JP5250248B2 - Defect end detection method and defect end detection device - Google Patents

Description

The present invention relates to a method for detecting a defect end portion and a defect end detection device. More specifically, the detection of the end of the defect or the like that detects the end of the defect or the like with respect to the inspection reference direction by transmitting / receiving ultrasonic waves to / from the non-continuous part of the material (hereinafter referred to as a defect or the like) from the vibrator. The present invention relates to a method and an apparatus for detecting a defect end portion.

  Conventionally, as ultrasonic transmission / reception methods for detecting defects, for example, those described in Patent Documents 1 and 2 are known. According to the method described in Patent Document 1, peak positions and peak values of wedge echoes, bottom surface echoes, defect echoes, etc. are calculated from received signals under various conditions, and positions, sizes, etc. are obtained from these values. ing. Therefore, the processing of the received signal is complicated and the measurement work is also complicated. In addition, it is difficult to easily detect the edge of the defect from the displayed waveform.

  Further, according to the method described in Patent Document 2, it is a method on the premise of so-called straddle scanning. For example, the probe is disposed on both sides of the weld line of the welded portion to be inspected. Therefore, since the arrangement of the probe is limited, the application site is limited.

On the other hand, a dB drop method and an L-line cut method are known as sizing measurement methods. However, although these methods can estimate the defect length, it is difficult to accurately measure the defect length. As other measurement methods, the TOFD method and the end echo method are also known. However, in the TOFD method, the probe has to be arranged so as to straddle the defect, and the applicable parts are limited. In the end echo method, the tester's skill and experience are required to identify the end echo, and the measurement results vary.
JP-A-9-257773 Japanese Patent Laid-Open No. 11-352111

  In view of such a conventional situation, an object of the present invention is to provide a method for detecting an end portion of a defect and the like, and a detection device for the end portion of the defect, which can easily and accurately detect the end portion of the defect. To do.

  In order to achieve the above-mentioned object, the feature of the method for detecting an end portion of a defect, etc. according to the present invention is a method for detecting the end portion of the defect or the like with respect to the inspection reference direction by transmitting and receiving ultrasonic waves from the vibrator. , A pair of transducers are arranged symmetrically with respect to a reference plane orthogonal to the inspection reference direction, the pair of transducers are moved in the inspection reference direction, and ultrasonic waves are transmitted to and received from the pair of transducers. The two-dimensional image of the signal is recorded, and the end portion is detected by the intersection of the defect signals in the synthesized two-dimensional image obtained by synthesizing the recorded two-dimensional image of each transducer.

  According to the above feature, signal intersections are formed on the synthesized two-dimensional image synthesized from the received signals of the pair of transducers. Since the position of the intersection can be specified geometrically, the defect end can be easily detected from the image. And the length of a defect etc. can be calculated | required by detecting the said edge part with respect to the both ends in the said test | inspection reference | standard directions, such as a defect.

  It is desirable to perform the synthesis by connecting the pair of transducers in parallel and simultaneously transmitting and receiving the ultrasonic waves to and from each transducer. According to the same feature, a synthesized two-dimensional image can be easily obtained by simultaneously transmitting and receiving ultrasonic waves. The synthesized two-dimensional image may be obtained by individually recording and synthesizing a two-dimensional image of the received signal for each transducer.

  The pair of transducers may be selected from a plurality of transducers of a phased array probe having a plurality of transducers. In such a case, it is desirable that the vibrator is moved by the selection.

  The feature of the defect end detection device according to the present invention is that the inspection reference in the configuration in which the end of the defect or the like with respect to the inspection reference direction is detected by transmitting and receiving ultrasonic waves from the vibrator to the defect or the like. A pair of transducers arranged symmetrically with respect to a reference plane orthogonal to the direction, and when the pair of transducers are moved in the inspection reference direction, ultrasonic waves are transmitted to and received from the pair of transducers, and the received signal is two-dimensional. Recording means for recording an image; and synthesis means for obtaining a synthesized two-dimensional image obtained by synthesizing the two-dimensional images recorded by the respective transducers, wherein the end portion is defined by an intersection of defect signals in the synthesized two-dimensional image. It is to detect.

  In the above-described configuration, the pair of transducers may be probes attached to a casing and capable of transmitting and receiving ultrasonic waves, and the combining means may be configured by connecting the input and output of the pair of transducers to each other. .

  The synthesizing unit may perform the synthesis by connecting the pair of transducers in parallel and simultaneously transmitting and receiving the ultrasonic waves to and from these transducers. The recording means individually records a two-dimensional image of the received signal for each transducer, and the synthesizing means obtains the synthesized two-dimensional image by synthesizing the images of these recording means. Also good.

  According to the features of the defect end detection method and the defect detection end device according to the present invention, it is possible to easily and accurately detect the defect end.

  Other objects, configurations, and effects of the present invention will become apparent from the following embodiments of the present invention.

Next, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a detection device 1 according to the present invention includes a signal processing device 2 such as a PC, a signal processing unit 3, a pulsar receiver 4, a position detecting encoder 5, a display unit 7 and a first pair. It consists of second vibrators 8 and 9. In the present embodiment, as a defect or the like, a planar defect 200 existing inside the inspection object 100 such as a steel plate as shown in FIGS. As shown in the figure, the defect 200 has a certain length, and its length direction can be estimated.

  In the present embodiment, the pair of transducers 8 and 9 is composed of a pair of first and second probes 10 and 20 each having a transducer. Transmission signals generated by the pulsar receiver 4 are input to the pair of probes 10 and 20, and ultrasonic waves are simultaneously transmitted from the pair of probes 10 and 20. The transmitted ultrasonic wave enters the inspection object 100 and is reflected by the defect 200. Reflected signals from the defect are received by the pair of probes 10 and 20 and output to the pulsar receiver 4. Each output reception signal is recorded as a two-dimensional image via the signal processing device 2 and the signal processing unit 3, and a combined two-dimensional image obtained by synthesizing these two-dimensional images is displayed on the display 7. FIG. 4 shows an example of a synthesized two-dimensional image displayed on the display unit 7. In the figure, the vertical axis represents the ultrasonic propagation distance, and the horizontal axis represents the scanning distance. The same applies to the following drawings.

  The encoder 5 operates in conjunction with the pair of probes 10 and 20 and detects the scanning positions of the probes 10 and 20. The position data of the pair of probes 10 and 20 is acquired by inputting a signal from the encoder 5 to the signal processing device 2 and performing arithmetic processing.

  As shown in FIGS. 1 to 3, the first probe 10 is an oblique angle probe, and generally includes a vibrator 11, a wedge 12, and a connector 13 that become the first vibrator 8. The wedge 12 is for adjusting the incident angle, and for example, an acrylic one is used. The ultrasonic wave excited by the vibrator 11 is made incident on the specimen surface 100 a through the wedge 12. At that time, a contact medium is interposed between the wedge 12 and the specimen surface 100a. In addition, an oblique probe having the same structure as that of the first probe 10 is used as the paired second probe 20. Reference numeral 21 denotes a vibrator serving as the second vibrator 9 that forms a pair with the vibrator 11. Reference numeral 22 corresponds to the wedge 12, and reference numeral 23 corresponds to the connector 13.

  As shown in FIGS. 1 to 3, the pair of probes 10 and 20 are symmetrical with respect to a plane 300 that is a reference plane that includes the midpoint of the distance between the probes and is orthogonal to the surface 100a to be inspected. It is fixed to the connection member 14. Then, the reference surface 300 is placed on the inspection object 100 so as to be orthogonal to the X-axis direction which is the inspection reference direction. In addition, the pair of transducers 11 and 21 have the same incident angle with respect to the surface 100a to be inspected, and the positions are set so that the transmission / reception direction axes of the ultrasonic waves intersect on the reference plane 300. With such a plane-symmetric arrangement with respect to the reference plane 300, the propagation distance of the ultrasonic wave between the intersection of the reference plane 300 and the defect 200 and the vibrators 11 and 21 becomes equal.

  The transducers 11 and 21 of the pair of probes 10 and 20 are electrically connected in parallel to the pulsar receiver 4 via connectors 13 and 23. Thereby, ultrasonic waves can be transmitted and received simultaneously in the pair of transducers 11 and 21. The ultrasonic waves transmitted from the transducer 11 are reflected by the defect, and the reflected signals are received by the transducers 11 and 21, respectively. Further, the ultrasonic wave transmitted from the vibrator 21 is reflected by the defect, and the reflected signals are received by the vibrators 11 and 21, respectively. Then, a two-dimensional image in which the position information of the encoder 5 is added to these received signals is recorded. By simultaneously transmitting and receiving ultrasonic waves, a synthesized two-dimensional image as shown in FIG. 4 can be obtained from the two-dimensional image of each received signal. That is, in this embodiment, a pair of vibrators 11 and 21 electrically connected in parallel constitutes a synthesizing unit. Then, as shown in FIG. 1, ultrasonic waves are transmitted and received between the pair of transducers 11 and 21 to detect defect end portions 200 a and 200 b generated inside the inspection object 100.

Next, a procedure for detecting a defect end in the present embodiment will be described.
First, the pair of probes 10 and 20 having the encoder 5 attached in the vicinity of the defect 200 are arranged so that the above-described reference plane 300 is orthogonal to the longitudinal direction of the defect 200. As shown in FIGS. 1 to 3, the defect 200 is a planar defect such as a crack having a certain length in the X-axis direction and a depth in the Z-axis direction.

  Next, ultrasonic waves are simultaneously transmitted and received by the pair of probes 10 and 20, and the inspection object 100 is scanned in the longitudinal direction X of the defect 200. This scanning direction is the inspection reference direction F and is orthogonal to the reference plane 300. Then, a two-dimensional image is obtained from the position signals of the pair of probes 10 and 20 sent from the encoder 5 and the ultrasonic reception signals received by the transducers 11 and 21. Each obtained two-dimensional image is generated through the signal processing device 2 and the signal processing unit 3 to generate a synthesized two-dimensional image illustrated in FIG.

Here, the detection principle of the defect edge part in the produced | generated synthetic | combination two-dimensional image is demonstrated.
FIG. 5 shows a schematic diagram of a synthesized two-dimensional image. Reference numerals A1, B1, and C1 indicate positions of the first probe 10, and reference numerals A2, B2, and C2 indicate positions of the paired second probes 20. Further, the center of the symbols A1 and A2 is the base point A, the center of B1 and B2 is the base point B, and the center of C1 and C2 is the base point C. Note that the base points A to C are merely a reference for convenience of explanation, and the probe positions A1 to C1 and A2 to C2 may be used as the base points.

  As shown in the figure, when the pair of probes 10 and 20 is moved from the base point A to the base point C, one substantially horizontal first signal P1 and a right-handed rise are displayed on the synthesized two-dimensional image. The second signal P2 and the third signal P3 descending to the right appear.

  The first signal P1 is obtained when the ultrasonic waves transmitted by the first and second probes 10 and 20 are reflected by the defect 200 and the reflected signal is received by the second and first probes 20 and 10. Signal. Since the first probe 10 and the second probe 20 are arranged symmetrically with respect to the reference plane 300 as described above, the propagation of ultrasonic waves between the first and second probes 10 and 20. The distance is almost constant and appears as a substantially horizontal waveform.

  The second signal P2 is a signal obtained by transmitting the ultrasonic wave in the first probe 10 and receiving the ultrasonic wave reflected by the defect end portion 200a by the first probe 10. The third signal P3 is a reflected signal from the defect end portion 200a transmitted and received in the second probe 20.

  When the pair of probes 10 and 20 are moved from the base point A to the base point C along the inspection reference direction F, the first probe 10 approaches the defect end portion 200a. The propagation path of the ultrasonic waves transmitted and received at will be reduced. Therefore, the second signal P2 appears as an inclined waveform that rises to the right. On the other hand, since the second probe 20 moves away from the defect end portion 200a, the propagation path of the ultrasonic wave expands. Therefore, the third signal P3 appears as an inclined waveform with a downward slope.

  The base point A is a point where the defect end portion 200a and the reference plane 300 coincide. Since the pair of probes 10 and 20 are arranged in plane symmetry with respect to the reference plane 300, the propagation distance of the ultrasonic wave at the first probe 10 and the propagation of the ultrasonic wave at the second probe 20. The distance will be equal. The ultrasonic wave propagation distance between the first and second probes 10 and 20 is also equal. Therefore, these signals P1 to P3 intersect with each other to form an intersection E. The defect end 200a can be detected by the intersection E.

  Similarly, at the other end 200b, an intersection is formed according to the principle described above. Therefore, by scanning in the longitudinal direction of the planar defect 200 that is the inspection reference direction F orthogonal to the reference surface 300, the length L of the defect can be easily measured from the position of both intersections E.

In the present embodiment, the planar defect is not limited to the shape shown in FIGS. 2 and 3, and the end portion can be detected in various shapes. Hereinafter, the detection example will be described.
Scanning was performed in the same manner as described above on a SUS plate in which a slit opened on the back side was formed as a simulated defect. A composite two-dimensional image of the scanning result is shown in FIG. As shown in the figure, the intersection E between the first signal P1 and the second and third signals P2 and P3 appears clearly, and it can be seen that the position of the end can be specified.

  Further, FIG. 7 shows the result of scanning in the same manner with a SUS plate in which a simulated defect having one end tapered in the above-described slit is formed. Also in the synthesized two-dimensional image shown in the figure, the intersection E appears in the same manner as described above, and it is possible to detect the end of the tapered end shape.

  Furthermore, the site | part of the to-be-inspected object which can be applied is not limited. For example, even in the case of the slit formed in the SUS welded portion, as shown in FIG. 8, the intersection E between the first signal P1 and the second and third signals P2 and P3 appears, and the defect end is detected. can do. Further, the defect length L2 obtained from both the intersections E and E coincided with the actually measured value. FIG. 9 shows SCC (stress corrosion cracking) inside the SUS weld. A composite two-dimensional image obtained as a result of scanning the weld is shown in FIG. FIG. 10A shows a synthesized two-dimensional image, and FIG. 10B shows the signals P1 to P3 in FIG. As shown in FIG. 10, an intersection E between the first signal P1 and the second and third signals P2 and P3 appears, and the end can be detected. Then, the defect length L3 can be measured from the detected end portion, which coincides with the actual measurement value L3 shown in FIG. As described above, it is possible to detect the end portion without arranging the pair of probes with the weld line of the welded portion interposed therebetween.

  Still another detection example will be described. In the above-described detection example, the probe is arranged with the ultrasonic wave transmitting / receiving direction in the direction in which the defect is located. However, in this application example, as shown in FIG. 11, the probes 10 and 20 that form a pair with the ultrasonic wave transmission / reception directions facing each other along the inspection reference direction F are described above with respect to the reference plane 300. Arrange them symmetrically. Even in the case of facing each other, the propagation distance of the ultrasonic wave is equal to the reference plane 300.

  When facing each other, as shown in FIG. 12, it is possible to measure the amount of penetration at the welded portions 211 and 212 in the T joint 110 composed of the first member 111 and the second member 112. When the pair of probes 10 and 20 are scanned in the width direction of the welded portion along the inspection reference direction F, as shown in FIG. 13, a composite two-dimensional image corresponding to the welded portion end portions 211a, 211b, and 212a, b. Intersections E1-4 appeared on the top. The ends of the welded portion can be detected by the intersections E1 to E4. And the penetration amount L between the welding part 211,212 from the cross | intersection part E2,3 can be measured. On the other hand, when the TOFD method shown in FIG. 14 is used, a substantially horizontal signal Q appears, but a signal from the end portion does not appear. Therefore, it is difficult to specify the end portion of the welded portion from the top of the image. It can be said that it is difficult to measure the amount. Although the T joint 110 has been described as an example, the amount of penetration can be similarly measured even with a single joint.

  Further, as shown in FIG. 15, it is also possible to detect the end portions 220a and 220b in the spot welded portion 220 of the inspection object 120 in which the first member 121 and the second member 122 are laminated. Here, the end portions 220a and 220b are boundary portions between the spot welded portion 220 and the joint surfaces 123 of the first and second members 121 and 122. Even in such a test object 120, the end portions 220a and 220b can be detected, and the nugget diameter L can be measured from the length between the end portions 220a and 220b.

  In this way, the pair of probes detects the ends of the defects and the like even when they are arranged in plane symmetry with respect to the direction in which the ultrasonic wave is transmitted and received in the direction in which the defects are located, Its length can be measured. Moreover, not only a planar defect but an edge part can be detected and a length can be measured in a discontinuous part of a material such as a welded part.

  Finally, the possibilities of yet another embodiment of the present invention will be described. In the following embodiments, members similar to those in the above embodiments are denoted by the same reference numerals.

  In the above-described embodiment, the paired vibrators 8 and 9 are configured by the pair of probes 10 and 20 having the same structure. However, it is not necessary to use a pair of probes, and it is only necessary to have a pair of transducers. The embodiment shown in FIG. 16 differs from the above embodiment in that a probe 30 provided with a pair of transducers inside the casing is used.

  In general, the probe 30 is provided with a pair of transducers 31 a and 31 b and a pair of wedges 32 a and 32 b inside the casing 35. The pair of vibrators 31 a and 31 b are attached so as to be plane-symmetric with respect to the reference plane 300 as in the above embodiment. The vibrators 31 a and 31 b are electrically connected to the pulsar receiver 4 in parallel through lead wires 36. That is, in the present embodiment, the pair of vibrators 31a and 31b constitutes a synthesizing unit. By incorporating the pair of vibrators 31a and 31b in the casing 35, the inspection apparatus can be further simplified. Then, the probe 30 is scanned along the inspection reference direction F perpendicular to the reference plane 300 to detect a defect end. In the present embodiment also, the pair of vibrators 31a and 31b can be attached to face each other inside the casing 35.

  In each of the above embodiments, ultrasonic waves were simultaneously transmitted and received from the pair of vibrators 8 and 9 to record two-dimensional images, respectively, and generate a synthesized two-dimensional image. However, in addition to the case where ultrasonic waves are transmitted and received at the same time, ultrasonic waves may be transmitted after a time.

  In such a case, the first probe 10 is connected to the first channel 41 of the multiplexer 40 and the second probe 20 is connected to the second channel 42 as shown in FIG. Then, the switches inside the multiplexer 40 are switched to input / output signals. First, a transmission signal is transmitted from the first probe 10 via the first channel 41, and ultrasonic waves are transmitted from the first probe 10. Then, the reflected signal reflected by the defect 200 or the like is received by the second probe 20, and the received signal is output through the second channel 42, and a first two-dimensional image G1 as shown in FIG. Record. The first signal P1 appears in the first two-dimensional image G1.

  Next, the switch of the second channel 42 is switched, ultrasonic waves are transmitted / received in the second probe 20 via the second channel 42, and the second two-dimensional image G2 shown in FIG. . A third signal P3 appears in the second two-dimensional image G2. And it switches to the 1st channel 41, an ultrasonic wave is transmitted / received in the 1st probe 10 via the 1st channel 41, and the 3rd two-dimensional image G3 shown in the figure (c) is recorded. A third signal P2 appears in the third two-dimensional image G3. The obtained two-dimensional images G1 to G3 are subjected to image processing by the signal processing unit 3 and synthesized to obtain a synthesized two-dimensional image I shown in FIG. On the synthesized two-dimensional image I, an intersection E between the first signal P1 and the second and third signals P2 and P3 is formed, and an end can be detected by the intersection E.

  In each of the above embodiments, the pair of vibrators 8 and 9 is used. However, the vibrator is not limited to the above-described structure. For example, it is possible to detect a defect end using a phased array probe. In such a case, a pair of transducers that are plane-symmetric with respect to a reference plane orthogonal to the inspection reference direction may be selected. When a phased array probe is used, scanning may be performed by moving the phased array probe itself, or scanning by electrically selecting a pair of transducers in the inspection reference direction. I do not care. Also in the present embodiment, a synthesized two-dimensional image is obtained using the multiplexer 40 described above.

  In the first and second embodiments, a composite two-dimensional image is obtained by simultaneously transmitting and receiving ultrasonic waves from a pair of transducers. However, ultrasonic waves may be transmitted from only the first transducer and received by both transducers, for example. In such a case, the third signal P3 does not appear in the synthesized two-dimensional image shown in FIG. However, since an intersection E between the first signal P1 and the second signal P2 is formed, it is possible to detect an end portion of the defect and measure the length by the intersection E.

  The vibrator may be configured such that the incident angle given by the angle formed by the transmitter mounting center axis and the normal of the specimen surface can be adjusted as appropriate.

  INDUSTRIAL APPLICABILITY The present invention can be used as a detection method and a detection apparatus for detecting an end portion of a planar defect or a discontinuous portion of a material and measuring the length.

It is a block diagram which shows the inspection apparatus which concerns on this invention. It is a schematic plan view which shows the positional relationship between a probe and a defect. It is a schematic sectional drawing which shows the positional relationship of a probe and a defect. It is a figure which shows an example of a synthetic | combination two-dimensional image. It is a figure explaining the principle of the edge part detection in a synthetic | combination two-dimensional image. It is a figure which shows an example of the synthetic | combination two-dimensional image in another example of a detection. It is a figure which shows the example of the synthetic | combination two-dimensional image in another example of a detection. It is a figure which shows the example of the synthetic | combination two-dimensional image in another example of a detection. It is a figure which shows SCC in a SUS welding part. It is a figure which shows an example of the synthetic | combination two-dimensional image in FIG. FIG. 3 is a view corresponding to FIG. 1 and showing another positional relationship between the probe and the defect. It is the schematic which shows arrangement | positioning of the probe in a T joint. It is a figure which shows an example of the synthetic | combination two-dimensional image in FIG. FIG. 14 is a diagram corresponding to FIG. 13 illustrating a comparative example using TOFD. It is the schematic which shows arrangement | positioning of the probe in a spot weld part. It is the schematic which shows other embodiment of a probe. It is the schematic which shows other embodiment. It is a schematic diagram of the two-dimensional image in FIG.

Explanation of symbols

1: detection device, 2: signal processing device, 3: signal processing unit, 4: pulser receiver, 5: encoder, 7: display, 8: first vibrator, 9: second vibrator, 10: first probe Tensile, 11: first vibrator, 12: wedge, 13: connector, 14: connecting member, 20: second probe, 21: second vibrator, 22: wedge, 23: connector, 30: probe Child, 31a, b: vibrator, 32a, b: wedge, 33: connector, 35: casing, 36: lead wire, 40: multiplex, 41: first channel, 42: second channel, 100: device under test 100a: surface, 110: object to be inspected (T joint), 111: first member, 112: second member, 120: object to be inspected, 121: first member, 122: second member, 123: bonding surface, 200: Planar defects (defects, etc.), 200a, b: end portions, 210: welded portions Defects, etc.), 211, 212: welded part, 220: spot welded part (defect etc.), 220a, b: end part (boundary part), 300: inspection target part, E: intersection part, G1 to G3: two-dimensional image , I: composite two-dimensional image, L: length, P1 to P3, Q: received signal,

Claims (10)

A method for detecting an end portion of a defect such as a defect that detects an end portion of the defect or the like with respect to an inspection reference direction by transmitting / receiving ultrasonic waves to / from a discontinuous portion of the material (hereinafter referred to as a defect). ,
A pair of transducers are arranged symmetrically with respect to a reference plane orthogonal to the inspection reference direction, the pair of transducers are moved in the inspection reference direction, and ultrasonic waves are transmitted to and received from the pair of transducers. A method for detecting an end portion of a defect or the like, in which a two-dimensional image is recorded and the end portion is detected by an intersection of defect signals in a combined two-dimensional image obtained by combining the recorded two-dimensional images of the respective transducers. The method for detecting an end portion of a defect or the like according to claim 1, wherein the length of the defect or the like is obtained by detecting the end portion with respect to both ends in the inspection reference direction of the defect or the like. The method for detecting a defect end portion according to claim 1 or 2, wherein the synthesis is performed by connecting the pair of transducers in parallel and simultaneously transmitting and receiving the ultrasonic waves to and from these transducers. The method for detecting a defect end portion according to claim 1 or 2, wherein the synthesized two-dimensional image is obtained by individually recording and synthesizing a two-dimensional image of the received signal for each transducer. 3. The defect end detection method according to claim 1, wherein the pair of transducers is selected from a plurality of transducers of a phased array probe including a plurality of transducers. The method for detecting a defect end portion according to claim 5, wherein the transducer is moved by the selection. An apparatus for detecting an end portion of a defect or the like that detects an end portion of the defect or the like with respect to an inspection reference direction by transmitting and receiving ultrasonic waves from a vibrator to a discontinuous portion of the material (hereinafter referred to as a defect or the like). ,
A pair of transducers arranged symmetrically with respect to a reference plane orthogonal to the inspection reference direction, and when the pair of transducers are moved in the inspection reference direction, ultrasonic waves are transmitted to and received from the pair of transducers and received signals Recording means for recording the two-dimensional image, and synthesizing means for obtaining a synthesized two-dimensional image obtained by synthesizing the recorded two-dimensional images of the respective transducers, and by the intersection of the defect signals in the synthesized two-dimensional image, A device for detecting an end of a defect or the like that detects the end. 8. The pair of transducers according to claim 7, wherein the pair of transducers are probes attached to a casing and capable of transmitting and receiving ultrasonic waves, and the synthesizing unit is configured by connecting input and output of the pair of transducers to each other. Detection device for defects and other edges. 8. The defect end detection apparatus according to claim 7, wherein the synthesizing unit performs the synthesis by connecting the pair of transducers in parallel and simultaneously transmitting and receiving the ultrasonic waves to and from the transducers. . The recording means individually records a two-dimensional image of the received signal for each transducer, and the synthesizing means obtains the synthesized two-dimensional image by synthesizing the images of these recording means. The apparatus for detecting an end portion of a defect or the like according to claim 7 or 8.