An eddy current detection method capable of showing the crack propagation direction

Abstract

An eddy current detection method capable of displaying the crack propagation direction according to the present invention is characterized in that different impedance plane diagram signals obtained by detecting with two sets of coils in eddy current detection and the probe signature and the probe moving direction are used to determine and display the crack propagation direction in the object to be detected. The angle between the crack and the probe traveling direction is displayed in real time, simplifying the operation difficulty of electromagnetic eddy current detection.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing, and particularly to a detection method and device capable of detecting the crack trend direction of metal materials by eddy current testing, and more particularly to an eddy current testing method capable of displaying the crack trend direction. Background Art

[0002] Eddy current testing should be an ideal technique for the fastest detection of surface crack defects, which can be achieved with minimal preparation work and relatively simple detection probe tools. It not only has the advantage of convenient portability of the detection tool, but also causes the least damage to the object to be detected. However, the use of electromagnetic eddy current technology in the field of non-destructive testing is restricted by many subjective and objective factors, including the need to use complex scanning movements or perform multiple scans on a component, as well as the understanding of vector map data generated by standard instrument detections, etc.

[0003] Moreover, in some in-service detection environments in the wild, such as high temperature, stains, irregular shapes of the detection objects, etc., when using high-precision sensor probe detection devices, there are many damages and high costs. There is an urgent need to improve the detection function and accuracy of simple coil-type eddy current detection devices by enhancing the analysis and calculation functions of software. Therefore, a simple and clear analysis result, making the electromagnetic eddy current detection with high professional and technical content foolproof and making the detection result very obvious, is a very much needed development direction for current eddy current testing.

[0004] In view of the above disadvantages and problems, the present invention adopts the following technical solutions. Summary of the Invention

[0005] The object of the present invention is to provide an eddy current testing method capable of displaying the crack trend direction, and the disclosed technical solution is as follows:

[0006] An eddy current testing method capable of displaying the crack trend direction, characterized in that it determines and displays the crack trend direction in the object to be detected by using the different impedance plane map signals obtained by detecting with two groups of coils in eddy current testing, and by using the probe signature and the probe moving direction Y. The specific method steps are as follows:

[0007] a. Set the probe signature direction X: According to the coil structure direction inside the probe, set a signature for the probe as a reference for the eddy current testing moving direction Y;

[0008] b. Obtain the impedance plane map information of eddy current testing: Perform electromagnetic eddy current non-destructive testing on the metal material to be detected, and extract the impedance information of the electromagnetic eddy current testing probe sensor;

[0009] c. Obtain the crack direction trend signal data: Analyze and calculate the impedance plane map signal, compare the corresponding parameter values, and determine the crack direction trend data;

[0010] d. Calculation and analysis of crack direction vector angle direction: The crack direction trend data is determined by using the impedance plane signal detection data, and the vector value of the crack direction trend is obtained by referring to the probe movement direction Y and the probe landmark direction X;

[0011] f. Result display: The real-time specific moving direction of the probe mark is used as the coordinate direction, and the crack trend is displayed on the coordinate screen of the detection and analysis instrument through the direction vector value. This allows eddy current detection operators to know the crack trend on the detected metal material in the simplest and fastest way.

[0012] Furthermore, if the probe moving direction Y and the probe landmark direction X are in the same direction, the crack vector line direction displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe moving direction Y as a reference. Like a mouse, the actual crack direction is displayed and marked very vividly, giving the tester a dynamic and vivid testing experience.

[0013] Furthermore, the probe moving direction Y and the probe marking direction X have a certain angle R, and the direction of the crack vector line displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe marking direction X as a reference. When it is necessary to determine that the shape of the metal part being tested is irregular and it is inconvenient to move in one direction, the angle display in different directions can be obtained by rotating the probe, which is convenient for specific testing of metal materials with irregular shapes in harsh environments.

[0014] Furthermore, it also includes displaying the depth of the crack. Through the eddy current detection signal impedance data analysis, the strength of the parameter signal is used as the display method of the crack depth. The deeper the crack, the longer the length of the crack vector line displayed, and the relationship is displayed in a positive growth. In the analysis and calculation of the impedance signal parameter value of the eddy current detection, the signal value and the crack depth are in a positive growth relationship.

[0015] Furthermore, the acquisition of eddy current detection impedance plane map information is to extract the signal values of two coils perpendicularly wound in the eddy current probe, and the two coils perpendicularly wound are set to time-sharing one coil transmitting and the other coil receiving, and one coil transmitting and receiving at the same time, and the other coil also transmitting and receiving at the same time, after high-frequency time-sharing detection obtains two detection signal values, superimposes and analyzes the vector values of the two coils on different impedance plane maps, so as to determine the direction of the crack. Because the magnetic flux vector values generated by the coil when transmitting and receiving at different angles are exactly the maximum and minimum in the 90-degree angle direction, respectively, the detection signal in any angle direction will not be missed.

[0016] Furthermore, the mutually perpendicularly wound coils are configured to extract the mutually perpendicular coil detection signal values from multiple groups of mutually cross-wound coils for comprehensive comparative analysis. For example, the detection signals of two groups of four coils that are cross-wound in a cross-shaped pattern and are perpendicular to each other can generate more comprehensive signal angle values, and can detect 360-degree detection signals without blind spots.

[0017] Furthermore, the eddy current detection signal also includes extracting the eddy current signal detected by the absolute eddy current detection coil as a compensation signal for the crack direction, compensating for the error of the lift-off value of the eddy current detection to the detection information.

[0018] Furthermore, the absolute eddy current detection signal value is the signal value of the electromagnetic eddy current detection coil which is completely perpendicular to the detection surface and has the largest magnetic flux.

[0019] Furthermore, the absolute eddy current detection signal value is the electromagnetic eddy current detection signal value extracted from the absolute coil additionally provided in addition to the non-directional detection coil.

[0020] Furthermore, when extracting the signal value of the Y signal data in the scanning moving direction of the probe in step c, the characteristic orientation information of the probe, that is, the characteristic direction of the probe itself, is extracted at the same time as the longitudinal axial direction displayed on the screen of the detection instrument. When it is necessary to determine that the shape of the metal part being detected is irregular and it is inconvenient to move in one direction, the angle display in different directions can be obtained by rotating the probe, which is convenient for specific detection of metal materials with irregular shapes in harsh environments.

[0021] According to the above technical scheme, the present invention has the following beneficial effects:

[0022] 1. The eddy current detection method of the present invention can display the direction of cracks. By performing vector analysis of the impedance plane diagram on the electromagnetic eddy current detection signal value, taking the iconic moving direction Y as a reference, and displaying it with the actual moving direction Y of the probe as a reference, the eddy current detection device can display the direction of cracks, and can display the angle between the crack and the moving direction of the probe in real time, thereby simplifying the difficulty of electromagnetic eddy current detection operation.

[0023] 2. In an eddy current detection method capable of displaying the direction of cracks of the present invention, by extracting multiple groups of non-directional coil detection signals and using different sending and receiving methods, 360-degree non-directional dead angle or blind spot detection of the detection probe is achieved.

[0024] 3. The extraction probe of the present invention is fixed with a symbolic direction, and the symbolic direction is used as the axial direction for judging and displaying the crack direction of the electromagnetic eddy current detection instrument, so that the crack direction determined by analysis can be converted to display in different directions, which is suitable for extracting metal detection with irregular detection of non-standardized and environmental materials;

[0025] III. In the present invention, an absolute eddy current detection is used as a reference compensation value, which has a lift-off compensation function for the eddy current detection coil, greatly improving the functional effect of the eddy current detection device of the present invention. Moreover, the lift-off compensation can realize the non-destructive detection of the detection metal anti-corrosion layer with uneven original thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic flow chart of the detection method of the best embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the eddy current detection signal of the best embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the eddy current detection signal of the best embodiment of the present invention;

[0029] Figure 4 It is a schematic diagram of the eddy current detection signal of the best embodiment of the present invention;

[0030] Figure 5 It is a schematic diagram of the eddy current detection signal of the best embodiment of the present invention;

[0031] Figure 6 It is a schematic diagram of the eddy current detection signal of the best embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0033] As Figure 1 shown in the flow chart, an eddy current detection method capable of displaying the crack direction is characterized in that by using the different impedance plane diagram signals obtained by detecting with two groups of coils in the eddy current detection, and using the probe signature and the probe moving direction Y, to determine and display the crack direction in the object to be detected. The specific method steps are as follows:

[0034] As Figures 2 to 5 shown, an eddy current detection method capable of displaying the crack direction is characterized in that by using the different impedance plane diagram signals obtained by detecting with two groups of coils in the eddy current detection, and using the probe signature and the probe moving direction Y, to determine and display the crack direction in the object to be detected. The specific method steps are as follows:

[0035] a. Set the probe signature direction X: According to the coil structure direction inside the probe, set a signature for the probe as a reference for the eddy current detection moving direction Y;

[0036] b. Obtain the eddy current detection impedance plane diagram information: Perform electromagnetic eddy current non-destructive detection on the metal material to be detected, and extract the impedance information of the electromagnetic eddy current detection probe sensor;

[0037] c. Obtain crack direction trend signal data: Analyze and calculate the impedance plane map signal, compare the corresponding parameter values, and determine the crack direction trend data;

[0038] d. Calculation and analysis of crack direction vector angle direction: The crack direction trend data is determined by using the impedance plane signal detection data, and the vector value of the crack direction trend is obtained by referring to the probe movement direction Y and the probe landmark direction X;

[0039] f. Result display: The real-time specific moving direction of the probe mark is used as the coordinate direction, and the crack trend is displayed on the coordinate screen of the detection and analysis instrument through the direction vector value. This allows eddy current detection operators to know the crack trend on the detected metal material in the simplest and fastest way.

[0040] Furthermore, if the probe moving direction Y and the probe landmark direction X are in the same direction, the crack vector line direction displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe moving direction Y as a reference. Like a mouse, the actual crack direction is displayed and marked very vividly, giving the tester a dynamic and vivid testing experience.

[0041] Furthermore, the probe moving direction Y and the probe marking direction X have a certain angle R, and the direction of the crack vector line displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe marking direction X as a reference. When it is necessary to determine that the shape of the metal part being tested is irregular and it is inconvenient to move in one direction, the angle display in different directions can be obtained by rotating the probe, which is convenient for specific testing of metal materials with irregular shapes in harsh environments.

[0042] Furthermore, it also includes displaying the depth of the crack. Through the eddy current detection signal impedance data analysis, the strength of the parameter signal is used as the display method of the crack depth. The deeper the crack, the longer the length of the crack vector line displayed, and the relationship is displayed in a positive growth. In the analysis and calculation of the impedance signal parameter value of the eddy current detection, the signal value and the crack depth are in a positive growth relationship.

[0043] Furthermore, the acquisition of eddy current detection impedance plane map information is to extract the signal values of two coils perpendicularly wound in the eddy current probe, and the two coils perpendicularly wound are set to time-sharing one coil transmitting and the other coil receiving, and one coil transmitting and receiving at the same time, and the other coil also transmitting and receiving at the same time, after high-frequency time-sharing detection obtains two detection signal values, superimposes and analyzes the vector values of the two coils on different impedance plane maps, so as to determine the direction of the crack. Because the magnetic flux vector values generated by the coil when transmitting and receiving at different angles are exactly the maximum and minimum in the 90-degree angle direction, respectively, the detection signal in any angle direction will not be missed.

[0044] Furthermore, the mutually perpendicularly wound coils are configured to extract the mutually perpendicular coil detection signal values from multiple groups of mutually cross-wound coils for comprehensive comparative analysis. For example, the detection signals of two groups of four coils that are cross-wound in a cross-shaped pattern and are perpendicular to each other can generate more comprehensive signal angle values, and can detect 360-degree detection signals without blind spots.

[0045] Furthermore, the eddy current detection signal also includes extracting the eddy current signal detected by the absolute eddy current detection coil as a compensation signal for the crack direction, compensating for the error of the lift-off value of the eddy current detection to the detection information.

[0046] Furthermore, the absolute eddy current detection signal value is the signal value of the electromagnetic eddy current detection coil which is completely perpendicular to the detection surface and has the largest magnetic flux.

[0047] Furthermore, the absolute eddy current detection signal value is the electromagnetic eddy current detection signal value extracted from the absolute coil additionally provided in addition to the non-directional detection coil.

[0048] like Figure 6 As shown in , when extracting the signal data value of the probe scanning moving direction Y in step c, the probe's iconic orientation information is extracted at the same time, that is, the iconic direction X of the probe itself, which is used as the longitudinal axial direction displayed on the detection instrument screen, that is, the displayed crack direction, and the angle R value between the iconic direction X and the crack direction is the same as the angle R value between the crack signal direction and the longitudinal axis direction. When it is necessary to determine that the shape of the metal part being detected is irregular and it is inconvenient to move in one direction, the probe can be rotated to obtain the angle display in different directions, which is convenient for specific detection of metal materials with special shapes in harsh environments.

[0049] The above is one embodiment of the present invention. In addition, it should be noted that any equivalent or simple changes made based on the structure, features and principles described in this patent concept are included in the protection scope of this patent.

Claims

1. An eddy current detection method capable of showing the crack propagation direction, characterized in that By using the different impedance plane map signals obtained by the two sets of coils in the eddy current test, and using the probe mark and the probe movement direction, the crack direction in the object being tested can be determined and displayed. The specific method steps are as follows: a. Set the probe landmark direction: According to the direction of the coil structure inside the probe, set a mark for the probe as a reference for the moving direction of eddy current testing; b. Obtaining eddy current detection impedance plane map information: Perform electromagnetic eddy current nondestructive testing on the metal material to be tested, and extract the impedance information of the electromagnetic eddy current detection probe sensor; c. Obtain crack direction trend signal data: analyze and calculate the impedance plane map signal, compare the corresponding parameter values, and determine the crack direction trend data; d. Calculation and analysis of crack direction vector angle direction: The crack direction trend data is determined by using the impedance plane signal detection data, and the vector value of the crack direction trend is obtained by referring to the probe movement direction and the probe landmark direction. If the probe movement direction and the probe landmark direction are in the same direction, the crack vector line direction displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe movement direction as a reference; if the probe movement direction and the probe landmark direction have a certain angle R, the crack vector line direction displayed on the screen coordinates of the eddy current testing instrument is the actual crack direction with the probe landmark direction as a reference; e. Result display: The real-time specific moving direction of the probe mark is used as the coordinate direction, and the crack trend is displayed on the coordinate screen of the detection and analysis instrument through the direction vector value.

2. The eddy current detection method capable of displaying the crack propagation direction according to claim 1, wherein It also includes displaying the crack depth. Through eddy current detection signal impedance data analysis, the strength of the parameter signal is used as a method of displaying the crack depth. The deeper the crack, the longer the length of the displayed crack vector line, showing a positive growth relationship.

3. The eddy current detection method capable of displaying the crack propagation direction according to claim 1, wherein The method for obtaining the eddy current detection impedance plane map information is to extract the signal values of two coils vertically wound together in the eddy current probe. The two coils vertically wound together are set to time-sharing, with one coil transmitting and the other coil receiving, and one coil transmitting and receiving at the same time, and the other coil also transmitting and receiving at the same time. After high-frequency time-sharing detection obtains the two detection signal values, they are superimposed and analyzed for the vector values of the two coils on different impedance plane maps, thereby determining the direction of the crack.

4. The eddy current detection method capable of displaying the crack propagation direction according to claim 3, wherein The two coils that are perpendicular to each other are arranged to extract detection signal values of the perpendicular coils from a plurality of groups of coils that are cross-wound to each other for comprehensive comparative analysis.

5. A eddy current testing method capable of showing the crack propagation direction according to any one of claims 1 to 4, characterized in that The eddy current detection signal also includes extracting the eddy current signal detected by the absolute eddy current detection coil as a compensation signal for the crack direction, compensating for the error of the lift-off value of the eddy current detection to the detection information.

6. The eddy current detection method capable of displaying the crack propagation direction according to claim 5, characterized in that The eddy current signal detected by the absolute eddy current detection coil is the signal value of the electromagnetic eddy current detection coil which is completely perpendicular to the detection surface and has the largest magnetic flux.

7. A eddy current testing method capable of displaying the crack propagation direction according to claim 6, characterized in that The eddy current signal detected by the absolute eddy current detection coil is the electromagnetic eddy current detection signal value extracted from the absolute coil additionally provided in addition to the non-directional detection coil.

8. A eddy current testing method capable of displaying the crack propagation direction according to claim 1, characterized in that When extracting the signal data value of the probe scanning movement direction signal in step c, the landmark orientation information of the probe is extracted at the same time, that is, the landmark direction inherent in the probe itself, which is used as the longitudinal axis direction of the display direction on the screen of the detection instrument.

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