Multi-frequency eddy current flaw detection equipment and method for phi 6.5 mm-phi 8.5 mm tantalum alloy cold-rolled ultra-small-diameter and ultra-thin-walled pipe

Abstract

The invention provides a multi-frequency eddy current flaw detection method for a phi 6.5 mm-phi 8.5 mm tantalum alloy cold-rolled ultra-small-diameter and ultra-thin-walled pipe, and relates to the technical field of tantalum alloy ultra-small-diameter flaw detection methods, and the multi-frequency eddy current flaw detection method comprises a pressing assembly, a penetrating type eddy current detection assembly, a rotary type eddy current detection assembly and an operation table; a to-be-detected pipe stably passes through the penetrating type eddy current detection assembly and the rotary type eddy current detection assembly through the pressing assembly, the penetrating type eddy current detection assembly and the rotary type eddy current detection assembly in advance, and the situation that vibration and shaking of the to-be-detected pipe affect the relative position between a detection coil and the pipe, and consequently detection signals are interfered is avoided; meanwhile, a penetrating type and rotating type combined mode is adopted, a multi-frequency eddy current detection mode is introduced, the detection angle is increased, and the electromagnetic coupling effect of the detection coil and the pipe is improved, so that the complex defect recognition capability and the anti-interference capability of the pipe to be detected are improved, and the detection accuracy and sensitivity are greatly improved; and efficient and accurate flaw detection of the tantalum alloy cold-rolled ultra-small-diameter ultra-thin-walled pipe with the diameter of 6.5-8.5 mm is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of tantalum alloy ultra-small diameter flaw detection methods, specifically relating to a multi-frequency eddy current flaw detection equipment and method for Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes. Background Technology

[0002] Tantalum alloy tubing, due to its high melting point, excellent corrosion resistance, and biocompatibility, has become an irreplaceable key material in aerospace, nuclear chemical industry, and high-end medical devices. With the evolution of core components towards lightweight and highly integrated designs, the demand for cold-rolled ultra-small diameter, ultra-thin-walled tantalum alloy tubing (Φ6.5 mm–Φ8.5 mm) is growing exponentially. However, the complex metal flow during the final cold rolling deformation of this tubing specification makes it highly susceptible to surface microcracks, subcutaneous porosity, and grain boundary micro-delamination at the 5–30 μm level. Simultaneously, the extreme geometric characteristics of a wall thickness / diameter ratio ≤0.025 mean that any defect deeper than 5% of the wall thickness can lead to penetration leakage during service life, placing an extreme requirement of "zero blind zone, zero false positives" on non-destructive testing.

[0003] Current eddy current testing of small-diameter rare metal pipes generally adopts a "single-frequency through-pass" method: the pipe material is tested at a frequency of 0.2–1.0 m·s. -1 A constant-speed pass through a self-comparing differential coil typically uses an excitation frequency fixed in the 1-3 MHz range. This mode can only obtain impedance signals at a single skin depth (δ≈0.15 mm), and cannot simultaneously achieve optimal sensitivity for both surface microcracks (depth 5–20 μm) and subsurface porosity (depth 50–100 μm). Therefore, developing a multi-frequency, multi-parameter, high-resolution eddy current testing technology for ultra-small diameter, ultra-thin-walled tantalum alloy tubes has become a bottleneck in high-end manufacturing. Summary of the Invention

[0004] In view of this, the present invention provides a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters of Φ6.5mm-Φ8.5mm.

[0005] It is also necessary to provide a multi-frequency eddy current flaw detection method for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters of Φ6.5mm-Φ8.5mm.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A multi-frequency eddy current flaw detection device for cold-rolled ultra-small diameter, ultra-thin-walled tantalum alloy tubes with diameters ranging from 6.5mm to 8.5mm includes a clamping assembly, a through-type eddy current detection assembly, a rotary eddy current detection assembly, and an operating table. At least two clamping assemblies are arranged on a frame at intervals between the clamping assemblies and the through-type and rotary eddy current detection assemblies. The clamping assemblies are located at the detection inlets of the through-type and rotary eddy current detection assemblies. The operating table is electrically connected to both the through-type and rotary eddy current detection assemblies. The clamping assemblies ensure that the tube under test is aligned on the same axis as it passes through the through-type and rotary eddy current detection assemblies. The through-type and rotary eddy current detection assemblies output multi-frequency excitation signals to perform multi-frequency detection on the tube under test, thereby comprehensively inspecting surface and internal defects.

[0008] Preferably, the through-type eddy current detection assembly includes a through-type eddy current detection probe, wherein the number of turns of the detection coil in the through-type eddy current detection probe is 50-80 turns and the wire diameter of the detection coil is 0.15mm-0.2mm, or the number of turns of the detection coil is 10-20 turns and the wire diameter of the detection coil is 0.05-0.1mm.

[0009] Preferably, the rotary eddy current detection assembly includes a rotary eddy current detection probe, wherein the number of turns of the detection coil in the rotary eddy current detection probe is 50-100, and the wire diameter of the detection coil is 0.15-0.2mm, or the number of turns of the detection coil is 10-20, and the wire diameter of the detection coil is 0.05-0.1mm.

[0010] Preferably, the frame material of the detection coil is high-frequency insulating ceramic or polytetrafluoroethylene, and the coil is wrapped with varnish, the temperature resistance of which is ≥200℃.

[0011] Preferably, the clamping assembly includes a support frame mounted on a frame body and clamping portions symmetrically arranged on both sides of the support frame. A transmission wheel is provided below the clamping portions on the frame body. Slide grooves are provided along the height direction on the other two sides of the support frame relative to the clamping portions. A drive screw is provided at the top of the support frame. The middle part of the drive screw is threaded to the support frame. One end of the drive screw is a free end, and the other end of the drive screw is connected to the clamping portions to drive the clamping portions to rise or fall. The gap between the clamping portions and the transmission wheel constitutes the space for the pipe to be tested to advance.

[0012] Preferably, the pressing part includes a sliding block and pressing plates disposed on both sides of the sliding block. A pressure roller is disposed at the lower part of the pressing plate. The top of the sliding block is rotatably connected to the drive screw. The sliding block is slidably connected to the slide groove. The pressure roller is located directly above the transmission wheel. The drive screw drives the pressure roller to rise and fall, adjusting the distance between the pressure roller and the transmission wheel.

[0013] Preferably, the pressing part further includes a fixing plate and a driving member disposed on both sides of the sliding block. The fixing plate is located above the pressing plate. One end of the fixing plate is fixedly connected to the sliding block, and the other end of the fixing plate is rotatably connected to the fixed end of the driving member. The telescopic end of the driving member is rotatably connected to one end of the pressing plate, and the other end of the pressing plate is rotatably connected to the sliding block, so as to control the relative position between the pressure roller and the transmission roller.

[0014] Preferably, the surfaces of the pressure roller and the transmission roller are provided with a wear-resistant layer. The wear-resistant layer is made of polyurethane composite material, with a thickness of 0.2mm-0.5mm and a hardness of Shore 60D-70D.

[0015] The multi-frequency eddy current testing method for inspecting Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes using the multi-frequency eddy current testing equipment described above includes the following steps:

[0016] S1: Under constant pressure and constant current, the detection parameters of the through-type eddy current detection component and the rotating eddy current detection component are verified using a comparison sample tube to obtain the detection parameters of the through-type eddy current detection component and the rotating eddy current detection component, so as to match the conductivity and magnetic permeability of the pipe to be tested.

[0017] S2: Based on the detection parameters of the through-type eddy current detection component and the rotating eddy current detection component obtained from the inspection, the pipe fitting under test is tested to obtain the test results of the pipe fitting under test;

[0018] S3: Output the quality status of the pipe fitting under test based on the test results.

[0019] Preferably, in step S2, the detection parameters of the through-type eddy current detection component include a frequency of 1kHz-50kHz, and the detection parameters of the rotating eddy current detection component include a high frequency and a low frequency, wherein the high frequency is 100kHz-1MHz and the low frequency is 10kHz-50kHz.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The present invention provides a multi-frequency eddy current flaw detection device for Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall pipes, comprising a clamping assembly, a through-type eddy current detection assembly, a rotary eddy current detection assembly, and an operating table. At least two clamping assemblies are provided, spaced apart from the through-type and rotary eddy current detection assemblies on a frame. The operating table is electrically connected to both the through-type and rotary eddy current detection assemblies for control and signal processing. The clamping assembly ensures that the pipe under test remains coaxial as it passes through the through-type and rotary eddy current detection assemblies, thereby preventing changes in the relative position between the detection coil and the pipe due to pipe vibration or shaking, which could interfere with the detection signal. The through-type eddy current detection component and the rotary eddy current detection component output multi-frequency excitation signals to perform multi-frequency detection on the pipe under test. The pipe under test is pre-stressed by the clamping component, through-type eddy current detection component, and rotary eddy current detection component to ensure stable passage of the pipe under test, preventing vibration and shaking of the pipe under test from affecting the relative position between the detection coil and the pipe, thus avoiding interference with the detection signal. Simultaneously, the combination of through-type and rotary methods introduces a multi-frequency eddy current detection mode, increases the detection angle, and improves the electromagnetic coupling effect between the detection coil and the pipe, thereby improving the ability to identify complex defects and resist interference in the pipe under test. This significantly improves the accuracy and sensitivity of the detection, achieving efficient and accurate flaw detection of Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall pipes. Attached Figure Description

[0022] Figure 1 This is a front view of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0023] Figure 2 This is a top view of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter, ultra-thin wall tubes made of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0024] Figure 3 This is a partial structural diagram of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0025] Figure 4 This is a partial front view of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0026] Figure 5 This is a partial side view of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter and ultra-thin wall tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0027] Figure 6 This is a partial structural diagram of a multi-frequency eddy current flaw detection equipment for cold-rolled ultra-small diameter, ultra-thin-walled tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm.

[0028] Figure 7 This is a schematic diagram of the clamping assembly.

[0029] Figure 8 This is a schematic diagram of the rotating eddy current detection component.

[0030] The diagram shows: a multi-frequency eddy current flaw detection equipment for tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes 10, a clamping assembly 100, a support frame 110, a sliding groove 111, a drive screw 112, a clamping part 120, a sliding block 121, a clamping plate 122, a pressure roller 123, a fixing plate 124, a drive component 125, a through-type eddy current detection assembly 200, a through-type eddy current detection probe 210, a high magnetic permeability shield 220, a rotary eddy current detection assembly 300, a rotary eddy current detection probe 310, a rotary centering and calibration part 320, a vertical mounting groove 321, a moving groove 3211, a bidirectional threaded screw 322, a moving block 323, a clamping wheel 324, a rotating handwheel 325, an operating table 400, a frame 500, and a transmission wheel 510. Detailed Implementation

[0031] The technical solutions and effects of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] For cold-rolled ultra-small diameter, ultra-thin walled tantalum alloy pipes with diameters of Φ6.5-8.5mm, the applicant uses the existing through-type eddy current testing method for inspection, which presents the following problems: If surface / near-surface defects (such as cracks, scratches) are to be detected, a higher frequency (50-200kHz) needs to be selected. At this time, the penetration depth (skin depth δ) is only 0.1-0.3mm, which can focus the surface signal but cannot detect defects deep in the inner wall; If inner wall / wall thickness defects (such as corrosion, wall thinning) need to be detected, the frequency needs to be reduced (5-20kHz), but after the penetration depth (skin depth δ) increases to 0.5-1mm, it may exceed the wall thickness of the pipe (the wall thickness of the pipe to be tested in this size is usually 1-5mm), resulting in "field overflow" and a decrease in signal-to-noise ratio; At the same time, for mixed defects that may be generated in tantalum alloy pipes during cold rolling (such as cracks accompanied by local wall thickness deviations), the single-frequency signal characteristics are singular, making it difficult to effectively distinguish and locate them. Therefore, this size inspection requires precise frequency matching based on the "defect location," and there is no universal frequency solution, which is significantly different from the "wide frequency adaptation" of large-diameter pipe fittings.

[0033] Please refer to Figures 1 to 8This invention provides a Φ6.5mm-Φ8.5mm... A multi-frequency eddy current flaw detection device 10 for tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes includes a clamping assembly 100, a through-type eddy current detection assembly 200, a rotary eddy current detection assembly 300, and an operating table 400. There are at least two clamping assemblies 100, which are spaced apart from the through-type eddy current detection assembly 200 and the rotary eddy current detection assembly 300 on a frame 500. For example, there are two clamping assemblies 100, one located on one side of the inlet of the through-type eddy current detection assembly 200, the other on the other side of the rotary eddy current detection assembly 300, and the third clamping assembly 100 on the other side of the rotary eddy current detection assembly 300; or there are three clamping assemblies 100, the through-type eddy current detection assembly 200, and the rotary eddy current detection assembly 300, arranged in a configuration of clamping assembly 100, through-type eddy current detection assembly 200, and clamping assembly 100. A rotary eddy current testing component 300 and a clamping component 100 are arranged. The operating table 400 is electrically connected to the through-type eddy current testing component 200 and the rotary eddy current testing component 300 respectively. The clamping component 100 ensures that the pipe under test is located on the same axis when passing through the through-type eddy current testing component 200 and the rotary eddy current testing component 300. The through-type eddy current testing component 200 and the rotary eddy current testing component 300 output multi-frequency excitation signals to perform multi-frequency testing on the pipe under test, so as to comprehensively detect the surface and internal defects of the pipe under test.

[0034] The control panel 400 is connected to a battery, which is connected to AC power to output constant voltage and constant current.

[0035] The present invention provides a multi-frequency eddy current testing device 10 for cold-rolled ultra-small diameter, ultra-thin-walled tubes of tantalum alloy with diameters ranging from 6.5mm to 8.5mm. The device includes a clamping assembly 100, a through-type eddy current testing assembly 200, a rotary eddy current testing assembly 300, and an operating table 400. Two or more sets of the clamping assembly 100 are arranged along the frame 500, spaced apart from the through-type and rotary eddy current testing assemblies 300. The operating table 400 is electrically connected to both types of eddy current testing assemblies for control and signal processing.

[0036] The function of the clamping assembly 100 is to ensure that the pipe under test remains coaxial when passing through the two detection assemblies, thereby avoiding changes in the relative position between the detection coil and the pipe due to pipe vibration or shaking, which would interfere with the detection signal.

[0037] This device employs a combination of through-type and rotary eddy current detection methods and outputs multi-frequency excitation signals to achieve multi-frequency eddy current detection of pipes. This design not only increases the detection coverage angle but also enhances the electromagnetic coupling effect between the detection coil and the pipe, thereby significantly improving the ability to identify complex defects and its anti-interference performance.

[0038] In summary, this system, through the integration of mechanical stabilization and multi-frequency eddy current technology, significantly improves the accuracy and sensitivity of the detection, enabling efficient and precise non-destructive testing of Φ6.5mm–Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes.

[0039] Compared to existing single-frequency through-feed eddy current testing methods, this invention utilizes multi-frequency collaborative detection to simultaneously capture signal characteristics of surface, subsurface, and internal defects, solving the problem that a single frequency cannot cover defects at different depths, thus improving the defect detection rate by over 30%. Furthermore, the combination of through-feed, rotating mechanisms, and multi-frequency technology enables 360° inspection of the pipe, avoiding the circumferential blind spots of traditional axial transport. In addition, the multi-frequency signals effectively suppress interference factors such as uneven pipe material and surface oxidation, reducing the false positive rate to below 5%, significantly improving the reliability of the inspection and making it more suitable for quality control of ultra-small diameter, ultra-thin-walled tantalum alloy pipes in high-end applications.

[0040] In one embodiment, the pipe under test can be tested either by passing through the through-type eddy current detection component 200 or by passing through the eddy current detection component. The accompanying drawings of this application illustrate the example of the pipe under test passing through the rotary eddy current detection component 300 and then through the through-type eddy current detection component 200.

[0041] In one embodiment, the through-type eddy current detection assembly 200 includes a through-type eddy current detection probe 210. The through-type eddy current detection probe 210 has 50-80 turns of a detection coil with a wire diameter of 0.15mm-0.2mm, or 10-20 turns of a detection coil with a wire diameter of 0.05-0.1mm. The appropriate detection coil is selected according to the thickness of the pipe wall to be tested, so as to improve the electromagnetic coupling effect and detection sensitivity.

[0042] In one embodiment, the detection coil in the through-type eddy current detection probe 210 has 50-80 turns and a wire diameter of 0.15mm-0.2mm, which is suitable for the detection of thin-walled pipes. It is generally applicable to pipes with a wall thickness ≤1mm, such as precision capillary tubes and instrument tubes made of rare metals like tantalum, niobium, and titanium, to enhance the electromagnetic coupling effect and improve the detection sensitivity for defects on and near the thin-walled surface (such as micro-cracks, pinholes, and uneven wall thickness). Using a thicker wire diameter can also reduce the resistance loss of the coil and ensure the stability of the detection signal.

[0043] The through-type eddy current testing probe 210 has a detection coil with 10-20 turns and a wire diameter of 0.05-0.1 mm. It is suitable for testing thicker-walled pipes, typically with wall thicknesses of 1-5 mm, such as titanium alloy structural pipes and tantalum-niobium alloy chemical pipes. This reduces the skin effect of the coil itself, allowing the magnetic field to penetrate deeper into the pipe wall, thus detecting defects on the inner wall or in the middle of the wall thickness (such as internal inclusions, delamination, and wall thickness deviations). Simultaneously, the fine wire diameter ensures coil winding accuracy while reducing the number of turns, preventing excessively large coil sizes that could lead to excessive gaps between the coil and the inner wall of the pipe, affecting coupling performance. Different detection coils can be selected based on the pipe wall thickness.

[0044] In one embodiment, the inner diameter of the detection coil in the through-type eddy current detection probe 210 is 0.5mm-1mm larger than the outer diameter of the pipe to be tested.

[0045] In one embodiment, the rotary eddy current detection assembly 300 includes a rotary eddy current detection probe 310. The rotary eddy current detection probe 310 has a detection coil with 50-100 turns and a wire diameter of 0.15-0.2 mm, or a detection coil with 10-20 turns and a wire diameter of 0.05-0.1 mm. The appropriate detection coil is selected according to the thickness of the pipe wall to be tested, so as to improve the electromagnetic coupling effect and detection sensitivity.

[0046] In one embodiment, the number of turns of the detection coil in the rotary eddy current detection probe 310 is 50-100, and the wire diameter of the detection coil is 0.15-0.2mm. It is suitable for the detection of thin-walled pipes, and is generally applicable to pipes with a wall thickness ≤1mm, such as precision capillary tubes and instrument tubes made of rare metals such as tantalum, niobium, and titanium. The high-speed rotation of the rotary probe can drive the coil to perform a 360° circumferential scan of the pipe wall; while the strong surface magnetic field of the high-turn coil can accurately capture minute defects on and near the surface of thin-walled pipes (such as micron-level cracks, pinholes, and local uneven wall thickness).

[0047] The rotary eddy current testing probe 310 has 10-20 turns of the detection coil and a wire diameter of 0.05-0.1mm, making it suitable for testing thicker-walled pipes, typically with a wall thickness of 1-5mm, such as titanium alloy structural pipes and tantalum-niobium alloy chemical pipes. This reduces the skin effect of the coil itself, allowing the magnetic field to penetrate deeper into the pipe wall, thereby detecting defects on the inner wall or in the middle of the wall thickness (such as internal inclusions, delamination, and wall thickness deviation). Combined with the moving detection mode of the rotary probe, it can complete the full-thickness defect screening of long-distance thick-walled pipes (such as internal inclusions, delamination, and internal wall corrosion pits).

[0048] In one embodiment, the gap between the rotary eddy current testing probe 310 and the pipe to be tested is ±0.05mm.

[0049] In one embodiment, the rotary eddy current detection assembly 300 further includes a rotary centering calibration unit 320. The rotary centering calibration unit 320 includes a vertical mounting groove 321, a bidirectional threaded screw 322 located within the vertical mounting groove 321, two moving blocks 323, and two clamping wheels 324 located on the same side of the vertical mounting groove 321. A moving groove 3211 is provided on the side of the vertical mounting groove 321. The vertical mounting groove 321 is installed at the entrance of the rotary eddy current detection probe 310. The two ends of the bidirectional threaded screw are connected to the vertical mounting groove 321. The mounting groove 321 is rotatably connected. One end of the bidirectional threaded screw 322 passes through the top of the vertical mounting groove 321 and is equipped with a rotating handwheel 325. Two moving blocks 323 are respectively set in different helical directions of the bidirectional threaded screw 322. The clamping wheel 324 is rotatably connected to the moving block 323. The two clamping wheels 324 are located at the inlet of the rotary eddy current detection probe 310. The rotating handwheel drives the bidirectional threaded screw 322 to rotate, thereby the two clamping wheels 324 move closer or further away from each other so that the pipe to be tested is coaxial with the inlet of the rotary eddy current detection probe 310.

[0050] The rotary centering calibration unit 320 controls the clamping force fluctuation of the pipe under test to within ±5%, eliminating signal interference caused by gap changes.

[0051] In one embodiment, the frame material of the detection coil is high-frequency insulating ceramic or polytetrafluoroethylene to avoid generating parasitic eddy currents that interfere with the detection signal. The coil is wrapped with varnish, and the temperature resistance of the varnish is ≥200℃ to ensure that the probe works stably in the range of -20℃ to 200℃.

[0052] In one embodiment, a high permeability shield 220 (such as a permalloy shielding layer) is installed around the through-type eddy current detection probe 210 and the rotary eddy current detection probe 310 to block external magnetic field interference with the eddy current signal.

[0053] In one embodiment, the clamping assembly 100 includes a support frame 110 mounted on a frame 500 and clamping portions 120 symmetrically arranged on both sides of the support frame 110. A drive wheel 510 is disposed below the clamping portions 120 on the frame 500. The drive wheel 510 has a lower center and higher ends to form a V-groove channel for transporting the pipe fitting to be tested. The drive wheel 510 is rotatably connected to the frame. Slide grooves 111 are provided along the height direction on the other two sides of the support frame 110 relative to the clamping portions 120. A drive screw 1 is disposed on the top of the support frame 110. 12. The middle part of the drive screw 112 is threadedly connected to the support frame 110. One end of the drive screw 112 is a free end, and the other end of the drive screw 112 is connected to the clamping part 120 to drive the clamping part 120 to rise or fall. The gap between the clamping part 120 and the transmission wheel 510 constitutes the space for the pipe to be tested to advance. The lifting and lowering of the clamping part 120 is controlled by the drive screw 112 to control the distance between the clamping part 120 and the transmission wheel 510, so as to avoid vibration of the pipe to be tested during the process of traveling and testing without affecting the pipe to be tested.

[0054] In one embodiment, the pressing part 120 includes a sliding block 121 and pressing plates 122 disposed on both sides of the sliding block 121. A pressure roller 123 is disposed at the lower part of the pressing plate 122. The top of the sliding block 121 is rotatably connected to the drive screw 112. The sliding block 121 is slidably connected to the slide groove 111. The pressure roller 123 is located directly above the transmission wheel 510. The drive screw 112 drives the pressure roller 123 to rise and fall, adjusting the distance between the pressure roller 123 and the transmission wheel 510.

[0055] In one embodiment, the pressing part 120 further includes a fixing plate 124 and a driving member 125 disposed on both sides of the sliding block 121. For example, the driving member 125 is a cylinder. The fixing plate 124 is located above the pressing plate 122. The fixing plate 124 and the pressing plate 122 form a C-shape. The pressing plate 122 itself is "V" shaped, and its tip is rotatably mounted with a pressure roller 123 via a pin. One end of the fixing plate 124 is fixedly connected to the sliding block 121, and the other end of the fixing plate 124 is rotatably connected to the fixed end of the driving member 125. The telescopic end of the driving member 125 is rotatably connected to one end of the pressing plate 122, so that the driving axis forms an acute angle with the vertical direction. The other end of the pressing plate 122 is rotatably connected to the sliding block 121 to control the relative position between the pressure roller 123 and the transmission wheel 510.

[0056] When adjusting the distance between the pressure roller 123 and the transmission roller 510, the drive screw 112 is pre-driven to rotate, causing the sliding block 121 to move downward as a whole, which in turn drives the pressure roller 123 to quickly approach the transmission roller 510. When the distance between the two reaches the preset value, the drive screw 112 is stopped from rotating. The drive component 125 is driven, and the telescopic end of the drive component 125 applies a downward force to the clamping plate 122 for fine adjustment and pressure, so as to stably press the pipe to be tested on the transmission roller 510, suppressing the jumping and vibration during the testing process. At the same time, while pressing, the pipe to be tested is given an auxiliary feeding force to promote its smooth conveying. Thus, the stability of the testing process is ensured, and high-efficiency online transmission is also taken into account.

[0057] In one embodiment, the surfaces of the pressure roller 123 and the transmission roller 510 are provided with a wear-resistant layer. The wear-resistant layer is made of polyurethane composite material, with a thickness of 0.2mm-0.5mm and a hardness of Shore 60D-70D, to prevent the tantalum alloy test tube from being scratched during the testing process.

[0058] The wear-resistant layer has an anti-slip texture to reduce slippage during high-speed rotation.

[0059] The multi-frequency eddy current testing method for inspecting Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter ultra-thin wall tubes using the multi-frequency eddy current testing equipment 10 described above includes the following steps:

[0060] S1: Under constant pressure and constant current, the detection parameters of the through-type eddy current detection component 200 and the rotary eddy current detection component 300 are verified using a comparison sample tube to obtain the detection parameters of the through-type eddy current detection component 200 and the rotary eddy current detection component 300, so as to match the conductivity and magnetic permeability of the pipe to be tested; the temperature of the comparison sample tube is 0℃-50℃;

[0061] S2: Based on the detection parameters of the through-type eddy current detection component 200 and the rotary eddy current detection component 300 obtained from the test, the pipe under test is tested under constant pressure and constant current to obtain the test result of the pipe under test; the temperature of the pipe under test is 0℃-50℃ to avoid excessive temperature difference causing coil impedance drift and affecting the detection accuracy;

[0062] Using constant voltage and constant current for calibration and detection can ensure the signal amplitude. At the same time, constant current limits the heating of the detection probe under high load, avoids impedance drift of the detection coil, and also prevents weak signal strength and low signal-to-noise ratio due to insufficient current, so as to maintain the detection stability of the probe.

[0063] Current graded adjustment: The current is dynamically adjusted according to the detection speed. During high-speed detection, the current is appropriately increased to enhance the signal response speed.

[0064] S3: Outputs the quality status of the pipe fitting based on the test results. The output will match different products or identify the pipe fitting as defective.

[0065] In one embodiment, in step S1, the comparative sample tube is prepared by the following steps: drilling five through holes along the axial direction of the standard tube to obtain the comparative sample tube;

[0066] The standard tube is identical to the tube under test and is free of any defects or damage. Two through holes are located in the blind zone of the comparison sample tube (located at both ends of the comparison sample tube) and the diameter of the two through holes is Φ0.5mm. The two Φ0.5mm through holes are 100mm away from the tube ends. Three through holes are evenly located in the effective area of ​​the comparison sample tube (located in the middle of the comparison sample tube) and the diameter of the three through holes is Φ0.3mm. The distance between the three Φ0.3mm through holes is 500mm, and the three through holes are distributed at 120° intervals along the circumference of the comparison sample tube. The "actual typical defects" (Φ0.3mm and Φ0.5mm through holes) are simulated manually to ensure that the testing benchmark matches the actual needs and that the testing equipment (such as probes and eddy current detectors) can accurately and comprehensively identify minute defects.

[0067] In one embodiment, when setting the eddy current flaw detector detection parameters using the comparison sample tube in step S1, the display amplitude of the Φ0.3mm hole provides the optimal signal-to-noise ratio. The optimal signal-to-noise ratio is determined as follows: compared with the display amplitudes of the three 0.3mm holes, the noise signal amplitude is ≤ 50% of the lowest display amplitude among the three 0.3mm holes, so that the detection equipment can clearly distinguish between the "real defect signal" and the "environmental / instrument noise signal". Furthermore, the deviation of the display amplitude of any Φ0.3mm hole from the average display amplitude of the three 0.3mm holes is within ±20%, and the deviation of the display amplitude of any 0.5mm hole from the average display amplitude of the three 0.3mm holes is within ±10%, ensuring a stable response to defect signals at different locations and avoiding signal fluctuations due to differences in defect location (e.g., end, middle) and size. This ensures the accuracy, stability, and consistency of the detection results, avoiding missed detections, false detections, or judgment deviations.

[0068] Adjust the detection speed: Use the Φ0.5mm holes near the two ends on the comparison sample tube to adjust the detection speed.

[0069] This ensures clear differentiation between the signals at the beginning and end of the pipe and the amplitude of the Φ0.3mm hole; it also prevents confusion between the signals at the beginning and end of the pipe and the defect signals of the Φ0.3mm hole, ensuring the accuracy of defect detection in the end area.

[0070] Defect assessment: If the display amplitude of the defect in the inspected pipe is ≤ the lowest display amplitude among the three 0.3 holes or there is no alarm display signal, it is considered qualified; if the display amplitude of the defect in the inspected pipe is greater than the display value of the 0.3 hole, it is considered unqualified or the location of the defect is unqualified.

[0071] In one embodiment, during the verification of the comparative sample tube, a through-type eddy current detection probe 210 is used for pre-detection. When the signal amplitude detected by the through-type eddy current detection probe 210 exceeds a preset threshold, the subsequent detection process of the rotary eddy current detection probe 310 is automatically triggered. The excitation frequency of the through-type eddy current detection probe 210 and the material information of the tube under test are synchronized to the rotary eddy current detection probe 310 as the initial values ​​of the detection parameters, shortening the parameter debugging time, so as to carry out phased collaborative detection, match the positioning of each in the detection process, and avoid functional overlap or omission.

[0072] In one embodiment, in step S2, the conveying speed of the pipe to be tested is 0.3m / min-1m / min, and the rotation speed of the rotary eddy current detection probe 310 is 30r / min-120r / min, so that the detection speed is consistent with the conveying cycle of the production line and the batch processing efficiency is guaranteed.

[0073] In one embodiment, in step S2, the detection parameters of the through-type eddy current detection component 200 include a frequency of 1kHz-50kHz, and the detection parameters of the rotating eddy current detection component 300 include a high frequency and a low frequency. The high frequency is 100kHz-1MHz, and the low frequency is 10kHz-50kHz, so that the parameters of the two probes are complementary and the defect judgment deviation is avoided due to parameter differences.

[0074] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection device, characterized in that, The utility model provides a kind of pipe detection device, including pressing assembly, through type eddy current detection assembly, rotary eddy current detection assembly, operating platform, the pressing assembly is at least two, the pressing assembly is spaced apart on frame with the through type eddy current detection assembly, rotary eddy current detection assembly, the pressing assembly is respectively located the detection entrance of the through type eddy current detection assembly, rotary eddy current detection assembly, the operating platform is respectively electrically connected with the through type eddy current detection assembly, rotary eddy current detection assembly, the pressing assembly makes the pipe to be measured pass through the through type eddy current detection assembly, rotary eddy current detection assembly when located same axis, the through type eddy current detection assembly, rotary eddy current detection assembly output multi-frequency excitation signal to the pipe to be measured for multi-frequency detection, to carry out comprehensive detection to the surface layer and internal defect of the pipe to be measured.

2. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 1, characterized in that, The through type eddy current detection assembly includes a through type eddy current detection probe, the number of turns of the detection coil in the through type eddy current detection probe is 50-80 turns, and the wire diameter of the detection coil is 0.15-0.2 mm, or the number of turns of the detection coil is 10-20 turns, and the wire diameter of the detection coil is 0.05-0.1 mm.

3. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 2, characterized in that, The rotary eddy current detection assembly includes a rotary eddy current detection probe, the number of turns of the detection coil in the rotary eddy current detection probe is 50-100 turns, and the wire diameter of the detection coil is 0.15-0.2 mm, or the number of turns of the detection coil is 10-20 turns, and the wire diameter of the detection coil is 0.05-0.1 mm.

4. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment according to claim 2 or 3, characterized in that, The skeleton material of the detection coil is high-frequency insulating ceramic or polytetrafluoroethylene, the coil is wrapped with enameled wire outside the coil, and the temperature resistance grade of the paint is greater than or equal to 200 DEG C.

5. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 1, wherein, The pressing assembly includes a support frame arranged on the frame body and pressing parts symmetrically arranged on both sides of the support frame, the frame body is arranged below the pressing parts to arrange a transmission wheel, the support frame is arranged with a sliding groove in the height direction relative to the other two sides of the pressing parts, the top of the support frame is arranged with a driving screw, the middle part of the driving screw is threadedly connected with the support frame, one end of the driving screw is a free end, the other end of the driving screw is connected with the pressing parts to drive the pressing parts to rise or fall, and the gap between the pressing parts and the transmission wheel constitutes a space for the pipe to be measured to advance.

6. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 5, wherein, The pressing part further includes a fixed plate arranged on both sides of the sliding block and a driving member, the fixed plate is located above the pressing plate, one end of the fixed plate is fixedly connected with the sliding block, the other end of the fixed plate is rotatably connected with the fixed end of the driving member, the telescopic end of the driving member is rotatably connected with one end of the pressing plate, and the other end of the pressing plate is rotatably connected with the sliding block, so as to control the relative position between the pressing wheel and the transmission wheel.

7. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 6, wherein, ​ 8. The Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall pipe multi-frequency eddy current flaw detection equipment of claim 6, wherein, The wear-resistant layer is made of polyurethane composite material, and has a thickness of 0.2-0.5mm and a hardness of 60D-70D (Shore).

9. A multi-frequency eddy current testing method using the Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall tube multi-frequency eddy current testing equipment according to claim 1, characterized in that, The method comprises the following steps: S1: verifying the detection parameters of the through-type eddy current detection assembly and the rotary eddy current detection assembly under constant voltage and constant current by using a contrast sample pipe, so as to match the conductivity and magnetic permeability of the pipe to be detected; S2: detecting the pipe to be detected based on the detection parameters of the through-type eddy current detection assembly and the rotary eddy current detection assembly obtained in the verification, so as to obtain a detection result of the pipe to be detected; S3: outputting the quality condition of the pipe to be detected according to the detection result of the pipe to be detected.

10. The multi-frequency eddy current testing method for testing the Φ6.5mm-Φ8.5mm tantalum alloy cold-rolled ultra-small diameter and ultra-thin wall tube by the multi-frequency eddy current testing equipment of claim 9, wherein, In the step S2, the frequency of the detection parameters of the through-type eddy current detection assembly is 1-50 kHz, the detection parameters of the rotary eddy current detection assembly include a high-frequency frequency and a low-frequency frequency, the high-frequency frequency is 100-1 MHz, and the low-frequency frequency is 10-50 kHz.

Images