CN1022202C - Automatic defect detection technology using electromagnetic ultrasonic - Google Patents
Automatic defect detection technology using electromagnetic ultrasonic Download PDFInfo
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- CN1022202C CN1022202C CN 90109231 CN90109231A CN1022202C CN 1022202 C CN1022202 C CN 1022202C CN 90109231 CN90109231 CN 90109231 CN 90109231 A CN90109231 A CN 90109231A CN 1022202 C CN1022202 C CN 1022202C
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Abstract
The present invention discloses an electromagnetic ultrasonic automatic flaw detection technology for steel plates. High-power pulsed current is generated by a transmitter, eddy current is generated in a steel plate by a probe through induction, plate waves are activated in the steel plate by the action of the eddy current and a magnetic field, and flaws in the steel plate are detected. The electromagnetic ultrasonic automatic flaw detection technology is mainly characterized in that the power of the transmitter is not lower than 50KW; a transmitting coil and a receiving coil of a transducer are respectively arranged below a magnetic pole of an electromagnet; and the size of the transmitting coil and the receiving coil is large. The electromagnetic ultrasonic automatic flaw detection technology can realize 100% flaw detection of steel plates as thick as 18mm.
Description
The invention belongs to the electromagnetic supersonic flaw detecting technology.Mainly be applicable to the automatic nondestructive examination of intermediate gauge steel plate (being commonly called as middle plate).
Middle plate is the big and wide steel of a kind of demand.Along with the development of technology, each industrial sector is more and more higher to the quality requirements of material such as steel plate, and particularly the steel of usefulness such as military project, boiler and pressure vessel all must can offer the user through behind the strict flaw detection.For this reason, the flaw detection task of steel plate is very heavy.
At present, the piezoelectric energy-conversion defectoscopy is generally adopted in the flaw detection of steel plate both at home and abroad.There is following shortcoming in this method: a large amount of oil of needs or water etc. were made couplant when (1) was detected, and had both improved cost, had consumed goods and materials, can make a large amount of oil and sewage pollution environment again, and can't work under the low temperature in the winter time; (2) pick-up unit (being piezoelectric probe) will directly contact with being visited the thing steel plate, and is strict to surface of steel plate smooth finish; (3) area of once detecting a flaw is little, and speed is low, and efficient is poor, and economic benefit is not high; (4) labor strength is big, and because artificial factor makes loss bigger.In recent years, developed hyperchannel (promptly many probes) piezoelectricity automatic flaw detection instrument, and though alleviated working strength of workers, not breaking through in essence of technology, and can only carry out the detection of pectination type to steel plate, loss is still higher.
The seventies rises and has risen electromagnetic acoustic pl. technology in the world, but development so far, this technology also can only detect the steel plate [(10TH WORLD CONFERENCE ON NON-DESTRUCTIVE TESTING), 1A-9,15～22] that thickness is no more than 6mm
The object of the present invention is to provide a kind of electromagnetic acoustic pl. technology that can carry out comprehensive quick detection to the steel plate of bigger thickness range.
Electromagnetic acoustic pl. technology is directly to inspire sound wave in being visited steel plate with electromagnetic method, and steel plate is equivalent to acoustic duct, incident acoustic wave after the surface of steel plate reflection, constructive interference and form Lamb ripple (being a kind of of Lamb wave).The Lamb wave that the Lamb wave composition that inspires in this way excites than piezoelectric approach is much pure, and its effective propagation distance is also much far away than piezoelectric approach, and sensitivity is also very high.
The used probe of electromagnetic supersonic flaw detecting is made up of electromagnet and transmitting coil, receiving coil.
The probe of existing pl. is to adopt horizontal direction magnetic field to excite Lamb wave, be that transducer winding (transmitting coil and receiving coil) is between magnet the two poles of the earth, make the magnetic line of force flatly pass coil winding plane (referring to accompanying drawing 2), in the ferromagnetism steel plate, excite Lamb wave.But this method leakage field is very big, and is also very limited by the magnetic induction density of coil even under the saturated situation of magnet, and the Lamb wave that so just can not inspire sufficient intensity comes, and the thickness that can survey steel plate is restricted.
The principle of work of electromagnetic supersonic flaw detecting of the present invention following (referring to accompanying drawing 1): transmitter is launched more powerful signal, deliver to the transmitting transducer in the probe, in steel plate, induce eddy current, pass through the action of a magnetic field, in steel plate, inspire Lamb wave, in the communication process of Lamb wave in steel plate, if run into defective or edges of boards, will produce reflection at interface, reflection wave be received transducer receive convert voltage signal to after, deliver to receiver, after machine data is handled as calculated, the position and the size of defective are noted, and shown printing or warning.
Main technical schemes of the present invention is: (1) excites the magnetic direction of Lamb wave perpendicular to surface of steel plate, be the transmitting coil of transducer and following (referring to the accompanying drawing 3) that receiving coil places two magnetic poles of probe electromagnet respectively, make the magnetic line of force vertically pass the coil winding plane.Like this, leakage field significantly reduces, and the magnetic induction density by coil improves greatly, and making it inspire Lamb wave in thicker steel plate becomes possibility.For this reason, the ampere turns of electromagnet there is certain requirement, requires more than 9000 ampere-turns.(2) adopt the power source of powerful transmitter as electromagnetic supersonic flaw detecting, the single carrier frequency pulse string of the present invention employing 〉=50KW transmitter, the waveform of transmitter output has only enough big power as shown in Figure 4, just can inspire the Lamb wave of sufficient intensity.(3) adopt large-sized transducer winding, produce enough wide acoustic beam, in steel plate, form Lamb wave, at first must produce enough wide acoustic beam.Could in steel plate, produce constructive interference like this, form Lamb wave (as accompanying drawing 5a); If acoustic beam is wide inadequately, just can not carry out constructive interference, can not form purer Lamb wave (as accompanying drawing 5b).Steel plate is thick more by visiting, and requires the acoustic beam of generation wide more.In order to reach the purpose of wide acoustic beam, the present invention has adopted large-sized transducer winding, and promptly the size of transmitting coil and receiving coil is big, is specially (90～100) * (40～50) mm, and each coil is totally 12 weeks, 24 winding slots.Transmitting coil and receiving coil are mutually the angle between 5 °～10 °, improve flaw detection sensitivity.
Adopt above-mentioned three technology measure, just can in the steel plate of the thick 18mm of reaching, inspire certain intensity Lamb wave, reach and survey the more purpose of steel plate.
Because the volume of transducer is bigger in the probe, single transducer can not the exploratory area can not the exploratory area much bigger than piezoelectric probe.For dead zone-eliminating, the present invention adopts two probes to visit same block plate, each probe only needs to survey 60～70% of steel plate area and gets final product, popped one's head in by another and survey in the blind area of a probe, like this, 20～40% steel plate area is arranged approximately by two common detections of probe, prevented from well to leak and visited.
In the flaw detection process, probe is done relative motion with steel plate.And transmitting coil and receiving coil are the bottoms that is in probe, therefore, must keep strict gap between probe and the steel plate, otherwise, with the sensitivity of influence flaw detection, also can not receive echo when serious, be advisable with 0.5～2.0mm in its gap.
According to technology provided by the present invention, can survey the inherent vice that thickness reaches the 18mm steel plate, and inspection speed is fast, the efficient height can be to 1.8 * 8m in 20 seconds
2Steel plate carry out 100% the flaw detection.
Compared with prior art, the present invention has following advantage:
1. the detectable thick inherent vice that reaches the 18mm steel plate, prior art can only be surveyed steel plate thick below the 6mm.
2. inspection speed is fast, and the efficient height can be to 1.8 * 8m in 20 seconds
2Steel plate carry out 100% flaw detection.
3. alleviated flaw detection personnel's labour intensity greatly, overcome artificial factor, reliability, accuracy improve greatly.
4. owing to can realize the noncontact flaw detection, the smooth finish of being visited surface of steel plate is not required.
5. do not need couplant, thereby be not subjected to the restriction of temperature, any weather conditions all can be detected a flaw.
Description of drawings
Accompanying drawing 1 is principle of work synoptic diagram of the present invention.1 is power transmitter among the figure, and 2,3 are probe, and 4 is receiver, and 5 is computing machine, and 6 for showing printing, and 7 for reporting to the police, and 10 is steel plate.
Accompanying drawing 2 is electromagnet the two poles of the earth of popping one's head in the existing electromagnetic supersonic flaw detecting technology and the synoptic diagram that concerns that receives transmitting coil and steel plate.8 is electromagnet among the figure, and 9 for transmitting and receiving coil, and 10 is steel plate.
Accompanying drawing 3 is the synoptic diagram that concerns of electromagnet, transmitting coil and the receiving coil of the present invention probe and steel plate.Among the figure shown in 8,10 as Fig. 2,11 is transmitting coil, 12 is receiving coil.
Accompanying drawing 4 is the waveform synoptic diagram of transmitter output signal of the present invention.13 is waveform among the figure, and τ is a pulse width, and T is the pulse repetition time.
Accompanying drawing 5 is a Lamb wave constructive interference synoptic diagram, and a is Lamb wave constructive interference of the present invention, and b is that acoustic beam does not have constructive interference when too narrow.W is a beam width among the figure, and H is a steel plate thickness, and 14 are the constructive interference district.
Claims (3)
1, a kind of automatic defect detection technology using electromagnetic ultrasonic sends the signal source with certain power by transmitter, by the transducer (electromagnet, transmitting coil and receiving coil) of probe, in steel plate, induce eddy current, with its magnetic field interaction, in steel plate, inspire Lamb wave, it is characterized in that:
Single carrier frequency pulse string transmitter of A, employing power 〉=50KW;
B, transmitting coil and receiving coil place probe electromagnet two magnetic poles below;
C, adopt large-sized transducer winding, promptly large-sized transmitting coil and receiving coil, the long 90～100mm of its coil, wide 40～50mm, each coil period number was 12 weeks, totally 24 winding slots;
The transmitting coil of D, transducer and receiving coil are mutually 5 °～10 ° angle.
2, inspection technique according to claim 1 is characterized in that the gap of popping one's head in steel plate is 0.5～2mm.
3, inspection technique according to claim 1 is characterized in that adopting two probes to visit same block plate simultaneously.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90109231 CN1022202C (en) | 1990-11-21 | 1990-11-21 | Automatic defect detection technology using electromagnetic ultrasonic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90109231 CN1022202C (en) | 1990-11-21 | 1990-11-21 | Automatic defect detection technology using electromagnetic ultrasonic |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1051086A CN1051086A (en) | 1991-05-01 |
| CN1022202C true CN1022202C (en) | 1993-09-22 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90109231 Expired - Fee Related CN1022202C (en) | 1990-11-21 | 1990-11-21 | Automatic defect detection technology using electromagnetic ultrasonic |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1022202C (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1061760C (en) * | 1995-12-26 | 2001-02-07 | 冶金工业部钢铁研究总院 | Magnetic fault detector |
| CN101354380B (en) * | 2007-07-23 | 2011-07-20 | 北京航空航天大学 | Vortex flow and electromagnetic ultrasonic combined type nondestructive detection method |
| CN101398411B (en) * | 2008-11-07 | 2012-04-25 | 哈尔滨工业大学 | Rail tread defect rapid scanning and detecting method and device thereof |
| CN101907584A (en) * | 2010-03-10 | 2010-12-08 | 浙江海洋学院 | Ship fatigue damage detection comparer |
| CN102721735A (en) * | 2012-07-13 | 2012-10-10 | 厦门大学 | Metal surface/sub-surface magnetic-acoustic imaging probe applying Lorentz force |
| CN104330477B (en) * | 2014-09-22 | 2017-04-05 | 中国石油天然气集团公司 | A kind of method for designing of the electromagnetic acoustic incentive probe based on magnetostrictive effect |
| CN104597138A (en) * | 2014-12-31 | 2015-05-06 | 钢研纳克检测技术有限公司 | Spiral guided wave electromagnetic ultrasonic transducer for detecting longitudinal and transverse defects of thin-wall steel pipe |
| CN104569155B (en) * | 2015-01-04 | 2017-04-19 | 华中科技大学 | Electromagnetic ultrasonic detection method for surface defects |
| JP6805630B2 (en) * | 2016-08-24 | 2020-12-23 | セイコーエプソン株式会社 | Ultrasonic devices, ultrasonic modules, and ultrasonic measuring devices |
| CN106824736B (en) * | 2017-01-09 | 2019-05-03 | 北京科技大学 | A kind of electromagnetic acoustic Lamb wave energy converter based on magnetostriction mechanism |
| CN107064289B (en) * | 2017-01-18 | 2024-03-29 | 中特检科技发展(北京)有限公司 | Method, device and system for multi-mode electromagnetic ultrasonic and magnetic leakage detection and sensor |
| CN108802185B (en) * | 2018-06-26 | 2020-12-29 | 哈尔滨工业大学 | Metal material defect detection sensor based on pulse eddy current and electromagnetic ultrasound |
-
1990
- 1990-11-21 CN CN 90109231 patent/CN1022202C/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| CN1051086A (en) | 1991-05-01 |
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