Multi-coil incremental permeability dynamic detection probe and yield strength detection method
By combining a multi-coil incremental permeability dynamic detection probe with permanent magnet magnetization, the problem of low detection efficiency in existing technologies has been solved, enabling rapid and continuous detection of material yield strength and improving detection efficiency and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-26
- Publication Date
- 2026-04-10
AI Technical Summary
Existing single-probe incremental permeability (IP) testing systems require the probe to remain relatively stationary with respect to the sample during low-frequency magnetization, resulting in low testing efficiency and an inability to achieve continuous and efficient material yield strength testing.
A multi-coil incremental permeability dynamic detection probe is used to collect IP signals at different positions during the sample movement using multiple coil groups. Combined with the magnetization effect of the permanent magnet, the IP parameters of the peak, valley and cross points are obtained through three coil groups respectively, and a performance prediction model is constructed to calculate the yield strength.
It enables rapid and continuous acquisition of permeability signals under multiple magnetization states during sample movement, improving detection efficiency. It can achieve a sample pass rate of over 90% within a 10% relative error accuracy range, with a detection speed of up to 3m/s and reduced system power consumption.
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Figure CN114859277B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of non-destructive testing, and particularly relates to a multi-coil incremental permeability dynamic detection probe and a yield strength detection method. BACKGROUND
[0002] Tensile test is one of the most widely used test methods for measuring the yield strength of cold-rolled steel sheets, because the results are reliable. This testing method is destructive, so it can only be used for sampling detection in the same batch of materials. The installation of the steel sheet and the tensile process require a lot of time, and continuous detection cannot be performed.
[0003] At present, a non-destructive testing device based on incremental permeability (IP) is proposed. IP is related to the reversibility of magnetic domain flipping, and can predict the yield strength of the material without damaging the material. The IP system includes a low-frequency excitation part for periodically magnetizing the sample, a high-frequency excitation part and a signal receiving part for collecting the incremental permeability signal of the sample in different states of magnetization of the sample, and obtaining specific IP parameters.
[0004] The IP parameters used to predict the yield strength include peak V max , valley V min , and zero-crossing point V cross , as shown in Figure 1 .
[0005] The peak V max is obtained near the coercivity of the sample to be tested. Near this point, if the grain diameter is large, the magnetic properties tend to be optimal, and the larger the V max .
[0006] The valley V min is obtained near the saturation magnetization state. At this time, the change of V min is mainly caused by the rotation of the magnetic moment, so fine grains play a dominant role at this state.
[0007] The crossing point V cross : At the crossing point, the low-frequency excitation given by the outside is close to 0, so the amplitude of the crossing point and the low-frequency excitation of the outside under the condition of 0 are closely related to the dislocation density and pinning effect of the material.
[0008] Since most of the IP detection systems currently used use single probe excitation and collection, it is necessary to ensure that the position between the detection probe and the sample is relatively stationary during the low-frequency magnetization process, in order to achieve the purpose of collecting information of a whole magnetization state. This makes most of the current IP detection devices limited to static detection, and the detection efficiency is not high. SUMMARY
[0009] The application provides a multi-coil incremental permeability dynamic detection probe and a yield strength detection method to solve the problems in the prior art.
[0010] The application provides a multi-coil incremental permeability dynamic detection probe, which comprises three coil groups and a U-shaped permanent magnet with an opening facing downward, each coil group is connected with a detection probe, in the three coil groups, coil group I is a saturation magnetization strength state detection coil group, coil group II is a coercive force state detection coil group, and coil group III is an initial magnetization state detection coil group, wherein coil group I is located in the middle of the U-shaped permanent magnet, and coil group I uses a material reaching a saturation magnetization state; coil group II is located at a relatively close position on both sides of the U-shaped permanent magnet and is used for detecting a maximum value of an incremental permeability signal; and coil group III is located at a relatively far position on both sides of the U-shaped permanent magnet and is used for detecting an incremental permeability signal in an initial magnetization stage.
[0011] The coil group II comprises a plurality of groups of small coils, the small coils are respectively connected with receiving coils and excitation coils, the excitation coils are connected with a signal acquisition card through a high-frequency constant current source and a DDS, the receiving coils are connected with the signal acquisition card through a lock-in amplifier, and the signal acquisition card is connected with a computer.
[0012] The coil group I comprises a plurality of groups of coils, each group of coils comprises a receiving coil and an excitation coil, the excitation coil is connected with a signal acquisition card through a high-frequency constant current source and a DDS, the receiving coil is connected with the signal acquisition card through a lock-in amplifier, and the signal acquisition card is connected with a computer.
[0013] The coil group III comprises two groups of coils distributed at both ends of the U-shaped permanent magnet, each group of coils comprises a receiving coil and an excitation coil, the excitation coil is connected with a signal acquisition card through a high-frequency constant current source and a DDS, the receiving coil is connected with the signal acquisition card through a lock-in amplifier, and the signal acquisition card is connected with a computer.
[0014] The application further provides a material yield strength detection method, wherein a sample to be detected is moved through a permanent magnet, the permanent magnet is used for magnetizing the sample to be detected, the magnetization degree of each part of the sample to be detected changes with the distance from the permanent magnet, the permeability signals in multiple magnetization states are acquired, and the yield strength of the sample to be detected is calculated according to a performance prediction model and the multiple permeability signals.
[0015] The detection method is specifically as follows:
[0016] 1) make the article to be detected move through the multi-coil incremental permeability dynamic detection probe of claim 1, obtain a plurality of IP parameters through three groups of coil groups respectively, the average value measured by each coil of coil group I is V min , the one with the maximum signal in the small coil group of coil group II is V max , and the IP parameters obtained by coil group III are V cross1 and V cross2 ;
[0017] 2) judge whether the yield strengths detected in coil group III are the same, if yes, proceed to step 3), otherwise return to step 1).
[0018] 3) take V min and V max as the predicted characteristic parameters, calculate the yield strength of the sample to be detected through a performance prediction model, and the performance prediction model is:
[0019]
[0020] Wherein, σ is the predicted yield strength of the sample, V min and V max are the maximum and minimum values of the incremental permeability signal respectively, and k is a fixed parameter related to the microstructure of the material and the probe lift-off.
[0021] The present application has the beneficial effects that:
[0022] 1. The probe mode of the multi-coil is used to detect the material in the non-magnetized state at different positions at the same time. In this way, the mechanical properties of the material can be quickly and efficiently predicted during the movement.
[0023] 2. Compared with the traditional static detection mode, the dynamic detection probe can be used for continuous detection to improve the detection efficiency and realize the purpose of pipeline detection operation.
[0024] 3. The new permanent magnet excitation method is used instead of the high-power low-frequency magnetizing coil, which reduces the power consumption of the system; only the parameter values used for prediction are collected, not the entire IP butterfly diagram information, which optimizes signal acquisition, transmission and storage.
[0025] 4. The yield value of the sample in operation can be quickly detected, and the data value of the full length of the sample can be obtained. Within the relative error accuracy range of 10%, the sample qualification rate is more than 90%, and the detection speed can reach 3m / s. BRIEF DESCRIPTION OF DRAWINGS
[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be 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.
[0027] Figure 1 This is a diagram illustrating IP parameters.
[0028] Figure 2 This is a schematic diagram of the structure of the present invention.
[0029] Figure 3 This is a schematic diagram of the probe signal acquisition section.
[0030] Figure 4 This is a flowchart for prediction using a multi-coil dynamic probe. Detailed Implementation
[0031] 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.
[0032] The multi-coil incremental permeability dynamic detection probe provided by this invention is as follows: Figure 2 As shown, it is divided into three coil groups: 1. The saturation magnetization state detection coil, called coil group I, is located in the middle of the U-shaped permanent magnet, where the magnetic field strength is the largest, and the material has reached the saturation magnetization state. 2. The coercivity state detection coil, called coil group II, is located on both sides of the U-shaped permanent magnet, closer to each other, and consists of multiple small coils, used to detect the maximum value of the incremental permeability signal. 3. The initial magnetization state detection coil, called coil group III, is located on both sides of the U-shaped permanent magnet, farther from each other, used to detect the incremental permeability signal in the initial stage of magnetization.
[0033] The probe signal acquisition section, such as Figure 3 As shown:
[0034] Coil group II includes several groups of small coils, which are connected to the receiving coil and the excitation coil respectively. The excitation coil is connected to the signal acquisition card through a high-frequency constant current source and a DDS. The receiving coil is connected to the signal acquisition card through a lock-in amplifier. The signal acquisition card is connected to a computer.
[0035] The coil group I includes several groups of coils, each group of coils includes a receiving coil and an excitation coil, the excitation coil is connected with a signal acquisition card through a high-frequency constant current source and a DDS, the receiving coil is connected with the signal acquisition card through a lock-in amplifier, and the signal acquisition card is connected with a computer.
[0036] The coil group III includes two groups of coils distributed at two ends of the U-shaped permanent magnet, each group of coils includes a receiving coil and an excitation coil, the excitation coil is connected with a signal acquisition card through a high-frequency constant current source and a DDS, the receiving coil is connected with the signal acquisition card through a lock-in amplifier, and the signal acquisition card is connected with a computer.
[0037] The application also provides a detection method of material yield strength, which makes the sample to be detected move through the permanent magnet, magnetizes the sample to be detected by the permanent magnet, changes the magnetization degree of each part of the sample to be detected with the distance from the permanent magnet, obtains the magnetic permeability signals in multiple magnetization states, and calculates the yield strength of the sample to be detected according to the performance prediction model and the multiple magnetic permeability signals.
[0038] The detection method is specifically as follows:
[0039] 1) make the sample to be detected move through the multi-coil incremental magnetic permeability dynamic detection probe in claim 1, obtain a plurality of IP parameters through the three groups of coils respectively, the average value measured by each coil of the coil group I is V min , the one with the maximum signal in the small coil group of the coil group II is V max , the IP parameters obtained by the coil group III are V cross1 and V cross2 , and details are shown in Table 1.
[0040] 2) judge whether the yield strengths detected in the coil group III are the same, if yes, step 3) is performed, otherwise, step 1) is returned.
[0041] 3) take V min and V max as the prediction characteristic parameters, calculate the yield strength of the sample to be detected through the performance prediction model, and the performance prediction model is as follows:
[0042]
[0043] Wherein, sigma is the predicted yield strength of the sample, V min and V max are the minimum value and the maximum value of the incremental magnetic permeability signal respectively, and k is a fixed parameter related to the microstructure of the material and the probe lift-off.
[0044] Table 1: response parameters of each coil group
[0045]
[0046] The method can be used to quickly detect the yield value of the sample in online operation, obtain the data value of the full length of the sample, and the sample qualification rate is more than 90% within the relative error accuracy range of 10%, and the detection speed can reach 3 m / s.
[0047] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the device embodiments, the above description is only the preferred implementation of the present application, and since it is basically similar to the method embodiments, it is described more simply, and the relevant parts can be referred to the part of the method embodiments. The above description is only the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, and the changes or replacements within the technical range disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A multi-coil incremental permeability dynamic detection probe, characterized in that: The device includes three coil groups and a U-shaped permanent magnet with its opening facing downwards. Each coil group is connected to a detection probe. Among the three coil groups, coil group I is the saturation magnetization state detection coil group, coil group II is the coercivity state detection coil group, and coil group III is the initial magnetization state detection coil group. Coil group I is located in the middle of the U-shaped permanent magnet and uses a material that has reached the saturation magnetization state. Coil group II is located on both sides of the U-shaped permanent magnet closer to each other and detects the maximum value of the incremental permeability signal. Coil group III is located on both sides of the U-shaped permanent magnet farther from each other and detects the incremental permeability signal in the initial stage of magnetization.
2. The multi-coil incremental permeability dynamic detection probe according to claim 1, characterized in that: The coil group II includes several small coils, which are respectively connected to the receiving coil and the excitation coil. The excitation coil is connected to the signal acquisition card through a high-frequency constant current source and a DDS. The receiving coil is connected to the signal acquisition card through a lock-in amplifier. The signal acquisition card is connected to a computer.
3. The multi-coil incremental permeability dynamic detection probe according to claim 1, characterized in that: The coil group I includes several groups of coils. Each group of coils includes a receiving coil and an excitation coil. The excitation coil is connected to the signal acquisition card through a high-frequency constant current source and a DDS. The receiving coil is connected to the signal acquisition card through a lock-in amplifier. The signal acquisition card is connected to a computer.
4. The multi-coil incremental permeability dynamic detection probe according to claim 1, characterized in that: The coil group III includes two groups of coils distributed at both ends of the U-shaped permanent magnet. Each group of coils includes a receiving coil and an excitation coil. The excitation coil is connected to the signal acquisition card through a high-frequency constant current source and a DDS. The receiving coil is connected to the signal acquisition card through a lock-in amplifier. The signal acquisition card is connected to a computer.
5. A method for testing the yield strength of a material, characterized in that: The sample under test is moved through a permanent magnet, which magnetizes the sample. The degree of magnetization at different parts of the sample varies with the distance from the permanent magnet. Magnetic permeability signals under multiple magnetization states are acquired. The yield strength of the sample is calculated based on the constructed performance prediction model and the multiple magnetic permeability signals. The specific detection method is as follows: 1) The object to be detected is moved through the incremental permeability dynamic detection probe with multiple coils as described in claim 1, and several IP parameters are obtained through three sets of coils respectively; 2) Determine whether the yield strength detected in coil group III is the same. If they are the same, proceed to step 3); otherwise, return to step 1. 3) The average value measured by each coil in coil group I and the signal with the largest value in the small coil group of coil group II are used as prediction feature parameters, and the yield strength of the sample under test is calculated by the performance prediction model.
6. The method for testing the yield strength of a material according to claim 5, characterized in that: In the yield strength testing method described in step 2), the IP parameter obtained by coil group III is denoted as V. cross1 and V cross2 If satisfied Proceed to step 3; otherwise, return to step 1.
7. The method for testing the yield strength of a material according to claim 5, characterized in that: The performance prediction model is as follows: where σ is the predicted yield strength of the sample, V min is the average value measured for each coil of coil set I, V max is the coil of coil set II with the largest signal, V min and V max are the minimum and maximum values of the incremental permeability signal, respectively, and k is a fixed parameter related to the microstructure of the material and the probe lift-off.