Method for evaluating hydrogen-induced elastic damage of hydrogenation equipment material
Patent Information
- Application Number
- CN202610988516.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-03
- Publication Date
- 2026-09-04
AI Technical Summary
[0003]然而，现有技术仍存在以下突出问题：第一，氢扩散行为与力学性能测试通常分离进行，试样从充氢环境转移至测试环境过程中扩散氢逸散和重新分布，导致测试结果无法真实反映服役状态下的材料响应；第二，传统方法多以平均氢浓度或表面氢浓度作为损伤评价指标，忽略了氢浓度在厚度方向上的梯度分布及其对弹性性能的非均匀影响；第三，电化学氢渗透曲线仅用于计算扩散系数或表面氢浓度，未能区分晶格扩散氢、可逆陷阱氢和不可逆陷阱氢对弹性性能的不同贡献；第四，预充氢后再进行拉伸或断裂测试的方式需施加宏观载荷，容易引入塑性变形和表面缺陷影响，不适合连续、无损地表征氢扩散过程中的弹性性能演化
本发明通过将检测试样直接安装于双室电化学氢渗透装置中，在同一充氢过程中同步获取氢渗透响应曲线和原位弹性响应信号，避免了传统方法中氢扩散测试与力学性能测试分离导致的氢逸散和测试误差。通过采用氢扩散反演模型获得厚度方向上的晶格扩散氢浓度分布和可逆陷阱氢浓度分布，并引入应变能权重函数进行加权积分得到等效参与弹性响应的氢损伤浓度，克服了以平均氢浓度评价弹性损伤的不足。最终基于等效氢损伤浓度、氢浓度梯度与弹性性能损伤指标之间的映射关系获得损伤程度，实现了对临氢设备材料氢致弹性损伤的连续、无损、准确评价。
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of hydrogen damage evaluation of materials for hydrogen-contaminated equipment, and particularly relates to a method for evaluating hydrogen-induced elastic damage to materials for hydrogen-contaminated equipment. Background Technology
[0002] Hydrogen-containing equipment is widely used in petrochemical, coal chemical, hydrogen energy storage and transportation, hydrogenation reactors, pressure vessels, and hydrogen pipelines. During service, hydrogen atoms can enter the interior of metallic materials through corrosion reactions, electrochemical processes, wet hydrogen sulfide environments, or high-pressure hydrogen environments, and diffuse and accumulate at locations such as crystal lattices, dislocations, grain boundaries, and inclusions, leading to degradation of the material's strength, plasticity, fracture toughness, and elastic properties. Currently, the evaluation of hydrogen damage to materials mainly employs methods such as electrochemical hydrogen permeation tests, mechanical tests after pre-charging with hydrogen, and thermal desorption analysis to obtain hydrogen diffusion parameters or hydrogen-induced changes in mechanical properties, respectively.
[0003] However, existing technologies still have the following prominent problems: First, hydrogen diffusion behavior and mechanical property testing are usually conducted separately. During the transfer of the sample from the hydrogen-filled environment to the test environment, diffused hydrogen escapes and redistributes, resulting in test results that cannot truly reflect the material response under service conditions. Second, traditional methods often use average hydrogen concentration or surface hydrogen concentration as damage evaluation indicators, ignoring the gradient distribution of hydrogen concentration in the thickness direction and its non-uniform effect on elastic properties. Third, electrochemical hydrogen permeation curves are only used to calculate the diffusion coefficient or surface hydrogen concentration, failing to distinguish the different contributions of lattice-diffused hydrogen, reversibly trapped hydrogen, and irreversibly trapped hydrogen to elastic properties. Fourth, the method of pre-filling with hydrogen before tensile or fracture testing requires the application of macroscopic loads, which easily introduces plastic deformation and surface defects, making it unsuitable for continuous and non-destructive characterization of elastic property evolution during hydrogen diffusion. Therefore, there is an urgent need for a method for evaluating the elastic property damage of hydrogen-exposed equipment materials that can simultaneously acquire hydrogen diffusion behavior and elastic property changes, consider the hydrogen concentration gradient and elastic response energy weights, and is applicable to service condition conversion. Therefore, this invention proposes a method for evaluating hydrogen-induced elastic damage of hydrogen-exposed equipment materials. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes a method for evaluating hydrogen-induced elastic damage to materials used in hydrogen-contaminated equipment, thereby resolving the issues present in the prior art.
[0005] To achieve the above objectives, the present invention provides a method for evaluating hydrogen-induced elastic damage to materials used in hydrogen-contaminated equipment, comprising: The test sample was installed in a dual-chamber electrochemical hydrogen permeation device. An electrochemical hydrogen charging boundary condition was applied to the hydrogen inlet side, and the hydrogen permeation response curve was obtained based on the signal collected from the hydrogen outlet side. During the electrochemical hydrogen charging process, an in-situ elastic wave excitation is applied to the test sample, and the elastic response signal is obtained based on the collected signal. The hydrogen permeation response curve was inverted using a hydrogen diffusion inversion model that includes lattice diffused hydrogen and trapped hydrogen to obtain the lattice diffused hydrogen concentration distribution and reversible trapped hydrogen concentration distribution in the thickness direction of the test sample. The in-situ elastic performance parameters are calculated based on the elastic response signal, and the elastic performance damage index is calculated based on the change from the uncharged hydrogen state. Based on the strain energy weighting function of the elastic wave propagation path in the thickness direction of the test sample, the lattice diffused hydrogen concentration distribution and the reversible trap hydrogen concentration distribution are weighted and integrated to obtain the equivalent hydrogen damage concentration participating in the elastic response. Based on the mapping relationship between the equivalent hydrogen damage concentration involved in the elastic response, the maximum hydrogen concentration gradient in the thickness direction, and the elastic performance damage index, the degree of elastic performance damage to the hydrogen-contaminated equipment material is obtained.
[0006] Optionally, during the electrochemical hydrogen charging process, the process of applying in-situ elastic wave excitation to the test sample and obtaining the elastic response signal based on the acquired signal includes: An in-situ elastic wave excitation with a stress amplitude less than 30% of the material's yield strength is applied to the test sample using a piezoelectric ultrasonic transducer. The longitudinal wave velocity and transverse wave velocity are obtained based on the transmitted waveforms collected on the same time axis, and the elastic response signal is obtained based on the longitudinal wave velocity and the transverse wave velocity.
[0007] Optionally, the hydrogen diffusion inversion model is: In the formula, For lattice-diffuse hydrogen concentration, For the concentration of hydrogen trapped, The lattice diffusion coefficient is... To detect the thickness direction coordinates of the sample. For time.
[0008] Optionally, the process of inverting the hydrogen permeation response curve using a hydrogen diffusion inversion model that includes lattice-diffused hydrogen and trapped hydrogen includes: Hydrogen diffusion control equations are constructed based on lattice-diffused hydrogen concentration and reversible trap hydrogen concentration. The occupation relationship between reversible trap hydrogen concentration and lattice diffuse hydrogen concentration was determined using the Oriani local equilibrium relation; The hydrogen permeation current is calculated based on the hydrogen diffusion control equation and the occupancy relationship. A target function is constructed based on the error between the calculated hydrogen permeation current and the hydrogen permeation response curve. Based on the minimization of the objective function, the lattice diffusion coefficient, reversible trap density, and trap equilibrium constant are obtained through inversion. The lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant are used to calculate the lattice diffusion hydrogen concentration distribution and the reversible trap hydrogen concentration distribution along the thickness direction of the test sample.
[0009] Optionally, the calculation expression for the occupancy relationship is: In the formula, For reversible trap density, This is the trap balance constant. For lattice-diffuse hydrogen concentration, This represents the concentration of hydrogen trapped in the trap.
[0010] Optionally, the expression for the objective function is: In the formula, To calculate the hydrogen permeation current, To measure the hydrogen permeation current, For regularization terms, The regularization coefficient is . To optimize the objective, This represents the time corresponding to the hydrogen permeation current.
[0011] Optionally, the process of calculating in-situ elastic performance parameters based on the elastic response signal and calculating elastic performance damage indicators based on the changes compared to the uncharged hydrogen state includes: The longitudinal wave velocity and transverse wave velocity are obtained based on the elastic response signal. The in-situ elastic modulus is calculated based on the longitudinal wave velocity, the transverse wave velocity, and the density of the test sample. The initial elastic modulus is obtained based on the initial elastic response signal collected in the uncharged state; The elastic modulus damage index is calculated based on the difference between the in-situ elastic modulus and the initial elastic modulus; The elastic modulus damage index is used as the elastic performance damage index.
[0012] Optionally, the expression for calculating the equivalent hydrogen damage concentration participating in the elastic response is: In the formula, Let be the hydrogen damage concentration that is equivalent to the elastic response at time t. L To detect the thickness of the sample, Let be the strain energy weighting function of the elastic wave propagation path or resonant mode in the thickness direction. The hydrogen concentration for reversible traps. This is the weighting coefficient for the effect of reversible trapped hydrogen on the elastic response.
[0013] Optionally, the mapping relationship is as follows: In the formula, As an indicator of elastic performance damage, The equivalent hydrogen damage concentration participating in the elastic response, This represents the maximum hydrogen concentration gradient along the thickness direction. For hydrogen exposure time history parameters, 、 、 、 、 These are the first material parameter, the second material parameter, the third material parameter, the fourth material parameter, and the fifth material parameter, respectively.
[0014] Compared with the prior art, the present invention has the following advantages and technical effects: This invention directly mounts the test sample into a dual-chamber electrochemical hydrogen permeation device, simultaneously acquiring the hydrogen permeation response curve and in-situ elastic response signal during the same hydrogen filling process. This avoids the hydrogen escape and testing errors caused by the separation of hydrogen diffusion testing and mechanical property testing in traditional methods. By employing a hydrogen diffusion inversion model, the lattice-diffused hydrogen concentration distribution and reversible trap hydrogen concentration distribution in the thickness direction are obtained. A strain energy weighting function is introduced for weighted integration to obtain the equivalent hydrogen damage concentration participating in the elastic response, overcoming the shortcomings of evaluating elastic damage based on average hydrogen concentration. Finally, the degree of damage is obtained based on the mapping relationship between the equivalent hydrogen damage concentration, hydrogen concentration gradient, and elastic property damage index, achieving continuous, non-destructive, and accurate evaluation of hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment. Attached Figure Description
[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart illustrating an embodiment of the present invention; Figure 2 This is a schematic diagram of the data processing and damage assessment process according to an embodiment of the present invention. Detailed Implementation
[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0017] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.
[0018] Example 1 The purpose of this invention is to provide a method for evaluating the elastic performance damage of materials in hydrogen-contaminated equipment based on electrochemical hydrogen permeation-in-situ elastic wave coupling, in order to solve the problems in the prior art such as the separation of hydrogen diffusion testing and elastic performance testing, the mismatch between hydrogen concentration characterization and actual elastic response, the difficulty in distinguishing the influence of different hydrogen states on elastic performance, and the difficulty in converting to service conditions.
[0019] like Figure 1 and Figure 2 As shown, this embodiment provides a method for evaluating hydrogen-induced elastic damage to materials used in hydrogen-contaminated equipment, including the following steps: S1, prepare a test sample and at least one compensation sample for the material of the hydrogen-contaminated equipment to be evaluated, wherein the test sample and the compensation sample have the same material state, the same heat treatment state and the same thickness.
[0020] The compensation test specimens include at least one of the following: uncharged hydrogen compensation specimens, corrosion compensation specimens, and temperature compensation specimens. The uncharged hydrogen compensation specimens are used to deduct the effects of test fixtures, coupling agents, and instrument drift on the elastic response signal. The corrosion compensation specimens are used to deduct the effects of electrolyte corrosion or surface condition changes on the elastic response signal. The temperature compensation specimens are used to deduct the effects of temperature changes on sound velocity, resonant frequency, or elastic modulus.
[0021] S2, the test sample is installed in a dual-chamber electrochemical hydrogen permeation device, with one side of the test sample as the hydrogen inlet side and the other side as the hydrogen outlet side; an electrochemical hydrogen charging boundary condition is applied to the hydrogen inlet side and an hydroxide boundary condition is applied to the hydrogen outlet side, and the hydrogen permeation response curve of the hydrogen permeation current on the outlet side as a function of time is collected.
[0022] Electrochemical hydrogen charging boundary conditions include one of constant current hydrogen charging, constant potential hydrogen charging, step current hydrogen charging, pulse current hydrogen charging, or service condition equivalent hydrogen charging; pulse current hydrogen charging includes at least two current density levels, and hydrogen diffusion parameters and hydrogen trapping parameters are inverted by the rising segment, steady-state segment, and decay segment of the hydrogen permeation current.
[0023] S3, during the electrochemical hydrogen charging process, applies in-situ elastic wave excitation or in-situ resonant excitation to the test sample without causing plastic deformation of the material, and simultaneously acquires hydrogen permeation current signal and elastic response signal on the same time axis.
[0024] In-situ elastic wave excitation is piezoelectric ultrasonic excitation, electromagnetic ultrasonic excitation, laser ultrasonic excitation, or low-amplitude mechanical vibration excitation; in-situ resonant excitation is bending resonance, longitudinal resonance, torsional resonance, or thickness resonance; the excitation stress amplitude is less than 30% of the yield strength of the test specimen, so that the test specimen maintains an elastic state during the collection process.
[0025] S4. Based on the hydrogen permeation response curve, a hydrogen diffusion inversion model including lattice diffused hydrogen and trapped hydrogen is established to obtain the lattice diffused hydrogen concentration distribution, the reversible trapped hydrogen concentration distribution, and at least one hydrogen trapping parameter in the thickness direction of the test sample.
[0026] Furthermore, as a specific implementation process of this embodiment, the process of inverting the hydrogen permeation response curve using a hydrogen diffusion inversion model that includes lattice diffused hydrogen and trapped hydrogen includes: constructing a hydrogen diffusion control equation based on the lattice diffused hydrogen concentration and the reversible trapped hydrogen concentration; determining the occupancy relationship between the reversible trapped hydrogen concentration and the lattice diffused hydrogen concentration using the Oriani local equilibrium relationship; calculating the calculated hydrogen permeation current based on the hydrogen diffusion control equation and the occupancy relationship; constructing an objective function based on the error between the calculated hydrogen permeation current and the hydrogen permeation response curve; inverting the lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant based on minimizing the objective function; and calculating the lattice diffused hydrogen concentration distribution and the reversible trapped hydrogen concentration distribution in the thickness direction of the detection sample based on the lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant.
[0027] The hydrogen diffusion inversion model satisfies the following form: in, For lattice-diffuse hydrogen concentration, For the concentration of hydrogen trapped, The lattice diffusion coefficient is... To detect the thickness direction coordinates of the sample. For time.
[0028] The concentration of trapped hydrogen is determined by the reversible trap occupancy relationship, which includes one of the Oriani local equilibrium relationship, the double trap kinetic relationship, or the multi-trap kinetic relationship.
[0029] The reversible trap occupancy relationship is as follows: in, For reversible trap density, This is the trap equilibrium constant. It is obtained through joint inversion by minimizing the error between the calculated and measured hydrogen permeation currents on the hydrogen outlet side. 、 、 And at least two parameters in the hydrogen flux on the hydrogen inlet side surface.
[0030] S5. Calculate the in-situ elastic performance parameters of the test sample during the hydrogen charging process based on the elastic response signal, and calculate the elastic performance damage index based on the change of the in-situ elastic performance parameters relative to the uncharged state.
[0031] In-situ elastic performance parameters include at least one of elastic modulus, shear modulus, bulk modulus, and Poisson's ratio; When collecting longitudinal wave velocity transverse wave speed of sound and material density At that time, the elastic modulus E is calculated according to the following relationship: When the resonant frequency f is sampled, the elastic modulus is calculated according to the following relationship: in, The resonance correction coefficient is determined by the specimen size, boundary constraints, and mode shape.
[0032] Elastic performance damage indicators include at least one of the following: elastic modulus damage indicators, shear modulus damage indicators, acoustic attenuation damage indicators, or phase hysteresis damage indicators. Elastic modulus damage index Calculated according to the following relationship: in, The initial elastic modulus is either in the uncharged state or after compensation and correction. Hydrogen charging time t The corresponding in-situ elastic modulus.
[0033] S6. Based on the strain energy weighting function of the elastic wave propagation path or resonant mode in the thickness direction of the test sample, the lattice diffuse hydrogen concentration distribution and the reversible trap hydrogen concentration distribution are weighted and integrated to obtain the equivalent hydrogen damage concentration participating in the elastic response.
[0034] Equivalent hydrogen damage concentration participating in elastic response Calculated according to the following relationship: in, L To detect the thickness of the sample, Let be the strain energy weighting function of the elastic wave propagation path or resonant mode in the thickness direction. The hydrogen concentration for reversible traps. This is the weighting coefficient for the effect of reversible trapped hydrogen on the elastic response.
[0035] Strain energy weighting function It is obtained through at least one of the following methods: finite element modal analysis, sound beam path integration, displacement field measurement in the thickness direction of the specimen, or standard specimen calibration. When resonant excitation is used, the strain energy weighting function is the normalized strain energy density of the corresponding resonant mode in the thickness direction; when ultrasonic transmission or reflection excitation is used, the strain energy weighting function is the acoustic energy density or sound pressure distribution function of the ultrasonic wave in the propagation path.
[0036] S7. Establish the mapping relationship between the hydrogen damage concentration, hydrogen concentration gradient and elastic performance damage index that are equivalent to the elastic response, and evaluate the elastic performance damage of hydrogen-contaminated equipment materials under hydrogen diffusion based on the mapping relationship.
[0037] The mapping relationship is as follows: In the formula, As an indicator of elastic performance damage, The equivalent hydrogen damage concentration participating in the elastic response, This represents the maximum hydrogen concentration gradient along the thickness direction. For hydrogen exposure time history parameters, 、 、 、 、 These are the first material parameter, the second material parameter, the third material parameter, the fourth material parameter, and the fifth material parameter, respectively. The mapping relationship is also used to determine the critical hydrogen damage concentration corresponding to when the elastic property damage reaches a preset threshold.
[0038] S8. Based on at least one of the parameters of service temperature of hydrogen-contaminated equipment, hydrogen partial pressure, medium pH value, sulfide concentration, cathodic protection potential or corrosion current density, determine the service equivalent hydrogen ingress boundary conditions, and substitute these boundary conditions into the hydrogen diffusion inversion model and elastic property damage mapping relationship to predict the degree of elastic property damage of hydrogen-contaminated equipment materials during service time.
[0039] Example 2 This invention discloses a method and system for evaluating the elastic property damage of materials used in hydrogen-contaminated equipment based on electrochemical hydrogen permeation-in-situ elastic wave coupling. The method includes: preparing test samples and compensation samples of the same material and size; installing the test sample in a dual-chamber electrochemical hydrogen permeation device; applying constant current, constant potential, or pulsed electrochemical hydrogen charging boundary on the hydrogen inlet side, and collecting hydrogen permeation current on the hydrogen outlet side; simultaneously applying non-destructive elastic wave or resonant excitation to the sample, and continuously collecting the synchronous response of sound velocity, attenuation, resonant frequency, and hydrogen permeation current over time; inverting the diffused hydrogen concentration, reversible trapped hydrogen concentration, and irreversible trapped hydrogen parameters based on the hydrogen permeation current; weighting the hydrogen concentration gradient in the thickness direction based on the strain energy distribution of the elastic wave propagation path or resonant mode to obtain the equivalent hydrogen damage concentration participating in the elastic response; establishing the relationship between the equivalent hydrogen damage concentration, hydrogen concentration gradient, and elastic property damage indicators, and converting them to the degree of elastic property damage under the service boundary conditions of the hydrogen-contaminated equipment. This method can simultaneously obtain hydrogen diffusion behavior and elastic property degradation response under the same sample and the same hydrogen charging state, reducing offline testing errors and improving the accuracy and reliability of hydrogen-induced elastic damage evaluation of hydrogen-containing equipment materials.
[0040] This embodiment uses low-alloy steel for hydrogen-bearing pressure vessels as the material to be evaluated. First, test specimens and compensation specimens are cut from the same plate or pipe location. The test specimens are sheet-like, with a thickness of 0.5 mm to 5 mm. Both main surfaces are progressively ground and polished, and then cleaned and dried with ethanol or acetone. The compensation specimens have the same material condition, heat treatment condition, thickness, and surface treatment as the test specimens.
[0041] The test sample is clamped in a dual-chamber electrochemical hydrogen permeation device. One side of the test sample is the hydrogen inlet side, where an electrolyte containing a hydrogen inlet promoter is added; the other side is the hydrogen outlet side, where an alkaline electrolyte is added. The hydrogen atoms diffusing to the hydrogen outlet side are oxidized into hydrogen ions by a constant potential, thereby obtaining the hydrogen permeation current on the outlet side.
[0042] A step current hydrogen charging procedure is applied to the hydrogen inlet side. Specifically, a lower current density is first applied to bring the sample into the initial hydrogen charging state; then the current density is increased to form a significant hydrogen concentration gradient in the thickness direction; finally, the hydrogen inlet current is reduced or stopped to collect the hydrogen permeation current decay segment. The above-mentioned rising segment, steady-state segment, and decay segment are used together to invert hydrogen diffusion parameters and hydrogen trapping parameters.
[0043] During the electrochemical hydrogen charging process, a pair of ultrasonic transducers are placed on the test sample to collect longitudinal wave velocity, transverse wave velocity, echo phase, and acoustic attenuation using either transmission or reflection methods. The ultrasonic excitation amplitude is controlled within a range that does not cause plastic deformation of the material. The data acquisition system records the hydrogen permeation current, hydrogen ingress current density, temperature, longitudinal wave velocity, transverse wave velocity, and acoustic attenuation using the same time reference.
[0044] Simultaneously, the compensation sample was placed in the same test environment without hydrogen charging or hydrogen inflow current, and the changes in sound velocity caused by temperature changes, electrolyte corrosion, probe coupling status, and instrument drift were collected. The measured sound velocity of the test sample was corrected by the compensation sample signal to obtain the sound velocity change caused by hydrogen diffusion.
[0045] Based on the density of the test sample Longitudinal wave speed and transverse wave speed of sound Calculate the elastic modulus during the hydrogen charging process: And calculate the elastic modulus damage index: in, This is the initial elastic modulus after compensation and correction in the uncharged state.
[0046] Furthermore, as a specific implementation process of this embodiment, the process of inverting the hydrogen permeation response curve using a hydrogen diffusion inversion model that includes lattice diffused hydrogen and trapped hydrogen includes: constructing a hydrogen diffusion control equation based on the lattice diffused hydrogen concentration and the reversible trapped hydrogen concentration; determining the occupancy relationship between the reversible trapped hydrogen concentration and the lattice diffused hydrogen concentration using the Oriani local equilibrium relationship; calculating the calculated hydrogen permeation current based on the hydrogen diffusion control equation and the occupancy relationship; constructing an objective function based on the error between the calculated hydrogen permeation current and the hydrogen permeation response curve; inverting the lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant based on minimizing the objective function; and calculating the lattice diffused hydrogen concentration distribution and the reversible trapped hydrogen concentration distribution in the thickness direction of the detection sample based on the lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant.
[0047] The hydrogen permeation current curve was inverted. The hydrogen diffusion governing equation is: in, For reversible trap density, This is the trap balance constant.
[0048] The error between the calculated hydrogen permeation current and the detected hydrogen permeation current on the hydrogen outlet side is used as the optimization objective function: In the formula, To calculate the hydrogen permeation current, To measure the hydrogen permeation current, For regularization terms, The regularization coefficient is . To achieve the optimization objective, an optimization algorithm is used to obtain... 、 、 And the hydrogen ingress side boundary flux, This represents the time corresponding to the hydrogen permeation current.
[0049] Furthermore, as a specific implementation process of this embodiment, the process of calculating the in-situ elastic performance parameters based on the elastic response signal and calculating the elastic performance damage index based on the change from the uncharged hydrogen state includes: obtaining the longitudinal wave velocity and transverse wave velocity based on the elastic response signal; calculating the in-situ elastic modulus based on the longitudinal wave velocity, transverse wave velocity, and the density of the test sample; obtaining the initial elastic modulus based on the initial elastic response signal collected in the uncharged hydrogen state; calculating the elastic modulus damage index based on the difference between the in-situ elastic modulus and the initial elastic modulus; and using the elastic modulus damage index as the elastic performance damage index.
[0050] According to the inversion and Further calculations were performed on the equivalent hydrogen damage concentration involved in the elastic response: in, Let be the energy weighting function of the ultrasonic wave in the thickness direction of the sample. The hydrogen concentration for reversible traps. This is the weighting coefficient for the effect of reversible trapped hydrogen on the elastic response.
[0051] For transmission ultrasound This can be taken as the normalized acoustic energy distribution along the propagation path. For reflection ultrasound, It can be determined based on the sound beam propagation depth, reflection interface, and attenuation coefficient. Compared to directly using the thickness-averaged hydrogen concentration, using... It can reflect the contribution of hydrogen damage in the actual sensitive area of elastic waves.
[0052] Establish the following elastic property damage mapping relationship: in, As an indicator of elastic performance damage, The equivalent hydrogen damage concentration participating in the elastic response, This represents the maximum hydrogen concentration gradient along the thickness direction. 、 、 、 、 These are the first material parameter, the second material parameter, the third material parameter, the fourth material parameter, and the fifth material parameter, respectively. The hydrogen exposure time history parameter can be taken as: Material parameters were obtained by fitting test data under multiple sets of electrochemical hydrogen-charging boundary conditions. 、 、 、 、 .when When the preset threshold is reached, the corresponding critical hydrogen damage concentration and critical service time are output.
[0053] Example 3 This embodiment also provides an elastic damage evaluation based on electrochemical hydrogen permeation and in-situ resonance. The difference between this embodiment and Embodiment 2 is that the elastic performance acquisition method adopts in-situ resonance testing.
[0054] The test sample is configured as a cantilever beam, simply supported beam, thin sheet, or circular plate structure, with its two sides in contact with the electrolyte on the hydrogen inlet and outlet sides, respectively, in an electrochemical hydrogen permeation device. A low-amplitude resonant excitation is applied to the sample using an electromagnetic exciter, piezoelectric exciter, or miniature vibration table, and the first or multiple resonant frequencies and damping of the sample are collected using a laser vibrometer, accelerometer, or impedance analyzer.
[0055] In the uncharged hydrogen state, the initial resonant frequency of the sample is first obtained. During the hydrogen charging process, the resonant frequency was continuously collected. Under the same boundary conditions and the same mode shape, the elastic modulus and resonant frequency satisfy the following: Based on this, the elastic modulus damage index is obtained: The normalized strain energy density of the selected resonant mode in the thickness direction of the specimen was obtained by finite element modal analysis. Subsequently, the lattice-diffused hydrogen concentration and the reversible-trap hydrogen concentration obtained from the inversion are substituted into the weighted integral formula to obtain the equivalent hydrogen damage concentration participating in the resonant response. .
[0056] This embodiment is applicable to scenarios where the sample thickness is thin, the ultrasonic transducer is difficult to couple stably, or high sensitivity is required to detect elastic changes.
[0057] Example 4 This embodiment also provides elastic property damage prediction under service boundary conditions. After obtaining the hydrogen diffusion parameters, trap parameters and elastic property damage mapping relationship of the material, damage prediction can be further performed based on the service environment of hydrogen-contaminated equipment.
[0058] For high-pressure hydrogen service environments, the surface hydrogen concentration on the hydrogen inlet side can be determined based on the hydrogen partial pressure and temperature; for wet hydrogen sulfide or corrosive environments, the hydrogen flux on the hydrogen inlet side can be determined based on the corrosion current density, cathodic protection potential, pH value, sulfide concentration, and temperature; for cathodic protection environments, the hydrogen flux on the hydrogen inlet side can be determined based on the protection potential and polarization current.
[0059] Substituting the above-mentioned service-equivalent hydrogen boundary conditions into the hydrogen diffusion inversion model, the variation of the wall thickness in the hydrogen-adjacent equipment direction with service time is calculated. , And the hydrogen concentration gradient. Then, the strain energy weighting function is determined based on the equipment wall thickness, elastic wave detection path, or sensitive area of the component. Calculate the equivalent hydrogen damage concentration involved in the elastic response under service conditions. .
[0060] Will By substituting the parameters of maximum hydrogen concentration gradient and hydrogen exposure time history into the elastic property damage mapping relationship, the degree of elastic property damage to the materials of hydrogen-exposed equipment after a specified service time can be predicted. When the predicted elastic property damage index exceeds the preset threshold, a risk warning, a suggested inspection cycle, or a suggested reduced load operating condition is output.
[0061] The present invention provides a method for synchronously acquiring hydrogen permeation current signals and elastic response signals under the same test sample, the same hydrogen filling process, and the same time axis by synchronously coupling electrochemical hydrogen permeation test and in-situ elastic wave / resonance test.
[0062] The present invention provides a testing device and method for placing a test sample in a dual-chamber electrochemical hydrogen permeation test cell, with one side of the test sample as the hydrogen inlet surface and the other side as the hydrogen outlet detection surface, and applying constant current, constant potential or pulsed hydrogen charging boundary conditions on the hydrogen inlet side, and collecting hydrogen permeation current on the hydrogen outlet side.
[0063] The present invention provides a method for obtaining elastic response parameters such as sound velocity, attenuation, phase, and resonant frequency of a sample through in-situ elastic wave excitation or in-situ resonant excitation during electrochemical hydrogen permeation, and calculating the in-situ elastic performance parameters and elastic damage index of the material accordingly.
[0064] The present invention provides a method for establishing a hydrogen diffusion-trap coupled inversion model based on hydrogen permeation current curves, and obtaining lattice diffused hydrogen concentration, reversible trap hydrogen concentration, diffusion parameters and trap parameters through inversion.
[0065] The present invention improves the evaluation method of hydrogen concentration distribution from the traditional average concentration or surface concentration to lattice-diffused hydrogen concentration based on the thickness direction distribution. With reversible trap hydrogen concentration The joint characterization method.
[0066] The present invention provides a strain energy weighting function for establishing elastic response based on the elastic wave propagation path, resonant mode, or local strain energy distribution of the sample. The method involves using this weighting function to weight the hydrogen concentration distribution in the thickness direction.
[0067] The present invention provides a method for calculating the equivalent hydrogen damage concentration participating in the elastic response by weighting the lattice diffuse hydrogen concentration and the reversible trapped hydrogen concentration using a strain energy weighting function. The method.
[0068] The present invention provides a method for establishing a mapping relationship between equivalent hydrogen damage concentration, hydrogen concentration gradient, hydrogen exposure time history and elastic property damage index.
[0069] The present invention provides a method for constructing a hydrogen-induced elastic property damage index of a material based on at least one parameter selected from elastic modulus, shear modulus, acoustic attenuation, phase hysteresis, resonant frequency, or damping variation.
[0070] The present invention provides a method for correcting the in-situ elastic response signal by means of non-hydrogen diffusion factors through hydrogen non-filling compensation, corrosion compensation and temperature compensation, so as to eliminate the influence of non-hydrogen diffusion factors on the elastic performance calculation results.
[0071] The present invention provides a method for converting laboratory electrochemical hydrogen charging conditions into equivalent hydrogen inlet boundary conditions for service of hydrogen-containing equipment based on parameters such as service temperature, hydrogen partial pressure, pH value, sulfide concentration, cathodic protection potential or corrosion current density.
[0072] The present invention provides a method for predicting the service damage degree, critical hydrogen damage concentration, risk level, inspection cycle or remaining life of materials in hydrogen-contaminated equipment based on service equivalent hydrogen entry boundary conditions, hydrogen diffusion-trap inversion model and elastic damage mapping relationship.
[0073] The present invention provides a method for evaluating hydrogen-induced elastic property damage of materials for hydrogen-contaminated equipment by establishing a closed-loop evaluation chain through hydrogen charging current signal, hydrogen diffusion, hydrogen concentration distribution in the thickness direction, strain energy-weighted hydrogen damage concentration, and elastic property damage index.
[0074] This invention synchronously acquires hydrogen permeation current and elastic response signals under the same sample, the same hydrogen charging process, and the same time axis, avoiding errors caused by the escape and redistribution of diffused hydrogen and inconsistent test conditions during the transfer of pre-charged hydrogen samples. This invention uses in-situ elastic wave or in-situ resonant excitation to obtain changes in elastic properties, eliminating the need to apply macroscopic tensile loads that cause plastic deformation to the sample, and enabling continuous and non-destructive characterization of elastic property degradation during hydrogen diffusion. This invention, through an inversion model incorporating lattice-diffused hydrogen and trapped hydrogen, can distinguish the influence of lattice-diffused hydrogen, reversible trapped hydrogen, and irreversible trapped parameters on elastic property damage, improving the physical interpretability of hydrogen damage evaluation. This invention introduces a strain energy weighting function for the elastic wave propagation path or resonant mode to weight the hydrogen concentration distribution in the thickness direction, obtaining the equivalent hydrogen damage concentration that truly participates in the elastic response, overcoming the shortcomings of evaluating elastic damage solely based on average or surface hydrogen concentration. This invention can convert laboratory electrochemical hydrogen charging boundary conditions to service boundary conditions for hydrogen-containing equipment, and is applicable to the prediction of hydrogen-induced elastic performance damage of pressure vessels, hydrogenation reactors, hydrogen storage containers, hydrogen pipelines, and equipment in wet hydrogen sulfide environments.
[0075] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A method for evaluating hydrogen-induced elastic damage to materials used in hydrogen-contaminated equipment, characterized in that, Includes the following steps: The test sample was installed in a dual-chamber electrochemical hydrogen permeation device. An electrochemical hydrogen charging boundary condition was applied to the hydrogen inlet side, and the hydrogen permeation response curve was obtained based on the signal collected from the hydrogen outlet side. During the electrochemical hydrogen charging process, an in-situ elastic wave excitation is applied to the test sample, and the elastic response signal is obtained based on the collected signal. The hydrogen permeation response curve was inverted using a hydrogen diffusion inversion model that includes lattice diffused hydrogen and trapped hydrogen to obtain the lattice diffused hydrogen concentration distribution and reversible trapped hydrogen concentration distribution in the thickness direction of the test sample. The in-situ elastic performance parameters are calculated based on the elastic response signal, and the elastic performance damage index is calculated based on the change from the uncharged hydrogen state. Based on the strain energy weighting function of the elastic wave propagation path in the thickness direction of the test sample, the lattice diffused hydrogen concentration distribution and the reversible trap hydrogen concentration distribution are weighted and integrated to obtain the equivalent hydrogen damage concentration participating in the elastic response. Based on the mapping relationship between the equivalent hydrogen damage concentration involved in the elastic response, the maximum hydrogen concentration gradient in the thickness direction, and the elastic performance damage index, the degree of elastic performance damage to the hydrogen-contaminated equipment material is obtained.
2. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 1, characterized in that, In the electrochemical hydrogen charging process, the process of applying in-situ elastic wave excitation to the test sample and obtaining the elastic response signal based on the acquired signal includes: An in-situ elastic wave excitation with a stress amplitude less than 30% of the material's yield strength is applied to the test sample using a piezoelectric ultrasonic transducer. The longitudinal wave velocity and transverse wave velocity are obtained based on the transmitted waveforms collected on the same time axis, and the elastic response signal is obtained based on the longitudinal wave velocity and the transverse wave velocity.
3. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 1, characterized in that, The hydrogen diffusion inversion model is as follows: In the formula, The concentration of hydrogen diffused through the lattice. For the concentration of hydrogen trapped, The lattice diffusion coefficient is... To detect the thickness direction coordinates of the sample. For time.
4. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 1, characterized in that, The process of inverting the hydrogen permeation response curve using a hydrogen diffusion inversion model that includes lattice-diffused hydrogen and trapped hydrogen includes: Hydrogen diffusion control equations are constructed based on lattice-diffused hydrogen concentration and reversible trap hydrogen concentration. The occupation relationship between reversible trap hydrogen concentration and lattice diffuse hydrogen concentration was determined using the Oriani local equilibrium relation; The hydrogen permeation current is calculated based on the hydrogen diffusion control equation and the occupancy relationship. A target function is constructed based on the error between the calculated hydrogen permeation current and the hydrogen permeation response curve. Based on the minimization of the objective function, the lattice diffusion coefficient, reversible trap density, and trap equilibrium constant are obtained through inversion. The lattice diffusion coefficient, the reversible trap density, and the trap equilibrium constant are used to calculate the lattice diffusion hydrogen concentration distribution and the reversible trap hydrogen concentration distribution along the thickness direction of the test sample.
5. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 4, characterized in that, The calculation expression for the occupancy relationship is: In the formula, For reversible trap density, This is the trap balance constant. The concentration of hydrogen diffused through the lattice. This represents the concentration of hydrogen trapped in the trap.
6. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 5, characterized in that, The expression for the objective function is: In the formula, To calculate the hydrogen permeation current, To measure the hydrogen permeation current, For regularization terms, The regularization coefficient is . To optimize the objective, This represents the time corresponding to the hydrogen permeation current.
7. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 1, characterized in that, The process of calculating in-situ elastic performance parameters based on the elastic response signal and calculating elastic performance damage indices based on the changes compared to the uncharged hydrogen state includes: The longitudinal wave velocity and transverse wave velocity are obtained based on the elastic response signal. The in-situ elastic modulus is calculated based on the longitudinal wave velocity, the transverse wave velocity, and the density of the test sample. The initial elastic modulus is obtained based on the initial elastic response signal collected in the uncharged state; The elastic modulus damage index is calculated based on the difference between the in-situ elastic modulus and the initial elastic modulus; The elastic modulus damage index is used as the elastic performance damage index.
8. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 7, characterized in that, The expression for calculating the equivalent hydrogen damage concentration participating in the elastic response is as follows: In the formula, Let be the hydrogen damage concentration that is equivalent to the elastic response at time t. L To detect the thickness of the sample, Let be the strain energy weighting function of the elastic wave propagation path or resonant mode in the thickness direction. The hydrogen concentration for reversible traps. The weighting coefficients represent the influence of reversible trapped hydrogen on the elastic response. The concentration of lattice-diffuse hydrogen is distributed along the thickness direction.
9. The method for evaluating hydrogen-induced elastic damage to materials in hydrogen-contaminated equipment according to claim 1, characterized in that, The mapping relationship is as follows: In the formula, As an indicator of elastic performance damage, The equivalent hydrogen damage concentration participating in the elastic response, This represents the maximum hydrogen concentration gradient along the thickness direction. For hydrogen exposure time history parameters, 、 、 、 、 These are the first material parameter, the second material parameter, the third material parameter, the fourth material parameter, and the fifth material parameter, respectively.