Method, system and program product for detecting degree of sensitization

Abstract

The application relates to a sensitization degree detection method, system and program product. The method is applied to a controller of a sensitization degree detection system; the system further comprises an excitation module and a magnetic field sensor; the excitation module comprises a plurality of excitation coils, and the magnetic fields generated by the excitation coils are coherent and offset at the installation position of the magnetic field sensor; the method comprises the following steps: instructing the excitation module to generate an alternating magnetic field with a preset frequency; the alternating magnetic field is used for exciting the sensitization phase of a to-be-detected sample to generate an induced magnetic field; a target voltage waveform of the to-be-detected sample is acquired; the target voltage waveform is measured by the magnetic field sensor and is used for representing the distortion of the induced magnetic field of the to-be-detected sample due to the alternating magnetic field; and the sensitization degree of the to-be-detected sample is determined based on the target voltage waveform. The application can improve the sensitization degree detection efficiency and realize nondestructive detection of the sensitization degree.

Description

Technical Field

[0001] This application relates to the field of equipment safety testing technology, and in particular to a sensitization degree testing method, system, and program product. Background Technology

[0002] Austenitic stainless steels (such as S31608 and S30408) are widely used in critical equipment such as catalytic cracking units, hydrogenation reactors, heat exchangers, and storage tanks due to their excellent corrosion resistance and high-temperature performance. However, these materials are prone to sensitization during service or heat treatment at temperatures ranging from 500℃ to 900℃, where chromium-rich carbides (such as Cr12C6) precipitate at grain boundaries, leading to chromium depletion at grain boundaries and reduced resistance to intergranular corrosion. Sensitization not only significantly weakens the material's corrosion resistance but may also reduce toughness and strength, and even trigger failures such as stress corrosion cracking and intergranular corrosion, seriously threatening the safe operation of the equipment.

[0003] Currently, the main methods for detecting the degree of sensitization of austenitic stainless steel include chemical corrosion method, dual-loop electrochemical potentiodynamic reactivation method, and metallographic microscopy analysis.

[0004] However, the aforementioned traditional sensitization detection methods often fail to provide rapid, quantitative, and real-time on-site assessments, thus affecting the efficiency of equipment safety testing. Summary of the Invention

[0005] Therefore, it is necessary to provide a sensitization degree detection method, system, and program product that can improve the efficiency of sensitization degree detection in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a sensitization degree detection method applied to the controller of a sensitization degree detection system; the system further includes an excitation module and a magnetic field sensor; the excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled at the installation position of the magnetic field sensor; the method includes:

[0007] The excitation module generates an alternating magnetic field of a preset frequency; the alternating magnetic field is used to excite the sensitized phase of the sample to generate an induced magnetic field.

[0008] Acquire the target voltage waveform for the sample under test; the target voltage waveform is obtained by measuring through a magnetic field sensor and is used to represent the induced magnetic field distortion of the sample under test due to the alternating magnetic field;

[0009] The degree of sensitization of the sample under test is determined based on the target voltage waveform.

[0010] In one embodiment, determining the degree of sensitization of the sample to be tested based on the target voltage waveform includes:

[0011] Based on the target voltage waveform, the target spectrum is obtained;

[0012] The degree of sensitization of the sample to be tested is determined based on the target spectrum.

[0013] In one embodiment, determining the sensitization level of the sample to be tested based on the target spectrum includes:

[0014] If the target spectrum contains only a single fundamental wave, it is determined that the sample under test has not been sensitized.

[0015] If the target spectrum contains the fundamental frequency and harmonic components, the degree of sensitization of the sample to be tested is determined based on the amplitude and phase information of each harmonic component.

[0016] In one embodiment, the degree of sensitization of the sample under test is determined based on the amplitude and phase information of each harmonic component, including:

[0017] Based on the amplitude and phase information, the harmonic distortion rate and phase difference parameter are obtained; among them, the harmonic distortion rate is used to characterize the normalized distortion degree of the odd harmonic amplitude relative to the fundamental wave; the phase difference parameter is used to characterize the deviation of the phase of each harmonic component from the linear harmonic relationship of the fundamental wave.

[0018] Based on the harmonic distortion rate and phase difference parameters, a multidimensional feature vector is obtained;

[0019] The degree of sensitization of the sample to be tested is determined based on the multidimensional feature vector.

[0020] In one embodiment, the harmonic components include the 3rd harmonic, the 5th harmonic, and the 7th harmonic.

[0021] In one embodiment, the method further includes:

[0022] If in the first detection mode, a first frequency adjustment command is sent to the excitation module;

[0023] If in the second detection mode, a second frequency adjustment command is sent to the excitation module;

[0024] If in the third detection mode, a third frequency adjustment command is sent to the excitation module;

[0025] The detection depths corresponding to the first detection mode, the second detection mode, and the third detection mode increase sequentially; the target adjustment frequencies corresponding to the first frequency adjustment command, the second frequency adjustment command, and the third frequency adjustment command decrease sequentially.

[0026] Secondly, this application provides a sensitization degree detection system, which includes a controller, an excitation module, and a magnetic field sensor;

[0027] The excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled out at the installation position of the magnetic field sensor.

[0028] The controller is used to implement the steps of the method in any of the first aspects.

[0029] In one embodiment, the plurality of excitation coils include a main excitation coil and a compensating excitation coil;

[0030] The main magnetic field generated by the main excitation coil and the compensation magnetic field generated by the compensation excitation coil are coherently canceled out at the installation position of the magnetic field sensor.

[0031] In one embodiment, the magnetic field sensor includes a GMR sensor.

[0032] Thirdly, this application provides a computer program product, including a computer program, wherein when the computer program is executed by a processor, it implements the steps of the method in any of the second aspects.

[0033] The aforementioned sensitization degree detection method, system, and program product include a system comprising a controller, an excitation module, and a magnetic field sensor. The excitation module comprises multiple excitation coils, and the magnetic fields generated by each excitation coil coherently cancel each other out at the installation position of the magnetic field sensor. The method can instruct the excitation module of the system to generate an alternating magnetic field of a preset frequency to excite the sensitized phase of the sample to generate an induced magnetic field. Then, the target voltage waveform for the sample is acquired through the magnetic field sensor, and the sensitization degree of the sample is determined based on the target voltage waveform. Through the above method, this application can significantly improve the detection efficiency of sensitization degree. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a diagram illustrating the application environment of a sensitization level detection method in one embodiment;

[0036] Figure 2 This is a flowchart illustrating a sensitization level detection method in one embodiment;

[0037] Figure 3 This is a schematic diagram of the first process for determining the degree of sensitization of a sample in one embodiment;

[0038] Figure 4 This is a schematic diagram of the second process for determining the sensitization level of a sample in one embodiment;

[0039] Figure 5This is a schematic diagram of the third step in determining the sensitization level of a sample in one embodiment;

[0040] Figure 6 This is a flowchart illustrating the process of adjusting the excitation frequency according to the detection mode in one embodiment;

[0041] Figure 7 This is a structural block diagram of a sensitization level detection device in one embodiment;

[0042] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0044] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0045] Austenitic stainless steels (such as S31608 and S30408) are widely used in critical equipment such as catalytic cracking units, hydrogenation reactors, heat exchangers, and storage tanks due to their excellent corrosion resistance and high-temperature performance. However, these materials are prone to sensitization during service or heat treatment at temperatures between 500℃ and 900℃, where chromium-rich carbides (such as Cr12C6) precipitate at grain boundaries, leading to chromium depletion at grain boundaries and reduced resistance to intergranular corrosion. This sensitization phenomenon not only significantly weakens the corrosion resistance of austenitic stainless steel but may also reduce its toughness and strength, and even trigger failure accidents such as stress corrosion cracking and intergranular corrosion, seriously threatening the operational safety of the equipment.

[0046] Currently, existing technical methods for assessing the degree of sensitization of austenitic stainless steel mainly include: standard corrosion testing, metallographic methods, electrochemical potentiodynamic reactivation (EPR), and traditional magnetic methods. However, these traditional methods still have the following technical problems:

[0047] (1) Problems with traditional magnetic methods (e.g., handheld ferrite detectors): ① Limitations of static permeability measurement (incompatible principle): Traditional ferrite detectors are based on constant magnetic fields or low-frequency permeability measurement. However, the volume percentage of ferromagnetic phases generated by sensitization (such as the chromium-depleted region magnetism associated with chromium-rich carbides) is extremely low and its distribution is diffuse. Traditional equipment measures the "bulk permeability" of the material, and its weak signal changes are easily masked by the material's shape effect, surface roughness, and environmental background magnetic field, making it impossible to extract the characteristics of trace sensitized phases. ② Traditional magnetic methods lack nonlinear feature analysis capabilities (poor recognition): The "processing-induced martensite" generated during the processing of austenitic stainless steel also has magnetism, and traditional permeability measurement methods cannot distinguish between "processing magnetism" and "thermally sensitized magnetism". Traditional ferrite detectors can only output a comprehensive magnetic value (FN or %), lacking the ability to dynamically analyze nonlinear features such as high-order harmonics in the magnetic response signal, resulting in a high false alarm rate. ③ Insufficient sensitivity of traditional magnetic methods for signal extraction: Ferrite analyzers are typically designed for ferrite content of 1%-10% or higher. For trace amounts of precipitation in the early stages of sensitization (far below 0.1%), the signal-to-noise ratio of the sensor probe is insufficient, making it difficult to separate extremely weak induced magnetic field fluctuations from the strong excitation background signal. ④ Inadequate calibration system of traditional magnetic methods: Traditional ferrite analyzers are calibrated using standard plates with known ferrite content, while sensitization detection requires establishing a quantitative correspondence between magnetic adsorption force and electrochemical sensitization (such as DOS value), which existing calibration systems cannot meet.

[0048] (2) Problems with Electrochemical Potentiodynamic Reactivation (EPR) devices: ① EPR devices are not completely non-destructive: The detection process requires the use of corrosive electrolytes, which can cause slight erosion to the sample surface, making it a micro-destructive or destructive test, and cannot fully meet the requirements of truly non-destructive testing. ② Poor on-site adaptability and complex operation: EPR devices (such as electrochemical workstations, electrolytic cells, etc.) are bulky and difficult to carry to complex industrial sites for in-situ testing. At the same time, professional personnel are required to perform fine surface treatment (such as polishing) and complex electrochemical parameter settings, making the operation process cumbersome and time-consuming. ③ High cost of EPR devices: Electrochemical workstation equipment is expensive, and electrolytes are consumables, resulting in high purchase and maintenance costs, which is not conducive to the promotion and application of EPR devices in grassroots or on-site testing institutions.

[0049] (3) Problems with destructive benchmark methods (e.g., standard corrosion tests and metallographic methods): ① Destructive benchmark methods require destructive sampling: Standard corrosion tests and metallographic methods fundamentally require cutting samples from the components or equipment being tested, which is a destructive test. For critical equipment in service, such destructive sampling is unacceptable. ② Destructive benchmark methods have long testing cycles: Corrosion tests usually require long processing times of several hours to several days (e.g., 24-120 hours); metallographic analysis requires a complex sample preparation process, which is difficult to meet the needs of rapid on-site testing. ③ Destructive benchmark methods can only perform offline sampling inspections: These methods cannot achieve in-situ, continuous, and real-time monitoring of in-service equipment. ④ Destructive benchmark methods have high skill requirements for operators: Especially metallographic methods, which have extremely high requirements for sample preparation quality and observer experience. The evaluation results are highly subjective, affecting the objectivity and repeatability of the test.

[0050] To address the aforementioned issues, this application provides a sensitization degree detection method, which offers a new approach for non-destructive evaluation of the sensitization degree of austenitic stainless steel.

[0051] The sensitization degree detection method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, the sensitization level detection system 10 includes a controller 102, an excitation module 104, and a magnetic field sensor 106; the excitation module 104 includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled at the installation position of the magnetic field sensor 106.

[0052] For example, the magnetic field sensor 106 may be disposed at the center of the probe of a detection device on which the sensitization level detection system 10 is installed. Optionally, the magnetic field sensor 106 may include a GMR (Giant Magneto-Resistance) sensor.

[0053] In some examples, the excitation module 104 may include a main excitation coil and a set of counter-wound compensating excitation coils. Specifically, the compensating excitation coils may be arranged coaxially with or adjacent to the main excitation coil. Furthermore, the two sets of coils are precisely arranged in space so that the main magnetic field generated by the main excitation coil and the compensating magnetic field generated by the compensating excitation coil coherently cancel each other out at the location where the magnetic field sensor 106 is originally placed at the center of the device probe. This differential cancellation structure design, which generates a "physical zero field," allows the magnetic field sensor 106 to remain in a "silent" equilibrium state when it is not in contact with the sensitized phase of the test sample 20. Only when a slight change in the internal magnetism of the test sample 20 disrupts this equilibrium will the magnetic field sensor 106 respond, thereby improving the detection device's ability to capture trace amounts (below 0.05%) of the sensitized phase.

[0054] In one exemplary embodiment, such as Figure 2 As shown, a method for detecting the degree of sensitization is provided, which is then applied to... Figure 1 Taking controller 102 as an example, the explanation includes the following steps S202 to S206. Wherein:

[0055] Step S202: Instruct the excitation module 104 to generate an alternating magnetic field of a preset frequency.

[0056] The alternating magnetic field can be used to excite the sensitized phase of the sample 20 to generate an induced magnetic field.

[0057] For example, the sample to be tested 20 may include an austenitic material sample to be tested. For instance, the sample to be tested 20 may be an austenitic-Federium duplex stainless steel or an austenitic stainless steel weld joint and weld overlay, etc.

[0058] In some examples, an alternating current of a specific frequency can be supplied to the electromagnetic coil via a drive circuit, enabling the excitation module 104 to generate an alternating magnetic field of the same frequency around the excitation coil according to Ampere's law. Furthermore, the excitation coil in the excitation module 104 can utilize a magnetic core to converge and guide magnetic lines of force to the probe pole piece on which the magnetic field sensor 106 is mounted. The magnetic field strength H is proportional to the product of the number of turns N of the excitation coil and the current I, i.e., H∝NI. Due to the constant current drive, the waveform of the excitation magnetic field generated by the excitation module 104 is a perfect simple harmonic wave. This excitation magnetic field can penetrate the surface of the material under test, thereby exciting a magnetization response within the material of the sample 20.

[0059] Specifically, the controller 102 of the sensitization degree detection system 10 can instruct the excitation module 104 to generate an alternating magnetic field of a preset frequency to excite the sensitized phase of the sample 20 to generate an induced magnetic field.

[0060] It should be noted that the interaction mechanism between the alternating magnetic field and the microstructure of the sample 20 is as follows:

[0061] ① Unsensitized state (reference state): For qualified austenitic stainless steel workpieces, the matrix structure is paramagnetic austenite. When an alternating magnetic field penetrates this matrix, almost no induced magnetic moment is generated inside the material, and the magnetic circuit remains linear. At this time, the differential cancellation structure formed by the excitation module 104 at the probe position takes effect, and the magnetic signal waveform fed back from the sample 20 to the magnetic field sensor 106 remains a very weak pure sine wave with no obvious phase shift or waveform distortion.

[0062] ② Sensitized State (Distorted State): When austenitic materials become sensitized due to service or welding heat, chromium-rich carbides precipitate at the grain boundaries, accompanied by chromium-depleted regions. These regions undergo magnetic transformation, producing extremely fine ferromagnetic particles (such as σ phases or magnetic carbides). Under the excitation of an alternating magnetic field, these particles repeatedly magnetize and demagnetize along the direction of the excitation magnetic field. Because the ferromagnetic phase has a nonlinear magnetization curve (i.e., the B-H curve), their feedback to the magnetic field is no longer a simple proportional relationship, but rather produces a magnetization jump similar to "hysteresis" when the magnetic field reverses. This microscopic nonlinear magnetization response superimposes a "distorted signal" onto the macroscopic induced magnetic field. Furthermore, from the perspective of the magnetic signal waveform, the originally smooth sine wave will exhibit a small "shoulder" or a smoothed-out top. Mathematically, these waveform distortions are represented by the introduction of high-order frequency components into the fundamental signal. The differential cancellation structure formed by the excitation module 104 can eliminate the strong fundamental background, so that the waveform distortion features caused by the sensitization phase can be displayed with extremely high contrast, thus providing the most original and authentic data source for subsequent signal processing.

[0063] Step S204: Obtain the target voltage waveform for the sample 20 to be tested.

[0064] The target voltage waveform is measured by the magnetic field sensor 106 and is used to represent the induced magnetic field distortion of the sample 20 under test due to the alternating magnetic field.

[0065] Specifically, the user can place the probe containing the magnetic field sensor 106 close to the sample 20 to be tested, and then the controller 102 can obtain the target voltage waveform corresponding to the sample 20 to be tested through the magnetic field sensor 106.

[0066] For example, when the probe containing the magnetic field sensor 106 is in close contact with the surface of unsensitized standard austenitic stainless steel, the vector fields generated by the excitation module 104 cancel each other out at the spatial location of the magnetic field sensor 106 due to the effect of the differential cancellation structure. Taking the magnetic field sensor 106 as a GMR sensor as an example, the magnetoresistive bridge inside the GMR sensor will be in a near-equilibrium state at this time, and the output voltage of the magnetic field sensor 106 will be close to zero. It can be understood that the above-mentioned magnetic field balance and silent monitoring mechanism design can give the detection device an extremely low detection background value (similar to listening to a faint sound in the dead of night). Within the magnetic field balance region constructed by the excitation module 104 through the differential cancellation structure, any tiny fluctuation in permeability caused by changes in the internal structure of the material will break this magnetic field balance, thereby achieving extremely high detection sensitivity.

[0067] In some examples, when the probe containing the magnetic field sensor 106 approaches a region where sensitization occurs, the ferromagnetic characteristics of chromium carbides, σ phases, or locally chromium-depleted regions precipitated at grain boundaries cause these magnetic particles to be repeatedly magnetized under the influence of an alternating magnetic field. The magnetic dipoles corresponding to these tiny magnetic particles generate a localized, time-varying induced magnetic field. Taking the magnetic field sensor 106 as a GMR sensor as an example, this induced magnetic field acts like a weak fluctuation superimposed on the background field. This fluctuation can penetrate the sensitive layer of the GMR sensor, causing a change in the spin scattering state between the nanomagnetic layers inside the GMR sensor. Even if the volume percentage of the sensitized phase in the sample 20 is extremely low (e.g., less than 0.1%), its binding and twisting effect on the magnetic field lines will form a feedback magnetic field characteristic sufficient to be detected by the GMR sensor. Furthermore, after the GMR sensor captures the aforementioned feedback magnetic field, its resistance value will fluctuate synchronously and at a high frequency with the instantaneous intensity of the feedback magnetic field. By using a preset constant bias current, the resistance change of the GMR sensor is instantly converted into voltage fluctuations. After differential amplification and filtering, these voltage fluctuations are finally output as a continuously changing analog voltage waveform, which is the target voltage waveform.

[0068] Step S204: Determine the degree of sensitization of the sample 20 to be tested based on the target voltage waveform.

[0069] Understandably, the target voltage waveform output by the magnetic field sensor 106 contains not only amplitude information reflecting the amount of sensitized phase, but also phase information reflecting the magnetization hysteresis characteristics. That is, the target voltage waveform acts like a magnetic fingerprint of the material in the sample 20, accurately and objectively recording the dynamic magnetic properties of the sensitized particles within the austenitic stainless steel, thus serving as a key physical criterion for quantitatively assessing the degree of sensitization in the sample 20.

[0070] Specifically, the controller 102 can accurately determine the degree of sensitization of the sample 20 to be tested based on the target voltage waveform output by the magnetic field sensor 106.

[0071] The above-described sensitization degree detection method can instruct the excitation module 104 of the system to generate an alternating magnetic field of a preset frequency to excite the sensitized phase of the sample 20 to generate an induced magnetic field. Then, the magnetic field sensor 106 acquires the target voltage waveform for the sample 20. Based on the target voltage waveform, the sensitization degree of the sample 20 is determined. In this way, the present application can achieve true non-destructive and non-contact detection, thereby significantly improving the detection efficiency of sensitization degree while ensuring the integrity of the component and service safety.

[0072] In one embodiment, such as Figure 3As shown, based on the target voltage waveform, the sensitization degree of the sample 20 to be tested is determined, including the following steps S302 to S304. Wherein:

[0073] Step S302: Based on the target voltage waveform, obtain the target spectrum.

[0074] Step S304: Determine the degree of sensitization of the sample 20 to be tested based on the target spectrum.

[0075] For example, the target voltage waveform in the time domain can be decomposed into the target spectrum using the Fast Fourier Transform (FFT).

[0076] In some possible implementations, after the target voltage waveform is output by the magnetic field sensor 106, the controller 102 can perform high-order digital filtering on the target voltage waveform to remove random noise. Furthermore, to ensure the accuracy of subsequent phase analysis, coherent sampling technology (i.e., the sampling clock is strictly synchronized with the excitation signal) can also be used to process the target voltage waveform.

[0077] Specifically, the controller 102 can analyze the target voltage waveform in the time domain into a target spectrum in the frequency domain, and then determine the degree of sensitization of the sample 20 to be tested based on the amplitude characteristics and / or phase characteristics of the fundamental wave and each harmonic of the target spectrum.

[0078] In one embodiment, such as Figure 4 As shown, the degree of sensitization of the sample 20 to be tested is determined based on the target spectrum, including the following steps S402 to S404. Wherein:

[0079] In step S402, if the target spectrum contains only a single fundamental wave, it is determined that the sample 20 to be tested has not been sensitized.

[0080] Step S404: If the target spectrum contains the fundamental wave and each harmonic component, the degree of sensitization of the sample 20 to be tested is determined based on the amplitude and phase information of each harmonic component.

[0081] It is understandable that the target spectrum extracts not only the amplitudes of the fundamental frequency and each harmonic, but also... It also simultaneously extracted the phase angle of each frequency component. In practical applications, if the material of the test sample 20 is not sensitized at all, the target spectrum will show a single fundamental frequency; if the material of the test sample 20 shows sensitization characteristics, the target spectrum will show significant characteristic peaks at 3f, 5f, and 7f (f is the fundamental frequency). These higher harmonics are caused by the "nonlinear magnetization response" generated by the ferromagnetic particles (chromium-depleted regions / carbides) precipitated inside the material under an alternating magnetic field.

[0082] Specifically, if the target spectrum contains only a single fundamental wave, the controller 102 can determine that the current sample 20 under test has not been sensitized. However, if the target spectrum contains the fundamental wave and each harmonic component, it indicates that the current sample 20 under test has been sensitized. The controller 102 can further determine the specific degree of sensitization of the sample 20 under test based on the amplitude and phase information of each harmonic component of the target spectrum.

[0083] In one embodiment, such as Figure 5 As shown, the degree of sensitization of the sample 20 under test is determined based on the amplitude and phase information of each harmonic component, including the following steps S502 to S506. Wherein:

[0084] Step S502: Based on the amplitude information and phase information, the harmonic distortion rate and phase difference parameters are obtained.

[0085] Step S504: Based on the harmonic distortion rate and phase difference parameters, obtain the multidimensional feature vector.

[0086] Step S506: Determine the degree of sensitization of the sample 20 to be tested based on the multidimensional feature vector.

[0087] Among them, the harmonic distortion rate can be used to characterize the normalized distortion degree of the odd harmonic amplitude relative to the fundamental wave; the phase difference parameter can be used to characterize the deviation of the phase of each harmonic component from the linear harmonic relationship of the fundamental wave.

[0088] Specifically, the controller 102 can calculate the harmonic distortion rate and phase difference parameters based on the amplitude and phase information of each harmonic component. Then, based on the harmonic distortion rate and phase difference parameters, it can further calculate the multidimensional feature vector. Finally, based on the multidimensional feature vector, it can determine the degree of sensitization of the sample 20 to be tested.

[0089] For example, the harmonic distortion rate is used to represent amplitude-type features. It does not calculate full-band distortion, but rather specifically calculates the normalized distortion of odd-order harmonic amplitudes relative to the fundamental frequency. In some examples, the harmonic distortion rate can be calculated based on the amplitude information of each harmonic component according to Formula 1 below:

[0090] (Formula 1)

[0091] in, The fundamental amplitude, These represent the amplitudes of the 3rd, 5th, and 7th harmonics, respectively. It should be noted that this harmonic distortion rate index can effectively filter out overall signal fluctuations caused by probe jitter.

[0092] Furthermore, the phase difference parameter is used to represent phase-related characteristics. It can be understood that due to the hysteresis phenomenon in the magnetization of the ferromagnetic phase, the higher harmonics of the induced signal will have a specific phase delay relative to the fundamental wave. Therefore, based on the deviation of each harmonic phase from the linear harmonic relationship of the fundamental wave, the phase difference parameter can be obtained. Taking the 3rd harmonic as an example, its corresponding phase difference parameter is shown in Formula 2 below:

[0093] (Formula 2)

[0094] in, The phase difference of the third harmonic. and These represent the absolute phases of the third harmonic and the fundamental frequency, extracted via FFT. Based on the harmonic distortion rate and phase difference parameters calculated above, a multidimensional feature vector required for model judgment can be constructed.

[0095] In some examples, the constructed multidimensional feature vector can be input into a sensitization degree judgment model based on a regression algorithm and pre-fitted from a large amount of measured data. For example, the sensitization degree judgment model can be obtained based on the following construction process: Select austenitic stainless steel standard samples of different grades (such as 304, 316L, etc.) and different sensitization degrees. First, measure the precise intergranular corrosion susceptibility (DOS value) of these samples through the standard electrochemical potential reactivation (EPR) experiment as the "EPR-DOS true value". Then, use the magnetic field sensor 106 of the sensitization degree detection system 10 described in this application to collect the magnetic response feature vector of the corresponding sample. Then, by mathematically fitting the above "magnetic response feature vector" and "EPR-DOS true value", a high-precision mapping database between the two is established. Based on this high-precision mapping database, the sensitization degree judgment model is constructed.

[0096] In practical applications, when using the sensitization degree detection system 10 for online detection, the controller 102 can input the multi-dimensional feature vector calculated in real time into the aforementioned sensitization degree judgment model to obtain the equivalent electrochemical reactivation rate (DOS%). Furthermore, this model not only includes a single linear relationship but also incorporates frequency parameters as correction factors.

[0097] In some possible implementations, based on the skin effect principle, the sensitization degree judgment model can also calculate the probe depth weight according to the current excitation frequency, and use the probe depth weight to correct the calculation results for the depth dimension.

[0098] In one embodiment, the harmonic components include the 3rd harmonic, the 5th harmonic, and the 7th harmonic.

[0099] Specifically, the controller 102 can determine the sensitization level of the current sample 20 to be tested based on the amplitude and phase information of the 3rd, 5th and 7th harmonics.

[0100] In one embodiment, such as Figure 6 As shown, the method further includes steps S602 to S606. Wherein:

[0101] Step S602: If the system is in the first detection mode, a first frequency adjustment command is sent to the excitation module 104.

[0102] Step S604: If the second detection mode is in effect, a second frequency adjustment command is sent to the excitation module 104.

[0103] In step S606, if the third detection mode is in progress, a third frequency adjustment command is sent to the excitation module 104.

[0104] The detection depths corresponding to the first detection mode, the second detection mode, and the third detection mode increase sequentially; the target adjustment frequencies corresponding to the first frequency adjustment command, the second frequency adjustment command, and the third frequency adjustment command decrease sequentially.

[0105] It should be noted that the effective penetration depth of electromagnetic waves in a conductor With excitation frequency It is inversely proportional to the square root, and the calculation process is shown in Formula 3 below:

[0106] (Formula 3)

[0107] in, For penetration depth, Pi For the excitation frequency, The material's magnetic permeability, The electrical conductivity of the material.

[0108] For example, the controller 102 can adjust the output frequency of the excitation module 104 in real time according to actual detection requirements via commands. This allows for the processing of austenitic stainless steel (with an electrical conductivity of approximately...) Layered and graded detection from the surface to the core.

[0109] For example, the first detection mode can be a high-resolution surface detection mode, targeting detection scenarios with a depth of 0.5mm-2mm. In the first detection mode, the controller 102 sends a first frequency adjustment command to increase the excitation frequency f to 1000Hz-5000Hz. In this high-frequency range, the electromagnetic field will produce a significant skin effect, causing the induced magnetic field to be highly concentrated on the material surface. Utilizing the first detection mode can effectively suppress stray interference from the deep substrate, greatly improving the detection sensitivity for trace precipitates and fine chromium-depleted areas on the weld surface, heat-affected zone surface, and other areas.

[0110] Furthermore, the second detection mode can be a conventional wall thickness coverage detection mode, targeting detection scenarios with a depth of 2mm-10mm. In the second detection mode, the controller 102 sends a second frequency adjustment command to adjust the excitation frequency f to 100Hz-1000Hz. Within this mid-frequency range, the magnetic field penetration capability and signal induction intensity can be effectively balanced, allowing magnetic lines of force to uniformly penetrate stainless steel plates of commonly used industrial thicknesses, thereby achieving a comprehensive assessment of the sensitization degree of the entire material cross-section.

[0111] Furthermore, the third detection mode can be a large wall thickness and inner wall penetration detection mode, targeting detection scenarios with depths exceeding 10mm. In the third detection mode, the controller 102 sends a third frequency adjustment command to adjust the excitation frequency f to 10Hz-100Hz. It can be understood that by utilizing the extremely strong penetrating characteristics of low-frequency magnetic fields, it is possible to ensure that the magnetic field energy can reach the back or inner wall region of the workpiece, thereby capturing the magnetic response distortion signal inside the thick-walled structure.

[0112] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0113] In one exemplary embodiment, such as Figure 1As shown, this application provides a sensitization degree detection system, which includes a controller, an excitation module, and a magnetic field sensor; the excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled at the installation position of the magnetic field sensor; the controller is used to implement the steps of the method described in any one of the above method embodiments.

[0114] For example, the controller may include a high-performance central processing unit. The high-performance central processing unit may be a 32-bit embedded microprocessor (MCU) with a hardware floating-point unit (FPU) and a digital signal processing (DSP) instruction set.

[0115] It is understood that the solution to the problem provided in this application is similar to the solution from the perspective of the sensitization degree detection method described above. Therefore, the specific limitations of the embodiments of this application and one or more sensitization degree detection system embodiments provided below can be found in the limitations of the sensitization degree detection method embodiments above, and will not be repeated here.

[0116] In one embodiment, the plurality of excitation coils include a main excitation coil and a compensating excitation coil; the main magnetic field generated by the main excitation coil and the compensating magnetic field generated by the compensating excitation coil coherently cancel each other out at the installation position of the magnetic field sensor.

[0117] In one embodiment, the magnetic field sensor includes a GMR sensor.

[0118] It is understandable that high-sensitivity giant magneto-resistance (GMR) sensors have excellent magnetic field resolution and can directly capture the extremely weak induced magnetic field distortion signal caused by trace amounts of sensitized precipitates in austenitic stainless steel under the excitation of an alternating magnetic field at a specific frequency.

[0119] Based on the same inventive concept, this application also provides a sensitization degree detection device for implementing the sensitization degree detection method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the sensitization degree detection device provided below can be found in the limitations of the sensitization degree detection method described above, and will not be repeated here.

[0120] In one exemplary embodiment, such as Figure 7As shown, this application provides a sensitization degree detection device 700, which is used as a controller in a sensitization degree detection system; the system also includes an excitation module and a magnetic field sensor; the excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled at the installation position of the magnetic field sensor; the device 700 includes:

[0121] The magnetic field excitation unit 702 is used to instruct the excitation module to generate an alternating magnetic field of a preset frequency; the alternating magnetic field is used to excite the sensitized phase of the sample to be tested to generate an induced magnetic field.

[0122] The waveform acquisition unit 704 is used to acquire the target voltage waveform for the sample under test; the target voltage waveform is obtained by measuring the magnetic field sensor and is used to represent the induced magnetic field distortion of the sample under test due to the alternating magnetic field.

[0123] The sensitization detection unit 706 is used to determine the degree of sensitization of the sample to be tested based on the target voltage waveform.

[0124] In one embodiment, the sensitization detection unit 706 is further configured to obtain a target spectrum based on a target voltage waveform; and determine the degree of sensitization of the sample to be tested based on the target spectrum.

[0125] In one embodiment, the sensitization detection unit 706 is further configured to determine that the sample to be tested is not sensitized if the target spectrum contains only a single fundamental wave; and to determine the degree of sensitization of the sample to be tested based on the amplitude and phase information of each harmonic component if the target spectrum contains the fundamental wave and each harmonic component.

[0126] In one embodiment, the sensitization detection unit 706 is further configured to obtain harmonic distortion rate and phase difference parameter based on amplitude information and phase information; wherein, the harmonic distortion rate is used to characterize the normalized distortion degree of odd harmonic amplitude relative to the fundamental wave; the phase difference parameter is used to characterize the deviation of the phase of each harmonic component from the linear harmonic relationship of the fundamental wave; a multidimensional feature vector is obtained based on the harmonic distortion rate and phase difference parameter; and the sensitization degree of the sample to be tested is determined based on the multidimensional feature vector.

[0127] In one embodiment, the harmonic components include the 3rd harmonic, the 5th harmonic, and the 7th harmonic.

[0128] In one embodiment, the device 700 further includes: a frequency adjustment unit, configured to send a first frequency adjustment command to the excitation module if it is in a first detection mode; send a second frequency adjustment command to the excitation module if it is in a second detection mode; and send a third frequency adjustment command to the excitation module if it is in a third detection mode; wherein the detection depths corresponding to the first detection mode, the second detection mode, and the third detection mode increase sequentially; and the target adjustment frequencies corresponding to the first frequency adjustment command, the second frequency adjustment command, and the third frequency adjustment command decrease sequentially.

[0129] Each module in the aforementioned sensitization level detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0130] In one exemplary embodiment, this application provides a sensitization detection device, which may include four functional modules: a programmable alternating excitation module, a magnetic response signal pickup module, a signal processing and conversion module, and a comprehensive control and display module.

[0131] In one embodiment, the programmable alternating excitation module is the magnetic field source of the device, which induces the sensitized phase in the austenitic stainless steel sample to generate a dynamic magnetic response signal by generating a controlled alternating magnetic field (AC).

[0132] For example, the programmable alternating excitation module includes a waveform generation unit, a precision drive circuit, an excitation coil, and a magnetic core assembly.

[0133] Specifically, the waveform generation unit is integrated on the main circuit board of the handheld terminal, and its core is a microprocessor based on Direct Digital Synthesis (DDS) technology. The waveform generation unit can output a continuously adjustable sinusoidal AC signal with a frequency ranging from 10Hz to 5000Hz via a high-precision digital-to-analog converter (DAC) according to a preset detection mode. Its frequency adjustment step can reach 0.1Hz, and the total harmonic distortion (THD) of the waveform is controlled below 0.05%, ensuring extremely high purity of the original signal source and avoiding misjudgments caused by poor signal source quality.

[0134] Furthermore, a precision drive circuit can be positioned between the waveform generation unit and the external probe of the device. This precision drive circuit can employ a high-performance power amplifier array and a constant current negative feedback loop. Its function is to convert the weak voltage waveform into a constant alternating current capable of driving the inductive load. It should be noted that, to address coil resistance fluctuations caused by changes in ambient temperature, this precision drive circuit can automatically adjust the output voltage, thereby ensuring that the peak excitation current in the excitation coil (typically set between 0.1A and 1.5A) remains constant. This constant current characteristic of the aforementioned precision drive circuit ensures that the magnetic field strength H does not drift with time and temperature throughout the sensitization detection process, laying the physical foundation for quantitative analysis.

[0135] Furthermore, the excitation coil can be wound with high-purity oxygen-free copper wire, with the total number of turns set between 500 and 1500 turns depending on the detection requirements. The center of the excitation coil can be nested with a soft magnetic core (such as manganese-zinc ferrite or permalloy), which can be designed in a U-shape or can shape, with its open end facing the sample being tested. This closed magnetic circuit design allows for highly concentrated and vertically guided magnetic lines of force onto the sample surface, thereby maximizing induction efficiency.

[0136] In some examples, a set of counter-wound compensation coils is placed coaxially with or adjacent to the main excitation coil. These two sets of coils are precisely positioned in space so that the main magnetic field and the compensation magnetic field coherently cancel each other out at the location where the GMR sensor would normally be placed in the center of the probe. This "physical zero-field" design ensures that the GMR sensor remains in a "silent" equilibrium state when not in contact with the sensitized phase. The sensor only responds when a minute change in the sample's internal magnetism disrupts this equilibrium, significantly enhancing the device's ability to capture trace amounts (below 0.05%) of the sensitized phase.

[0137] In one embodiment, the magnetic response signal pickup module is used to accurately capture extremely weak magnetic field disturbances caused by the sensitized phase inside the material from a complex magnetic field environment and convert them into high-quality electrical signals that can be processed by subsequent circuits without loss.

[0138] For example, the magnetic response signal pickup module may include a highly sensitive GMR sensor and an embedded pre-signal conditioning circuit.

[0139] Specifically, GMR sensors are manufactured based on the giant magnetoresistance effect of nanoscale multilayer film structures, typically integrating magnetoresistors internally. To achieve maximum detection efficiency, the GMR sensor is mounted using a precision mounting process at the geometric center of the probe's physical structure, i.e., the "zero equilibrium point" of the excitation magnetic field. This positioning design ensures that the sensor has an extremely high common-mode rejection ratio for the excitation main magnetic field perpendicular to the surface, enabling it to sensitively detect changes in the horizontal component caused by the deflection of magnetic field lines due to material sensitization. Compared to traditional induction coils, this micron-scale solid-state sensor maintains consistently high sensitivity even at extremely low frequencies.

[0140] Furthermore, the embedded pre-amplifier signal conditioning circuit can be placed close to the back of the GMR sensor, with the lead distance between them controlled at the millimeter level to minimize the interference of spatial electromagnetic coupling noise and trace inductance on weak signals.

[0141] In some possible implementations, the embedded preamplifier signal conditioning circuit can consist of an ultra-low noise differential amplifier, a multi-stage active bandpass filter, and an impedance matching unit. The core function of this conditioning circuit is to capture the microvolt level of the sensor output. The electrical transition is linearly amplified to the millivolt (mV) or even volt (V) level. Furthermore, to ensure signal purity, the circuit board of this embedded pre-amplifier signal conditioning circuit can adopt a multi-layer shielded structure and be equipped with an independent precision regulated power supply, thereby effectively filtering out common industrial frequency interference and high-frequency radio frequency noise, providing a high signal-to-noise ratio analog waveform for subsequent digital processing.

[0142] In one embodiment, the signal processing and conversion module is used to receive the raw analog voltage signal output from the GMR sensor and use high-performance computing algorithms to perform in-depth analysis and mathematical conversion on it, restoring the originally unintuitive waveform distortion into clear material performance indicators.

[0143] For example, the signal processing and conversion module may include a high-precision synchronous sampling unit, a high-performance central processing unit, and a storage unit.

[0144] Specifically, the high-precision synchronous sampling unit is located at the front end of the main processing board of the handheld terminal. Its core component is a 24-bit high-resolution multi-channel synchronous analog-to-digital converter (ADC). Understandably, to capture extremely weak high-order harmonic components, this synchronous sampling unit employs oversampling technology, with its sampling frequency set to 128 times or higher than the excitation signal frequency, thereby ensuring the complete reconstruction of minute details of the induced waveform in the time domain. Furthermore, the sampling process is strictly synchronized with the waveform generation unit via an internal clock. This coherent sampling design effectively eliminates phase jitter caused by frequency drift, enabling the system to identify signal increments at the nanovolt (nV) level.

[0145] Furthermore, the high-performance central processing unit can employ a 32-bit embedded microprocessor with a hardware floating-point arithmetic unit and a digital signal processing instruction set. This processor can be installed in an anti-static electromagnetic shielding box inside the handheld device and is responsible for executing complex real-time spectrum analysis algorithms. Understandably, the processor's powerful computing capabilities ensure that the system can complete Fourier transforms and statistical inferences of massive amounts of data within milliseconds, ensuring the real-time presentation of detection results.

[0146] Furthermore, the storage unit includes a feature model database, which consists of high-speed non-volatile memory and pre-loaded with a sensitization degree judgment model established through extensive comparative experiments, characterizing the correlation between magnetic response feature vectors and sensitization degree levels. In practical applications, the feature model database not only contains standard response curves for common grades of austenitic stainless steel such as 304 and 316, but can also further store compensation algorithm parameters for environmental temperature drift and sensor lift-off effects, thereby effectively reducing the interference of the field environment on detection accuracy.

[0147] In one embodiment, the integrated control and display module serves as the user terminal and function scheduling center of the device. It integrates the technical outputs of all the aforementioned equipment modules, transforming complex physical data into decision-making information easily understood by testing personnel. It is understood that the integrated control and display module is not only the window for human-machine interaction but also the logical command center for the entire testing process.

[0148] For example, the integrated control and display module may include a high-resolution interactive control unit and a main system logic coordination center.

[0149] Specifically, the high-resolution interactive control unit can be positioned at the top center of the handheld device's viewing angle. It primarily consists of a high-refresh-rate, fully laminated color liquid crystal display (LCD) and a set of industrial-grade waterproof silicone buttons. The display features an anti-glare design, ensuring clear display of detected waveforms and values ​​even in bright outdoor light. The display can integrate a dedicated graphics acceleration driver, enabling real-time dynamic rendering of magnetic response characteristic curves. The buttons are ergonomically positioned, allowing operators to perform blind operation via tactile feedback and quickly switch parameters, even while wearing protective gloves.

[0150] Furthermore, the main system logic coordination center can be an auxiliary control chipset installed on the main circuit board inside the grip. Positioned between the programmable alternating excitation module and the signal processing and conversion module, it acts as a bridge. The main system logic coordination center manages the power consumption strategy of the entire system and can automatically adjust the display brightness and excitation intensity based on the detection status. In addition, the main system logic coordination center also includes a high-precision real-time clock (RTC) and a temperature monitoring unit, used to record the precise time of each detection in real time and to perform final temperature drift correction on the displayed values ​​based on the current ambient temperature.

[0151] In practical applications, before the equipment begins measurement, the user inputs basic information about the workpiece to be measured, such as the stainless steel grade and estimated wall thickness, through the high-resolution interactive control unit. The main system logic coordination center then retrieves the corresponding feature reference curve from the feature model database based on the input information. This process pre-calibrates the complex physical background, ensuring that the subsequent measurement data has reference coordinates. This parameter preset logic effectively reduces the professional background requirements for operators, simplifying the previously unintuitive electromagnetic parameter settings into a menu-driven operation. Furthermore, after the signal processing and conversion module outputs digital features, the high-resolution interactive control unit further processes this data. This time, it not only displays a simple percentage value but also draws a dynamic feature vector diagram on the screen. For example, the equipment's LCD screen simultaneously displays a histogram comparing the amplitudes of the fundamental and higher harmonics, as well as the evolution trend of phase with frequency. This multi-dimensional presentation helps technicians intuitively judge the reliability of the detection signal. If abnormal fluctuations occur in the waveform, the system will automatically prompt "unstable coupling," effectively avoiding false detections caused by poor probe contact.

[0152] In some possible implementations, the integrated control and display module can also have a built-in strict logic discrimination program that can compare the calculated reactivation rate (DOS%) with the discrimination criteria in real time, and then display the sensitization level detection results on the display screen in three levels: "qualified", "slightly sensitized", and "severely sensitized" according to the severity of sensitization.

[0153] To further illustrate the technical solution of this application, this application provides the following exemplary detection process based on the above-mentioned sensitization degree detection device, which specifically includes steps A1 to A4:

[0154] Step A1: After the device is turned on, the programmable alternating excitation module sends out a sweep frequency calibration signal to capture the background noise of the ambient magnetic field in the air and set it as the reference zero point. This step can eliminate the interference of the ambient magnetic field on the GMR sensor, thereby ensuring the purity of the measurement results.

[0155] Step A2: The operator places the probe against the sample to be tested. The alternating magnetic field generated by the excitation module penetrates the sample. Due to the difference in magnetic properties between the austenite matrix and the sensitized precipitates, the induced magnetic field waveform is distorted. The GMR sensor detects this magnetic field disturbance caused by microstructural changes in real time and converts it into electrical characteristics.

[0156] Step A3: The acquired waveform is digitally decomposed, and the amplitude and phase information of the higher harmonics are extracted by fast Fourier transform. Then, the device determines the nonlinear deviation of the induction signal relative to the excitation signal through preset calculation logic, and constructs the corresponding multidimensional feature vector. The development state of the chromium-depleted region inside the sample material is determined by the multidimensional feature vector.

[0157] Step A4: Substitute the extracted multidimensional feature vector into the judgment model to calculate a quantitative sensitivity index. Then, using the integrated control and display module, the originally non-intuitive electromagnetic fluctuations are converted into specific percentage values ​​and safety levels, which are then displayed in real time on the display screen.

[0158] Through the above exemplary detection process, users can use the sensitization level detection device described in this application to complete the quality risk assessment of key service components with just simple visual confirmation. The whole process takes only a few seconds and does not damage the surface of the workpiece.

[0159] It should be noted that, compared with traditional sensitization level detection schemes, the technical solutions corresponding to the above embodiments of this application have at least the following beneficial technical effects:

[0160] (1) This application achieves truly non-destructive and non-contact testing, ensuring the integrity and service safety of the components under test. Specifically, the testing process of this application does not involve chemical reagents, does not require grinding of passivation films or polishing electrolysis, ensuring the structural integrity of stainless steel components, and is particularly suitable for high-pressure vessels and pipelines that are sensitive to corrosion. In addition, the equipment structure design based on this application is lightweight and portable, supporting rapid on-site point testing and online continuous monitoring of in-service equipment without the need for downtime or sampling, which greatly reduces testing costs and workpiece repair risks.

[0161] (2) Based on the GMR sensor and physical cancellation structure, this application can achieve ultra-high sensitivity and signal-to-noise ratio. Specifically, this application solves the technical problem of traditional electromagnetic detection's difficulty in capturing extremely small amounts of sensitized phase through innovation in the macroscopic detection paradigm. The high-sensitivity giant magnetoresistive sensor (i.e., GMR sensor) used in this application has a magnetic field resolution at the nanotesla (nT) level, which can accurately capture the weak magnetic field distortion caused by trace amounts of sensitized phase (content even lower than 0.05%).

[0162] (3) This application constructs a physically balanced detection zone at the sensor location through the precise layout of the differential compensation structure in the excitation module, effectively counteracting the strong background excitation magnetic field. This "physical zeroing" design ensures that the sensor can focus on weak feature signals, significantly improving the detection signal-to-noise ratio in complex industrial environments.

[0163] (3) This application, based on precise quantitative assessment of spectral characteristics, possesses extremely strong anti-interference capabilities. Specifically, the device of this application integrates advanced signal processing logic, enabling a scientific conversion from "magnetic response characteristics" to "sensitization level." This application utilizes Fast Fourier Transform to extract the 3rd and 5th harmonic components in the induced signal. Since only the ferromagnetic sensitized phase exhibits nonlinear magnetization characteristics, this method effectively eliminates linear interference such as lift-off effects and surface roughness, thereby ensuring the accuracy of the assessment results and enhancing the anti-interference capability of the detection process. Furthermore, this application can directly output quantitative sensitization indicators through a mapping model between magnetic feature vectors and electrochemical reactivation rate (DOS%) (i.e., a sensitization degree detection system). This overcomes the limitations of traditional non-destructive testing, which can only qualitatively determine the degree of damage and cannot accurately quantify it.

[0164] (4) The frequency of this application is dynamically adjustable, thereby achieving in-depth tomography and improving adaptability to different working conditions. Specifically, this application can utilize the skin effect principle of electromagnetic fields to enable the equipment to have the flexibility to detect different thicknesses and layers. In practical applications, users can adjust the working frequency (10Hz-5000Hz) according to the workpiece wall thickness to achieve targeted detection of surface sensitization or deep structures, meeting diverse needs from thin plate welds to thick-walled pressure-bearing components. This frequency-adjustable design, combined with a miniaturized handheld structure, enables the equipment to adapt to workpieces with complex geometries such as curved surfaces and corners, effectively improving the applicability of the equipment in various application scenarios.

[0165] In one exemplary embodiment, an electronic device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8 As shown, this electronic device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data such as target voltage waveforms and target spectrum. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a sensitivity detection method.

[0166] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the electronic device to which the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0167] In one embodiment, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0168] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0169] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0170] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0171] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0172] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for detecting the degree of sensitization, characterized in that, A controller for a sensitization level detection system; the system also includes an excitation module and a magnetic field sensor; the excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled out at the mounting position of the magnetic field sensor; The method includes: The excitation module is instructed to generate an alternating magnetic field of a preset frequency; the alternating magnetic field is used to excite the sensitized phase of the sample to generate an induced magnetic field. Acquire a target voltage waveform for the sample under test; the target voltage waveform is measured by the magnetic field sensor and is used to represent the induced magnetic field distortion of the sample under test due to the alternating magnetic field; The degree of sensitization of the sample under test is determined based on the target voltage waveform.

2. The method according to claim 1, characterized in that, The determination of the sensitization degree of the sample under test based on the target voltage waveform includes: Based on the target voltage waveform, the target spectrum is obtained; The degree of sensitization of the sample to be tested is determined based on the target spectrum.

3. The method according to claim 2, characterized in that, Determining the sensitization level of the sample to be tested based on the target spectrum includes: If the target spectrum contains only a single fundamental wave, then it is determined that the sample under test has not been sensitized; If the target spectrum contains a fundamental frequency and harmonic components, the degree of sensitization of the sample under test is determined based on the amplitude and phase information of the harmonic components.

4. The method according to claim 3, characterized in that, The determination of the sensitization degree of the sample under test based on the amplitude and phase information of each harmonic component includes: Based on the amplitude information and the phase information, the harmonic distortion rate and phase difference parameter are obtained; wherein, the harmonic distortion rate is used to characterize the normalized distortion degree of the odd harmonic amplitude relative to the fundamental wave; the phase difference parameter is used to characterize the deviation of the phase of each harmonic component from the linear harmonic relationship of the fundamental wave. Based on the harmonic distortion rate and the phase difference parameter, a multidimensional feature vector is obtained; The degree of sensitization of the sample to be tested is determined based on the multidimensional feature vector.

5. The method according to claim 3, characterized in that, The harmonic components include the 3rd harmonic, the 5th harmonic, and the 7th harmonic.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: If in the first detection mode, a first frequency adjustment command is sent to the excitation module; If the second detection mode is in effect, a second frequency adjustment command is sent to the excitation module. If the third detection mode is in effect, a third frequency adjustment command is sent to the excitation module. The detection depths corresponding to the first detection mode, the second detection mode, and the third detection mode increase sequentially; the target adjustment frequencies corresponding to the first frequency adjustment command, the second frequency adjustment command, and the third frequency adjustment command decrease sequentially.

7. A sensitization degree detection system, characterized in that, The system includes a controller, an excitation module, and a magnetic field sensor; The excitation module includes multiple excitation coils, and the magnetic fields generated by each excitation coil are coherently canceled out at the installation position of the magnetic field sensor. The controller is used to implement the steps of the method according to any one of claims 1 to 5.

8. The system according to claim 7, characterized in that, The plurality of excitation coils includes a main excitation coil and a compensating excitation coil; The main magnetic field generated by the main excitation coil and the compensation magnetic field generated by the compensation excitation coil are coherently canceled out at the installation position of the magnetic field sensor.

9. The system according to claim 7 or 8, characterized in that, The magnetic field sensor includes a GMR sensor.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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