Ultrasonic flaw detector and ultrasonic flaw detecting method

Abstract

To accurately evaluate a flaw having an unknown position and depth.SOLUTION: An ultrasonic flaw detector includes a first sensor including a plurality of first elements configured to transmit ultrasonic waves to a target and receive reflection waves of the ultrasonic waves; a second sensor including a plurality of second elements configured to transmit ultrasonic waves to the target and receive reflection waves of the ultrasonic waves, the second sensor being arranged on a side opposite to the first sensor across a detection region of the target; and an analysis device that analyzes a flaw in the detection region. The first element is configured to receive a second diffraction wave as a diffraction wave of the ultrasonic wave transmitted from the second element, and the second element is configured to receive a first diffraction wave as a diffraction wave of the ultrasonic wave transmitted from the first element. The analysis device includes a grid creation unit that divides the detection region to create a plurality of grids, and an image generation unit that generates an image by associating the reflection wave with at least one of the first diffraction wave and the second diffraction wave for each of the plurality of grids.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an ultrasonic flaw detection device and an ultrasonic flaw detection method for detecting a defect in a target using ultrasonic waves. [Background technology]

[0002] A conventionally known method is the TOFD (Time Of Flight Diffraction) method, in which a transmitting probe and a receiving probe are arranged opposite each other, ultrasonic waves are transmitted from the transmitting probe, and diffracted waves of the ultrasonic waves generated from the tip of a flaw are received by the receiving probe.Patent Document 1 discloses an ultrasonic flaw detection device in which the transmitting probe and the receiving probe are each a phased array probe having a plurality of elements capable of transmitting and receiving ultrasonic waves, and an ultrasonic beam is focused at any position of a target to detect flaws. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5829175 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a phased array probe is used, the ultrasonic convergence point must be set before flaw detection can begin. Therefore, while ultrasonic flaw detection using a phased array probe can evaluate defects whose position and depth are known, it cannot properly evaluate locations that are off the convergence point, making it difficult to evaluate defects whose position and depth are unknown.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an ultrasonic flaw detection device and an ultrasonic flaw detection method that can evaluate defects whose positions and depths are unknown with high accuracy. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the ultrasonic flaw detection device of the present disclosure is an ultrasonic flaw detection device for detecting defects in an object using ultrasonic waves, and comprises: a first sensor including a plurality of first elements configured to transmit ultrasonic waves to the object and receive reflected waves of the ultrasonic waves; a second sensor including a plurality of second elements configured to transmit ultrasonic waves to the object and receive reflected waves of the ultrasonic waves, and positioned on the opposite side of the first sensor across a detection area of ​​the object; and an analysis device for analyzing the defects in the detection area, wherein the first elements are configured to receive second diffracted waves, which are diffracted waves of the ultrasonic waves transmitted from the second elements, and the second elements are configured to receive first diffracted waves, which are diffracted waves of the ultrasonic waves transmitted from the first elements; and the analysis device includes a grid creation unit that divides the detection area to create a plurality of grids, and an image generation unit that generates an image by associating the reflected waves with at least one of the first diffracted waves and the second diffracted waves for each of the plurality of grids.

[0007] In order to achieve the above-mentioned object, the ultrasonic flaw detection method of the present disclosure is an ultrasonic flaw detection method using an ultrasonic flaw detection device that includes a first sensor including a plurality of first elements configured to transmit ultrasonic waves to the target and receive reflected waves of the ultrasonic waves, in order to detect defects in the target using ultrasonic waves, and a second sensor including a plurality of second elements configured to transmit ultrasonic waves to the target and receive reflected waves of the ultrasonic waves, wherein the first elements are configured to be able to receive second diffracted waves that are diffracted waves of the ultrasonic waves transmitted from the second elements, and the second elements are configured to receive first diffracted waves that are diffracted waves of the ultrasonic waves transmitted from the first elements, and the ultrasonic flaw detection method includes the steps of: arranging the first sensor and the second sensor on opposite sides of a detection area of ​​the target; dividing the detection area to create a plurality of grids; and generating an image by associating the reflected waves with at least one of the first diffracted waves and the second diffracted waves for each of the plurality of grids. [Effects of the Invention]

[0008] According to the ultrasonic flaw detection device and ultrasonic flaw detection method disclosed herein, defects whose positions and depths are unknown can be evaluated with high accuracy. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a schematic configuration of an ultrasonic flaw detection device according to an embodiment. [Figure 2] 4A and 4B are diagrams illustrating an example of a reflected wave and a diffracted wave received by a first element according to an embodiment. [Figure 3] 6A and 6B are diagrams illustrating an example of a reflected wave and a diffracted wave received by a second element according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating a surface reflected wave according to an embodiment. [Figure 5] FIG. 10 is a diagram for explaining a defect reflected wave according to an embodiment. [Figure 6] FIG. 10 is a diagram illustrating a second surface reflected wave according to an embodiment. [Figure 7] 4A and 4B are diagrams for explaining a first diffracted wave and a second diffracted wave according to an embodiment. [Figure 8] 1 is a schematic functional block diagram of an analysis device according to an embodiment. [Figure 9] FIG. 4 is a diagram showing waveform data of a first surface reflected wave and a second surface reflected wave according to an embodiment. [Figure 10] FIG. 1 is a diagram illustrating a grid according to an embodiment. [Figure 11] 1 is a flowchart of an ultrasonic flaw detection method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an ultrasonic flaw detection device and an ultrasonic flaw detection method according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0011] <Ultrasonic flaw detection equipment> An ultrasonic flaw detection device according to the present disclosure detects a defect in a target using ultrasonic waves. FIG. 1 is a diagram schematically illustrating the configuration of an ultrasonic flaw detection device 1 according to one embodiment. The target is not particularly limited as long as ultrasonic waves A can be propagated inside, and may be, for example, a heat transfer tube or an evaporation tube provided in a boiler. In the present disclosure, the ultrasonic flaw detection device 1 will be described using an example in which a defect De in an evaporation tube 100 is detected using ultrasonic waves A.

[0012] (composition) 1, the ultrasonic flaw detection device 1 includes a first sensor 2, a second sensor 4, and an analysis device 6. In one embodiment, as illustrated in FIG. 1, the ultrasonic flaw detection device 1 further includes a wedge 8, a temperature acquisition device 10, and a cooling device 12.

[0013] The first sensor 2 includes a plurality of first elements 14 held by a holder 3. Each of the plurality of first elements 14 is configured to transmit ultrasonic waves A to the evaporation tube 100 and receive reflected waves B of the ultrasonic waves A. FIG. 2 is a diagram illustrating an example of reflected waves B and diffracted waves C received by the first elements 14 according to one embodiment. As shown in FIG. 2, the first elements 14 receive a surface-reflected wave B1, which is reflected by an arbitrary point p1 on the surface 101 facing the exterior of the evaporation tube 100, of the reflected waves B of the ultrasonic waves A transmitted from the first elements 14. In one embodiment, the surface-reflected wave B1 passes through the wedge 8. The first elements 14 receive a defect-reflected wave B2, which is reflected by an arbitrary point p2 on the defect De, of the reflected waves B of the ultrasonic waves A transmitted from the first elements 14. The defect-reflected wave B2 propagates in the order of the evaporation tube 100 and the wedge 8.

[0014] Furthermore, the first element 14 is configured to be able to receive a second diffracted wave C2, which is a diffracted wave C of the ultrasonic wave A transmitted from the second element 16, which will be described later. As shown in Fig. 2, the first element 14 receives the second diffracted wave C2 emitted from the tip p3 of the defect De when the ultrasonic wave A transmitted from the second element 16 reaches the tip p3 of the defect. The second diffracted wave C2 propagates through the evaporation tube 100 and the wedge 8 in this order.

[0015] The second sensor 4 includes a plurality of second elements 16 held by a second holder 5. Each of the plurality of second elements 16 is configured to transmit ultrasonic waves A to the evaporation tube 100 and receive reflected waves B of the ultrasonic waves A. FIG. 3 is a diagram illustrating an example of reflected waves B and diffracted waves C received by the second element 16 according to one embodiment. As shown in FIG. 3, the second element 16 receives a surface-reflected wave B4, which is reflected by a point p1 on the surface 101 of the evaporation tube 100, among the reflected waves B of the ultrasonic waves A transmitted from the second element 16. In one embodiment, the surface-reflected wave B4 passes through the wedge 8. The second element 16 receives a defect-reflected wave B5, which is reflected by a point p2 on the defect De among the reflected waves B of the ultrasonic waves A transmitted from the second element 16. The defect-reflected wave B5 propagates in the order of the evaporation tube 100 and the wedge 8.

[0016] Furthermore, the second element 16 is configured to be able to receive a first diffracted wave C1, which is a diffracted wave C of the ultrasonic wave A transmitted from the first element 14. As shown in Fig. 3, the ultrasonic wave A transmitted from the first element 14 reaches the tip p3 of the defect De, and the second element 16 receives the first diffracted wave C1 emitted from the tip p3 of the defect. The first diffracted wave C1 propagates through the evaporation tube 100 and the wedge 8 in this order.

[0017] In one embodiment, as illustrated in FIG. 1 , the first sensor 2 and the second sensor 4 are mounted on a wedge 8. Ultrasonic waves A transmitted through the wedge 8 are incident on the evaporation tube 100 (see FIGS. 2 and 3 ). The wedge 8 includes a contact surface 18 that contacts the surface 101 of the evaporation tube 100 and a mounting surface 20 on which the first sensor 2 and the second sensor 4 are mounted. The mounting surface 20 includes a first inclined portion 22 and a second inclined portion 24 that are inclined with respect to the contact surface 18. The first inclined portion 22 approaches the surface 101 of the evaporation tube 100 toward one side of the extension direction D1 in which the evaporation tube 100 extends. The second inclined portion 24 extends from the other end 23 of the first inclined portion 22 on the other side of the extension direction D1 toward the other side of the extension direction D1. The second inclined portion 24 moves away from the surface 101 of the evaporation tube 100 toward one side of the extension direction D1.

[0018] The second sensor 4 is disposed on the opposite side of the first sensor 2 across the detection region R of the evaporation tube 100. That is, the ultrasonic flaw detection device 1 employs a time-of-flight diffraction (TOFD) method in which a transmitting probe (first element 14 or second element 16) and a receiving probe (first element 14 or second element 16) are disposed facing each other, ultrasonic waves A are transmitted from the transmitting probe, and diffracted waves C of the ultrasonic waves A emitted from the tip p3 of the defect De are received by the receiving probe. In one embodiment, as illustrated in FIG. 1 , the first sensor 2 is mounted on the first inclined portion 22, and the second sensor 4 is mounted on the second inclined portion 24. The detection region R of the evaporation tube 100 is included between the first element 14 located on the other side among the plurality of first elements 14 and the second element 16 located on one side among the plurality of second elements 16 in the extension direction D1.

[0019] In one embodiment, the wedge 8 is formed as a single continuous component using the same material. That is, the wedge 8 does not have an acoustic isolation portion 200 (shown by a dashed line in FIG. 1 ) between the first sensor 2 and the second sensor 4 that prevents the transmission of ultrasonic waves A. Therefore, as shown in FIG. 2 , the first element 14 receives a second surface-reflected wave B3 that is reflected by the surface 101 of the evaporation tube 100 out of the reflected wave B of the ultrasonic waves A transmitted from the second element 16. Similarly, as shown in FIG. 3 , the second element 16 receives a second surface-reflected wave B6 that is reflected by the surface 101 of the evaporation tube 100 out of the reflected wave B of the ultrasonic waves A transmitted from the first element 14.

[0020] In one embodiment, the first sensor 2 is configured to receive, at all first elements 14, a reflected wave B of an ultrasonic wave A transmitted from one first element 14 (so-called full matrix capture (FMC) is applied). Furthermore, the first sensor 2 is configured to receive, at all first elements 14, a diffracted wave C of the ultrasonic wave A transmitted from one second element 16. Similarly, the second sensor 4 is configured to receive, at all second elements 16, a reflected wave B of the ultrasonic wave A transmitted from one second element 16 (so-called FMC is applied). Furthermore, the second sensor 4 is configured to receive, at all second elements 16, a diffracted wave C of the ultrasonic wave A transmitted from one first element 14.

[0021] The surface reflected wave B1, defect reflected wave B2, second surface reflected wave B3, and second diffracted wave C2 received by the first element 14 have been described with reference to Fig. 2. Similarly, the surface reflected wave B4, defect reflected wave B5, second surface reflected wave B6, and first diffracted wave C1 received by the second element 16 have been described with reference to Fig. 3. Next, the reflected wave B and first diffracted wave C1 received by the first element 14, and the reflected wave B and second diffracted wave C2 received by the second element 16 will be further described with reference to Figs. 4 to 7.

[0022] The surface reflected wave B1 of ultrasonic wave A transmitted from the first element 14 is received not only by the first element 14 that transmitted the ultrasonic wave A, but also by the remaining first elements 14. FIG. 4 is a diagram for explaining the surface reflected wave B1 according to one embodiment. As illustrated in FIG. 4, the multiple first elements 14 include a one-side first element 14A and an other-side first element 14B that is different from the one-side first element 14A. The reflected wave B includes a first surface reflected wave B11 received by the other-side first element 14B out of the surface reflected wave B1 of ultrasonic wave A transmitted from the one-side first element 14A (ultrasonic wave A reflected at point p1). Furthermore, the reflected wave B includes a second surface reflected wave B12 received by the one-side first element 14A out of the surface reflected wave B1 of ultrasonic wave A transmitted from the other-side first element 14B (ultrasonic wave A reflected at point p1). In the present disclosure, the route along which the first surface-reflected wave B11 propagates from point p1 to the other-side first element 14B is referred to as the surface reflection route rt1, and the route along which the second surface-reflected wave B12 propagates from point p1 to the one-side first element 14A is referred to as the second surface reflection route rt2. The route of the ultrasonic wave A from the one-side first element 14A to point p1 is the same as the second surface reflection route rt2 (although in FIG. 4, the route is shifted for ease of explanation). The route of the ultrasonic wave A from the other-side first element 14B to point p1 is the same as the surface reflection route rt1 (although in FIG. 4, the route is shifted for ease of explanation). The one-side first element 14A and the other-side first element 14B are any two first elements 14 among the multiple first elements 14.

[0023] Similarly, the surface reflected waves B4 of ultrasonic wave A transmitted from the second element 16 are received not only by the second element 16 that transmitted the ultrasonic wave A, but also by the remaining second elements 16. As illustrated in FIG. 4, the multiple second elements 16 include a one-side second element 16A and an other-side second element 16B that is different from the one-side second element 16A. The reflected waves B include a third surface reflected wave B41 received by the other-side second element 16B out of the surface reflected waves B4 of ultrasonic wave A transmitted from the one-side second element 16A (ultrasonic wave A reflected at point p1). Furthermore, the reflected waves B include a fourth surface reflected wave B42 received by the one-side second element 16A out of the surface reflected waves B4 of ultrasonic wave A transmitted from the other-side second element 16B (ultrasonic wave A reflected at point p1). In the present disclosure, the route along which the third surface reflected wave B41 propagates from point p1 to the other-side second element 16B is referred to as the third surface reflection route rt3, and the route along which the fourth surface reflected wave B42 propagates from point p1 to the one-side second element 16A is referred to as the fourth surface reflection route rt4. The route of the ultrasonic wave A from the one-side second element 16A to point p1 is the same as the fourth surface reflection route rt4 (although it is shifted in FIG. 4 for the sake of explanation). The route of the ultrasonic wave A from the other-side second element 16B to point p1 is the same as the third surface reflection route rt3 (although it is shifted in FIG. 4 for the sake of explanation). The one-side second element 16A and the other-side second element 16B are any two second elements 16 among the multiple second elements 16.

[0024] The defect reflected wave B2 of the ultrasonic wave A transmitted from the first element 14 is received not only by the first element 14 that transmitted the ultrasonic wave A but also by the remaining first elements 14. FIG. 5 is a diagram for explaining the defect reflected wave B2 according to one embodiment. As illustrated in FIG. 5, the multiple first elements 14 include a one-side first element 14A and an other-side first element 14B that is different from the one-side first element 14A. The reflected wave B includes a first defect reflected wave B21 received by the other-side first element 14B from the defect reflected wave B2 of the ultrasonic wave A transmitted from the one-side first element 14A (ultrasonic wave A reflected at point p2). Furthermore, the reflected wave B includes a second defect reflected wave B22 received by the one-side first element 14A from the defect reflected wave B2 of the ultrasonic wave A transmitted from the other-side first element 14B (ultrasonic wave A reflected at point p2). In the present disclosure, the route along which the first defect reflected wave B21 propagates from point p2 to the other-side first element 14B is referred to as range evaluation route rt5, and the route along which the second defect reflected wave B22 propagates from point p2 to the one-side first element 14A is referred to as second range evaluation route rt6. The route of the ultrasonic wave A from the one-side first element 14A to point p2 is the same as the second range evaluation route rt6 (although it is shifted in FIG. 5 for ease of explanation). The route of the ultrasonic wave A from the other-side first element 14B to point p2 is the same as the range evaluation route rt5 (although it is shifted in FIG. 5 for ease of explanation). The one-side first element 14A illustrated in FIG. 5 may be the same first element 14 as the one-side first element 14A illustrated in FIG. 4, or may be a different first element 14. The other-side first element 14B illustrated in FIG. 5 may be the same first element 14 as the other-side first element 14B illustrated in FIG. 4, or may be a different first element 14.

[0025] Similarly, the defect reflected wave B5 of ultrasonic wave A transmitted from the second element 16 is received not only by the second element 16 that transmitted the ultrasonic wave A, but also by the remaining second elements 16. As illustrated in FIG. 5, the multiple second elements 16 include a one-side second element 16A and an other-side second element 16B that is different from the one-side second element 16A. The reflected wave B includes a third defect reflected wave B51 of the defect reflected wave B5 of ultrasonic wave A transmitted from the one-side second element 16A (ultrasonic wave A reflected at point p2) that is received by the other-side second element 16B. Furthermore, the reflected wave B includes a fourth defect reflected wave B52 of the defect reflected wave B5 of ultrasonic wave A transmitted from the other-side second element 16B (ultrasonic wave A reflected at point p2) that is received by the one-side second element 16A. In the present disclosure, the route along which the third defect reflected wave B51 propagates from point p2 to the other-side second element 16B is referred to as the third range evaluation route rt7, and the route along which the fourth defect reflected wave B52 propagates from point p2 to the one-side second element 16A is referred to as the fourth range evaluation route rt8. The route of the ultrasonic wave A from the one-side second element 16A to point p2 is the same as the fourth range evaluation route rt8 (although it is shifted in FIG. 5 for the sake of explanation). The route of the ultrasonic wave A from the other-side second element 16B to point p2 is the same as the third range evaluation route rt7 (although it is shifted in FIG. 5 for the sake of explanation). The one-side second element 16A illustrated in FIG. 5 may be the same second element 16 as the one-side second element 16A illustrated in FIG. 4, or may be a different second element 16. The other-side second element 16B illustrated in FIG. 5 may be the same second element 16 as the other-side second element 16B illustrated in FIG. 4, or may be a different second element 16.

[0026] 6 is a diagram illustrating second surface reflected waves B3 and B6 according to an embodiment. As illustrated in FIG. 6, the reflected wave B includes a one-side second surface reflected wave B31 received by any one first element 14C among the second surface reflected waves B3 of ultrasonic waves A transmitted from any one second element 16C. Furthermore, the reflected wave B includes a other-side second surface reflected wave B61 received by the second element 16C among the second surface reflected waves B6 of ultrasonic waves A transmitted from the first element 14C. In the present disclosure, the route along which the one-side second surface reflected wave B31 propagates from any reflection point p4 on the surface 101 to the first element 14C is referred to as a one-side second surface reflection route rt9, and the route along which the other-side second surface reflected wave B61 propagates from the reflection point p4 to the second element 16C is referred to as a other-side second surface reflection route rt10. The route of the ultrasonic wave A from the first element 14C to the reflection point p4 is the same as the second surface reflection route rt9 on one side (shifted in FIG. 6 for the sake of explanation). The route of the ultrasonic wave A from the second element 16C to the reflection point p4 is the same as the second surface reflection route rt10 on the other side (shifted in FIG. 6 for the sake of explanation).

[0027] 7 is a diagram illustrating a first diffracted wave C1 and a second diffracted wave C2 according to one embodiment. As illustrated in FIG. 7, the plurality of first elements 14 includes a first depth-evaluation element 14D, and the plurality of second elements 16 includes a second depth-evaluation element 16D. The first diffracted wave C1 includes a first depth-evaluation diffracted wave C11 received by the second depth-evaluation element 16D out of the first diffracted wave C1 of the ultrasonic wave A transmitted from the first depth-evaluation element 14D. The second diffracted wave C2 includes a second depth-evaluation diffracted wave C21 received by the first depth-evaluation element 14D out of the second diffracted wave C2 of the ultrasonic wave A transmitted from the second depth-evaluation element 16D. In the present disclosure, the route along which the first evaluation diffracted wave C11 propagates from the tip p3 of the defect De to the second depth-evaluation element 16D is referred to as the depth evaluation route rt11, and the route along which the second depth-evaluation diffracted wave C21 propagates from the tip p3 of the defect De to the first depth-evaluation element 14D is referred to as the second depth evaluation route rt12. The route of the ultrasonic wave A from the first depth-evaluation element 14D to the tip p3 of the defect De is the same as the second depth evaluation route rt12 (although it is shifted in FIG. 7 for the sake of explanation). The route of the ultrasonic wave A from the second depth-evaluation element 16D to the tip p3 of the defect De is the same as the depth evaluation route rt11 (although it is shifted in FIG. 7 for the sake of explanation).

[0028] Although not shown, in one embodiment, the first element 14 also receives a reflected wave B transmitted from the second element 16 and reflected by the inner surface 102 of the evaporation tube 100. Although not shown, in one embodiment, the second element 16 also receives a reflected wave B transmitted from the first element 14 and reflected by the inner surface 102 of the evaporation tube 100. Note that the evaporation tube 100 may be a rifled tube having spiral ribs on the inner surface 102.

[0029] 1, the temperature acquisition device 10 is, for example, a temperature sensor, and is capable of acquiring the temperature of the detection region R. The temperature acquisition device 10 may be of a contact type and acquire the temperature of the detection region R by contacting the evaporation tube 100, or may be of a non-contact type and acquire the temperature of the detection region R by measuring radiant heat from the evaporation tube 100. The temperature acquisition device 10 may acquire the temperature of the detection region R directly, or may acquire the temperature of the detection region R indirectly, for example, by measuring an electrical resistance value.

[0030] 1 , the cooling device 12 is, for example, a cooling spray that sprays cooling gas G to cool the detection region R. The configuration of the cooling device 12 is not limited as long as it can cool the detection region R. The cooling device 12 cools the detection region R when at least one of the first element 14 and the second element 16 is transmitting or receiving ultrasonic waves A.

[0031] The analysis device 6 detects defects De in the detection area R. The analysis device 6 is, for example, a computer, and includes a processor such as a CPU or GPU (not shown), memories such as a ROM or RAM, and an I / O interface. The analysis device 6 realizes each functional unit of the analysis device 6 by the processor operating (calculating, etc.) according to instructions of a program loaded into the memory. Each functional unit of the analysis device 6 will be described below with reference to FIG. 8. In some embodiments, the analysis device 6 is a cloud server provided in a cloud environment.

[0032] 1 , the analysis device 6 is electrically connected to each of the first sensor 2, the second sensor 4, and the temperature acquisition device 10. The analysis device 6 acquires the reflected wave B and the second diffracted wave C2 received by the first element 14 from the first sensor 2. The analysis device 6 acquires the reflected wave B and the first diffracted wave C1 received by the second element 16 from the second sensor 4. The analysis device 6 acquires the temperature t of the detection region R from the temperature acquisition device 10.

[0033] 8 is a schematic functional block diagram of an analysis device 6 according to one embodiment. As shown in FIG. 8, the analysis device 6 includes a grid creation unit 58 and an image generation unit 60. In one embodiment, the analysis device 6 further includes a position identification unit 52, a relative position identification unit 54, a correction unit 56, a defect depth evaluation unit 62, and a defect range evaluation unit 64.

[0034] The position identifying unit 52 identifies the position of the first sensor 2 relative to the evaporation tube 100 based on the surface reflected wave B1 (see FIG. 2 ) received by the first element 14. In one embodiment, the first element 14 receives the surface reflected wave B1 reflected at various points p1 on the surface 101. In one embodiment, each of the multiple first elements 14 receives the surface reflected wave B1. In one embodiment, the position identifying unit 52 identifies the position of the first sensor 2 based on at least one of the first surface reflected wave B11 and the second surface reflected wave B12 if the waveform of the first surface reflected wave B11 has the same shape as the inverted waveform of the second surface reflected wave B12. The position identifying unit 52 identifies the position of the first sensor 2, for example, from the time it takes to receive the first surface reflected wave B11. The position identifying unit 52 identifies the position of the first sensor 2, for example, from the average of the time it takes to receive the first surface reflected wave B11 and the time it takes to receive the second surface reflected wave B12.

[0035] The "same shape as the inverted waveform" will be described with reference to FIG. 9. FIG. 9 is a diagram showing waveform data of a first surface reflected wave B11 and a second surface reflected wave B12. As shown in FIG. 9, the first surface reflected wave B11 received by the other-side first element 14B includes a first waveform X1. Similarly, the second surface reflected wave B12 received by the one-side first element 14A includes a second waveform X2. The route taken by the ultrasonic wave A transmitted by the one-side first element 14A until it is received by the other-side first element 14B as the first surface reflected wave B11 is the same as the route taken by the ultrasonic wave A transmitted by the other-side first element 14B until it is received by the one-side first element 14A as the second surface reflected wave B12. These routes are both the surface reflection route rt1 and the second surface reflection route rt2. In other words, the elapsed time E1 from when the first element 14A on one side transmits ultrasonic wave A until it is received by the first element 14B on the other side as the first surface reflected wave B11 is equal to the elapsed time E2 from when the first element 14B on the other side transmits ultrasonic wave A until it is received by the first element 14A on the one side as the second surface reflected wave B12. Therefore, when the first waveform X1 is inverted with respect to the time axis O at the center of the elapsed time E1, it has the same shape as the second waveform X2.

[0036] The relative position determining unit 54 determines the relative position of the second sensor 4 with respect to the first sensor 2 based on the second surface reflected waves B3 and B6 received by the second element 16. In one embodiment, if the waveform of the second surface reflected wave B31 on one side has the same shape as the inverted waveform of the second surface reflected wave B61 on the other side, the relative position determining unit 54 determines the relative position of the second sensor 4 with respect to the first sensor 2 based on at least one of the second surface reflected wave B31 on one side and the second surface reflected wave B61 on the other side. The relative position determining unit 54 determines the relative position of the second sensor 4, for example, from the time it takes to receive the second surface reflected wave B31 on one side. The relative position determining unit 54 determines the relative position of the second sensor 4, for example, from the average of the time it takes to receive the second surface reflected wave B31 on one side and the time it takes to receive the second surface reflected wave B61 on the other side.

[0037] The route taken by the ultrasonic wave A transmitted by the first element 14C until it is received by the second element 16C as the second surface reflected wave B61 on the other side is the same as the route taken by the ultrasonic wave A transmitted by the second element 16C until it is received by the first element 14C as the second surface reflected wave B31 on one side (see FIG. 6). These routes are the second surface reflection route rt9 on one side + the second surface reflection route rt10 on the other side. Therefore, this is the same relationship as the "same shape as the inverted waveform" described above, and so a description thereof will be omitted.

[0038] The correction unit 56 corrects the sound velocities of the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2 according to the temperature t acquired by the temperature acquisition device 10. For example, the correction unit 56 corrects the sound velocities of the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2 so that they each decrease as the temperature t increases, and corrects the refraction angle between the wedge 8 and the evaporation tube 100 and the time it takes for the ultrasonic wave A to be received by each element.

[0039] The grid creation unit 58 divides the detection region R to create multiple grids 70. FIG. 10 is a diagram illustrating a grid 70 (a TFM grid used in the TFM described later) according to one embodiment. As shown in FIG. 10, the grid creation unit 58 creates multiple grids 70 by dividing the detection region R along both the extension direction D1 and the radial direction D2 of the evaporation tube 100. In the embodiment illustrated in FIG. 10, the grid creation unit 58 acquires shape data of the evaporation tube 100, identifies the detection region R based on the acquired shape data, and then forms a rectangular grid 70. The shorter side of the rectangular grid 70 is shorter than the wavelength of the ultrasonic wave A. In one embodiment, the grid creation unit 58 identifies the detection region R using the position of the first sensor 2 identified by the position identification unit 52 and the relative position of the second sensor 4 identified by the relative position identification unit 54, and divides the identified detection region R to create multiple grids 70. In some embodiments, the grid 70 has a square shape, and one side of the square grid 70 is shorter than the wavelength of the ultrasonic wave A.

[0040] The analysis device 6 employs the so-called total focusing method (TFM). TFM is an image construction method that constructs an image by processing data on the reflected wave B and diffracted wave C received by the first element 14 and the second element 16, respectively. As described above, the first sensor 2 and the second sensor 4 employ FMC. Therefore, the ultrasonic flaw detection device according to one embodiment detects defects De in the evaporation tube 100 by constructing an image Im of the evaporation tube 100 using FMC / TFM. The image generation unit 60 generates an image Im by associating the reflected wave B with at least one of the first diffracted wave C1 and the second diffracted wave C2 for each of the multiple grids 70. Note that, for grids 70 that do not include defects De, the image Im is generated by associating the grids 70 with none of the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2.

[0041] In one embodiment, the image generating unit 60 generates an image Im based on a reflected composite wave obtained by combining reflected waves B received by each of the multiple first elements 14 from a common grid 70. The image generating unit 60, for example, colors the common grid 70 in accordance with the magnitude of the amplitude of the waveform of the reflected composite wave. In some embodiments, the image generating unit 60 generates the reflected composite wave by taking into account the phase consistency rate (a numerical value indicating the degree to which the phases of the received waveforms are aligned) of the reflected waves B received by each of the multiple first elements 14 from the common grid 70. With this configuration, it is possible to reduce noise contained in the reflected composite wave and generate a clearer image Im compared to when the phase consistency rate is not taken into account.

[0042] In one embodiment, the image generating unit 60 generates an image Im based on a second diffracted composite wave obtained by combining the second diffracted waves C2 received by each of the multiple first elements 14 from the common grid 70. The image generating unit 60, for example, colors the common grid 70 according to the magnitude of the amplitude of the waveform of the second diffracted composite wave. In some embodiments, the image generating unit 60 generates the second diffracted composite wave by taking into account the phase matching rate of the second diffracted waves C2 received by each of the multiple first elements 14 from the common grid 70. With this configuration, it is possible to reduce noise contained in the second diffracted composite wave and generate a clearer image Im compared to when the phase matching rate is not taken into account.

[0043] In one embodiment, the image generating unit 60 generates an image Im based on a second reflected composite wave obtained by combining reflected waves B received by each of the multiple second elements 16 from a common grid 70. The image generating unit 60, for example, colors the common grid 70 in accordance with the magnitude of the amplitude of the waveform of the second reflected composite wave. In some embodiments, the image generating unit 60 generates the second reflected composite wave by taking into account the phase matching rate of the reflected waves B received by each of the multiple second elements 16 from the common grid 70. With this configuration, it is possible to reduce noise contained in the second reflected composite wave and generate a clearer image Im compared to when the phase matching rate is not taken into account.

[0044] In one embodiment, the image generating unit 60 generates an image Im based on a first diffracted composite wave obtained by combining the first diffracted waves C1 received by each of the multiple second elements 16 from a common grid 70. The image generating unit 60, for example, colors the common grid 70 according to the magnitude of the amplitude of the waveform of the first diffracted composite wave. In some embodiments, the image generating unit 60 generates the first diffracted composite wave by taking into account the phase matching rate of the first diffracted waves C1 received by each of the multiple second elements 16 from the common grid 70. With this configuration, it is possible to reduce noise contained in the first diffracted composite wave and generate a clearer image Im compared to when the phase matching rate is not taken into account.

[0045] In one embodiment, the image generating unit 60 generates an image Im by associating the reflected wave B, whose sound speed has been corrected, with at least one of the first diffracted wave C1, whose sound speed has been corrected, and the second diffracted wave C2, whose sound speed has been corrected, for each of the multiple grids 70.

[0046] In some embodiments, the ultrasonic waves A include shear waves, and the image generating unit 60 generates an image Im by associating a reflected wave B of the shear wave ultrasonic waves A and at least one of a first diffracted wave C1 and a second diffracted wave C2 of the shear wave ultrasonic waves A with each of the plurality of grids 70. In some embodiments, the ultrasonic waves A include longitudinal waves, and the image generating unit 60 generates an image Im by associating a reflected wave B of the longitudinal wave ultrasonic waves A and at least one of a first diffracted wave C1 and a second diffracted wave C2 of the longitudinal wave ultrasonic waves A with each of the plurality of grids 70.

[0047] In some embodiments, the ultrasonic waves A include longitudinal waves, and the image generating unit 60 generates an image Im by associating, for each of the plurality of grids 70, a reflected wave B of a shear wave generated when the longitudinal ultrasonic waves A are reflected by the defect De with at least one of a first diffracted wave C1 and a second diffracted wave C2 of a shear wave generated when the longitudinal ultrasonic waves A are diffracted by the defect De. Similarly, the image Im is generated by associating, for each of the plurality of grids 70, a reflected wave B of a longitudinal wave generated when the shear ultrasonic waves A are reflected by the defect De with at least one of a first diffracted wave C1 and a second diffracted wave C2 of a longitudinal wave generated when the shear ultrasonic waves A are diffracted by the defect De.

[0048] If the waveform of the first depth-evaluation diffracted wave C11 has the same shape as the inverted waveform of the second depth-evaluation diffracted wave C21, the defect depth evaluation unit 62 evaluates the depth of the defect De based on at least one of the first depth-evaluation diffracted wave C11 and the second depth-evaluation diffracted wave C21. The defect depth evaluation unit 62 evaluates the depth of the defect De, for example, from the magnitude of the amplitude of the waveform of the first depth-evaluation diffracted wave C11. The defect depth evaluation unit 62 evaluates the depth of the defect De, for example, from the average magnitude of the amplitude of the waveform of the first depth-evaluation diffracted wave C11 and the amplitude of the waveform of the second depth-evaluation diffracted wave C21.

[0049] The route taken by the ultrasonic wave A transmitted by the first depth-evaluation element 14D until it is received by the second depth-evaluation element 16D as the first depth-evaluation diffracted wave C11 is the same as the route taken by the ultrasonic wave A transmitted by the second depth-evaluation element 16D until it is received by the first depth-evaluation element 14D as the second depth-evaluation diffracted wave C21 (see FIG. 7). These routes are the depth evaluation route rt11+the second depth evaluation route rt12. Therefore, this is the same relationship as the "same shape as the inverted waveform" described above, and a description thereof will be omitted.

[0050] If the waveform of the first defect reflected wave B21 has the same shape as the inverted waveform of the second defect reflected wave B22, the defect range evaluation unit 64 evaluates the range of the defect De based on at least one of the first defect reflected wave B21 and the second defect reflected wave B22. The defect range evaluation unit 64 evaluates the range of the defect De, for example, based on the presence or absence of the waveform of the first defect reflected wave B21.

[0051] The route taken by ultrasonic wave A transmitted by one side first element 14A until it is received by the other side first element 14B as a first defect reflected wave B21 is the same as the route taken by ultrasonic wave A transmitted by the other side first element 14B until it is received by the one side first element 14A as a second defect reflected wave B22 (see FIG. 5). These routes are range evaluation route rt5+second range evaluation route rt6. Therefore, this is the same relationship as the "same shape as the inverted waveform" described above, and so a description thereof will be omitted.

[0052] In one embodiment, the image generating unit 60 obtains the depth of the defect De from the defect depth evaluating unit 62, and generates an image Im based on the depth of the defect De. The image generating unit 60, for example, applies a color to the grid 70 that corresponds to the depth of the defect De. In one embodiment, the image generating unit 60 obtains the range of the defect De from the defect range evaluating unit 64, and generates an image Im based on the range of the defect De. The image generating unit 60, for example, applies a color to the grid 70 that corresponds to the range of the defect De.

[0053] (Actions and Effects) The following describes the operation and effect of an ultrasonic flaw detector 1 according to one embodiment. According to one embodiment, the ultrasonic flaw detector 1 applies both the TOFD method and the TFM method, divides a detection region R into a plurality of grids 70, and generates an image Im in which a reflected wave B and at least one of a first diffracted wave C1 and a second diffracted wave C2 are associated with each of the plurality of grids 70. This allows for evaluation of a defect De, the position and depth of which are unknown. Furthermore, the defect De can be detected from the reflected wave B and the first diffracted wave C1 of the ultrasonic wave A transmitted from each of the plurality of first elements 14, and the reflected wave B and the second diffracted wave C2 of the ultrasonic wave A transmitted from each of the plurality of second elements 16. In other words, since ultrasonic waves A are transmitted from multiple directions toward the defect De (in the case of a phased array probe, convergent beam flaw detection is performed from one direction), the defect De can be evaluated with high accuracy.

[0054] According to the first embodiment, by applying both the TOFD method and the TFM method, it is possible to acquire reflected waves B and diffracted waves C for defects De on the surface 101 of the evaporation tube 100 or near the surface 101, and evaluate the defects De with high accuracy. According to the first embodiment, by applying both the TOFD method and the TFM method, even if the detection region R includes multiple defects De, it is possible to acquire reflected waves B and diffracted waves C for each of the multiple defects De, and evaluate the defects De with high accuracy.

[0055] Each of the first element 14 and the second element 16 receives many waveforms. Therefore, in order to separate the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2 from the received waveforms containing a large amount of information, the position of the first sensor 2 relative to the detection area R, the position of the second sensor 4 relative to the detection area R, and the relative position of the second sensor 4 relative to the first sensor 2 must be identified. According to one embodiment, the position of the first sensor 2 relative to the evaporation tube 100 is identified based on the surface reflected wave B1 received by the first element 14, and the relative position of the second sensor 4 relative to the first sensor 2 is identified based on the second surface reflected wave B6 received by the second element 16. The detection area R is then identified using the positions of the first sensor 2 and the second sensor 4. Therefore, the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2 can be separated from the received waveforms to generate an image Im. If the relative position of the second sensor 4 is identified, the position of the second sensor 4 with respect to the detection area R can be easily identified. Furthermore, according to the first embodiment, the position of the first sensor 2 with respect to the detection area R, the position of the second sensor 4 with respect to the detection area R, and the relative position of the second sensor 4 with respect to the first sensor 2 are identified, so that even if the surface 101 or the inner surface 102 of the evaporation tube 100 is a curved surface or an uneven surface, the defect De can be evaluated with high accuracy.

[0056] According to the first embodiment, when the waveform of the first diffracted wave C11 for depth evaluation has the same shape as the inverted waveform of the second diffracted wave C21 for depth evaluation, the depth of the defect De is evaluated using at least one of the first diffracted wave C11 for depth evaluation and the second diffracted wave C21 for depth evaluation. In other words, since the same waveform is received by both the first element 14 and the second element 16, the depth of the defect De can be evaluated with high accuracy even for a defect De whose position and depth are unknown.

[0057] According to one embodiment, if the waveform of the first defect reflected wave B21 has the same shape as the inverted waveform of the second defect reflected wave B22, the extent of the defect De is evaluated based on at least one of the first defect reflected wave B21 and the second defect reflected wave B22. In other words, because the same waveform is received by both the first element 14 and the second element 16, the extent of the defect De can be evaluated with high accuracy for a defect De whose position and depth are unknown. For example, it can be evaluated whether the defect De is located inside the evaporation tube 100 or continues from the surface 101.

[0058] According to one embodiment, the detection region R is cooled while at least one of the first element 14 and the second element 16 is transmitting or receiving ultrasonic waves A, so that the defect De is deformed by thermal stress, facilitating detection of the tip p3 of the defect De. Furthermore, according to one embodiment, the image generator 60 generates an image Im by associating the reflected wave B, whose sound speed has been corrected, with at least one of the first diffracted wave C1, whose sound speed has been corrected, and the second diffracted wave C2, whose sound speed has been corrected, for each of the plurality of grids 70. Therefore, an appropriate image Im can be generated that takes into account changes in the sound speeds of the reflected wave B, the first diffracted wave C1, and the second diffracted wave C2 due to temperature changes.

[0059] Although the ultrasonic flaw detection device 1 according to one embodiment includes the wedge 8, the temperature acquisition device 10, and the cooling device 12, these are not essential components of the ultrasonic flaw detection device 1 according to the present disclosure. The ultrasonic flaw detection device 1 applies both the TOFD method and the TFM method, and therefore can acquire the surface reflected waves B1 and B4 and the second surface reflected waves B3 and B6 even without including the wedge 8.

[0060] <Ultrasonic flaw detection method> An ultrasonic flaw detection method according to one embodiment is a method for detecting a defect De in an evaporation tube 100 by ultrasonic waves A using an ultrasonic flaw detection device 1 including the first sensor 2 and the second sensor 4 described above. Fig. 11 is a flowchart of the ultrasonic flaw detection method according to one embodiment. As shown in Fig. 11, the ultrasonic flaw detection method includes a placement step S1, a grid creation step S2, an image generation step S3, and a movement step S4.

[0061] In the placement step S1, the first sensor 2 and the second sensor 4 are placed on opposite sides of the detection region R of the evaporation tube 100. In the grid creation step S2, the detection region R is divided to create multiple grids 70. In the image generation step S3, an image Im is generated by associating the reflected wave B with at least one of the first diffracted wave C1 and the second diffracted wave C2 for each of the multiple grids 70. If the movement step S4 is not performed after the image generation step S3, the ultrasonic flaw detection method according to the embodiment ends. For example, if a defect De cannot be confirmed from the image Im, the ultrasonic flaw detection method according to the embodiment ends. If the movement step S4 is performed after the image generation step S3, the process proceeds to the movement step S4. The movement step S4 is performed if a defect De can be confirmed from the image Im. In the movement step S4, after the image generation step S3 is performed, the first sensor 2 and the second sensor 4 are moved while maintaining the relative position of the second sensor 4 with respect to the first sensor 2. Then, the image generating step S3 is performed again after the first sensor 2 and the second sensor 4 are moved.

[0062] The ultrasonic flaw detection method according to one embodiment generates an image Im in which the reflected wave B is associated with at least one of the first diffracted wave C1 and the second diffracted wave C2 for each of the plurality of grids 70. Therefore, the ultrasonic flaw detection method according to one embodiment can evaluate the defect De as long as it exists in the detection region R. In other words, the ultrasonic flaw detection method according to one embodiment does not need to adjust the positions of the first sensor 2 and the second sensor 4 so that the defect De is located at the center of the extension direction D1 of the detection region R.

[0063] According to an ultrasonic flaw detection method of one embodiment, when the first sensor 2 and the second sensor 4 are moved while maintaining the relative position of the second sensor 4 with respect to the first sensor 2, the tracking of the first diffracted wave C1 with respect to this movement can be confirmed in the image Im, and it can be determined that a significant first diffracted wave C1 has been acquired (with the conventional TOFD method or the TOFD method plus a phased array probe, it is difficult to distinguish the weak first diffracted wave C1 from noise). Similarly, the tracking of the second diffracted wave C2 with respect to this movement can be confirmed in the image Im, and it can be determined that a significant second diffracted wave C2 has been acquired.

[0064] The contents described in each of the above embodiments can be understood, for example, as follows.

[0065] [1] The ultrasonic flaw detector (1) according to the present disclosure is an ultrasonic flaw detector for detecting a defect (De) in an object (100) by ultrasonic waves (A), a first sensor (2) including a plurality of first elements (14) configured to transmit the ultrasonic waves to the object and receive reflected waves (B) of the ultrasonic waves; a second sensor (4) including a plurality of second elements (16) configured to transmit the ultrasonic waves to the target and receive reflected waves (B) of the ultrasonic waves, the second sensor (4) being disposed on the opposite side of the first sensor across a detection region (R) of the target; an analysis device (6) for analyzing the defect in the detection area, The first element is configured to be able to receive a second diffracted wave (C2) that is a diffracted wave (C) of the ultrasonic wave transmitted from the second element, The second element is configured to be able to receive a first diffracted wave (C1) that is a diffracted wave (C) of the ultrasonic wave transmitted from the first element, The analysis device a grid creating unit (58) that divides the detection area to create a plurality of grids (70); and an image generating section (60) that generates an image (Im) by associating the reflected wave with at least one of the first diffracted wave and the second diffracted wave for each of the plurality of grids.

[0066] According to the configuration described in [1] above, the ultrasonic flaw detection device divides the detection area into a plurality of grids and generates an image in which the reflected wave and at least one of the first diffracted wave and the second diffracted wave are associated with each of the plurality of grids. This makes it possible to evaluate defects whose positions and depths are unknown. Furthermore, it is possible to detect defects from the reflected waves and first diffracted waves of ultrasonic waves transmitted from each of the plurality of first elements and the reflected waves and second diffracted waves of ultrasonic waves transmitted from each of the plurality of second elements. In other words, ultrasonic waves are transmitted from multiple directions toward the defect (in the case of a phased array probe, focused beam flaw detection is performed from one direction), so defects can be evaluated with high accuracy.

[0067] [2] In some embodiments, in the configuration described in [1] above, a wedge (8) including a contact surface (18) that contacts the object and a mounting surface (20) on which the first sensor and the second sensor are mounted; The analysis device Among the reflected waves of the ultrasonic waves transmitted from the first element, the reflected waves reflected by the surface (101) of the object and transmitted through the wedge are referred to as surface reflected waves (B1, B6). a position identification unit (52) that identifies a position of the first sensor relative to the object based on the surface reflected wave (B1) received by the first element; and a relative position determination unit (54) that determines the relative position of the second sensor with respect to the first sensor based on the surface reflected wave (B6) received by the second element. The grid creation unit specifies the detection area using the position of the first sensor and the relative position of the second sensor, and creates the plurality of grids by dividing the specified detection area.

[0068] In order to separate the reflected wave, the first diffracted wave, and the second diffracted wave from the received waveform, which contains a lot of information, it is necessary to determine the position of the first sensor relative to the detection area, the position of the second sensor relative to the detection area, and the relative position of the second sensor relative to the first sensor. According to the configuration described in [2] above, the position of the first sensor relative to the object is determined based on the surface reflected wave received by the first element, and the relative position of the second sensor relative to the first sensor is determined based on the surface reflected wave received by the second element. The detection area is then determined using the position of the first sensor and the relative position of the second sensor. Therefore, the reflected wave, the first diffracted wave, and the second diffracted wave can be separated from the received waveform to generate an image. Note that if the relative position of the second sensor is determined, the position of the second sensor relative to the detection area can be easily determined.

[0069] [3] In some embodiments, in the configuration described in [2] above, the first diffracted wave includes a depth-evaluation first diffracted wave (C11) transmitted from a depth-evaluation first element (14D) that is one of the plurality of first elements and received by a depth-evaluation second element (16D) that is one of the plurality of second elements; The second diffracted wave includes a depth-evaluation second diffracted wave (C21) transmitted from the depth-evaluation second element and received by the depth-evaluation first element, The analysis device The device further includes a defect depth evaluation unit (62) that evaluates the depth of the defect based on at least one of the first diffracted wave for depth evaluation and the second diffracted wave for depth evaluation if the waveform of the first diffracted wave for depth evaluation has the same shape as the inverted waveform of the second diffracted wave for depth evaluation.

[0070] According to the configuration described in [3] above, the depth of a defect whose position and depth are unknown can be evaluated with high accuracy.

[0071] [4] In some embodiments, in the configuration described in [2] or [3] above, The reflected waves include a first defect reflected wave (B21) of the reflected waves of the ultrasonic waves transmitted from a one-side first element (14A) that is one of the plurality of first elements, which is reflected by the defect and received by an other-side first element (14B) that is another one of the plurality of first elements, and a second defect reflected wave (B22) of the reflected waves of the ultrasonic waves transmitted from the other-side first element, which is reflected by the defect and received by the one-side first element, The analysis device The system further includes a defect range evaluation unit (64) that, if the waveform of the first defect reflected wave has the same shape as the inverted waveform of the second defect reflected wave, evaluates the range of the defect based on at least one of the first defect reflected wave and the second defect reflected wave.

[0072] According to the configuration described in [4] above, it is possible to evaluate the extent of a defect with a high degree of accuracy, even if the position and depth of the defect are unknown.

[0073] [5] In some embodiments, in the configuration described in any one of [2] to [4] above, The wedge does not have an acoustic isolation portion (200) formed between the first sensor and the second sensor that prevents the transmission of the ultrasonic waves.

[0074] The configuration described in [2] above makes it possible to separate the reflected wave, the first diffracted wave, and the second diffracted wave from the received waveform, which contains a lot of information, so there is no need to form an acoustic isolation section in the wedge. According to the configuration described in [5] above, no acoustic isolation section is formed in the wedge, which makes it easier to prepare the wedge.

[0075] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, a temperature acquisition device (10) capable of acquiring the temperature (t) of the detection area; a cooling device (12) for cooling the detection area, the analysis device further includes a correction unit (56) that corrects the sound velocity of the reflected wave, the sound velocity of the first diffracted wave, and the sound velocity of the second diffracted wave in accordance with the temperature acquired by the temperature acquisition device; The image generating unit generates the image by associating the reflected wave, whose sound speed has been corrected, with at least one of the first diffracted wave, whose sound speed has been corrected, and the second diffracted wave, whose sound speed has been corrected, for each of the plurality of grids.

[0076] According to the configuration described in [6] above, the defect tip can be easily detected by deforming the defect due to thermal stress. Also, an appropriate image can be generated that takes into account the changes in the sound speed of the reflected wave, the sound speed of the first diffracted wave, and the sound speed of the second diffracted wave due to temperature changes.

[0077] [7] The ultrasonic flaw detection method according to the present disclosure is an ultrasonic flaw detection method using an ultrasonic flaw detection device (1) that includes a first sensor (2) including a plurality of first elements (14) configured to transmit ultrasonic waves (A) to the target and receive reflected waves of the ultrasonic waves to detect a defect (De) in the target (100) using ultrasonic waves, and a second sensor (4) including a plurality of second elements (16) configured to transmit ultrasonic waves to the target and receive reflected waves (B) of the ultrasonic waves, wherein the first elements are configured to be able to receive second diffracted waves (C2) that are diffracted waves (C) of the ultrasonic waves transmitted from the second elements, and the second elements are configured to be able to receive first diffracted waves (C1) that are diffracted waves (C) of the ultrasonic waves transmitted from the first elements, A step (S1) of arranging the first sensor and the second sensor on opposite sides of a detection region (R) of the object; A step (S2) of dividing the detection area to create a plurality of grids (70); and generating an image (Im) by associating the reflected wave with at least one of the first diffracted wave and the second diffracted wave for each of the plurality of grids (S3).

[0078] The method described in [7] above has the same effect as that described in [1] above.

[0079] [8] In some embodiments, in the method according to [7] above, a step (S4) of moving the first sensor and the second sensor while maintaining a relative position of the second sensor with respect to the first sensor after the step of generating the image; The step of generating an image is performed again after moving the first sensor and the second sensor.

[0080] The method described in [7] generates an image in which the reflected wave and at least one of the first diffracted wave and the second diffracted wave are associated with each of the multiple grids. In other words, the ultrasonic flaw detection method described in [7] can evaluate defects as long as they exist in the detection area. According to the method described in [8], when the first sensor and the second sensor are moved while maintaining the relative position of the second sensor with respect to the first sensor, the tracking of the first diffracted wave with respect to this movement can be confirmed, and it can be determined that a significant first diffracted wave has been acquired (with the conventional TOFD method or the TOFD method plus a phased array probe, it is difficult to distinguish the weak first diffracted wave from noise). Similarly, the tracking of the second diffracted wave with respect to this movement can be confirmed, and it can be determined that a significant second diffracted wave has been acquired. [Explanation of symbols]

[0081] 1 Ultrasonic wound device 2. First Sensor 3 Holding body 4 Second Sensor 5 Second holder 6 Analysis device 8 Wedges 10 Temperature acquisition device 12 Cooling device 14 First element 16 Second element 18 Contact surface 20 Placement surface 22 1st slope part 24 2nd slope part 52 Location identification part 54 Relative position determination unit 56 Correction unit 58 Grid Creation Department 60 Image generation unit 62 Defect depth evaluation section 64 Defect Range Evaluation Section 70 grid 100 Evaporation tube 101 Surface 102 Inside 200 Acoustic isolation section A. Ultrasound B Reflected wave B1 Surface reflected wave (received by the first element) B11 1st surface reflected wave B12 2nd surface reflected wave B2 Defect reflected wave (received by the first element) B21 First defect reflection wave B22 Second defect reflection wave B3 Second surface reflected wave (received by the first element) B31 Second surface reflection on one side B4 Surface reflected wave (received by the second element) B41 3rd surface reflected wave B42 4th surface reflected wave B5 Defect reflected wave (received by the second element) B51 Third defect reflection wave B52 4th defect reflected wave B6 Second surface reflected wave (received by the second element) B61 Second surface reflection wave on the other side C Diffracted wave C1 First diffracted wave C11 First diffracted wave for depth evaluation C2 Second diffracted wave C21 Second diffracted wave for depth evaluation D1 Extending direction D2 radial direction Defect G Cooling gas Im Images Timeline R detection area S1 Placement Step S2 Grid Creation Steps S3 Image Generation Step S4 Movement step X1 First waveform X2 Second waveform p1 Any point on the surface p2 Any point of the defect p3 Tip of defect p4 Any reflection point on the surface rt1 Surface reflection route rt2 Second surface reflection route rt3 Third surface reflection route rt4 Fourth surface reflection route rt5 Range Evaluation Route RT6 Second Range Evaluation Route RT7 Third Range Assessment Route RT8 4th Range Assessment Route rt9 Second surface reflection route on one side rt10 Second surface reflection route on the other side rt11 depth evaluation route rt12 Second depth evaluation route t temperature

Claims

1. An ultrasonic flaw detector for detecting defects in a target using ultrasonic waves, a first sensor including a plurality of first elements configured to transmit the ultrasonic waves to the object and receive reflected waves of the ultrasonic waves; a second sensor including a plurality of second elements configured to transmit the ultrasonic waves to the target and receive reflected waves of the ultrasonic waves, the second sensor being disposed on the opposite side of the detection region of the target from the first sensor; an analysis device that analyzes the defects in the detection area; the first element is configured to be able to receive a second diffracted wave that is a diffracted wave of the ultrasonic wave transmitted from the second element, the second element is configured to be able to receive a first diffracted wave that is a diffracted wave of the ultrasonic wave transmitted from the first element, The analysis device a grid creation unit that divides the detection area to create a plurality of grids; an image generating unit that generates an image by associating the reflected wave with at least one of the first diffracted wave and the second diffracted wave for each of the plurality of grids, Ultrasonic flaw detection equipment.

2. a wedge including a contact surface that is brought into contact with the object and a mounting surface on which the first sensor and the second sensor are mounted; The analysis device When the reflected wave of the ultrasonic wave transmitted from the first element is reflected by the surface of the object and transmitted through the wedge, the reflected wave is defined as a surface reflected wave, a position identification unit that identifies a position of the first sensor relative to the object based on the surface reflected wave received by the first element; a relative position determination unit that determines a relative position of the second sensor with respect to the first sensor based on the surface reflected wave received by the second element, the grid creation unit specifies the detection area using the position of the first sensor and the relative position of the second sensor, and creates a plurality of the grids by dividing the specified detection area. The ultrasonic flaw detector according to claim 1.

3. the first diffracted wave includes a depth-evaluation first diffracted wave transmitted from a depth-evaluation first element that is one of the plurality of first elements and received by a depth-evaluation second element that is one of the plurality of second elements; the second diffracted wave includes a depth-evaluation second diffracted wave transmitted from the depth-evaluation second element and received by the depth-evaluation first element, The analysis device and a defect depth evaluation unit that, if the waveform of the first diffracted wave for depth evaluation has the same shape as an inverted waveform of the second diffracted wave for depth evaluation, evaluates the depth of the defect based on at least one of the first diffracted wave for depth evaluation and the second diffracted wave for depth evaluation. The ultrasonic flaw detector according to claim 2.

4. The reflected waves include a first defect reflected wave, which is one of the reflected waves of the ultrasonic waves transmitted from a one-side first element that is one of the plurality of first elements and is reflected by the defect and received by an other one of the plurality of first elements, and a second defect reflected wave, which is one of the reflected waves of the ultrasonic waves transmitted from the other-side first element and is reflected by the defect and received by the one-side first element, The analysis device a defect extent evaluation unit that, if the waveform of the first defect reflected wave is identical to the inverted waveform of the second defect reflected wave, evaluates the extent of the defect based on at least one of the first defect reflected wave and the second defect reflected wave. The ultrasonic flaw detector according to claim 2 or 3.

5. the wedge does not have an acoustic isolation portion formed between the first sensor and the second sensor that prevents transmission of the ultrasonic waves; The ultrasonic flaw detector according to claim 2 or 3.

6. a temperature acquisition device capable of acquiring the temperature of the detection area; a cooling device that cools the detection area, the analysis device further includes a correction unit that corrects the sound velocity of the reflected wave, the sound velocity of the first diffracted wave, and the sound velocity of the second diffracted wave in accordance with the temperature acquired by the temperature acquisition device; the image generating unit generates the image by associating the reflected wave, the sound speed of which has been corrected, with at least one of the first diffracted wave, the sound speed of which has been corrected, and the second diffracted wave, the sound speed of which has been corrected, for each of the plurality of grids. The ultrasonic flaw detector according to any one of claims 1 to 3.

7. An ultrasonic flaw detection method using an ultrasonic flaw detection device, comprising: a first sensor including a plurality of first elements configured to transmit ultrasonic waves to the target and receive reflected waves of the ultrasonic waves, and a second sensor including a plurality of second elements configured to transmit ultrasonic waves to the target and receive reflected waves of the ultrasonic waves, in order to detect defects in the target using ultrasonic waves; wherein the first elements are configured to be able to receive second diffracted waves that are diffracted waves of the ultrasonic waves transmitted from the second elements, and the second elements are configured to be able to receive first diffracted waves that are diffracted waves of the ultrasonic waves transmitted from the first elements, positioning the first sensor and the second sensor on opposite sides of a detection region of the object; Dividing the detection area to create a plurality of grids; and generating an image by associating the reflected wave with at least one of the first diffracted wave and the second diffracted wave for each of the plurality of grids. Ultrasonic flaw detection method.

8. after generating the image, moving the first sensor and the second sensor while maintaining a relative position of the second sensor with respect to the first sensor; the step of generating an image is re-performed after moving the first sensor and the second sensor. The ultrasonic flaw detection method according to claim 7.

Images