JP4452001B2 - Flaw detection method and flaw detection apparatus using phased array - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flaw detection method and a flaw detection apparatus using a phased array, and the height of a defect is evaluated using a surface reflected wave.
[0002]
[Prior art]
For example, ultrasonic flaw detection is applied when detecting defects such as piping in various plants such as nuclear power plants by nondestructive inspection. As an example of conventional ultrasonic flaw detection, a technique called TOFD (Time Flight Diffraction) method is known. In the TOFD method, the transmitting probe and the receiving probe are arranged to face each other, and the height of the defect is measured from the difference in propagation time of the surface wave, the bottom surface wave, and the diffraction wave from the defect end portion, and the defect is quantified. Is.
[0003]
[Problems to be solved by the invention]
In conventional ultrasonic flaw detection, the diffraction wave from the edge of the defect is detected and obtained from the path difference, so the diffraction wave from the edge of the defect may be very small depending on the shape of the defect. It was. For this reason, if there is noise or the like, it may be difficult to detect the diffracted wave, which may make it difficult to quantify the defects.
[0004]
The present invention has been made in view of the above situation, and an object of the present invention is to provide a flaw detection method and a flaw detection apparatus using a phased array that can easily quantify defects regardless of the shape or the like.
[0010]
[Means for Solving the Problems]
To achieve the above Symbol purpose flaw detection method according to the phased array of the present invention, a plurality of sets of probes group of aliquots plurality of said plurality of probe with arranging a large number of probes in an array formation In addition, a phased array probe is formed by dividing the plurality of sets of probe groups into a transmission group and a reception group, and a reflected wave reflected by the surface of the defect is detected by the probe group of the reception group. The transmission group of the probe group of the transmission group is adjusted by adjusting the incident angle of the synthesized wavefront of the ultrasonic wave by setting the delay time of ultrasonic transmission of each probe of the probe group of the transmission group Are sequentially switched to transmit ultrasonic waves, while the probe group of the reception group is sequentially switched to receive reflected waves each time an ultrasonic wave is transmitted from each probe group of the transmission group. The probe group of the transmission group that sent the sound wave and the reflected wave And evaluating the height of the defect by locating the probe group Shin the receiving group.
[0015]
Also, flaw detection apparatus of the present invention to achieve the above object, a large number of probe a plurality of sets form said plurality of probe to the the divided was probe group by several double as well as arranged in an array and a phased array transducer which is divided into a plurality of sets of single loop and receiving single loop send a probe group, in probe group of the receiving group, a reflected wave reflected by the surface of the defect So that the ultrasonic wave transmission delay time of each probe of the probe group of the transmission group is set to adjust the incident angle of the composite wavefront of the ultrasonic wave, and the probe of the transmission group The group is sequentially switched to transmit the ultrasonic waves, while the probe group of the reception group is sequentially switched to receive the reflected wave every time an ultrasonic wave is transmitted from each probe group of the transmission group. and controlling to, said reaction with probe group that sent the send single loop ultrasonic Wherein the by locating the probe group received received single loop waves and a processing unit to evaluate the height of the defect.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
This embodiment utilizes a so-called phased array method. Therefore, this phased array method will be described with reference to FIG. FIG. 1 shows a concept representing the principle of the phased array method.
[0018]
As shown in the figure, the phased array method uses a phased array probe I in which a plurality of ultrasonic probes 1 are arranged in an array, and each probe of the phased array probe I is used. By appropriately setting the delay time DT of the transmission wave 3 of the ultrasonic wave transmitted from the child 1 and shifting the phase of each transmission wave 3, the traveling direction of the combined wavefront 3a (ultrasonic incident direction: incident) The angle D) is adjusted in a desired direction. By using such a phased array method, it is possible to easily change the incident angle simply by adjusting the setting of the delay time of ultrasonic transmission, and ultrasonic flaw detection that changes the incident angle of the transmission wave 3 becomes very effective. .
[0019]
By arbitrarily changing the incident angle of the transmission wave 3 by controlling the delay time DT, the wide range inside the flaw detection member 2 can be scanned with the ultrasonic transmission wave 3, and the transmission wave 3 can be scanned in any direction. This is because it can be converged to. This relationship is the same when the phased array probe 1 is set to the reception mode. In other words, a wide range of reflected waves can be detected by controlling the reception timing of each probe 1 of the phased array probe I on the receiving side.
[0020]
A reference example of the present invention will be described with reference to FIG. FIG. 1 shows an outline of a state in which a flaw detection method is performed by a flaw detection apparatus according to a reference example of the present invention.
[0021]
As shown in the figure, the phased array probe 11 has a large number (for example, 128 channels) of probes (elements) arranged in an array, and a large number of one or more probes are made into a set. A plurality of probe groups 12 are formed. The probe group 12 is divided into a transmission group 13 and a reception group 14 from the center to the left and right, and the probe group 12 of the transmission group 13 and the reception group 14 is configured as a transmission / reception pair symmetrically from the center. . That is, probe groups 12 (1) to 12 (6) of the transmission group 13 are formed from the center to the right side, and probe groups 12 (1) to 12 (6) of the reception group 14 are formed from the center to the left side. Has been.
[0022]
Then, the reflected wave of the ultrasonic wave transmitted from the probe group 12 {circle around (1)} of the transmission group 13 is controlled by the control unit 15 so as to be received only by the probe group 12 {circle around (1)} of the reception group 14. Between the probe groups 12 (2), between the probe groups 12 (3), between the probe groups 12 (4), between the probe groups 12 (5) and between the probe groups 12 (6) Transmission and reception are controlled to be possible. Information of the phased array probe 11 is input to the arithmetic processing unit 16.
[0023]
The phased array probe 11 described above is disposed at a predetermined position after the position of the defect 20 is specified. The composite wavefront from the probe group 12 {circle around (1)} is controlled so as to transmit the transmission wave 18 a of the probe group 12 {circle around (1)} of the transmission group 13 toward the corner portion of the defect 20. The reflected wave 19a, which is a surface reflection echo reflected from the surface of the defect 20, is received by the probe group 12 (1) of the reception group 14. At this position, the probe groups 12 (2), the probe groups 12 (3), the probe groups 12 (4), the probe groups 12 (5), and the probe group 12 ▲ 6 Transmit and receive between each other.
[0024]
At this time, the probe group 12 from which the reflected wave 19 is received is determined according to the height of the defect 20 (for example, in the case of the illustrated example, the probe group 12 (2), the probe group 12 (3)). (Reflected wave 19 is received). When the height of the defect 20 in the illustrated example is low, the reflected wave 19 is received by the probe group 12 {circle around (2)}, and the reflected wave 19 is not received by the probe group 12 of other reception groups 14. Further, when the height of the defect 20 in the illustrated example is high, the reflected wave 19 is received by the probe group 12 (4), the probe group 12 (5), or the probe group 12 (6). It will be.
[0025]
Thus, the probe group 12 of the reception group 14 that has received the reflected wave 19 from the transmission group 13 configured in a pair is analyzed in association with the arithmetic processing unit 16, thereby using the surface reflection echo. The height of the defect 20 existing substantially vertically can be accurately evaluated, and the defect 20 can be easily quantified regardless of the shape of the tip.
[0026]
It is possible to evaluate the height of the defect 20 by switching all the probe groups 12 of the phased array probe 11 to the transmission group 13 at the time of transmission and to the reception group 14 at the time of reception.
[0027]
A reference example of the present invention will be described with reference to FIG. FIG. 3 shows an outline of a state in which the flaw detection method by the flaw detection apparatus according to the reference example of the present invention is performed. In addition, the same code | symbol is attached | subjected to the same member as the member shown in FIG.
[0028]
As shown in the figure, the phased array probe 22 has a large number (for example, 128 channels) of probes (elements) arranged in an array, and a plurality of probes are grouped into a set. A plurality of groups 12 are formed. The probe group 12 is divided into a transmission group 13 and a reception group 14 from the center to the left and right, and the probe group 12 of the transmission group 13 includes probe groups 12 (1) to 12 (6) from the center to the right side. Is formed. The reception group 14 is controlled by the control unit 15 so that all the probe groups 12 can receive (reception means).
[0029]
The phased array probe 22 described above is arranged at a predetermined position after the position of the defect 21 is specified. The composite wavefront from the probe group 12 {circle around (1)} is controlled so as to send the transmission wave 18 a of the probe group 12 {circle around (1)} of the transmission group 13 toward the corner portion of the defect 21. The reflected wave 19 a reflected from the surface of the defect 21 is received at the center of the probe group 12 of the reception group 14. At this position, transmission waves 18 are sequentially transmitted from the probe groups 12 (2) to 12 (6), and the reflected waves 19 received by the probe group 12 of the reception group 14 are transmitted to the probe group 13 of the transmission group 13. 12 is specified.
[0030]
In the illustrated example, the reflected wave 19 of the transmission wave 18 transmitted by the probe groups 12 (1) and 12 (2) of the transmission group 13 is received by the probe group 12 of the reception group 14. Yes. At this time, when the inclination angle of the defect 21 is on the vertical side, the reception group 14 includes, for example, transmission waves 18 transmitted from the probe groups 12 (1), 12 (2), 12 (3). The reflected wave 19 is received. In the case of the reverse inclination angle, the probe group 12 of the transmission group 13 that has transmitted the received reflected wave 19 decreases.
[0031]
As a result, by identifying and analyzing the probe groups 12 {circle around (1)} to {circle around (3)} that sent the reflected wave 19 received by the reception group 14, even if the defect 21 is inclined. The height of the defect 21 can be evaluated using the surface reflection echo, and the defect 21 can be easily quantified regardless of the shape of the tip.
[0032]
It is also possible to evaluate the height of the defect 21 by switching all the probe groups 12 of the phased array probe 22 to the transmission group 13 at the time of transmission and to the reception group 14 at the time of reception. It is also possible to switch all the probe groups 12 of the phased array probe 22 to the transmission group 13 and provide a separate receiving means.
[0033]
Further, the reception group 14 of the phased array probe 22 is set to the probe groups 12 (1) to (6), and all the probe groups 12 of the transmission group 13 can be controlled to be transmittable. is there. In this case, the height of the inclined defect 21 can be evaluated by specifying the probe groups 12 (1) to (6) that have received the reflected wave 19. At this time, it is possible to switch all the phased array probes 22 to the reception group 14 and provide a separate transmission means.
[0034]
The implementation embodiment of the present invention will be described with reference to FIG. The Figure 4 schematically shows the state that implement the inspection method according to flaw detection apparatus according to the implementation embodiments of the present invention. In addition, the same code | symbol is attached | subjected to the same member as the member shown in FIG.
[0035]
As shown in the figure, the phased array probe 32 has a large number (for example, 128 channels) of probes (elements) arranged in an array, and a large number of one or more probes are grouped together. A plurality of probe groups 12 are formed. The probe group 12 is divided into a transmission group 13 and a reception group 14 from the center to the left and right, and probe groups 12 (1) to 12 (6) of the transmission group 13 are formed from the center to the right, and from the center to the left The probe groups 12 (1) to 12 (6) of the reception group 14 are formed.
[0036]
The probe groups 12 (1) to 12 (6) of the reception group 14 are sequentially switched every time an ultrasonic wave is transmitted from the probe groups 12 (1) to 12 (6) of the transmission group 13. The positions of the probe groups 12 {circle around (1)} to {circle around (6)} at which the reflected wave is received for each transmitted wave are specified. Information of the phased array probe 32 is input to the arithmetic processing unit 16.
[0037]
The phased array probe 32 described above is arranged at a predetermined position after the position of the defect 31 is specified. The composite wavefront from the probe group 12 {circle around (1)} is controlled so that the transmission wave 18 a of the probe group 12 {circle around (1)} of the transmission group 13 is transmitted toward the defect 31. The reflected wave 19 a reflected from the surface is received by the reception group 14. At this time, the probe groups 12 (1) to 12 (6) of the reception group 14 are sequentially switched, and the probe of the reception group 14 received by the reflected wave 19a of the transmission wave 18a from the probe group 12 (1) is received. The child groups 12 (1) to 12 (6) are specified. The probe groups 12 {circle around (1)} to {circle around (6)} of the reception group 14 are sequentially switched for each transmission wave 18 of the probe group 12 {circle around (2)} to {circle around (6)} of the transmission group 13 to receive the reflected wave 19a. The probe groups 12 {circle around (1)} to 12 {circle around (6)} of the reception group 14 to be identified are specified.
[0038]
At this time, the reception position of the probe group 12 of the reception group 14 from which the reflected wave 19 is received is determined according to the shape and height of the defect 31 (for example, in the case of the illustrated example, the probe group of the transmission group 13). The transmission wave 18 from 12 (4) is received by the probe group 12 (2) of the reception group 14). A defect 31 whose shape is discontinuous by deformation using a surface reflection echo by specifying and analyzing the reception position of the probe group 12 of the reception group 14 from which the reflected wave 19 is received by the arithmetic processing unit 16. The height of the defect 31 can be evaluated, and the defect 31 can be easily quantified regardless of the shape of the tip.
[0039]
It is possible to evaluate the height of the defect 31 by switching all the probe groups 12 of the phased array probe 32 to the transmission group 13 at the time of transmission and to the reception group 14 at the time of reception.
[0043]
【The invention's effect】
In the flaw detection method using the phased array according to the present invention, a plurality of probes are arranged in an array, a plurality of probe groups are formed by dividing the plurality of probes into a plurality, and the plurality of probes are formed. A group of probe groups is divided into a transmission group and a reception group to form a phased array probe, and the reflected waves reflected on the surface of the defect are received by the probe group of the reception group. The ultrasonic transmission delay time of each probe of the probe group of the transmission group is set to adjust the incident angle of the composite wavefront of the ultrasonic wave, and the probe group of the transmission group is sequentially switched to change the ultrasonic wave. On the other hand, each time an ultrasonic wave is transmitted from each probe group of the transmission group, the probe group of the reception group is sequentially switched to receive a reflected wave and transmit the ultrasonic wave. Probe group and the reception group that received the reflected wave The position of the probe group since so as to evaluate the height of the defect by specific, it is possible to evaluate the height and the status of wound using surface reflected echo. As a result, it is possible to easily quantify the scratches regardless of the shape of the tip and the state of the scratches even in a noisy material.
[0047]
Also, flaw detection apparatus of the present invention, a number of probe a plurality of sets form said plurality of probe to the the divided was probe group by several double as well as arranged in an array, and, said plurality a phased array probe is divided into a set of single loop and receiving single loop send a probe group, in probe group of the receiving group, so that the reflected wave reflected by the surface of the defect is received In addition, the ultrasonic transmission delay time of each probe of the probe group of the transmission group is set to adjust the incident angle of the synthesized wavefront of the ultrasonic wave, and the probe group of the transmission group is sequentially switched. The ultrasonic wave is transmitted, and the probe group of the reception group is controlled so that the reflected wave is received by sequentially switching each time an ultrasonic wave is transmitted from each probe group of the transmission group. parts and the received and the received probe group that sent the send single loop ultrasound said reflected wave Since a height Review worth arithmetic processing unit of the defect by locating the probe group loop, it is possible to evaluate the height and the status of wound using surface reflected echo. As a result, it is possible to easily quantify the scratches regardless of the shape of the tip and the state of the scratches even in a noisy material.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram conceptually showing the principle of a phased array method.
FIG. 2 is a schematic view of a state in which a flaw detection method is performed by a flaw detection apparatus according to a reference example of the present invention.
FIG. 3 is a schematic view of a state in which a flaw detection method is performed by a flaw detection apparatus according to a reference example of the present invention.
Schematic view of a state to have performed testing method by flaw detector according to the implementation embodiments of the present invention; FIG.

Claims (2)

A plurality of probes are arranged in an array, and a plurality of probe groups are formed by dividing the plurality of probes into a plurality of groups, and the plurality of probe groups are defined as transmission groups. Form a phased array probe divided into receiving groups,
The ultrasonic transmission delay time of each probe of the probe group of the transmission group is set so that the reflected wave reflected by the defect surface is received by the probe group of the reception group. Adjust the incident angle of the synthesized wavefront of the sound wave,
The probe groups of the transmission group are sequentially switched to transmit ultrasonic waves, while the probe groups of the reception group are sequentially switched each time an ultrasonic wave is transmitted from each probe group of the transmission group. Receive the reflected wave,
Evaluating the height of the defect by identifying the position of the probe group of the transmission group that has transmitted the ultrasonic wave and the probe group of the reception group that has received the reflected wave;
A flaw detection method using a phased array. Numerous probe a plurality of sets form said plurality of probe to the the divided was probe group by several double as well as arranged in an array, and, transmitting the plurality of sets of probes groups Groups And phased array probe divided into receiving groups,
The ultrasonic transmission delay time of each probe of the probe group of the transmission group is set so that the reflected wave reflected by the defect surface is received by the probe group of the reception group. Adjusting the incident angle of the synthesized wave front of the sound wave, the probe group of the transmission group sequentially switches and sends out the ultrasonic wave, while the probe group of the reception group is each probe group of the transmission group Each time an ultrasonic wave is transmitted from a control unit that sequentially switches and receives a reflected wave; and
An arithmetic processing unit that evaluates the height of the defect by specifying the position of the probe group of the transmission group that has transmitted the ultrasonic wave and the probe group of the reception group that has received the reflected wave;
A flaw detection apparatus comprising:

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