Electromagnetic ultrasonic nondestructive testing method for magnetic powder

Abstract

The invention belongs to the technical field of nondestructive testing, and discloses a magnetic powder electromagnetic ultrasonic nondestructive testing method which specifically comprises the following steps: S1, pretreatment: removing burrs, oxide skin, oil stains and other smudginess on the surface of a test piece through a physical method; s2, appearance inspection: observing that the surface of the test piece is free of cracks and other obvious defects; s3, debugging the system; s4, comprehensive sensitivity testing; s5, magnetic powder and electromagnetic ultrasonic detection; s6, observing and analyzing; and S7, demagnetization and post-treatment are carried out. According to the invention, the surface, only surface and internal defects of the test piece can be detected, so that the defect detection capability is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-destructive testing, and particularly relates to a magnetic particle electromagnetic ultrasonic non-destructive testing method. Background Art

[0002] Magnetic particle testing is a commonly used non-destructive testing method for detecting defects in ferromagnetic specimens. The basis of magnetic particle testing is the interaction between the leakage magnetic field at the defect and the magnetic particles. It utilizes the difference in magnetic permeability between the surface and near-surface (such as cracks, slag inclusions, hair cracks, etc.) of ferromagnetic specimens and that of steel. After magnetization, the magnetic field at these material discontinuities will be distorted, forming partial magnetic flux leakage out of the specimen surface to generate a leakage magnetic field, thereby attracting magnetic particles to form magnetic particle accumulation at the defect. Under appropriate lighting conditions, the position and shape of the defect are revealed.

[0003] Magnetic particle testing can only detect defects on the surface and near-surface of the specimen. The magnetic particle method cannot detect internal defects of the specimen. Magnetic particle testing cannot simultaneously take into account the detection of surface and internal defects, nor can it achieve the simultaneous detection of surface and internal defects. Therefore, there is an urgent need for a new magnetic particle testing method to achieve the simultaneous detection of surface and internal defects. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that magnetic particle testing cannot simultaneously take into account the detection of surface defects and internal defects.

[0005] To solve the above technical problem, the specific technical solution of the present invention is as follows:

[0006] A magnetic particle electromagnetic ultrasonic non-destructive testing method specifically includes the following steps:

[0007] S1. Pretreatment: Remove burrs, scale, oil stains and other dirt on the surface of the specimen by physical methods;

[0008] S2. Appearance inspection: Observe that there are no cracks and other obvious defects on the surface of the specimen;

[0009] S3. Debug the system: Check whether the actions such as electrodes, coils, magnetic suspension liquid spraying and discharging, clamping, and loosening of the magnetic particle testing system are operating normally; Check whether the power supply, voltage stabilizer, and oscilloscope of the electromagnetic ultrasonic system are operating normally;

[0010] S4. Comprehensive sensitivity test:

[0011] S401. Test the ultraviolet intensity to make the ultraviolet intensity at a distance of 40 cm from the light source not less than 1000 μW / cm 2 ;

[0012] S402. Press the grooved side of the Type A sensitivity test piece tightly against the surface of the cup body;

[0013] S403. Magnetize, sprinkle the magnetic suspension liquid, and at the same time irradiate the test piece with an ultraviolet lamp. If the magnetic marks of artificial defects are clearly visible, the comprehensive sensitivity meets the requirements.

[0014] S5. Magnetic particle and electromagnetic ultrasonic testing;

[0015] S6. Observe and analyze;

[0016] S7. Demagnetize and post-process.

[0017] Furthermore, S5 specifically includes the following steps:

[0018] S501. Circumferential magnetization of magnetic particles and electromagnetic ultrasonic. Clamp the test piece between the two electrodes of the magnetic particle testing machine, place the high-frequency coil closely against the surface of the test piece, and place the magnet on the surface of the high-frequency coil. The magnetic particle testing machine magnetizes 2 - 3 times, each time for 2 - 3 s. When magnetizing, pass alternating current through the high-frequency coil to form electromagnetic ultrasonic waves. At the same time, sprinkle the magnetic suspension liquid, and after sprinkling the magnetic suspension liquid, magnetize 1 - 2 more times, each time for 2 - 3 s, so that the flowing magnetic powder is fully absorbed and accumulated by the leakage magnetic field at the defect.

[0019] S502. Move the high-frequency coil and the magnet in sequence: According to the steps of S501, conduct a full - range scanning test on the test piece and collect the electromagnetic ultrasonic signals at various positions of the test piece.

[0020] S503. Longitudinal magnetization of magnetic particles and electromagnetic ultrasonic. Place the test piece in the middle of the coil of the magnetic particle testing machine, place the high-frequency coil closely against the surface of the test piece, and place the magnet on the surface of the high-frequency coil. The magnetic particle testing machine magnetizes 2 - 3 times, each time for 2 - 3 s. When magnetizing, pass alternating current through the high-frequency coil to form electromagnetic ultrasonic waves. At the same time, sprinkle the magnetic suspension liquid, and after sprinkling the magnetic suspension liquid, magnetize 1 - 2 more times, each time for 2 - 3 s, so that the flowing magnetic powder is fully absorbed and accumulated by the leakage magnetic field at the defect, which is beneficial for the magnetic powder to show defects at the magnetic leakage.

[0021] S504. Move the high-frequency coil and the magnet in sequence. According to the steps of S503, conduct a full - range scanning test on the test piece and collect the electromagnetic ultrasonic signals at various positions of the test piece.

[0022] Furthermore, S6 specifically includes the following steps:

[0023] S601. Turn off the fluorescent lamp, irradiate the surface of the test piece with an ultraviolet lamp under darkroom conditions. Utilize the leakage magnetic field escaping from the surface defects and internal defects of the test piece, and the magnetic powder adsorbs and aggregates at the magnetic leakage. A light green bright fluorescence forms at the defect, and carefully confirm and judge.

[0024] S602. If there are doubts, wipe off the magnetic marks, re - magnetize, sprinkle the magnetic suspension liquid, and then carefully observe and analyze to judge the defects.

[0025] S603. Mark the position, size and nature of the defect with a marker pen at the defect location, and analyze the defect quantitatively, qualitatively and positionally to obtain a conclusion.

[0026] S604. Under a fluorescent lamp, transmit the collected electromagnetic ultrasonic signals into an oscilloscope, and separate and extract the electromagnetic ultrasonic signals in the oscilloscope. Among them, the separated eddy current signals are mainly used to detect surface and near-surface defects of the test piece; the separated ultrasonic signals are mainly used to detect internal defects of the test piece.

[0027] S605. Comprehensive evaluation: Further evaluate the composite defects of the test piece to complete the comprehensive non-destructive evaluation of the surface, near-surface and internal defects of the test piece.

[0028] Furthermore, S7 specifically includes the following steps:

[0029] S701. Clean the magnetic suspension liquid on the surface of the test piece.

[0030] S702. Demagnetize by the passing method. Select to turn on the power supply of the demagnetizer, turn on the demagnetization switch, press the right shift button, and move the tray and trolley with the test piece from the left side of the coil to the right side of the coil.

[0031] S703. Measure the residual magnetism. Use a magnetic field meter to check the residual magnetism of the test piece after demagnetization, and require that the residual magnetism is not greater than 0.2 Tm.

[0032] The present invention has the following advantages: It can take into account the detection of surface, only surface and internal defects of the test piece, thereby improving the defect detection ability. Description of the Drawings

[0033] Figure 1 It is a flow chart of the magnetic particle electromagnetic ultrasonic non-destructive testing method according to an embodiment of the present invention.

[0034] Explanation of the marks in the figure: 1. Magnet; 2. High-frequency coil; 3. Test piece; 4. Magnetic suspension liquid; 5. Eddy current; 6. Ultrasonic wave. Detailed Embodiment

[0035] In order to better understand the purpose, structure and function of the present invention, the present invention will be further described in detail below with reference to the drawings.

[0036] As Figure 1As shown in the figure, this embodiment provides a new type of magnetic particle electromagnetic ultrasonic non-destructive testing method, which adopts the mutual assistance method of the magnetic particle method and the electromagnetic ultrasonic method. When the specimen (3) is subjected to magnetic particle testing, the magnetic suspension liquid (4) is sprinkled during the magnetization of the specimen (3), and at the same time, the magnet (1), the high-frequency coil (2) and the specimen (3) that make up the electromagnetic ultrasonic are placed in the magnetic suspension liquid (4), where the high-frequency coil (2) is closely attached to the surface of the specimen (3), and the magnet (1) is placed on the surface of the high-frequency coil (2). Based on the principle of electromagnetic induction, the magnetic suspension liquid (4) is sprinkled during magnetization. At the same time, an alternating current is passed through the high-frequency coil (2), and eddy currents (5) are generated on the surface of the specimen. The eddy currents (5) further magnetize the specimen, so that more effective leakage magnetic fields are obtained on the surface and inside of the specimen after magnetization, which is beneficial to the easier adsorption and accumulation of magnetic powder at the magnetic leakage points to display defects. Under the action of the static magnetic field generated by the magnet (1), the charged particles on the surface of the specimen are deflected by the force and vibrate to form electromagnetic ultrasonic waves. Finally, the specimen (3) is observed and analyzed in all directions with an ultraviolet lamp under darkroom conditions to realize the detection of surface and near-surface defects of the specimen; the detection of surface and near-surface defects of the specimen is realized by extracting and analyzing the eddy current (5) signal in the electromagnetic ultrasonic wave; the detection of internal defects of the specimen is realized by extracting and analyzing the ultrasonic wave (6) signal in the electromagnetic ultrasonic wave, and finally the non-destructive evaluation of the composite defects of the specimen is completed.

[0037] A new type of magnetic particle electromagnetic ultrasonic non-destructive testing method, characterized by including the following steps:

[0038] S01 Pretreatment: Remove burrs, oxide scales, oil stains and other dirt on the surface of the specimen by physical methods;

[0039] S02 Appearance inspection, observe that there are no cracks and other obvious defects on the surface of the specimen;

[0040] S03 Debug the system: Check whether the actions such as the electrodes, coils, magnetic suspension liquid spraying and discharging, clamping and loosening of the magnetic particle testing system are operating normally; check whether the power supply, voltage stabilizer and oscilloscope of the electromagnetic ultrasonic system are operating normally;

[0041] S04 Comprehensive sensitivity test, including the following steps:

[0042] S0401 Use an ultraviolet intensity meter to measure the ultraviolet intensity, and the ultraviolet intensity at a distance of 40 cm from the light source is not less than 1000 μW / cm 2 ;

[0043] S0402 Use double-sided transparent tape to stick the grooved side of the Type A sensitivity test piece closely to the surface of the cup body;

[0044] S0403 Magnetize, sprinkle the magnetic suspension liquid, and at the same time irradiate the test piece with an ultraviolet lamp. If the magnetic marks of the artificial defects are clearly visible, the comprehensive sensitivity meets the requirements;

[0045] S05 Magnetic particle and electromagnetic ultrasonic testing, including the following steps:

[0046] For S0501 magnetic particle circumferential magnetization and electromagnetic ultrasonic testing, the test piece is clamped between two electrodes of a magnetic particle testing machine. The high-frequency coil is closely attached to the surface of the test piece, and the magnet is placed on the surface of the high-frequency coil. The magnetic particle testing machine is magnetized (2 - 3) times, each time for (2 - 3) s. When magnetizing, an alternating current is passed through the high-frequency coil, eddy currents are generated on the surface of the test piece, and the eddy currents further magnetize the test piece, enabling the test piece to obtain more effective leakage magnetic fields on the surface and inside after magnetization. Under the action of the static magnetic field generated by the magnet, the charged particles on the surface of the test piece are deflected by the force and vibrate to form electromagnetic ultrasonic waves. At the same time, a magnetic suspension liquid is sprayed. After spraying the magnetic suspension liquid, it is magnetized (1 - 2) times again, each time for (2 - 3) s, so that the flowing magnetic particles are fully absorbed and accumulated by the leakage magnetic field at the defect, which is conducive to the magnetic particles showing defects at the magnetic leakage;

[0047] For S0502, the high-frequency coil and the magnet are moved successively, and the test piece is scanned and detected in all directions according to the above S501 steps, and the electromagnetic ultrasonic signals at various positions of the test piece are collected;

[0048] For S0503 magnetic particle longitudinal magnetization and electromagnetic ultrasonic testing, the test piece is placed in the middle of the coil. The high-frequency coil is closely attached to the surface of the test piece, and the magnet is placed on the surface of the high-frequency coil. The magnetic particle testing machine is magnetized (2 - 3) times, each time for (2 - 3) s. When magnetizing, an alternating current is passed through the high-frequency coil, eddy currents are generated on the surface of the test piece, and the eddy currents further magnetize the test piece, enabling the test piece to obtain more effective leakage magnetic fields on the surface and inside after magnetization. Under the action of the static magnetic field generated by the magnet, the charged particles on the surface of the test piece are deflected by the force and vibrate to form electromagnetic ultrasonic waves. At the same time, a magnetic suspension liquid is sprayed. After spraying the magnetic suspension liquid, it is magnetized (1 - 2) times again, each time for (2 - 3) s, so that the flowing magnetic particles are fully absorbed and accumulated by the leakage magnetic field at the defect, which is conducive to the magnetic particles showing defects at the magnetic leakage;

[0049] For S0504, the high-frequency coil and the magnet are moved successively, and the test piece is scanned and detected in all directions according to the above S05 / 03 steps, and the electromagnetic ultrasonic signals at various positions of the test piece are collected.

[0050] For S06 observation and analysis, it includes the following steps:

[0051] For S0601, turn off the fluorescent lamp, irradiate the surface of the test piece with an ultraviolet lamp under darkroom conditions. Utilize the leakage magnetic fields escaping from the surface defects and internal defects of the test piece, and the magnetic particles adsorb and accumulate at the magnetic leakage. A light green bright fluorescence is formed at the defect, and carefully confirm and judge;

[0052] For S0602, if there are doubts, the magnetic marks should be wiped off, remagnetized, the magnetic suspension liquid should be sprayed, and then carefully observe and analyze to judge the defect;

[0053] For S0603, mark the position, size and nature of the defect with a marker pen at the judged defect, and make an analysis of the defect quantification, qualification and positioning to obtain a conclusion;

[0054]

[0054] Under a fluorescent lamp, the collected electromagnetic ultrasonic signals are transmitted into an oscilloscope, and the electromagnetic ultrasonic signals are separated and extracted in the oscilloscope. Among them, the separated eddy current signals are mainly used to detect surface and near-surface defects of the specimen; the separated ultrasonic signals are mainly used to detect internal defects of the specimen.

[0055] Comprehensive evaluation: further evaluate the composite defects of the specimen to complete the comprehensive non-destructive evaluation of the surface and near-surface defects and internal defects of the specimen.

[0056]

[0055] S07 Demagnetization and post-treatment, including the following steps:

[0057] S0701 Clean the magnetic suspension liquid on the surface of the specimen;

[0058]

[0056] S0702 Demagnetize by the passing method. Select to turn on the power supply of the demagnetizer, turn on the demagnetization switch, press the right shift button, and move the tray and trolley with the specimen from the left side to the right side of the coil.

[0059] S0703 Measure the residual magnetism. Use a magnetic field meter to check the residual magnetism of the specimen after demagnetization, and require that the residual magnetism is not greater than 0.2 Tm.

[0060] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, for those skilled in the art, several deformations and improvements can still be made without departing from the principle of the present invention, and these should also be regarded as belonging to the protection scope of the present invention.

Claims

1. A magnetic powder electromagnetic ultrasonic nondestructive testing method, characterized in that, Specifically, it includes the following steps: S1. Pretreatment: Remove burrs, scale, oil stains and other dirt on the surface of the specimen by physical methods; S2. Appearance inspection: Observe that there are no cracks or other obvious defects on the surface of the specimen; S3. Debug the system: Check whether the actions such as electrodes, coils, magnetic suspension spraying and discharging, clamping and loosening of the magnetic particle testing system are operating normally; Check whether the power supply, voltage stabilizer and oscilloscope of the electromagnetic ultrasonic system are operating normally; S4. Comprehensive sensitivity test: S401. Test the ultraviolet intensity to ensure that the ultraviolet intensity at a distance of 40 cm from the light source is not less than 1000 μW / cm 2 ; S402. Press the grooved side of the Type A sensitivity test piece tightly against the surface of the cup body; S403. Magnetize and sprinkle the magnetic suspension liquid. At the same time, irradiate the test piece with an ultraviolet lamp. If the magnetic traces of artificial defects are clearly visible, the comprehensive sensitivity meets the requirements; S5. Magnetic particle and electromagnetic ultrasonic testing; S6. Observation and analysis; S7. Demagnetization and post-treatment.

2. The magnetic particle electromagnetic ultrasonic nondestructive testing method according to claim 1, characterized in that S5 specifically includes the following steps: S501. Circumferential magnetization of magnetic particles and electromagnetic ultrasonic. Clamp the specimen between the two electrodes of the magnetic particle testing machine. The high-frequency coil is closely attached to the surface of the specimen, and the magnet is placed on the surface of the high-frequency coil. The magnetic particle testing machine is magnetized 2 - 3 times, 2 - 3 seconds each time; When magnetizing, an alternating current is passed through the high-frequency coil to form electromagnetic ultrasonic waves; At the same time, sprinkle the magnetic suspension liquid. After sprinkling the magnetic suspension liquid, magnetize 1 - 2 times again, 2 - 3 seconds each time, so that the flowing magnetic particles are fully absorbed and accumulated by the leakage magnetic field at the defect; S502. Move the high-frequency coil and the magnet in sequence: According to the steps of S501, scan and detect the specimen in all directions, and collect the electromagnetic ultrasonic signals at various positions of the specimen; S503. Longitudinal magnetization of magnetic particles and electromagnetic ultrasonic. Place the specimen in the middle of the coil of the magnetic particle testing machine. The high-frequency coil is closely attached to the surface of the specimen, and the magnet is placed on the surface of the high-frequency coil. The magnetic particle testing machine is magnetized 2 - 3 times, 2 - 3 seconds each time. When magnetizing, an alternating current is passed through the high-frequency coil to form electromagnetic ultrasonic waves. At the same time, sprinkle the magnetic suspension liquid. After sprinkling the magnetic suspension liquid, magnetize 1 - 2 times again, 2 - 3 seconds each time, so that the flowing magnetic particles are fully absorbed and accumulated by the leakage magnetic field at the defect, which is beneficial for the magnetic particles to show defects at the magnetic leakage; S504. Move the high-frequency coil and the magnet in sequence. According to the steps of S503, scan and detect the specimen in all directions, and collect the electromagnetic ultrasonic signals at various positions of the specimen.

3. The magnetic particle electromagnetic ultrasonic nondestructive testing method according to claim 2, wherein S6 specifically includes the following steps: S601. Turn off the fluorescent lamp. Under darkroom conditions, irradiate the surface of the specimen with an ultraviolet lamp. Utilize the leakage magnetic field escaping from the surface defects and internal defects of the specimen. The magnetic particles are adsorbed and aggregated at the magnetic leakage. A light green bright fluorescence is formed at the defect. Carefully confirm and judge; S602. If there are doubts, wipe off the magnetic traces, remagnetize, sprinkle the magnetic suspension liquid, and then carefully observe and analyze to judge the defects; S603. Mark the position, size and nature of the defects with a marker pen at the judged defects, and make an analysis on the quantification, qualification and location of the defects to obtain a conclusion; S604. Under the fluorescent lamp, transmit the collected electromagnetic ultrasonic signals into the oscilloscope, and separate and extract the electromagnetic ultrasonic signals in the oscilloscope. Among them, the separated eddy current signals are mainly used to detect the surface and near-surface defects of the specimen; The separated ultrasonic signals are mainly used to detect the internal defects of the specimen. S605. Comprehensive evaluation: Further evaluate the composite defects of the test piece to complete the comprehensive non-destructive evaluation of the surface and near-surface defects and internal defects of the test piece.

4. The magnetic particle electromagnetic ultrasonic nondestructive testing method according to claim 3, wherein S7 specifically includes the following steps: S701. Clean the magnetic suspension liquid on the surface of the test piece; S702. Demagnetize by the passing method. Select to turn on the power supply of the demagnetizer, turn on the demagnetization switch, press the right shift button, and move the tray and trolley with the test piece from the left side of the coil to the right side of the coil; S703. Measure the residual magnetism. Use a magnetic field meter to test the residual magnetism of the test piece after demagnetization, and require that the residual magnetism is not greater than 0.2 Tm.

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