method can predict and evaluate the hydrogen damage risk without damaging the shock tube body, and provides a reliable basis and guidance for comprehensive and detailed inspection and service risk assessment of the high-pressure and high-temperature hydrogen-driven shock tunnel.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hypersonic test equipment, and particularly relates to a method for nondestructively predicting hydrogen damage of a shock tube. BACKGROUND

[0002] The shock tunnel is a pulse type test device for generating high-speed test gas flow by using shock compression of test gas and then through steady expansion.

[0003] In order to obtain better driving performance, using superhigh-pressure and high-temperature hydrogen as driving gas is an effective means to improve the driving performance of the shock tunnel. The higher the pressure and temperature of the hydrogen are, the stronger the driving capacity is. However, with the increase of the pressure and temperature of the hydrogen, the risk of hydrogen damage of the shock tube material is more prominent.

[0004] Hydrogen damage refers to that hydrogen gas is easy to enter the inside of the material through adsorption, penetration and diffusion, which is easy to cause the performance of the shock tube material to decrease, and hydrogen damage (which belongs to hydrogen embrittlement in a broad sense) such as hydrogen-induced plastic damage, hydrogen-induced crack, hydrogen-induced delayed fracture and hydrogen corrosion. Moreover, the shock tube stores high-pressure hydrogen gas for a long time. Once the shock tube is damaged by hydrogen, hydrogen leakage and even explosion and other major accidents may occur.

[0005] For superhigh-pressure and high-temperature hydrogen, there is no material that can be completely "immune", and only through strengthening the service detection can the hydrogen damage be found as early as possible to avoid safety accidents. Since the overall size of the shock tube is large and the structure is relatively complex, it is difficult to perform nondestructive testing on the whole, and the cycle is long, and small defects are not easy to detect. At the same time, the shock tube is of high value and is difficult to be damaged for sampling to measure the mechanical performance damage. Therefore, how to realize the prediction and evaluation of the hydrogen damage risk of the shock tube without damaging the body of the shock tube is an important problem faced by the superhigh-pressure and high-temperature hydrogen driven shock tunnel.

[0006] At present, it is urgent to develop a method for nondestructively predicting hydrogen damage of a shock tube. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a method for nondestructively predicting hydrogen damage of a shock tube to overcome the defects of the prior art.

[0008] The method for nondestructively predicting hydrogen damage of a shock tube of the present application comprises the following steps:

[0009] S10. Setting two monitoring sections;

[0010] S20. Respectively performing original control group detection of the two monitoring sections;

[0011] S30. Installing the two monitoring sections;

[0012] S40. Performing detection of the two monitoring sections after the shock tunnel test;

[0013] S50. Perform comparative analysis to determine the risk of hydrogen damage, and determine whether to continue monitoring or conduct a comprehensive inspection;

[0014] S601. If the risk of hydrogen damage is low: continue the shock tunnel test, and repeat S40 and S50;

[0015] S602. If the risk of hydrogen damage is high: stop the shock tunnel test and conduct a comprehensive inspection.

[0016] Further, the S10 sets two monitoring sections, specifically as follows:

[0017] The monitoring section I is a pipe section in communication with the pipe body of the shock tube driving section, and a plurality of parallel annular monitoring sample grooves are arranged on the pipe wall of the monitoring section I, and tensile samples and hydrogen content samples are placed in the monitoring sample grooves; the monitoring section II is a circular ring piece with the same cross-sectional size as the pipe body of the shock tube driving section.

[0018] Further, the S20 respectively performs original control group detection on the two monitoring sections, specifically as follows:

[0019] At least 3 groups of tensile samples and hydrogen content samples are extracted from the monitoring section I, and chemical composition, microstructure, hydrogen content, and mechanical property detection are performed, and recorded as T01 group; at the same time, non-destructive testing is performed on the monitoring section II, and recorded as T02 group; T01 group and T02 group are the original control group.

[0020] Further, the S30 installs two monitoring sections, specifically as follows:

[0021] The monitoring section I is installed at the upstream end of the shock tube driving section; the monitoring section II is clamped by a clamping film mechanism and installed at the downstream end of the shock tube driving section, and the monitoring section II has the same temperature, pressure, stress level and service time as the pipe body of the shock tube, and is used to simulate the service environment of the pipe body of the shock tube.

[0022] Further, the S40 performs shock tunnel test influence detection, specifically as follows:

[0023] After L times of shock tunnel test, at least 3 groups of tensile samples and hydrogen content samples are extracted from the monitoring section I, and chemical composition, microstructure, hydrogen content, and mechanical property detection are performed, and recorded as TL1 group; first, non-destructive testing is performed on the monitoring section II, and then, chemical composition, microstructure, hydrogen content, and mechanical property detection are performed on the section from the monitoring section II, and the detection results are recorded as TL2 group.

[0024] Further, the S50 performs comparative analysis, specifically as follows:

[0025] The detection results of the TL1 group and the T01 group, the TL2 group and the T022 group are compared respectively, and the analysis obtains the tensile sample and the hydrogen content sample of the monitoring section I, the decarburization amount, the hydrogen penetration amount in the material, the crack defect number or size growth of the monitoring section II after the L times shock wave tunnel test, the mechanical property loss trend including the yield strength, the tensile strength, the elongation, the section shrinkage, and the like, and the design safety tolerance of the shock wave tube driving section is compared, the hydrogen damage risk of the shock wave tube driving section is evaluated, and it is determined whether to continue the shock wave tunnel test or to carry out the shock wave tube comprehensive inspection.

[0026] Further, the shock wave tunnel test of S601 is continued, and specifically as follows.

[0027] If the shock wave tunnel test is continued, the remaining tensile sample and the hydrogen content sample of the monitoring section I are re-fixed in the monitoring sample groove, the monitoring section II is re-fixed on the film clamping mechanism, the M times shock wave tunnel test is continued, and S40 is repeated to obtain the detection results of the TM1 group and the TM2 group.

[0028] The detection results of the TM1 group, the TL1 group and the T01 group are compared, and the detection results of the TM2 group, the TL2 group and the T02 group are compared; if none of them exceeds the design safety tolerance of the shock wave tube driving section, the shock wave tunnel test is continued.

[0029] Further, the shock wave tunnel test of S602 is stopped and the comprehensive inspection is carried out, and specifically as follows.

[0030] If it is found that the design safety tolerance of the shock wave tube driving section is exceeded, the shock wave tunnel test is stopped, the comprehensive inspection of the shock wave tube is carried out, and the fault of the shock wave tube is excluded.

[0031] Further, the tensile sample and the hydrogen content sample of the monitoring section I are more than 60 pieces.

[0032] Further, the tensile sample and the hydrogen content sample of the monitoring section I and the monitoring section II are manufactured by using the same batch of materials as the shock wave tube body, or are manufactured by using the segmented materials of the shock wave tube body.

[0033] The method for predicting the hydrogen damage of the shock wave tube without damage in the application has the following characteristics:

[0034] 1. The monitoring section and the monitoring sample are made of the same batch of materials as the shock wave tube, which can represent the real material level of the shock wave tube body.

[0035] 2. The monitoring section and the monitoring sample are served in the same period and environment as the shock wave tube body, which can completely reproduce the real service working condition of the shock wave tube body.

[0036] 3. The monitoring sample can fully reproduce the hydrogen service environment of the shock tube body, including pressure, temperature, medium, time, and can truly characterize the hydrogen damage risk of high pressure and high temperature hydrogen; at the same time, due to the smaller size of the monitoring sample, the hydrogen penetration depth and penetration amount are more severe than the actual shock tube body, and the hydrogen damage risk of the shock tube body is more safe.

[0037] 4. The monitoring section II can fully reproduce the hydrogen service environment and stress level of the shock tube body, and can represent the hydrogen damage risk level of the actual shock tube body.

[0038] 5. The detection results of the monitoring sample in the monitoring section I and the section detection results of the monitoring section II are compared, and the influence law of stress level on hydrogen damage can be obtained.

[0039] The method for nondestructive prediction of hydrogen damage of the shock tube can realize the prediction and evaluation of hydrogen damage risk without damaging the shock tube body, and provides reliable basis and guidance for the comprehensive and detailed inspection and service risk assessment of the high pressure and high temperature hydrogen driven shock wind tunnel. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The flow chart of the method for nondestructive prediction of hydrogen damage of the shock tube. DETAILED DESCRIPTION

[0041] The present application will be described in detail below in combination with the drawings and examples.

[0042] Example 1:

[0043] As shown in the figure, the method for nondestructive prediction of hydrogen damage of the shock tube of the present embodiment comprises the following steps: Figure 1 S10. Set two monitoring sections;

[0044] S20. Perform original control group detection of the two monitoring sections respectively;

[0045] S30. Install the two monitoring sections;

[0046] S40. Perform detection of the two monitoring sections after the shock wind tunnel test;

[0047] S50. Perform comparative analysis to determine the hydrogen damage risk and determine whether to continue monitoring or perform comprehensive inspection;

[0048] S601. If the hydrogen damage risk is low: continue the shock wind tunnel test, and repeat S40 and S50;

[0049] S602. If the hydrogen damage risk is high: stop the shock wind tunnel test and perform comprehensive inspection.

[0050]

[0051] ​Further, the S10 is provided with two monitoring sections, specifically as follows:

[0052] The monitoring section I is a pipe section in communication with the pipe body of the shock tube driving section, and a plurality of parallel annular monitoring sample grooves are arranged on the pipe wall of the monitoring section I, and the tensile samples and hydrogen content samples are placed in the monitoring sample grooves; the monitoring section II is a circular ring piece with the same cross-sectional size as the pipe body of the shock tube driving section.

[0053] Further, the S20 is respectively performed with original control group detection of the two monitoring sections, specifically as follows:

[0054] At least three groups of tensile samples and hydrogen content samples are extracted from the monitoring section I, and chemical composition, microstructure, hydrogen content and mechanical property detection are respectively performed, and recorded as T01 group; at the same time, the non-destructive detection is performed on the monitoring section II, and recorded as T02 group; T01 group and T02 group are the original control group.

[0055] Further, the S30 is installed with two monitoring sections, specifically as follows:

[0056] The monitoring section I is installed at the upstream end of the shock tube driving section; the monitoring section II is clamped by a film clamping mechanism and installed at the downstream end of the shock tube driving section, and the monitoring section II has the same temperature, pressure, stress level and service time as the pipe body of the shock tube, and is used to simulate the service environment of the pipe body of the shock tube.

[0057] Further, the S40 is performed with shock tunnel test influence detection, specifically as follows:

[0058] After L times of shock tunnel test, at least three groups of tensile samples and hydrogen content samples are extracted from the monitoring section I, and chemical composition, microstructure, hydrogen content and mechanical property detection are respectively performed, and recorded as TL1 group; the non-destructive detection is first performed on the monitoring section II, and then the chemical composition, microstructure, hydrogen content and mechanical property detection are performed on the section of the monitoring section II, and the detection results are recorded as TL2 group.

[0059] Further, the S50 is performed with comparative analysis, specifically as follows:

[0060] The detection results of TL1 group and T01 group, and TL2 group and T022 group are compared respectively, the decarburization amount, hydrogen penetration amount in the material, crack defect number or size increase of the tensile samples and hydrogen content samples of the monitoring section I and the monitoring section II after L times of shock tunnel test, and the mechanical property loss trend including yield strength, tensile strength, elongation and reduction of area are analyzed, and compared with the design safety margin of the shock tube driving section, the hydrogen damage risk of the shock tube driving section is evaluated, and it is determined whether to continue the shock tunnel test or to carry out the shock tube comprehensive inspection.

[0061] Further, the S601 continues to carry out the shock tunnel test, and the specific process is as follows.

[0062] If the shock tunnel test is continued, the remaining tensile samples and hydrogen content samples of the monitoring section I are refixed in the monitoring sample groove, the monitoring section II is refixed on the film clamping mechanism, the M times of shock tunnel test are continued, and the S40 is repeated to obtain the corresponding TM1 group and TM2 group detection results.

[0063] The detection results of the TM1 group, the TL1 group and the T01 group are continuously compared, and the detection results of the TM2 group, the TL2 group and the T02 group are continuously compared, and if all of them do not exceed the design safety tolerance of the shock tube driving section, the shock tunnel test is continued.

[0064] Further, the S602 stops the shock tunnel test and carries out comprehensive inspection, and the specific process is as follows.

[0065] If it is found that the design safety tolerance of the shock tube driving section is exceeded, the shock tunnel test is stopped, the comprehensive inspection of the shock tube is carried out, and the fault of the shock tube is excluded.

[0066] Further, the tensile samples and hydrogen content samples of the monitoring section I are more than 60.

[0067] Further, the tensile samples and hydrogen content samples of the monitoring section I and the monitoring section II are manufactured by using the same batch of materials as the shock tube body, or are manufactured by using the segmented materials of the shock tube body.

[0068] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, and all the features disclosed in the present application, or the steps in all the methods or processes disclosed in the present application, except for the mutually exclusive features and / or steps, can be combined in any manner, and the present application is not limited to specific details and the figures shown and described herein.

Claims

1. A method for non-destructive prediction of shock tube hydrogen damage, characterized in that: The following steps are involved: S10. Set up two monitoring segments; Monitoring section I is the section of the tube connected to the shock tube drive section. Several parallel, annular monitoring sample slots are set on the tube wall of monitoring section I. Tensile samples and hydrogen content samples are placed in the monitoring sample slots. Monitoring section II is a circular ring with the same cross-sectional dimensions as the shock tube drive section. S20. Conduct original control group tests for the two monitoring periods respectively; At least three groups of tensile specimens and hydrogen content specimens were extracted from monitoring section I and tested for chemical composition, microstructure, hydrogen content, and mechanical properties, respectively, and recorded as group T01. At the same time, non-destructive testing was performed on monitoring section II, recorded as group T02. Groups T01 and T02 served as the original control groups. S30. Install two monitoring segments; Install the monitoring section I at the upstream end of the shock tube driving section; The monitoring section II is clamped by a clamping mechanism and installed at the downstream end of the shock tube driving section. The monitoring section II has the same temperature, pressure, stress level and service time as the shock tube body, which is used to simulate the service environment of the shock tube body. S40. Testing of two monitoring sections after shock wave wind tunnel testing; After L shock tunnel tests, extract at least three groups of tensile specimens and hydrogen content specimens from monitoring section I and conduct tests on chemical composition, microstructure, hydrogen content, and mechanical properties, respectively. These are recorded as group TL1. First, perform nondestructive testing on monitoring section II. Then, slice the surface of monitoring section II and conduct tests on chemical composition, microstructure, hydrogen content, and mechanical properties. The test results are recorded as group TL2. S50. Conduct comparative analysis to determine the risk of hydrogen damage and decide whether to continue monitoring or conduct a comprehensive inspection. The test results of the TL1 group were compared with those of the T01 group, and the TL2 group with those of the T022 group. The results of the tensile and hydrogen content specimens of monitoring section I, as well as those of monitoring section II, after L shock tunnel tests were analyzed to determine the amount of decarburization, the amount of hydrogen permeation into the material, the number or size growth of cracks in the material, and the deterioration trends of mechanical properties, including yield strength, tensile strength, elongation, and reduction of area. These results were compared with the design safety margin of the shock tube drive section to assess the hydrogen damage risk of the shock tube drive section and determine whether to continue shock tunnel testing or conduct a comprehensive shock tube inspection. S601. If the risk of hydrogen damage is low: Continue with the shock tunnel test and repeat S40 and S50. S602. If the risk of hydrogen damage is high: Stop the shock tunnel test and conduct a comprehensive inspection.

2. The method for non-destructive prediction of shock tube hydrogen damage according to claim 1, characterized in that: The S601 is continued to be subjected to shock wave wind tunnel testing, as follows; If the shock tunnel test is to be continued, the remaining tensile specimens and hydrogen content specimens of monitoring section I are re-fixed in the monitoring specimen slot, and monitoring section II is re-fixed on the clamping mechanism; the shock tunnel test is continued M times; S40 is repeated to obtain the corresponding test results of group TM1 and group TM2; Continue to compare the test results of group TM1, group TL1, and group T01, as well as the test results of group TM2, group TL2, and group T02; if none of them exceeds the design safety tolerance of the shock tube drive section, continue to conduct shock wind tunnel testing.

3. The method for non-destructive prediction of shock tube hydrogen damage according to claim 1, characterized in that: The shock wave wind tunnel test of S602 was stopped and a comprehensive inspection was carried out, as follows: If it is found that the design safety margin of the shock tube drive section is exceeded, the shock tunnel test shall be stopped, a comprehensive inspection of the shock tube shall be carried out, and the shock tube fault shall be eliminated.

4. The method for non-destructive prediction of shock tube hydrogen damage according to claim 1, characterized in that: The number of tensile specimens and hydrogen content specimens in the monitoring section I is more than 60 respectively.

5. The method for non-destructive prediction of shock tube hydrogen damage according to claim 1, characterized in that: The tensile test specimen and hydrogen content test specimen of the monitoring section I and the monitoring section II are manufactured from the same batch of materials as the shock tube body, or are manufactured from materials divided from the shock tube body.

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