JP4634336B2 - Ultrasonic flaw detection method and ultrasonic flaw detection apparatus - Google Patents

Description

  The present invention relates to an ultrasonic flaw detection method and an ultrasonic flaw detection apparatus, and more particularly to an ultrasonic flaw detection method and an ultrasonic flaw detection apparatus to which a phased array method using two-dimensionally arranged array sensors is applied.

  As one of the ultrasonic flaw detection methods, a method called a phased array method using an array sensor in which transducers are arranged one-dimensionally and two-dimensionally is known. In the phased array method using an array sensor (one-dimensional array sensor) in which transducers are arranged one-dimensionally, scanning patterns such as sector scanning and linear scanning are controlled by controlling the delay time given to each transducer. It is possible to apply. In sector scanning, transmission and reception are performed along sector scanning lines centered on one point on a transducer on which ultrasonic waves are arranged one-dimensionally, and brightness modulation is performed according to the amplitude of a reflected signal (A scope) on each sector scanning line. Ultrasonic waves that can detect defects and the like are transmitted and received from images (sector scanned images). Thereby, it is possible to detect a defect or the like by using an image (linear scanning image) whose luminance is modulated in accordance with the amplitude of the A scope on the parallel line. In the phased array method using an array sensor (two-dimensional array sensor) in which transducers are two-dimensionally arranged, ultrasonic waves are transmitted and received along scanning lines that change three-dimensionally. It is possible to obtain an image (three-dimensional scanned image) whose luminance is modulated in accordance with the amplitude of the A scope.

  In the phased array method using a one-dimensional array sensor, the reflected echo intensity from the ultrasonic wave incident from the direction orthogonal to the defect is the strongest, and the reflected echo intensity decreases as the inclination of the ultrasonic wave incident on the defect increases. Become. On the other hand, the phased array method using a two-dimensional array sensor can change the incident direction of ultrasonic waves three-dimensionally. For this reason, ultrasonic waves can be incident from a direction orthogonal to the defect tilted with respect to the ultrasonic sensor, the intensity drop of the reflected echo is reduced, and the defect can be detected with high accuracy. There has been proposed an ultrasonic inspection apparatus that performs ultrasonic flaw detection using such a two-dimensional array sensor and three-dimensionally displays defects inside the object to be inspected (see, for example, Patent Document 1).

JP 2005-241611 A

  According to the ultrasonic inspection apparatus described in Patent Literature 1, there is an advantage that even a defect tilted with respect to the ultrasonic sensor can be quickly and visually detected. However, it is difficult to carry out detailed measurement of defect dimensions based on the obtained three-dimensional image. In particular, the reflected echo from the tip of the stress corrosion cracking (SCC) that has entered the weld zone of austenitic stainless steel may be equivalent to the intensity from the reflected echo from the welded structure. Discrimination is often difficult. In addition, the shape of the defect tip has a complicated appearance and may be inclined with respect to the scanning direction of the ultrasonic sensor. In flaw detection using a conventional one-dimensional array sensor, first, a rough defect depth is determined from a sector scan image or a linear scan image. After that, the echo from the defect tip is identified by manually rotating the one-dimensional array sensor (swinging scan), injecting ultrasonic waves from the front of the defect and scanning the one-dimensional array sensor back and forth. It was done by comprehensively judging from the behavior. According to the identification, the dimension of the defect height was measured. Such a method takes a lot of time to measure the dimension of the defect.

  An object of the present invention is to provide an ultrasonic flaw detection method and an ultrasonic flaw detection apparatus capable of quickly grasping the size of a detected defect and improving the accuracy of the size.

A feature of the present invention that achieves the above-described object is that a first sector scan is performed by an ultrasonic wave in a thickness direction of an object to be inspected, and a second sector scan is performed by an ultrasonic wave in a direction intersecting the thickness direction.
The first sector scan image information in the thickness direction including the image information of the defect existing in the inspection object is created based on the reflected echo signal obtained by the first sector scan, and includes the image information of the defect. The second sector scanning image information in the intersecting direction is created based on a reflected echo signal obtained by the second sector scanning.

  According to the present invention, since the first sector scanned image information and the second sector scanned image each including the image information of the defect are created, the time required for creating the image information is shortened, and the dimension (size) and the position of the defect are quickly determined. Can grasp. In addition, the accuracy of the dimension of the obtained defect is improved.

  The above-described object is to obtain the image information of each of the plurality of first B scopes and the plurality of first C scopes including the image information of the defect existing in the inspection object at the second sector at a certain ultrasonic incident angle in the first sector scan. Each of the second B scope image information is generated by combining a plurality of first B scope image information, and the second C scope image information is generated by combining a plurality of first C scope image information. It can be achieved even if created.

  Since the second B scope image information and the second C scope image information are created, the time required for creating the image information is shortened, and the size and position of the defect can be quickly grasped. In addition, the accuracy of the dimension of the obtained defect is improved.

  The second sector scan is preferably performed in a range set in a direction crossing the thickness direction.

  According to the present invention, the size of a detected defect can be quickly grasped, and the accuracy of the obtained size can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  An ultrasonic flaw detector which is a preferred embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the ultrasonic flaw detector 40 of this embodiment includes a two-dimensional array sensor 1, an ultrasonic transmission / reception processor 15, a display device 16, and an input device 17. The two-dimensional array sensor 1, the display device 16, and the input device 17 are connected to the ultrasonic transmission / reception processing device 15, respectively.

  As shown in FIG. 1B, the two-dimensional array sensor 1 is configured by two-dimensionally arranging a plurality of rectangular transducers 21 for transmission and reception (hereinafter simply referred to as transducers) in a planar shape. The ultrasonic transmission / reception processing device 15 includes a transmission delay circuit 5, a pulse generator 6, an amplifier 7, an A / D circuit 8, a reception delay circuit 9, an addition circuit 10, a control circuit (control device) 11, a waveform data storage memory (first memory) 1 storage device) 12 and an arithmetic circuit (image information creation device) 13. Individual transducers 21 of the two-dimensional array sensor 1 are connected to the pulse generator 6 and the amplifier 7. The input device 17 is connected to the control circuit 11 and the arithmetic circuit 13. The data recording device (second storage device) 14 is connected to the arithmetic circuit 13. The control circuit 11 is connected to the transmission delay circuit 5 and the arithmetic circuit 13. The transmission delay circuit 5 is connected to the pulse generator 6. The amplifier 7 is connected to the reception delay circuit 9 via the A / D circuit 8, and the reception delay circuit 9 is connected to the arithmetic circuit 13 via the addition circuit 10. The waveform data storage memory 12 is connected to the control circuit 11 and the arithmetic circuit 13. Incidentally, the z-axis direction shown in FIG. 1 is the depth direction of the device under test 3, the x-axis direction is one direction in a plane orthogonal to the z-axis direction, and the y-axis direction is the x-axis direction in the plane. It is a direction orthogonal to. The origin of the x, y, and z coordinates is the center of the two-dimensional array sensor 1.

  In the ultrasonic flaw detection performed in this embodiment, a phased array method is applied. The operator inputs a flaw detection start command to the input device 17. When receiving a flaw detection start command from the input device 17, the control circuit 11 which is an electronic scanning device controls the transmission delay circuit 5 to generate a plurality of trigger signals having different delay times from the transmission delay circuit 5. The pulse generator 6 to which these trigger signals are input transmits a pulse signal to each of the plurality of transducers 21 of the two-dimensional array sensor 1 to excite each transducer 21. The delay time set by the transmission delay circuit 5 is a delay time that enables sector scanning in the xy direction with respect to each sector scanning line of sector scanning in the yz direction in the inspection object 3. 22 is a sector scanning range in the xy direction, and 23 is a sector scanning range in the yz direction. The ultrasonic wave 4 generated by excitation of the vibrator 21 is incident on the inspection object 3, propagates through the inspection object 3, and is reflected by the defect 2 existing in the inspection object 3. The reflected ultrasonic waves are received by the transducers 21 and converted into electric signals. These electric signals are amplified by the amplifier 7 and then converted into digital signals by the A / D circuit 8. Each digital signal output from the A / D circuit 8 is adjusted in offset time by the reception delay circuit 9 and added by the adder circuit 10. The added digital signal is input to the arithmetic circuit 13 as A scope information (waveform data) of each sector scanning line in the two-direction sector scanning ranges 22 and 23, which is the ultrasonic flaw detection result. It is stored in the data storage memory 12. The arithmetic circuit 13 displays on the display device 16 the image information of the sector scanning range 23 in the yz direction and the sector scanning range 22 in the xy direction, whose luminance is modulated by the amplitude of the A scope. The incident angle 24 of the ultrasonic wave in the xy direction is represented by θ ′, and the incident angle 25 of the ultrasonic wave in the yz direction is represented by θ. Here, as another method, the maximum value of the amplitude of each A scope of the sector scanning line in the sector scanning range 23 is extracted in the adding circuit 10 and superimposed in the direction of the sector scanning range 22 to obtain one sector scanned image. good.

Control of sector scanning in the yz direction and sector scanning in the xy direction, that is, control of each transducer 21 of the two-dimensional array sensor 1 executed by the control circuit 11 to which the flaw detection start command is input will be described with reference to FIG. . The sector scanning range 23 in the yz direction is defined as θ ₁ ≦ θ ≦ θ _n , and the sector scanning range 22 in the xy direction is defined as θ ′ ₁ ≦ θ ′ ≦ θ ′ _n . First, at an incident angle θ in the yz direction, sector scanning in the xy direction (θ ′ ₁ ≦ θ ′ ≦ θ ′ _n ) is performed (step 401). At this time, the control circuit 11 controls the transmission delay circuit 11 to perform a plurality of triggers having different delay times in order to perform sector scanning in the xy direction (θ ′ ₁ ≦ θ ′ ≦ θ ′ _n ) at the incident angle θ. Generate a signal. Due to the generation of these trigger signals, one focal point on which each ultrasonic wave transmitted from each transducer 21 converges is the sector scan in the xy direction of θ ′ ₁ ≦ θ ′ ≦ θ ′ _n at the incident angle θ in the yz direction. Sector scanning in the xy direction moving in the range 22 is performed. The waveform data of the A scope obtained based on the ultrasonic waves received by these vibrators 21 is stored in the waveform data storage memory 12 by the arithmetic circuit 13. Control in step 401 is Kaee repeated until the determination of step 402 becomes θ = θ _n. That is, when θ is θ ₁ ≦ θ <θ _n , the control circuit 11 repeatedly executes the control of step 401 while increasing θ from θ ₁ by Δθ. When it is determined in step 402 If it is θ = θ _n, an image creation command is output to the arithmetic circuit 13 (step 403). The data of the sector scanning ranges 22 and 23 are input from the input device 17 by the operator.

  The arithmetic circuit 13 creates image information to be displayed when an image creation command is input. The image information created by the arithmetic circuit 13 is output to the display device 16 and displayed. The image information shown in FIG. 3 is an example of image information created by the arithmetic circuit 13 and displayed on the display device 16. This image information includes sector scan image information 201 in the sector scan range 22 in the xy direction and sector scan image information 205 in the sector scan range 23 in the yz direction. The image information shown in FIG. 3 further includes A scope image information 225 at an arbitrary sector scanning line (an incident angle θ ′) in the sector scanning range 22 in the xy direction, and an arbitrary sector in the sector scanning range 23 in the yz direction. The A scope image information 230 at the scanning line (a certain incident angle θ) is included. 210 is an input field for the incident angle θ ′, and 215 is an input field for the incident angle θ.

The image creation processing and defect height dimension calculation processing executed by the arithmetic circuit 13 will be described based on the processing flow of FIG. Here, an example of ultrasonic flaw detection of a defect 2 (see FIG. 1A) that is inclined with respect to the y direction and that has developed from the back surface of the inspection object 3 will be described in detail. 5 to 8 are also used in order to help understanding of image processing.
First, the arithmetic circuit 13 that has input the image creation command outputs initial display image information (see FIG. 5) stored in the data recording device 14 to the display device 16. Thereafter, the arithmetic circuit 13 inputs the incident angle θ (step 101). The input of the incident angle θ to the arithmetic circuit 13 is performed when the operator inputs the incident angle θ (for example, θ = 45 °) into the input field 215 of the initial display image information displayed on the display device 16. The waveform data of sector scanning in the xy direction at the incident angle θ is input (step 102). That is, the waveform data of sector scanning in the xy direction at the incident angle θ is read from the waveform data storage memory 12 and input to the arithmetic circuit 13. Sector scanned image information in the xy direction at the incident angle θ is created (step 103). Using the read waveform data, sector scan image information 201 in the xy direction at an incident angle θ (for example, θ = 45 °) is created (see FIG. 6). The sector scanned image information 201 includes, for example, reflected echo image information 220 having a large amplitude. The reflected echo having a large amplitude is the amplitude of the reflected signal from the ultrasonic wave 26 incident on the defect 2 from the front when the ultrasonic wave is incident on the defect 2 tilted with respect to the y direction in the sector scanning range 22 in the xy direction. This is caused by an increase in. When the waveform data includes reflection echo data having a large amplitude, the sector scan image information 201 includes image information 220 of the reflection echo having a large color and a large amplitude. The operator recognizes the presence of a reflected echo having a large amplitude by looking at the image information (see FIG. 6) displayed on the display device 16.

  Next, A scope image information is generated at an incident angle θ ′ in the xy direction that directly faces a reflection echo having a large amplitude (step 104). The incident angle θ ′ is input to the arithmetic circuit 13 when the operator inputs the incident angle θ ′ (for example, θ ′ = 20 °) into the input field 210 displayed on the display device 16. The incident angle θ ′ can be read by the operator from the displayed image information (see FIG. 6). The arithmetic circuit 13 takes in the waveform data at the input incident angle θ ′ from the waveform data storage memory 12 and creates the A scope image information 225 of the incident angle θ ′ based on the waveform data. The created A scope image information 225 (see FIG. 7) is output to the display device 16 and displayed.

  The sector scan image information in the yz direction at the input incident angle θ ′ and the A scope image information at the incident angle θ are created (step 105). The arithmetic circuit 13 takes in the waveform data of the sector scanning range 23 in the yz direction at the incident angle θ ′ (for example, θ ′ = 20 °) input in step 104 from the waveform storage memory 12. By using these waveform data, sector scan image information 205 and A scope image information 230 in the yz direction at the incident angle θ ′ are created. These pieces of image information are output and displayed on the display device 16 (see FIG. 8). In this example, the defect 2 exists at a position of θ = 45 ° and θ ′ = 20 °.

  In the example of the image information shown in FIG. 8, there is another reflection echo image information 235 having a large amplitude above the reflection echo image information 220 having a large amplitude. The presence of the image information 235 of another reflected echo having a large amplitude above the image information 22 indicates that the tip of the defect 2 exists at the position of the image information 235. The image information 235 is created based on the reflected echo signal from the tip of the defect 2.

  In step 106, the defect tip is determined. Specifically, it is determined whether the image information (for example, image information 220) of the reflection echo having a large amplitude existing at the incident angles θ and θ ′ is the image information of the tip of the defect. In other words, the determination of the defect tip is performed by using the second echo information (second image) having a large amplitude above the image information (first image information) 220 having the first amplitude reflected on the display device 16. It is determined whether or not 235 (referred to as two-image information) exists. When the determination result is “NO”, the processes of steps 101 to 106 are repeated until “YES”. If the determination result is “YES”, the process of step 107 is executed.

  When the image information of FIG. 8 is obtained, the second image information 235 exists above the first image information 220, so the determination in step 106 is “NO”. The operator uses the mouse on the screen of the display device 16 to move the arrow toward the first image information 220 in the sector scanned image information 205 so as to go to the second image information 235. The arithmetic circuit 13 displays a new incident angle θ (for example, θ = 50 °) in the input field in conjunction with the operation, inputs the new incident angle θ in step 101, and performs the processing from step 102 onward. Execute. That is, corresponding waveform data at θ = 50 ° is input at step 102, and sector scan image information in the xy direction at θ = 50 ° is created at step 103. Further, creation of A scope image information at θ ′ = 20 ° (step 104), creation of sector scanning image information at θ ′ = 20 °, and creation of A scope image information at θ = 50 ° (step 105), respectively. Do. Since the determination in step 106 is “Yes”, the processing in step 107 is executed.

If the determination result in step 106 is “YES”, the height dimension of the defect is obtained (step 107). The method for obtaining the height dimension of the defect will be specifically described. The arithmetic circuit 13 first reads the value of the beam path W ′ for the reflection echo having a large amplitude at the tip of the defect from the A scope image information 230 and uses the plate thickness T, the beam path W ′, and the incident angle θ of the inspection object 3. The height d of the defect is calculated from the following equation. The thickness T of the inspection object 3 is input from the input device 17 by the operator.
d = T−W′COSθ
The beam path length W is obtained by multiplying the time required for the ultrasonic wave incident on the inspection object to be reflected by a defect (for example, a flaw) and returned to the vibrator 21 by the speed of sound in the inspection object 3. , Calculated as half of the round trip propagation path.

  In Patent Document 1, a three-dimensional mesh is used when creating image information based on reflected echoes. The creation of image information using a three-dimensional mesh has the following problems. In other words, depending on the size of the three-dimensional mesh, it takes time to create image information, or the dimensional accuracy of defects is reduced. Specifically, if the 3D mesh is roughened, the time required for image creation is shortened, but the dimensional accuracy of the defect is reduced by the coarseness of the 3D mesh. Conversely, if the three-dimensional mesh is made fine, the dimensional accuracy of the defect is improved, but the creation time of the image information becomes long. Thus, conflicting problems occur depending on the size of the mesh. Moreover, since the method described in Patent Document 1 uses a three-dimensional mesh, it essentially takes time to create an image.

  On the other hand, in the present embodiment, sector image information (sector image in the thickness direction) obtained based on a reflected echo signal obtained by sector scanning in the thickness direction of the inspection object 3 (sector scanning in the yz direction). Information) 205, and sector image information (sector image information in the crossing direction) 201 obtained based on the reflected echo signal obtained by sector scanning in the direction crossing the thickness direction (sector scanning in the xy direction). Creating. Sector image information 201 and 205 is two-dimensional image information in two different directions. For this reason, the time required to create the sector image information 201 and 205 can be shortened compared to the image creation method using the three-dimensional mesh disclosed in Patent Document 1. By using the two-dimensional image information in two different directions, the three-dimensional shape of the defect and the position and size (dimension) of the defect in the three-dimensional space can be easily confirmed. Accuracy can be improved. In addition, since no mesh is used to create image information, the problems caused by using the above three-dimensional mesh do not occur. By displaying the sector image information 201 and 205 on the display device 16, the operator can easily grasp the position of the defect 2 by viewing the displayed image information.

  In this embodiment, A scope image information 225 at an arbitrary sector scanning line (for example, θ ′ = 20 °) in the sector scanning range 22 in the xy direction, and an arbitrary sector scanning line (in the sector scanning range 23 in the yz direction) For example, the A scope image information 230 at θ = 50 ° is created. By creating the A scope image information, it is possible to easily and accurately grasp the beam path to the defect 2 in the thickness direction of the inspection object 3 and the direction intersecting with the thickness direction. Thereby, the precision of the dimension of the obtained defect 2 can further be improved. In particular, the operator can easily recognize the position of the defect 2 by looking at the A scope image information 225.230 displayed on the display device 16. Since the A scope image information 225.230 is displayed together with the sector image information 201 and 205, the operator can easily recognize the position and size of the defect 2 in the three-dimensional space.

  An ultrasonic flaw detector according to another embodiment of the present invention will be described with reference to FIGS. The ultrasonic flaw detector 41 of the present embodiment has a configuration in which the position signal generator 18 and encoders (position detecting means) 19 and 20 are added to the configuration of the ultrasonic flaw detector 40 of the first embodiment. The position signal generator 18 is included in the ultrasonic transmission / reception processor 15 and is connected to the control circuit 11.

  As shown in FIG. 10, the sensor scanning device 50 that moves the two-dimensional array sensor 1 along the object to be inspected 3 includes a y-direction drive device 105 in which both ends are held by a pair of support members 115, and a y-direction drive. An x-direction drive device 101 is movably attached to the device 105. The two-dimensional array sensor 1 is attached to the x-direction drive device 101. The encoder 19 is connected to the y-direction drive device 105, and the encoder 20 is connected to the x-direction drive device 101. The two-dimensional array sensor 1 is moved in the y direction by the y direction driving device 105 and in the x direction by the x direction driving device 101. The ultrasonic cable 125 connects each transducer 2 to the pulse generator 6 and the amplifier 7 of the ultrasonic transmission / reception processing device 15. The encoder cable 130 connects the encoder 20 and the position signal generator 18 of the ultrasonic transmission / reception processing device 15. The encoder cable 135 connects the encoder 19 and the position signal generator 18. Here, the origin of the x coordinate, the y coordinate, and the z coordinate is assumed to be at one corner of the left corner of the object 3 as shown in FIG.

  As will be described in detail later, the arithmetic circuit 13 in the present embodiment is described below with reference to A in a plurality of sector scan lines in the sector scan range 22 in the xy direction at an incident angle θ of any ultrasonic wave in the sector scan range 23 in the yz direction. For each scope image information, B scope image information and C scope image information are created.

  A defect 2A that extends in the z-axis direction from the back surface of the inspection object 3 as shown in FIG. 10B exists, and this defect 2A is viewed from the surface of the inspection object 3 as shown in FIG. In this case, it is assumed that a portion (vertical portion) 31 perpendicular to the y-axis direction and a portion (tilted portion) 30 inclined with respect to the y-axis direction are provided. The tip of the defect 2A is located at the position of the defect depth d from the surface of the inspection object 3, and the defect depth d is constant in the vertical portion 31 and the inclined portion 30. Taking the ultrasonic flaw detection of the defect 2A as an example, the creation of image information for each of the B scope and the C scope executed by the arithmetic circuit 13 will be described.

  In the coordinate system shown in FIG. 10, the B scope image information is brightness-modulated in accordance with the amplitude of the A scope of the sector scanning line in which sector scanning is performed, and the position on the object to be inspected and the ultrasonic propagation time are orthogonal coordinates ( image information represented by a yz plane or an xz plane). This B scope image information can express the flaw detection result as a longitudinal sectional view of the object to be inspected. The C scope image information is expressed in the coordinate format of a plan view (xy plane) of the flaw detection result viewed from above the object to be inspected.

  A specific example of the image information of the B scope and the C scope will be described with reference to FIG. In ultrasonic flaw detection in which the two-dimensional array sensor 1 is scanned in the y direction by the y-axis moving device 110, the reflected echo of the ultrasonic wave 27 in the xy sector scanning range 22 and the sector scanning range 23 in the yz direction. B-scope image information 206 created based on the reflected echo of the ultrasonic wave 28 is shown in FIG. Further, FIG. 11A shows C scope image information 202 created based on these reflected echoes.

  Since the ultrasonic wave 27 and the ultrasonic wave 28 are directly incident on the vertical part 31 where the defect 2A faces the scanning direction 120 of the two-dimensional array sensor 1, the intensity of the reflected echo from the vertical part 31 is strong. Become. For this reason, the B scope image information 206 and the C scope image information 202 include image information of the vertical portion 31. However, since the ultrasonic wave 27 and the ultrasonic wave 28 do not enter perpendicularly to the inclined part 30 where the defect 2A is inclined with respect to the scanning direction 120 (does not enter directly), the intensity of the reflected echo from the inclined part 30 The image information of the inclined portion 30 does not appear in the B scope image information 206 and the C scope image information 202.

  The drive control of the sensor scanning device 50 executed by the control circuit 11 that has received the flaw detection start command from the input device 17 will be described with reference to FIG. When a flaw detection start command is input, the control circuit 11 executes the above-described control of each sector scanning shown in FIG. A detailed description of these sector scans is omitted.

The control circuit 13 inputs information on the inspection range of the x direction inspection range X1 ≦ X ≦ X2 and the y direction inspection range Y1 ≦ Y ≦ Y2 (step 201). The inspection range information input in step 201 is input from the input device 17 by the operator. The control circuit 11 outputs a sensor scanning command (step 202). The control circuit 11 outputs a sensor scanning command to the x-direction drive device 101 and the y-direction drive device 105. Each driving device is driven to align the two-dimensional array sensor 1 with an ultrasonic flaw detection start initial position (for example, X = X1, Y = Y1). Then, control by steps 401 and 402 shown in FIG. 2 is executed. In this embodiment, when it is determined that theta = theta _n in step 402, the determination of step 203 is performed.

  The encoder 19 measures the position of the two-dimensional array sensor 1 in the y direction, and the encoder 20 measures the position of the two-dimensional array sensor 1 in the x direction. These position measurement values are sent to the position signal generator 18, converted into position information, and input to the control circuit 13.

  In step 203, the position Y is determined. When the position Y is in the range of Y1 ≦ Y <Y2, a sensor scanning command for moving the two-dimensional array sensor 1 by ΔY in the y direction is output (step 202), and the y direction driving device 105 is driven. At the position where the two-dimensional array sensor 1 has moved by ΔY, control in steps 401 and 402 is executed, and sector scanning in the sector scanning ranges 22 and 23 is performed, respectively. Such movement of the two-dimensional array sensor 1 in the y direction and sector scanning in the sector scanning ranges 22 and 23 are repeated until it is determined in step 203 that the position Y is Y2 (Y = Y2). Each waveform data obtained by sector scanning in the sector scanning ranges 22 and 23, and positional information in the x direction and y direction measured by the encoders 19 and 20 (sector scanning, that is, positions where ultrasonic flaw detection is performed). Information) is stored in the waveform data storage memory 12 (step 204).

  Next, in step 205, the position X is determined. When the position X is in the range of X1 ≦ X <X2, a sensor scanning command for moving the two-dimensional array sensor 1 by ΔX in the x direction is output (step 202), and the x direction driving device 101 is driven. At the position where the two-dimensional array sensor 1 has moved by ΔX, the control in steps 401 and 402 is executed, and sector scanning in the sector scanning ranges 22 and 23 is performed, respectively. Steps 202, 203, 401, 402, and 204 are repeated until it is determined in step 205 that the position X is X2 (X = X2). When it is determined in step 205 that X = X2, the control circuit 11 outputs the image creation command in step 403 described above.

  The arithmetic circuit 13 that has received this image creation command executes the processing flow of the image creation process shown in FIG. 13 to create B scope image information and C scope image information. Note that, instead of when X = X2, Y = Y2, a sensor scanning command is output in step 202, the two-dimensional array sensor 1 is set at a predetermined position, and ultrasonic waves at that position in steps 401 and 402 are set. After the flaw detection is completed, the control circuit 11 may output an image creation command by the step 403. In this case, the B scope image information and C scope image information creation processing by the arithmetic circuit 13 can be performed in parallel with the movement operation of the two-dimensional array sensor 1 by the sensor scanning device 50 and ultrasonic flaw detection. For this reason, B scope image information and C scope image information can be obtained quickly.

An image creation process executed by the arithmetic circuit 13 based on the process flow shown in FIG. 13 will be described below. First, the respective waveform data and each position information at the incident angle θ in the yz direction and the incident angle θ ′ in the xy direction are read from the waveform data storage memory 12 and inputted (step 301). Here, the respective waveform data at the incident angle θ (θ ₁ ≦ θ ≦ θ _n ) and the incident angle θ ′ (θ ′ ₁ ≦ θ ′ ≦ θ ′ _n ) are input. Using each waveform data at a certain incident angle θ (for example, θ = θ ₁ ) and incident angle θ ′ (for example, θ ′ ₁ ≦ θ ′ ≦ θ ′ _n ), B scope image information and C scope image information are obtained. Each is created (step 302). Thereby, for example, at the incident angle θ ₁ in the yz direction, the B scope image information 206 and the C scope image information 202 (FIG. 14A) at an incident angle θ ′ (for example, θ ′ = θ ′ ₁ ) in a certain xy direction. (See (b)) is created.

In step 303, the incident angle θ ′ is determined. When the incident angle θ ′ is in the range of θ ′ ₁ ≦ θ ′ <θ ′ _n , the image information creation process in step 302 is performed. The image information creation processing in step 302 is repeated until it is determined in step S303 that θ ′ = θ ′ _n . Next, in step 304, the incident angle θ is determined. When the incident angle θ is in the range of θ ₁ ≦ θ <θ _n , image information creation processing in step 302 is performed. Image information creation processing in step 302, until it is determined that theta = theta _n in step S304, is repeated. The image information generating process is repeated in this way, for example, in FIG. 14, the incident angle theta ₁ of yz direction as shown in FIG. 15, the incident angle in the xy direction theta _{'(e.g., θ' = θ '1,} θ' = B-scope image information 206 and 207 and C-scope image information 202 and 203 (see FIGS. 14A and 14B, and FIGS. 15A and 15B) for θ ′ ₂ ) are created. Note that when the two-dimensional array sensor 1 is scanned in advance by the sensor scanning device 50 and the existence position of the defect 2A and the incident angle θ can be grasped, the process of step 303 is not performed without performing the process of step 304. The process of step 305 may be executed later.

When the determination in step 304 is θ = θ _n, the process of step 305 is performed. In step 305, the B scope image information and C scope image information created in step 302 are combined. For example, the B scope image information 206 and 207 are combined to create the B scope image information 208 (see FIG. 16A). Also, the C scope image information 202 and 203 are combined to create C scope image information 204 (see FIG. 16B). Then, the B scope image information 208 and the C scope image information 204 created in step 305 are output from the arithmetic circuit 13. These pieces of image information are displayed on the display device 16.

  In this embodiment, image information in two different directions of the B scope image information 208 in the thickness direction (xz direction) of the object 3 and the C scope image information 204 in the direction (xy direction) intersecting the thickness direction is obtained. create. The B scope image information 208 and the C scope image information 204 are also two-dimensional image information. In this embodiment as well, the time required to create the two-dimensional image information (B-scope image information 208 and C-scope image information 204) is shortened as compared with the prior art in Patent Document 1, as in the first embodiment. can do. Also, by using two-dimensional image information in two different directions, the three-dimensional shape of the defect and the position and size (dimension) of the defect in the three-dimensional space can be easily confirmed. ) Accuracy can be improved. Also in this embodiment, no mesh is used for creating image information, and therefore no problem caused by using a three-dimensional mesh occurs.

  In this embodiment, a plurality of first B scope image information (for example, B scope image information 206, 207) is synthesized to generate second B scope image information (for example, B scope image information 208). For this reason, the following problems can be solved, and even if there is a bent defect as shown in FIG. 10A in the inspection object 3, the second B scope image information representing the shape of the entire defect is accurately obtained. Can be created. That is, for a bent defect, since the ultrasonic wave incident at a certain incident angle does not face a part of the defect 2A (for example, the inclined part 30), some of the first B scope image information includes The image information of the part is not included. However, other 1B scope image information created using a reflected echo signal of an ultrasonic wave of another incident angle that is incident to the part (for example, the inclined part 30) of the defect 2A directly, Image information of a portion (for example, the inclined portion 30) is included. By combining the first B scope image information, image information of the entire bent defect (for example, the defect 2A in which the vertical portion 31 and the inclined portion 30 exist) can be created. This is also true when a plurality of first C scope image information (for example, C scope image information 202, 203) is synthesized to generate second B scope image information (for example, B scope image information 204).

1 shows a configuration of an ultrasonic flaw detector according to a preferred embodiment of the present invention, wherein (a) is an overall configuration diagram of the ultrasonic flaw detector, and (b) is a plan view of a two-dimensional array sensor. It is a flowchart which shows the control flow of the sector scan performed with the control circuit of FIG. It is explanatory drawing which shows an example of the image information displayed on the display apparatus of FIG. It is a flowchart which shows the flow of the image creation process and the height dimension calculation process of a defect which are performed with the arithmetic circuit of FIG. FIG. 5 is an explanatory diagram illustrating an example of initial display image information displayed on a display device when executing the process illustrated in FIG. 4. It is explanatory drawing which shows an example of the sector scanning image information of xy direction produced by step 103 of FIG. It is explanatory drawing which shows an example of A scope image information in incident angle (theta) 'produced by step 104 of FIG. FIG. 5 is an explanatory diagram showing an example of sector scan image information in the yz direction and an A scope image information at an incident angle θ created at step 105 in FIG. 4. The structure of the ultrasonic flaw detector which is another Example of this invention is shown, (a) is the whole block diagram of the ultrasonic flaw detector, (b) is a top view of a two-dimensional array sensor. The structure of the sensor scanning device used for the Example shown in FIG. 9 is shown, (a) is the top view, (b) is the side view. (A) is explanatory drawing of B scope image information, (b) is explanatory drawing of C scope image information. It is a flowchart which shows the control flow of the two-dimensional array sensor scan performed with the control circuit of FIG. 10 is a flowchart showing a flow of image creation processing executed by the arithmetic circuit of FIG. 9. FIG. 14 is an explanatory diagram illustrating an example of B scope image information and C scope image information created in step 302 of FIG. 13. FIG. 14 is an explanatory diagram showing another example of the B scope image information and the C scope image information created in step 302 of FIG. 13. FIG. 14 is an explanatory diagram illustrating an example of B scope image information and C scope image information created in step 305 of FIG. 13.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Two-dimensional array sensor, 5 ... Transmission circuit, 6 ... Pulse generator, 7 ... Amplifier, 8 ... A / D circuit, 9 ... Reception delay circuit, 10 ... Adder circuit, 11 ... Control circuit, 13 ... Arithmetic circuit, DESCRIPTION OF SYMBOLS 15 ... Ultrasonic transmission / reception processing apparatus, 16 ... Display apparatus, 18 ... Position signal generation part, 19, 20 ... Encoder, 21 ... Vibrator, 22 ... Sector scanning range in xy direction, 23 ... Sector scanning range in yz direction, 40 , 41 ... ultrasonic flaw detector, 50 ... sensor scanning device, 101 ... x-direction driving device, 110 ... y-direction driving device, 201 ... sector scanning image information in a sector scanning range in xy direction, 205 ... sector scanning in yz direction Sector scan image information in a range, 225... A-scope image information of a sector scan line in a sector scan range in the xy direction, 230... A sector of a sector scan line in a sector scan range in the yz direction. Up image information, 202,203,204 ... C scope image information, 206,207,208 ... B scope image information.

Claims (4)

An ultrasonic wave emitted from the transducer of the array sensor in which a plurality of transducers are two-dimensionally arranged is incident on the object to be inspected, and the reflected echo from the object to be inspected is received by the transducer, and the received reflected echo signal is received. In the ultrasonic flaw detection method for creating image information based on
Performing a first sector scan with the ultrasound in the thickness direction of the object to be inspected, performing a second sector scan with the ultrasound in a direction intersecting the thickness direction,
The first sector scan image information in the thickness direction including one image information and image information of a defect existing in the inspected object is created based on the reflected echo signal obtained by the first sector scan. The second sector scan image information in the intersecting direction including the image information of the defect and the other image information is created based on the reflected echo signal obtained by the second sector scan,
An ultrasonic flaw detection method comprising displaying the first sector scanned image information and the second sector scanned image information on a display device. The image information created based on the reflected echo signal includes the first A scope image information and the second A scope image information,
The first A scope image information is generated based on the reflected echo signal obtained at an ultrasonic incident angle passing through the defect in the first sector scan, and the second A scope image information is generated in the second sector scan. 2. The ultrasonic flaw detection method according to claim 1, wherein the first A scope image information and the second A scope image information are created on the basis of a signal of the reflected echo obtained at an ultrasonic incident angle passing through the defect and are displayed on a display device. An array sensor in which a plurality of transducers that generate ultrasonic waves are two-dimensionally arranged;
A control device that controls the plurality of vibrators so as to perform first sector scanning by the ultrasonic wave in a thickness direction of an object to be inspected and perform second sector scanning by the ultrasonic wave in a direction intersecting the thickness direction;
The first sector scan image information in the thickness direction, including image information of defects existing in the inspected body, is obtained by the first sector scan, and is generated by the inspected object by the incidence of the ultrasonic wave. The second sector scan image information in the intersecting direction, which is created based on the reflected echo signal received by the vibrator and includes the image information of the defect, is used as the reflected echo signal obtained by the second sector scan. An image information creation device to create based on;
An ultrasonic flaw detector comprising: a display device that displays the first sector scanned image information and the second sector scanned image information . The image information creation device creates first A scope image information based on the reflected echo signal obtained at an ultrasonic incident angle passing through the defect in the first sector scan, and generates second A scope image information. 4. The first A scope image information and the second A scope image information are generated on the basis of a signal of the reflected echo obtained at an ultrasonic incident angle passing through the defect in two-sector scanning, and the first A scope image information and the second A scope image information are output to a display device. ultrasonic flaw detector.

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