CN102053119A - Ultrasonic flaw detection method for fatigue cracks on thread part of bolt - Google Patents
Ultrasonic flaw detection method for fatigue cracks on thread part of bolt Download PDFInfo
- Publication number
- CN102053119A CN102053119A CN 201010216506 CN201010216506A CN102053119A CN 102053119 A CN102053119 A CN 102053119A CN 201010216506 CN201010216506 CN 201010216506 CN 201010216506 A CN201010216506 A CN 201010216506A CN 102053119 A CN102053119 A CN 102053119A
- Authority
- CN
- China
- Prior art keywords
- flaw detection
- probe
- workpiece
- bolt
- instrument
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention relates to the technical field of crack detection, in particular to an ultrasonic flaw detection method for fatigue cracks on the thread part of a bolt, which comprises the following steps of: the preparation of equipment and apparatuses, preparatory work for flaw detection, flaw detection operations, inspection and acceptance and processing, and closure. The thread part is scanned by utilizing incident transverse waves, the detection can be finished under undisassembly condition, and whether the thread part has the cracks or not is judged by the conditions of inherent echoes of threads, such as normality, attenuation or fading away. The method is simple, convenient, accurate and highly-efficient.
Description
Technical field
The present invention relates to the crack detection technical field, especially a kind of bolt thread position fatigue crack defect detection on ultrasonic basis.
Background technology
Cylinder and Main bearing bolt, the junction of cylinder head bolt is the key position of whole diesel engine, the firmness that connects, stability is directly connected to the operation of diesel engine, all the time, the flaw detection at bolt part screw thread position all is a difficult point, method of detection is generally: the back of disintegrating adopts magnetic to detect, infiltration detects or detects with normal probe from the termination, all there is the drawback that workpiece is had damage in these methods, at present, also there is not a kind of effective method to cylinder and Main bearing bolt, the connecting thread position of cylinder head bolt is detected, in case there is crackle in workpiece inside, bring hidden danger will for the operation of diesel engine.
Summary of the invention
In order to overcome the deficiency that existing cylinder and Main bearing bolt, cylinder head bolt junction lack effective detection method, the invention provides a kind of bolt thread position fatigue crack defect detection on ultrasonic basis.
The technical solution adopted for the present invention to solve the technical problems is: a kind of bolt thread position fatigue crack defect detection on ultrasonic basis may further comprise the steps: preliminary work → flaw detection operation → examination and processing → ending before the regulation at preparation machine and equipment → flaw detection position, test surface and the selection → flaw detection on the opportunity of flaw detection.
Preparation machine and equipment step comprise following instrument:
A. ultra-sonic defect detector: analog or digital ultrasonic flaw detector, its performance index should satisfy the requirement of JB/T10061 " A type pulse reflection ultra-sonic defect detector general technical specifications ", in the use, the calibrating of instrument should be before the deadline, by annual test and season performance verification;
B. pop one's head in;
C. test block: test block in kind, the cylinder head bolt sensitivity verification test block that comprises 16V280 diesel engine cylinder and the Main bearing bolt sensitivity verification test block that is provided with the dark big artificial defect of 2mm and be provided with the dark little artificial defect of 1mm;
D. couplant: 40～50# machine oil;
E. other annexes: marking pen, minute book and equipments of recording.
Preliminary work step before the flaw detection comprises:
A. remove the dirt of test surface influence coupling;
B. the adjusting of instrument: select test block, probe is moved to the workpiece top, regulate sound path and horizontal knob, the highest reflection wave of test block zero defect place's screw thread is transferred to all over the screen 80%, instrument was regulated and was finished this moment, rotate probe around workpiece, should guarantee in the rotation process to pop one's head in and workpiece between coupling, if the normal screw thread ripple disappearance in artificial defect corresponding section, just can carry out daily flaw detection operation after the compensation coupling difference, otherwise, inspection apparatus and probe performance answered, if malfunctioning, then need change probe or newspaper machine maintenance department maintenance device.
The flaw detection operation steps comprises:
A. the regulation, test surface at position of detecting a flaw and the selection on flaw detection opportunity detect relevant regulations and see Table 1.
Table 1
B. select probe, and regulate instrument;
C. on the workpiece test surface, be coated with couplant;
D. probe moves to the workpiece top, rotate more than the week around workpiece, the probe velocity of rotation should be not more than 1 week/5s, probe positions can be fixed by support, when normal screw thread ripple disappearance occurring or obviously reducing, should be judged to the harm defective, for the workpiece that need carry out scanning to whole crack site, probe should move forward and backward in rotation, promptly does the zigzag scanning;
E. in the flaw detection process, occur that waveform and previous step are rapid to be described differently, but the flaw detection personnel think and also should be judged to the harm defective when this defective has harmfulness;
F. should guarantee in the flaw detection process to pop one's head in and workpiece between coupling, during situations such as clutter is too many when occurring, the disappearance of shape reverse ejected wave, should check whether the state of coupling, probe, probe wire and instrument intact, if be not in good state, should adjust or change.
Check and accept with treatment step and comprise:
When a. finding the harm defective on the workpiece, should be judged to defectively, on workpiece, mark mark, hand over next procedure to handle;
When b. not finding the harm defective, it is qualified to be judged to, and beats flaw detection steel seal at cylinder and Main bearing bolt termination, at cylinder head bolt end skull rubber seal, hands over next procedure.
The ending step comprises:
A. tester in test block, whether the inspection apparatus performance parameter changes, as the artificial defect position occur horizontal shift change surpass 2% or the defective wave height reduce and reach 2dB or when above, the reply same day, tested workpiece detected again;
B. fill in corresponding detection record on request strictly according to the facts;
C. close instrument, arrangement flaw detection place.
The invention has the beneficial effects as follows, utilize incident shear wave double thread position to carry out scanning, under the situation of not disintegrating, can finish detection, situation by the intrinsic echo of screw thread, such as normal, decay or disappear to judge whether the screw thread position exists crackle, simple and convenient, precise and high efficiency.
Description of drawings
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 a is 16V280 diesel engine cylinder of the present invention and Main bearing bolt sensitivity verification test block synoptic diagram;
Fig. 1 b is a cylinder head bolt sensitivity verification test block synoptic diagram of the present invention;
Instrument was regulated synoptic diagram when Fig. 2 was angle probe of the present invention flaw detection;
Fig. 3 is an artificial defect of the present invention place waveform synoptic diagram.
1. big artificial defects among the figure, 2. little artificial defect.
Embodiment
In conjunction with the accompanying drawings, the present invention is further detailed explanation.These accompanying drawings are the synoptic diagram of simplification, basic structure of the present invention only is described in a schematic way, so it only show the formation relevant with the present invention.
A kind of bolt thread position fatigue crack defect detection on ultrasonic basis may further comprise the steps: preliminary work → flaw detection operation → examination before preparation machine and the equipment → flaw detection and processing → ending.
Preparation machine and equipment step comprise following instrument:
A. ultra-sonic defect detector: analog or digital ultrasonic flaw detector, its performance index should satisfy the requirement of JB/T10061 " A type pulse reflection ultra-sonic defect detector general technical specifications ", in the use, the calibrating of instrument should be before the deadline, by annual test and season performance verification;
B. pop one's head in;
As Fig. 1 a is 16V280 diesel engine cylinder of the present invention and Main bearing bolt sensitivity verification test block synoptic diagram, Fig. 1 b is a cylinder head bolt sensitivity verification test block synoptic diagram of the present invention, c. test block: test block in kind, the cylinder head bolt sensitivity verification test block that comprises 16V280 diesel engine cylinder and the Main bearing bolt sensitivity verification test block that is provided with the dark big artificial defect 1 of 2mm and be provided with the dark little artificial defect 2 of 1mm;
D. couplant: 40～50# machine oil;
E. other annexes: marking pen, minute book and equipments of recording.
Preliminary work step before the flaw detection comprises:
A. remove the dirt of test surface influence coupling;
Instrument is regulated synoptic diagram when being angle probe of the present invention flaw detection as Fig. 2, Fig. 3 is an artificial defect of the present invention place waveform synoptic diagram, b. the adjusting of instrument: select test block, probe is moved to the workpiece top, regulate sound path and horizontal knob, the highest reflection wave of test block zero defect place's screw thread is transferred to all over the screen 80%, instrument was regulated and to be finished this moment, rotated probe around workpiece, should guarantee in the rotation process to pop one's head in and workpiece between coupling, if the normal screw thread ripple disappearance in artificial defect corresponding section, just can carry out daily flaw detection operation after the compensation coupling difference, otherwise, inspection apparatus and probe performance answered, if malfunctioning, then need change probe or newspaper machine maintenance department maintenance device.
The flaw detection operation steps comprises:
A. the regulation, test surface at position of detecting a flaw and the selection on flaw detection opportunity detect relevant regulations and see Table 1.
Table 1
B. select probe, and regulate instrument;
C. on the workpiece test surface, be coated with couplant;
D. probe moves to the workpiece top, rotate more than the week around workpiece, the probe velocity of rotation should be not more than 1 week/5s, probe positions can be fixed by support, when normal screw thread ripple disappearance occurring or obviously reducing, should be judged to the harm defective, for the workpiece that need carry out scanning to whole crack site, probe should move forward and backward in rotation, promptly does the zigzag scanning;
E. in the flaw detection process, occur that waveform and previous step are rapid to be described differently, but the flaw detection personnel think and also should be judged to the harm defective when this defective has harmfulness;
F. should guarantee in the flaw detection process to pop one's head in and workpiece between coupling, during situations such as clutter is too many when occurring, the disappearance of shape reverse ejected wave, should check whether the state of coupling, probe, probe wire and instrument intact, if be not in good state, should adjust or change.
Check and accept with treatment step and comprise:
When a. finding the harm defective on the workpiece, should be judged to defectively, on workpiece, mark mark, hand over next procedure to handle;
When b. not finding the harm defective, it is qualified to be judged to, and beats flaw detection steel seal at cylinder and Main bearing bolt termination, at cylinder head bolt end skull rubber seal, hands over next procedure.
The ending step comprises:
A. tester in test block, whether the inspection apparatus performance parameter changes, as the artificial defect position occur horizontal shift change surpass 2% or the defective wave height reduce and reach 2dB or when above, the reply same day, tested workpiece detected again;
B. fill in corresponding detection record on request strictly according to the facts;
C. close instrument, arrangement flaw detection place.
Embodiment:
A kind of bolt thread position fatigue crack defect detection on ultrasonic basis may further comprise the steps: preliminary work → flaw detection operation → examination before preparation machine and the equipment → flaw detection and processing → ending.
Preparation machine and equipment step comprise following instrument:
A. ultra-sonic defect detector: analog or digital ultrasonic flaw detector, its performance index should satisfy the requirement of JB/T10061 " A type pulse reflection ultra-sonic defect detector general technical specifications ", in the use, the calibrating of instrument should be before the deadline, by annual test and season performance verification;
B. pop one's head in;
C. test block: test block in kind, the cylinder head bolt sensitivity verification test block that comprises 16V280 diesel engine cylinder and the Main bearing bolt sensitivity verification test block that is provided with the dark big artificial defect 1 of 2mm and be provided with the dark little artificial defect 2 of 1mm;
D. couplant: 45# machine oil;
E. other annexes: marking pen, minute book and equipments of recording.
Preliminary work step before the flaw detection comprises:
A. remove the dirt of test surface influence coupling;
B. the adjusting of instrument: select test block, probe is moved to the workpiece top, regulate sound path and horizontal knob, the highest reflection wave of test block zero defect place's screw thread is transferred to all over the screen 80%, instrument was regulated and was finished this moment, rotate probe around workpiece, should guarantee in the rotation process to pop one's head in and workpiece between coupling, if the normal screw thread ripple disappearance in artificial defect corresponding section, just can carry out daily flaw detection operation after the compensation coupling difference, otherwise, inspection apparatus and probe performance answered, if malfunctioning, then need change probe or newspaper machine maintenance department maintenance device.
The flaw detection operation steps comprises:
A. the regulation, test surface at position of detecting a flaw and the selection on flaw detection opportunity detect relevant regulations and see Table 1.
Table 1
| The workpiece title | The flaw detection position | The spy of using | Test surface | Flaw detection opportunity |
B. select probe, and regulate instrument;
C. on the workpiece test surface, be coated with couplant;
D. probe moves to the workpiece top, rotate more than the week around workpiece, the probe velocity of rotation should be not more than 1 week/5s, probe positions can be fixed by support, when normal screw thread ripple disappearance occurring or obviously reducing, should be judged to the harm defective, for the workpiece that need carry out scanning to whole crack site, probe should move forward and backward in rotation, promptly does the zigzag scanning;
E. in the flaw detection process, occur that waveform and previous step are rapid to be described differently, but the flaw detection personnel think and also should be judged to the harm defective when this defective has harmfulness;
F. should guarantee in the flaw detection process to pop one's head in and workpiece between coupling, during situations such as clutter is too many when occurring, the disappearance of shape reverse ejected wave, should check whether the state of coupling, probe, probe wire and instrument intact, if be not in good state, should adjust or change.
Check and accept with treatment step and comprise:
When a. finding the harm defective on the workpiece, should be judged to defectively, on workpiece, mark mark, hand over next procedure to handle;
When b. not finding the harm defective, it is qualified to be judged to, and beats flaw detection steel seal at cylinder and Main bearing bolt termination, at cylinder head bolt end skull rubber seal, hands over next procedure.
The ending step comprises:
A. tester in test block, whether the inspection apparatus performance parameter changes, as the artificial defect position occur horizontal shift change surpass 2% or the defective wave height reduce and reach 2dB or when above, the reply same day, tested workpiece detected again;
B. fill in corresponding detection record on request strictly according to the facts;
C. close instrument, arrangement flaw detection place.
This method is applicable to the threaded portion station ultrasonic wave flaw detection of 16V 280 diesel engine cylinders and Main bearing bolt and various cylinder head bolt.The detection at other bolt class part screw thread position can be carried out with reference to this method.
Claims (6)
1. a bolt thread position fatigue crack defect detection on ultrasonic basis is characterized in that: may further comprise the steps: preliminary work → flaw detection operation → examination before preparation machine and the equipment → flaw detection and processing → ending.
2. bolt thread according to claim 1 position fatigue crack defect detection on ultrasonic basis is characterized in that: preparation machine and equipment step comprise following instrument:
A. ultra-sonic defect detector: analog or digital ultrasonic flaw detector, its performance index should satisfy the requirement of JB/T10061 " A type pulse reflection ultra-sonic defect detector general technical specifications ", in the use, the calibrating of instrument should be before the deadline, by annual test and season performance verification;
B. pop one's head in;
C. test block: test block in kind comprises 16V280 diesel engine cylinder and the Main bearing bolt sensitivity verification test block that is provided with the dark big artificial defect (1) of 2mm and is provided with the cylinder head bolt sensitivity verification test block of the dark little artificial defect (2) of 1mm;
D. couplant: 40～50# machine oil;
E. other annexes: marking pen, minute book and equipments of recording.
3. bolt thread according to claim 1 position fatigue crack defect detection on ultrasonic basis is characterized in that: the preliminary work step before the flaw detection comprises:
A. remove the dirt of test surface influence coupling;
B. the adjusting of instrument: select test block, probe is moved to the workpiece top, regulate sound path and horizontal knob, the highest reflection wave of test block zero defect place's screw thread is transferred to all over the screen 80%, instrument was regulated and was finished this moment, rotate probe around workpiece, should guarantee in the rotation process to pop one's head in and workpiece between coupling, if the normal screw thread ripple disappearance in artificial defect corresponding section, just can carry out daily flaw detection operation after the compensation coupling difference, otherwise, inspection apparatus and probe performance answered, if malfunctioning, then need change probe or newspaper machine maintenance department maintenance device.
4. bolt thread according to claim 1 position fatigue crack defect detection on ultrasonic basis is characterized in that: the flaw detection operation steps comprises:
A. select probe, and regulate instrument;
B. on the workpiece test surface, be coated with couplant;
C. probe moves to the workpiece top, rotate more than the week around workpiece, the probe velocity of rotation should be not more than 1 week/5s, probe positions can be fixed by support, when normal screw thread ripple disappearance occurring or obviously reducing, should be judged to the harm defective, for the workpiece that need carry out scanning to whole crack site, probe should move forward and backward in rotation, promptly does the zigzag scanning;
D. in the flaw detection process, occur that waveform and previous step are rapid to be described differently, but the flaw detection personnel think and also should be judged to the harm defective when this defective has harmfulness;
E. should guarantee in the flaw detection process to pop one's head in and workpiece between coupling, during situations such as clutter is too many when occurring, the disappearance of shape reverse ejected wave, should check whether the state of coupling, probe, probe wire and instrument intact, if be not in good state, should adjust or change.
5. bolt thread according to claim 1 position fatigue crack defect detection on ultrasonic basis is characterized in that: examination comprises with treatment step:
When a. finding the harm defective on the workpiece, should be judged to defectively, on workpiece, mark mark, hand over next procedure to handle;
When b. not finding the harm defective, it is qualified to be judged to, and beats flaw detection steel seal at cylinder and Main bearing bolt termination, at cylinder head bolt end skull rubber seal, hands over next procedure.
6. bolt thread according to claim 1 position fatigue crack defect detection on ultrasonic basis is characterized in that: the ending step comprises:
A. tester in test block, whether the inspection apparatus performance parameter changes, as the artificial defect position occur horizontal shift change surpass 2% or the defective wave height reduce and reach 2dB or when above, the reply same day, tested workpiece detected again;
B. fill in corresponding detection record on request strictly according to the facts;
C. close instrument, arrangement flaw detection place.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010216506 CN102053119A (en) | 2010-07-05 | 2010-07-05 | Ultrasonic flaw detection method for fatigue cracks on thread part of bolt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010216506 CN102053119A (en) | 2010-07-05 | 2010-07-05 | Ultrasonic flaw detection method for fatigue cracks on thread part of bolt |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102053119A true CN102053119A (en) | 2011-05-11 |
Family
ID=43957659
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010216506 Pending CN102053119A (en) | 2010-07-05 | 2010-07-05 | Ultrasonic flaw detection method for fatigue cracks on thread part of bolt |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102053119A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102830177A (en) * | 2011-06-13 | 2012-12-19 | 松下电器产业株式会社 | Abnormality checking apparatus and abnormality checking method |
| CN104483383A (en) * | 2014-12-05 | 2015-04-01 | 长春航空液压控制有限公司 | Ultrasonic detection method of plunger spring |
| CN106153721A (en) * | 2016-06-21 | 2016-11-23 | 中国飞机强度研究所 | A kind of crack in bolt detection method and screw thread crack detection device |
| CN108896666A (en) * | 2018-04-26 | 2018-11-27 | 天津市昊达泛美科技有限公司 | Bolt cylinder Guided waves system and its detection method |
| CN109187742A (en) * | 2018-08-24 | 2019-01-11 | 中国飞机强度研究所 | Whether a kind of detection bolt hole has the method and spade-type tool of hole-edge crack |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008008827A (en) * | 2006-06-30 | 2008-01-17 | Ryoden Shonan Electronics Kk | Ultrasonic probe and ultrasonic flaw detection device |
| CN101178387A (en) * | 2007-11-19 | 2008-05-14 | 中国南车集团戚墅堰机车车辆工艺研究所 | No disassembly screw bolt helical burr root endurance crack ultrasonic wave detection method and detection probe |
-
2010
- 2010-07-05 CN CN 201010216506 patent/CN102053119A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008008827A (en) * | 2006-06-30 | 2008-01-17 | Ryoden Shonan Electronics Kk | Ultrasonic probe and ultrasonic flaw detection device |
| CN101178387A (en) * | 2007-11-19 | 2008-05-14 | 中国南车集团戚墅堰机车车辆工艺研究所 | No disassembly screw bolt helical burr root endurance crack ultrasonic wave detection method and detection probe |
Non-Patent Citations (3)
| Title |
|---|
| 《机车车辆工艺》 200712 张顺启等 吊杆螺栓螺纹部位疲劳裂纹超声波探伤 , 第6期 2 * |
| 《超声检测》 200908 郭伟 超声检测设备的选择；耦合与补偿 , 1 * |
| 《铁道机车车辆工人》 201105 胡德明 主轴承螺栓螺纹部位疲劳裂纹超声波探伤方法 , 第5期 2 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102830177A (en) * | 2011-06-13 | 2012-12-19 | 松下电器产业株式会社 | Abnormality checking apparatus and abnormality checking method |
| CN102830177B (en) * | 2011-06-13 | 2014-11-12 | 松下电器产业株式会社 | Abnormality checking method and abnormality checking apparatus |
| CN104483383A (en) * | 2014-12-05 | 2015-04-01 | 长春航空液压控制有限公司 | Ultrasonic detection method of plunger spring |
| CN106153721A (en) * | 2016-06-21 | 2016-11-23 | 中国飞机强度研究所 | A kind of crack in bolt detection method and screw thread crack detection device |
| CN108896666A (en) * | 2018-04-26 | 2018-11-27 | 天津市昊达泛美科技有限公司 | Bolt cylinder Guided waves system and its detection method |
| CN109187742A (en) * | 2018-08-24 | 2019-01-11 | 中国飞机强度研究所 | Whether a kind of detection bolt hole has the method and spade-type tool of hole-edge crack |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105388212B (en) | The supersonic detection method of defect in a kind of thick walled composite tubular shape structure | |
| CN102053119A (en) | Ultrasonic flaw detection method for fatigue cracks on thread part of bolt | |
| EP1952137B1 (en) | System and method for ultrasonically detecting discontinuous fibers in composite laminates | |
| CN111122702B (en) | Water immersion ultrasonic detection method for internal defects of aviation bearing ring forge piece | |
| JP6441321B2 (en) | Improved inspection method by ultrasonic transmission | |
| CN103063742B (en) | A kind of surface wave in-situ method of detection of band coating spinner blade | |
| CN108387639B (en) | Nondestructive testing method for multilayer bonding component | |
| CN105510441B (en) | Multichannel combination probe linkage detection method | |
| CN208383810U (en) | It is a kind of for detecting the ultrasound contrast test block of threeway internal flaw | |
| CN104155367A (en) | Reference block of ultrasonic flaw detection and application method thereof | |
| CN101551361B (en) | Device for detecting lamination defect with ultrasonic wall thickness inspection and detecting method thereof | |
| CN108362772A (en) | A kind of ultrasonic flaw detection method of detection DPF carrier insides damage | |
| CN101368931A (en) | On-service supersonic inspection method of heavy and medium plate mill roller | |
| CN105510442A (en) | Dynamic linkage focus detection method adopting multiple phased array probes | |
| CN113252783A (en) | Method for detecting A-type pulse surface wave of crack of reverse T-shaped blade root groove | |
| CN107247090A (en) | A kind of turbine rotor wheel rim T-slot detection method | |
| CN110412127A (en) | The ultrasonic inspection probe and detection method of a kind of turret head of coaming plate and forming board connection bolt | |
| CN102565189A (en) | Ultrasonic detection method for metallic phase of metallic materials | |
| CN206020347U (en) | Ultrasonic examination detection reference block | |
| EP2157425A1 (en) | Method for non-destructive testing of metallic workpieces for flaws using ultrasound | |
| CN1268922C (en) | Electromagnetic guided wave detector and method for sea platform structure defect | |
| CN105467009B (en) | A kind of lossless detection method of pneumatic equipment bladess spar cap location determination | |
| CN209525311U (en) | The secondary caliberating device of long-range underwater removable multi-functional ultrasonic examination | |
| Felicetti | Assessment of an industrial pavement via the impact acoustics method | |
| CN203745424U (en) | Automatic detection device for defects of flange |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20110511 |