An electromagnetic ultrasonic testing method and device based on orientation transformation and multi-feature fusion

Abstract

The application discloses an electromagnetic ultrasonic detection method and device based on azimuth transformation and multi-feature fusion, and the method comprises the following steps: selecting a detection area on the surface of a metal material sample to be detected; installing an EMAT azimuth transformation detection device on the detection area, and setting initial parameters of the EMAT azimuth transformation detection device; performing azimuth transformation scanning by using the EMAT azimuth transformation detection device, integrating detection signals at different azimuths, and obtaining all signal data in the detection area; processing the signal data and extracting multi-features to obtain a comprehensive feature value matrix; and obtaining material uniformity representation based on the comprehensive feature value matrix, and quantifying the material difference representation. The application uses a single vibration direction EMAT to realize vibration direction adjustment of an excited sound field through azimuth transformation scanning, and has higher material uniformity detection sensitivity.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic nondestructive testing technology, specifically relating to an electromagnetic ultrasonic testing method and device based on orientation transformation and multi-feature fusion. Background Technology

[0002] During the manufacturing processes of metallic materials, including smelting, continuous casting / casting, rolling, forging, and heat treatment, variations in material homogeneity are often caused by factors such as compositional segregation, differences in grain size and phase structure, uneven distribution of inclusions and porosity, and uneven residual stress. These variations may be accompanied by internal defects such as delamination, porosity, cracks, and slag inclusions. This inhomogeneity leads to spatial dispersion in the material's elasticity, strength, toughness, and hardness, resulting in decreased processing stability, increased risk of deformation and cracking, and difficulty in ensuring consistent quality during subsequent machining, forming, welding, and heat treatment. During service, it easily leads to stress concentration and fatigue crack initiation, inducing significantly reduced fatigue life, brittle fracture, or stress corrosion cracking, posing significant risks to load-bearing, pressure-bearing, and critical safety structures. Therefore, efficient and reliable non-destructive testing and evaluation of the material homogeneity and internal defects of metallic materials during the manufacturing and delivery stages are of significant engineering importance.

[0003] Existing methods for detecting material homogeneity and internal defects include metallographic / hardness sampling, chemical composition analysis, conventional contact ultrasound, X-ray testing, and electromagnetic methods such as eddy current testing. Among these, metallographic and hardness testing largely rely on sample preparation, limiting representativeness and coverage; X-ray testing faces limitations in radiation protection, penetration capability in thick and large components, efficiency, and cost; eddy current methods are more sensitive to surface and near-surface conditions but lack the ability to evaluate deep defects and bulk homogeneity; while piezoelectric ultrasound is widely used, it typically relies on coupling agents and is significantly affected by surface roughness, coatings, high temperatures, and online high-speed testing conditions. Fluctuations in the coupling state also introduce amplitude and attenuation uncertainties, affecting the stable quantitative characterization of material homogeneity parameters. Furthermore, currently used ultrasonic testing methods often determine material state based on fixed directions or single characteristics (such as echo amplitude), making them susceptible to grain orientation, microstructure anisotropy, coupling state, and noise, resulting in incomplete descriptions and insufficient quantitative capabilities of "material homogeneity / consistency." This is especially true for samples of the same material from different batches, with different heat treatment states, and different microstructure homogeneity distributions, which are difficult to reliably distinguish using only a single characteristic. Therefore, there is an urgent need for a detection method and device that is coupling-free, adaptable to online operating conditions, and capable of evaluating material uniformity. To this end, a method is proposed that collects multi-directional data within a two-dimensional region and integrates multiple features such as amplitude, phase, transit time, noise, and spectrum to establish a stable quantitative index. Summary of the Invention

[0004] This invention aims to address the shortcomings of existing technologies and provides the following solutions: An electromagnetic ultrasonic testing method based on orientation transformation and multi-feature fusion includes the following steps: Select a test area on the surface of the metal material sample being tested; An EMAT orientation change detection device is installed in the detection area, and the initial parameters of the EMAT orientation change detection device are set. The EMAT orientation change detection device is used to perform orientation change scanning, acquire detection signals from different orientations, and integrate them to obtain all signal data in the detection area. The signal data is processed and multiple features are extracted to obtain a comprehensive feature value matrix; Based on the comprehensive eigenvalue matrix, the material uniformity is characterized, and the material differences are quantitatively characterized.

[0005] Preferably, the method for selecting the detection area includes: According to the testing requirements, test point O is selected on the surface of the metal material sample to be tested; Choose a point O as the center point and a radius of R The circular region is used as the detection area. .

[0006] Preferably, the method for setting the initial parameters of the EMAT orientation change detection device includes: Set the scanning parameters of the EMAT orientation change detection device: in, ri Indicates the first i The radius of each scan, dr Indicates the step size of the radius scan. i Indicates the scan radius sequence number. θj Indicates the first j Each scanning angle, dθ This indicates the step size for rotating the scan angle. j Indicates the scanning angle sequence number. dr This indicates the preset scan radius. dθ Indicates the preset angle step; The EMAT orientation change detection device is set to operate in pulse echo mode, and electromagnetic ultrasound detection parameters are set, including: detection frequency, excitation voltage, receiving gain, sampling frequency, and sampling length. These detection parameters are kept constant during the detection process.

[0007] Preferably, the method for obtaining the signal data includes: The EMAT azimuth transformation detection device is used to perform azimuth transformation scanning in each azimuth. At this location, trigger EMAT once or multiple times and collect echo signals to obtain different azimuths. Detection signal , where t is time; Detection signal at the same point Repeat sampling n The average value of the detected signal is obtained by averaging the results of these operations. in, express n The average value of each detected signal, k Indicates the first k Secondary sampling; The signal data is obtained based on the average value: Among them, D S This represents signal data.

[0008] Preferably, the method for obtaining the comprehensive eigenvalue matrix includes: The average value is filtered to obtain the filtered signal; Based on the filtered signal, the feature matrix is ​​obtained: Among them, D F Represents the characteristic matrix, Indicates amplitude characteristics, Indicates the phase of the maximum peak value of the bottom echo. Indicates the time of crossing. Indicates the maximum noise value. Indicates the noise level. Indicates the sound waves of the material; Based on the feature matrix, the orientation is obtained. place M 3D feature vector: in, express M 3D feature vectors Representing the characteristic matrix D F The eigenvalues ​​in; For each eigenvalue Perform independent normalization to obtain the normalized eigenvalues: in, Represents the normalized eigenvalues; Based on the normalized feature values, construct the normalized feature vector: in, This represents the normalized eigenvectors; Based on the normalized feature vector, the first value is calculated according to the amplitude feature. m Weight coefficients for each feature value: in, qm Represents the correlation coefficient. Represents the mean of the eigenvalues. u Indicates a uniformity reference quantity. The mean of the uniformity reference value. wm Indicates the weighting coefficient; Based on the weighting coefficients, the comprehensive eigenvalue matrix is ​​obtained: in, This represents the comprehensive eigenvalue matrix.

[0009] Preferably, the method for obtaining the material differences includes: in, This indicates differences in material composition. This represents a dataset of standard specimen characteristics.

[0010] The present invention also provides an electromagnetic ultrasonic testing device based on orientation transformation and multi-feature fusion. The device is used to implement the above-mentioned method and includes: an electromagnetic ultrasonic sensor, a scanning device, a motion control system, an electromagnetic ultrasonic testing system, and a computer. The electromagnetic ultrasonic sensor includes a transducer coil, a magnet, a housing, and a connector, and is used to excite and receive ultrasonic waves on the surface of a metal material. The scanning device includes a support frame, a rotating motion component, a radial motion component, and a sensor clamping component, used to realize orientation-changing scanning motion, including scanning radius and scanning angle changes; The motion control system controls the motion of the scanning device based on control signals; The electromagnetic ultrasonic testing system includes an electromagnetic ultrasonic excitation source, a signal acquisition module, a signal amplification module, and a signal conditioning module, which are used to connect to the EMAT orientation transformation detection device and control the detection parameters to realize electromagnetic ultrasonic detection. The computer is used to carry detection and motion control software to realize electromagnetic ultrasonic detection and orientation change scanning control, and is also used to realize data acquisition, storage and post-processing.

[0011] Preferably, in the scanning device: The support frame includes an adsorption locking base and a ring track, which are used to install and connect various moving parts. During testing, the support frame is installed and fixed to the surface of the material being tested. The rotary motion component includes a rotating shaft and a driving device, which is used to drive the radial motion component, the sensor clamping component and the sensor to perform circumferential rotational motion. The radial motion component includes a linear guide rail and a driving device for realizing the radial translation of the sensor, while the radial motion component as a whole is driven by the rotary motion component to realize circumferential rotation; The sensor clamping component includes a sensor clamping mechanism and a guiding mechanism for clamping an electromagnetic field ultrasonic sensor. The guiding mechanism is mounted on the linear guide rail of the radial motion component, and its radial movement distance is adjusted by the radial motion component.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention utilizes EMAT with a single vibration direction to achieve the adjustment of the vibration direction of the excitation sound field through orientation transformation scanning, which has higher sensitivity for material uniformity detection; (2) The present invention uses multi-feature fusion and image representation to make the material uniformity assessment have higher detection sensitivity, accuracy and reliability; (3) The EMAT of the present invention does not require a coupling agent and can perform in-situ online detection. Combined with the scanning device, it has higher detection efficiency and reliability. Attached Figure Description

[0013] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the device structure according to an embodiment of the present invention; Figure 3 This is a simplified scanning diagram of the electromagnetic ultrasonic sensor according to an embodiment of the present invention; Figure 4This is a schematic diagram of orientation transformation scanning according to an embodiment of the present invention, wherein (a) is a schematic diagram of scanning at the starting position, (b) is a schematic diagram of scanning with a radial distance less than the sensor radius D / 2, and (c) is a schematic diagram of scanning with a radial distance greater than the sensor radius D / 2; Figure 5 This is a schematic diagram of the detection signal at a certain location according to an embodiment of the present invention; Figure 6 This is a schematic diagram (polar coordinates) of material uniformity characterization through multi-feature fusion in an embodiment of the present invention. Figure 7 This is a schematic diagram (polar coordinates) of C-scan slices at different depths according to an embodiment of the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Example 1 In this embodiment, as Figure 1 As shown, an electromagnetic ultrasonic testing method based on orientation transformation and multi-feature fusion includes the following steps: S1. Select the test area on the surface of the metal material sample to be tested.

[0018] Methods for selecting the detection area include: According to the testing requirements, select test point O on the surface of the metal material sample to be tested; In this embodiment, point O is selected as the center point and the radius is... R The circular area is used as the detection area. .

[0019] S2. Install the EMAT orientation change detection device in the detection area and set the initial parameters of the EMAT orientation change detection device.

[0020] In this embodiment, an EMAT orientation transformation detection device is installed on the surface of the metal material sample being tested. The center of the detection device is aligned with the detection point O, and the distance between the working surface of the EMAT front end and the sample surface is ensured. h Satisfy 0 < h ≤0.5mm.

[0021] The method for setting the initial parameters of the EMAT orientation change detection device includes: setting the scanning parameters of the EMAT orientation change detection device: in, ri Indicates the first i The radius of each scan, dr Indicates the step size of the radius scan. i Indicates the scan radius sequence number. θj Indicates the first j Each scanning angle, dθ This indicates the step size for rotating the scan angle. j Indicates the scanning angle sequence number. dr This indicates the preset scan radius. dθ This indicates the preset angle step; the EMAT orientation change detection device is set to operate in pulse echo mode, and the electromagnetic ultrasonic detection parameters are set, including: detection frequency, excitation voltage, receiving gain, sampling frequency, and sampling length. The detection parameters are kept constant during the detection process.

[0022] S3. Use the EMAT orientation change detection device to perform orientation change scanning, acquire detection signals from different orientations, and integrate them to obtain all signal data in the detection area.

[0023] In this embodiment, the method for obtaining signal data includes: Azimuth transformation scanning was performed using the EMAT azimuth transformation detection device at each azimuth. At this location, trigger EMAT once or multiple times and collect echo signals to obtain different azimuths. Detection signal ,in t For time; to improve the signal-to-noise ratio, the detection signal at the same point... Repeat sampling n The average value of the detected signal is obtained by averaging the results of these operations. in, express n The average value of each detected signal, k Indicates the first k Sub-sampling; signal data obtained based on average value: Among them, D S This represents signal data.

[0024] S4. Process the signal data and extract multiple features to obtain a comprehensive eigenvalue matrix.

[0025] In this embodiment, the method for obtaining the comprehensive eigenvalue matrix includes: The filtered signal is obtained by filtering the average value: in, The filter signal is represented by FIL, which represents the specified filter function, such as bandpass filtering or Gaussian filtering. The same filter parameters are maintained for all detected signals during filtering.

[0026] Based on the filtered signal, the amplitude characteristics of the echo from the bottom surface of the sample are extracted: Define the bottom echo time window: in, τb Indicates the bottom surface echo time window. tb 1 indicates the start time of the time window. tb 2 indicates the end time of the time window. tb 1< tb 2; Filtered signal The peak-to-peak value represents the amplitude characteristics: in, Indicates amplitude characteristics.

[0027] Constructing analytic signals based on filtered signals: in, The signal is represented by analytic signal, and HT represents Hilbert transform; the envelope signal is obtained based on the analytic signal. in, Represents the envelope signal; obtain the peak time of the bottom echo envelope based on the envelope signal: in, This indicates the peak time of the bottom surface echo envelope.

[0028] The phase of the maximum peak value of the bottom echo is obtained based on the analytical signal: in, This indicates the phase of the maximum peak value of the bottom surface echo.

[0029] The peak time of the bottom echo envelope is extracted as the transit time based on the peak time of the bottom echo envelope: in, Indicates the time elapsed.

[0030] Define a noise time window that does not include the initial wave and the valid echo: Extract the filtered signal within the noise time window. Maximum noise level: in, This indicates the maximum noise level.

[0031] Further, the noise level is calculated based on the maximum noise value of the signal: in, Indicates the noise level.

[0032] The ultrasonic wave velocity of the material is calculated based on the sample thickness H, and the acoustic wave velocity is obtained by calculating the transit time and sample thickness. in, This indicates the sound waves of the material.

[0033] Through the above steps, the feature matrix is ​​obtained: Among them, D F Represents the characteristic matrix, Indicates amplitude characteristics, Indicates the phase of the maximum peak value of the bottom echo. Indicates the time of crossing. Indicates the maximum noise value. Indicates the noise level. Indicates the sound waves of the material; Each feature value is normalized, and a corresponding weighting coefficient is set according to the different sensitivities of each feature to material uniformity. The features are then weighted and summed to obtain the comprehensive feature value of the scanned position.

[0034] Specifically, the azimuth is obtained based on the feature matrix. place M 3D feature vector: in, express M 3D feature vectors Representing the characteristic matrix D F The eigenvalues ​​in the data; for each eigenvalue Perform independent normalization to obtain the normalized eigenvalues: in, Let represent the normalized eigenvalues; based on the normalized eigenvalues, construct the normalized eigenvectors: in, This represents the normalized eigenvector; based on the normalized eigenvector, the first eigenvector is calculated according to the magnitude feature. m Weight coefficients for each feature value: in, qm Represents the correlation coefficient. Represents the mean of the eigenvalues. u Indicates a uniformity reference quantity. The mean of the uniformity reference value. wm Represents the weighting coefficients; based on the weighting coefficients, the comprehensive eigenvalue matrix is ​​obtained: in, This represents the comprehensive eigenvalue matrix.

[0035] S5. Based on the comprehensive eigenvalue matrix, the material uniformity is characterized, and the material differences are quantitatively characterized.

[0036] Specifically, material homogeneity characterization involves using orientation information to represent both single-feature information matrices and comprehensive eigenvalue matrices. Using coordinates as the axes, 2D polar coordinate grayscale images are plotted to represent the material uniformity distribution in the measured area. Further statistical analysis is performed on the feature information from different orientations, calculating the average value, dispersion, coefficient of variation, etc., to quantitatively characterize the material uniformity. In addition, polar coordinate C-scan images were plotted using the detection signal dataset, and the presence of internal defects was analyzed through depth slicing.

[0037] Optionally, a standard metal sample of the same material as the test sample is prepared, and a characteristic dataset of the standard sample is established using the method described above. Furthermore, a consistency evaluation standard was established based on a standard dataset. The material differences between the test sample and the standard sample were quantified through feature data comparison. Methods for characterizing material differences included: in, This indicates differences in material composition. This represents a dataset of standard specimen characteristics.

[0038] Example 2 In this embodiment, as Figure 2 As shown, an electromagnetic ultrasonic testing device based on orientation transformation and multi-feature fusion includes: an electromagnetic ultrasonic sensor, a scanning device, a motion control system, an electromagnetic ultrasonic testing system, and a computer.

[0039] Electromagnetic ultrasonic sensors are mainly composed of transducer coils, magnets, housings, connectors, etc. They have a clear excitation waveform and a single vibration direction. They can be butterfly coils, straight wire coils, etc., and are used to excite and receive ultrasonic waves on the surface of metal materials.

[0040] The scanning device mainly consists of a support frame, a rotary motion component, a radial motion component, and a sensor clamping component. It is used to achieve oriented scanning motion of the EMAT (Electromagnetic Ultrasonic Sensor), including changes in scanning radius and scanning angle. Within the scanning device: the support frame mainly consists of an adsorption locking base and a ring track, used to install and connect the various moving components. During detection, the support frame is fixed to the surface of the material being tested. The rotary motion component mainly consists of a rotating shaft and a drive device, which can be manual or automatic. This component drives the radial motion component, the sensor clamping component, and the sensor to rotate circumferentially. The radial motion component mainly consists of a linear guide rail and a drive device, used to achieve radial translation of the sensor. The drive device can be automatic or manual. Simultaneously, the entire radial motion component is driven by the rotary motion component to achieve circumferential rotation. The sensor clamping component consists of a sensor clamping mechanism and a guide mechanism, used to clamp the electromagnetic field ultrasonic sensor. The guide mechanism is mounted on the linear guide rail of the radial motion component, and its radial movement distance is adjusted by the radial motion component.

[0041] The motion control system controls the movement of the scanning device based on control signals.

[0042] The electromagnetic ultrasonic testing system includes an electromagnetic ultrasonic excitation source, a signal acquisition module, a signal amplification module, and a signal conditioning module. It is used to connect to the EMAT orientation transformation testing device and control the testing parameters to realize electromagnetic ultrasonic testing.

[0043] The computer is used to carry detection and motion control software to realize electromagnetic ultrasonic detection and orientation change scanning control, and also to realize data acquisition, storage and post-processing functions.

[0044] like Figure 3 The example shown uses a transverse wave EMAT composed of a transducer coil resembling a straight conductor. It demonstrates how, by moving the EMAT radially while simultaneously rotating it at varying angles, different orientations of the EMAT can be achieved. Through a step-by-step scanning method described in Example 1, full coverage detection of the detection area is achieved. The radial value r is represented by the distance r between the center of the EMAT and the detection point O during radial movement.

[0045] like Figure 4 As shown, the diagram illustrates the orientation transformation scan, where (a) is the scan diagram at the starting position, (b) is the scan diagram at a radial distance less than the sensor radius D / 2, and (c) is the scan diagram at a radial distance greater than the sensor radius D / 2.

[0046] like Figure 5 The image shows a schematic diagram of the detection signal at a certain location.

[0047] Figure 6 A schematic diagram (polar coordinates) of material homogeneity characterization based on multi-feature fusion. Figure 7 This is a schematic diagram of C-scan slices at different depths (polar coordinates).

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An electromagnetic ultrasonic testing method based on orientation transformation and multi-feature fusion, characterized in that, Includes the following steps: Select a test area on the surface of the metal material sample being tested; An EMAT orientation change detection device is installed in the detection area, and the initial parameters of the EMAT orientation change detection device are set. The EMAT orientation change detection device is used to perform orientation change scanning, acquire detection signals from different orientations, and integrate them to obtain all signal data in the detection area. The signal data is processed and multiple features are extracted to obtain a comprehensive feature value matrix; Based on the comprehensive eigenvalue matrix, the material uniformity is characterized, and the material differences are quantitatively characterized.

2. The electromagnetic ultrasonic detection method based on orientation transformation and multi-feature fusion according to claim 1, characterized in that, The method for selecting the detection area includes: According to the testing requirements, test point O is selected on the surface of the metal material sample to be tested; Choose a point O as the center point and a radius of R The circular region is used as the detection area. .

3. The electromagnetic ultrasonic detection method based on orientation transformation and multi-feature fusion according to claim 2, characterized in that, The method for setting the initial parameters of the EMAT orientation change detection device includes: Set the scanning parameters of the EMAT orientation change detection device: in, ri Indicates the first i The radius of each scan, dr Indicates the step size of the radius scan. i Indicates the scan radius sequence number. θj Indicates the first j Each scanning angle, dθ This indicates the step size for rotating the scan angle. j Indicates the scanning angle sequence number. dr This indicates the preset scan radius. dθ Indicates the preset angle step; The EMAT orientation change detection device is set to operate in pulse echo mode, and electromagnetic ultrasound detection parameters are set, including: detection frequency, excitation voltage, receiving gain, sampling frequency, and sampling length. These detection parameters are kept constant during the detection process.

4. The electromagnetic ultrasonic detection method based on orientation transformation and multi-feature fusion according to claim 3, characterized in that, The methods for obtaining the signal data include: The EMAT azimuth transformation detection device is used to perform azimuth transformation scanning in each azimuth. At this location, trigger EMAT once or multiple times and collect echo signals to obtain different azimuths. Detection signal , where t is time; Detection signal at the same point Repeat sampling n The average value of the detected signal is obtained by averaging the results of these operations. in, express n The average value of each detected signal, k Indicates the first k Secondary sampling; The signal data is obtained based on the average value: Among them, D S This represents signal data.

5. The electromagnetic ultrasonic detection method based on orientation transformation and multi-feature fusion according to claim 4, characterized in that, The methods for obtaining the comprehensive eigenvalue matrix include: The average value is filtered to obtain the filtered signal; Based on the filtered signal, the feature matrix is ​​obtained: Among them, D F Represents the characteristic matrix, Indicates amplitude characteristics, Indicates the phase of the maximum peak value of the bottom echo. Indicates the time of crossing. Indicates the maximum noise value. Indicates the noise level. Indicates the sound waves of the material; Based on the feature matrix, the orientation is obtained. place M 3D feature vector: in, express M 3D feature vectors Representing the characteristic matrix D F The eigenvalues ​​in; For each eigenvalue Perform independent normalization to obtain the normalized eigenvalues: in, Represents the normalized eigenvalues; Based on the normalized feature values, construct the normalized feature vector: in, This represents the normalized eigenvectors; Based on the normalized feature vector, the first value is calculated according to the amplitude feature. m Weight coefficients for each feature value: in, qm Represents the correlation coefficient. Represents the mean of the eigenvalues. u Indicates a uniformity reference quantity. The mean of the uniformity reference value. wm Indicates the weighting coefficient; Based on the weighting coefficients, the comprehensive eigenvalue matrix is ​​obtained: in, This represents the comprehensive eigenvalue matrix.

6. The electromagnetic ultrasonic detection method based on orientation transformation and multi-feature fusion according to claim 4, characterized in that, The methods for obtaining the characteristics of material differences include: in, This indicates differences in material composition. This represents a dataset of standard specimen characteristics.

7. An electromagnetic ultrasonic testing device based on orientation transformation and multi-feature fusion, the device being used to implement the method according to any one of claims 1-6, characterized in that, include: Electromagnetic ultrasonic sensors, scanning devices, motion control systems, electromagnetic ultrasonic testing systems, and computers; The electromagnetic ultrasonic sensor includes a transducer coil, a magnet, a housing, and a connector, and is used to excite and receive ultrasonic waves on the surface of a metal material. The scanning device includes a support frame, a rotating motion component, a radial motion component, and a sensor clamping component, used to realize orientation-changing scanning motion, including scanning radius and scanning angle changes; The motion control system controls the motion of the scanning device based on control signals; The electromagnetic ultrasonic testing system includes an electromagnetic ultrasonic excitation source, a signal acquisition module, a signal amplification module, and a signal conditioning module, which are used to connect to the EMAT orientation transformation detection device and control the detection parameters to realize electromagnetic ultrasonic detection. The computer is used to carry detection and motion control software to realize electromagnetic ultrasonic detection and orientation change scanning control, and is also used to realize data acquisition, storage and post-processing.

8. The electromagnetic ultrasonic testing device based on orientation transformation and multi-feature fusion according to claim 7, characterized in that, In the scanning device: The support frame includes an adsorption locking base and a ring track, which are used to install and connect various moving parts. During testing, the support frame is installed and fixed to the surface of the material being tested. The rotary motion component includes a rotating shaft and a driving device, which is used to drive the radial motion component, the sensor clamping component and the sensor to perform circumferential rotational motion. The radial motion component includes a linear guide rail and a driving device for realizing the radial translation of the sensor, while the radial motion component as a whole is driven by the rotary motion component to realize circumferential rotation; The sensor clamping component includes a sensor clamping mechanism and a guiding mechanism for clamping an electromagnetic field ultrasonic sensor. The guiding mechanism is mounted on the linear guide rail of the radial motion component, and its radial movement distance is adjusted by the radial motion component.

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