Ultrasonic flaw detection device and ultrasonic flaw detection method

Abstract

This ultrasonic flaw detection device 100 comprises a probe 120 that transmits ultrasonic waves to the interior of a test body T and receives ultrasonic waves reflected inside the test body T, a delay material 130 disposed between the probe 120 and the test body T, a temperature adjustment mechanism 140 that adjusts the temperature of the delay material 130, a first temperature detection unit 150 that detects the temperature of the test body T, and a control unit that controls the temperature adjustment mechanism 140 on the basis of the temperature of the test body T detected by the first temperature detection unit 150.

Description

Ultrasonic flaw detection device and ultrasonic flaw detection method

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2023-66959 filed on April 17, 2023, the contents of which are incorporated herein by reference.

[0002] One ultrasonic flaw detection method using an ultrasonic flaw detector is the angle beam method, in which ultrasonic waves are incident on the test object at an angle. In the angle beam method, a delay line is placed between the probe and the test object, and the ultrasonic waves transmitted from the probe are refracted at the interface between the delay line and the test object, irradiating the ultrasonic waves at a target position inside the test object. Hereinafter, the target position inside the test object may be referred to as the "target position."

[0003] However, when the temperature of the test object changes, the propagation speed of the ultrasonic wave in the test object changes, and the refraction angle of the ultrasonic wave at the interface between the delay material and the test object changes. Therefore, when testing a test object whose temperature changes, depending on the temperature of the test object, the ultrasonic wave may not be irradiated to the target position, making it impossible to test the target position.

[0004] Therefore, a technique has been developed in which the angle of the probe relative to the object to be inspected is mechanically changed depending on the temperature of the object to be inspected, thereby keeping the angle of refraction of ultrasonic waves constant (for example, Patent Document 1).

[0005] Japanese Patent Application Publication No. 1-203967

[0006] However, the technique having a mechanism for changing the installation angle of the probe as described in Patent Document 1 has the problem that the device becomes large in size.

[0007] In view of the above, an object of the present disclosure is to provide an ultrasonic flaw detection device and an ultrasonic flaw detection method that are capable of inspecting a target position with a simple configuration.

[0008] In order to solve the above problem, an ultrasonic flaw detection device according to one embodiment of the present disclosure includes a probe that transmits ultrasonic waves into the interior of the test object and receives the ultrasonic waves reflected from the interior of the test object, a delay material arranged between the probe and the test object, a temperature adjustment mechanism that adjusts the temperature of the delay material, a first temperature detection unit that detects the temperature of the test object, and a control unit that controls the temperature adjustment mechanism based on the temperature of the test object detected by the first temperature detection unit.

[0009] In addition, the control unit may refer to test object sound speed information indicating the relationship between the test object's sound speed and temperature, and delay material sound speed information indicating the relationship between the delay material's sound speed and temperature, and control the temperature adjustment mechanism based on the test object's temperature detected by the first temperature detection unit.

[0010] The control unit may also refer to the sound speed information of the test object, calculate the sound speed of the test object from the temperature of the test object detected by the first temperature detection unit, calculate the sound speed of the delay line based on the sound speed of the test object, refer to the sound speed information of the delay line, calculate a target temperature of the delay line from the sound speed of the delay line, and control the temperature adjustment mechanism based on the target temperature.

[0011] The ultrasonic flaw detector may also include a storage unit that stores in advance the test object sound velocity information and the delay line sound velocity information.

[0012] In addition, the ultrasonic flaw detection device may be provided with a second temperature detection unit that detects the temperature of the delay material, and the control unit may perform feedback control on the temperature adjustment mechanism based on the temperature of the delay material detected by the second temperature detection unit.

[0013] In order to solve the above problem, an ultrasonic flaw detection method according to one aspect of the present disclosure detects the temperature of an object to be inspected, transmits ultrasonic waves into the interior of the object to be inspected, and receives the ultrasonic waves reflected inside the object to be inspected. The method adjusts the temperature of a delay material arranged between the object to be inspected and the probe, based on the detected temperature of the object to be inspected.

[0014] According to the present disclosure, it is possible to inspect a target position with a simple configuration.

[0015] Fig. 1 is a schematic diagram showing the general configuration of an ultrasonic flaw detection device according to this embodiment. Fig. 2 is a diagram explaining the movement direction of a probe constituting the ultrasonic flaw detection device according to this embodiment. Fig. 3 is a block diagram showing an example of the functional configuration of the ultrasonic flaw detection device according to this embodiment. Fig. 4 is a diagram explaining an example of test object sound velocity information and delay line temperature information according to this embodiment. Fig. 5 is a flowchart showing the processing flow of the ultrasonic flaw detection method according to this embodiment.

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for ease of understanding and do not limit the present disclosure unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0017] [Ultrasonic Flaw Detector 100] Fig. 1 is a schematic diagram showing the overall configuration of the ultrasonic flaw detector 100 according to this embodiment. Fig. 2 is a diagram explaining the movement direction of a probe 110 constituting the ultrasonic flaw detector 100 according to this embodiment. In Figs. 1 and 2 of this embodiment, the X-axis, Y-axis, and Z-axis, which intersect perpendicularly, are defined as shown. In Fig. 1, the dashed line indicates ultrasonic waves transmitted from the ultrasonic flaw detector 100. In Fig. 1, the dashed line indicates the normal (perpendicular line) to the interface IF between the delay material 130 and the object to be inspected T. In Fig. 2, the dashed line indicates the weld line WL of the welded portion WR.

[0018] 1, an ultrasonic flaw detection device 100 uses ultrasonic waves to inspect an object to be inspected T. In this embodiment, the object to be inspected T has regions with different temperatures. For example, the temperature of the object to be inspected T increases from the bottom to the top.

[0019] In this embodiment, the ultrasonic flaw detection device 100 inspects, for example, a welded portion WR provided on an inspection object T having regions with different temperatures. The welded portion WR extends, for example, in the Y-axis direction in Figures 1 and 2. The locus of the center of the welded portion WR in the X-axis direction in Figure 1, that is, an imaginary line that passes through the center of the welded portion WR in the X-axis direction in Figure 1 and extends in the Y-axis direction in Figure 1, is defined as the weld line WL of the welded portion WR.

[0020] As shown in FIG. 1 , the ultrasonic flaw detection device 100 includes a probe 110 and a control device 210 .

[0021] The probe 110 includes a probe 120 , a delay material 130 , a temperature adjustment mechanism 140 , a first temperature detection unit 150 , and a second temperature detection unit 152 .

[0022] As shown in Fig. 2, the probe 110 is moved along the weld line WL of the welded portion WR by a movement mechanism (not shown). That is, the probe 110 is moved in the Y-axis direction in Figs. 1 and 2 by the movement mechanism. The probe 110 is also moved so that the shortest distance between the weld line WL of the welded portion WR and the probe 110 is maintained at a predetermined set distance SD. The set distance SD will be described later.

[0023] 1 , the probe 120 transmits ultrasonic waves into the interior of the test object T and receives ultrasonic waves reflected from the interior of the test object T. The probe 120 includes, for example, a transmitting unit 122 having a transducer that transmits ultrasonic waves, and a receiving unit 124 having a transducer that receives ultrasonic waves (see FIG. 3 ).

[0024] The delay material 130 is disposed between the probe 120 and the test object T. The delay material 130 contacts the probe 120 and the test object T.

[0025] The delay material 130 holds (fixes) the probe 120 so that the incident angle θi of the ultrasonic waves transmitted by the probe 120 at a reference temperature is a predetermined incident angle θI. The reference temperature is, for example, room temperature (25°C). The incident angle θi is the angle between the propagation direction of the ultrasonic waves in the delay material 130 and the normal (perpendicular line) to the interface IF between the delay material 130 and the object T. The incident angle θi changes depending on the temperature of the delay material 130.

[0026] The delay material 130 propagates the ultrasonic waves transmitted from the probe 120 and causes them to be incident on the object to be inspected T. The speed of sound (propagation speed) of the ultrasonic waves in the delay material 130 is different from the speed of sound (propagation speed) of the ultrasonic waves in the object to be inspected T. Therefore, the ultrasonic waves transmitted from the probe 120 and propagating through the delay material 130 are refracted at a predetermined refraction angle θr at the interface IF between the delay material 130 and the object to be inspected T. The refraction angle θr is the angle between the normal (perpendicular line) to the interface IF between the delay material 130 and the object to be inspected T and the propagation direction of the ultrasonic waves in the object to be inspected T. The refraction angle θr changes depending on the temperature of the object to be inspected T.

[0027] The probe 120 and the delay line 130 are installed on the inspection object T so that, when the temperature of the inspection object T is a reference temperature, ultrasonic waves transmitted from the probe 120 propagate to a target position P inside the inspection object T. The target position P is, for example, a position on the weld line WL of the welded portion WR. In other words, when the temperature of the inspection object T is the reference temperature, the distance between the probe 110 (the probe 120 and the delay line 130) and the welded portion WR at which the ultrasonic waves transmitted from the probe 120 propagate to the target position P is the set distance SD. The set distance SD is determined based on the angle of incidence θI at the reference temperature, the angle of refraction θR at the reference temperature, and the target position P. The angle of incidence θI and the angle of refraction θR are set in advance through experiments, simulations, etc.

[0028] The material constituting the delay body 130 is determined appropriately depending on the material constituting the test object T. The sound velocity of the material constituting the delay body 130 may be different from the sound velocity of the material constituting the test object T. The delay body 130 is made of, for example, a resin such as acrylic or polystyrene, glass, or metal.

[0029] The temperature adjustment mechanism 140 adjusts the temperature of the delay material 130. In this embodiment, the temperature adjustment mechanism 140 adjusts the temperature of the delay material 130, for example, when the temperature of the test object T is not within a reference temperature range. The reference temperature range is a temperature range that includes the reference temperature. For example, the reference temperature range is a range of ±25°C from the reference temperature.

[0030] The temperature adjustment mechanism 140 has, for example, either one or both of a mechanism for heating the delay body 130 and a mechanism for cooling the delay body 130. The mechanism for heating the delay body 130 is, for example, an electric heater. The mechanism for cooling the delay body 130 is, for example, a Peltier element cooler. The temperature adjustment mechanism 140 is provided, for example, on the outer periphery of the delay body 130. The temperature adjustment mechanism 140 is provided on the delay body 130 so as not to block the ultrasonic waves transmitted by the probe 120 and the ultrasonic waves received by the probe 120.

[0031] Furthermore, the temperature adjustment mechanism 140 may be, for example, a mechanism for circulating a heat medium through the delay material 130. In this case, a passage for the heat medium may be formed within the delay material 130, and the temperature adjustment mechanism 140 may adjust the temperature of the delay material 130 by flowing the heat medium through the passage.

[0032] The first temperature detection unit 150 detects the temperature of the test object T. The first temperature detection unit 150 is, for example, a temperature sensor.

[0033] The second temperature detection unit 152 detects the temperature of the delay material 130. The second temperature detection unit 152 is, for example, a temperature sensor.

[0034] The control device 210 manages and controls the ultrasonic flaw detection device 100. Fig. 3 is a block diagram showing an example of the functional configuration of the ultrasonic flaw detection device 100 according to this embodiment. In Fig. 3, dashed arrows indicate the flow of signals. As shown in Fig. 3, the control device 210 includes a control unit 212 and a storage unit 214.

[0035] The control unit 212 is configured by a semiconductor integrated circuit including a CPU (central processing unit). The control unit 212 reads programs, parameters, etc. for operating the CPU from the ROM. The control unit 212 manages and controls the entire ultrasonic flaw detection device 100 in cooperation with RAM as a work area and other electronic circuits.

[0036] The control unit 212 controls the transmitting unit 122 of the probe 120 to transmit ultrasonic waves from the transmitting unit 122. The control unit 212 also analyzes the ultrasonic waves received by the receiving unit 124 to detect the presence or absence of defects at the target position P and in the vicinity of the target position P.

[0037] The control unit 212 also acquires the temperature of the test object T from the first temperature detection unit 150 and acquires the temperature of the delay material 130 from the second temperature detection unit 152. The control unit 212 controls the temperature adjustment mechanism 140 based on the acquired temperatures of the test object T and the delay material 130.

[0038] The storage unit 214 is composed of a ROM, a RAM, a flash memory, a HDD, etc. The storage unit 214 stores programs and various data used by the control unit 212. The storage unit 214 stores, for example, inspection object sound velocity information and delay line sound velocity information in advance. The inspection object sound velocity information is information indicating the relationship between the inspection object sound velocity and temperature. The delay line temperature information is information indicating the relationship between the sound velocity and temperature of the delay line 130.

[0039] 4 is a diagram illustrating an example of inspection object sound velocity information and delay line temperature information according to this embodiment. In FIG. 4, the vertical axis represents the propagation velocity (sound velocity) [m / s]. In FIG. 4, the horizontal axis represents temperature [°C]. Here, the inspection object sound velocity information when the inspection object T is made of steel is taken as an example, and the delay line temperature information when the delay line 130 is made of acrylic is taken as an example.

[0040] Referring to the inspection object sound velocity information as shown in FIG. 4, for example, the sound velocity of the ultrasonic wave in the inspection object T is 3265 m / s when the temperature of the inspection object T is −30° C., 3265 m / s when the temperature of the inspection object T is −20° C., 3256 m / s when the temperature of the inspection object T is −10° C., 3252 m / s when the temperature of the inspection object T is 0° C., 3252 m / s when the temperature of the inspection object T is 10° C., and 3230 m / s when the temperature of the inspection object T is 20° C.

[0041] Also, as shown in Figure 4, when referring to the delay material sound speed information, for example, the sound speed of the ultrasonic wave in the delay material 130 is 2833 m / s when the temperature of the delay material 130 is -30°C, 2810 m / s when the temperature of the delay material 130 is -20°C, 2788 m / s when the temperature of the delay material 130 is -10°C, 2762 m / s when the temperature of the delay material 130 is 0°C, 2733 m / s when the temperature of the delay material 130 is 10°C, and 2710 m / s when the temperature of the delay material 130 is 20°C.

[0042] Thus, the speed of sound decreases with increasing temperature, regardless of the material.

[0043] [Ultrasonic Flaw Detection Method] Next, an ultrasonic flaw detection method using the ultrasonic flaw detection device 100 will be described. Fig. 5 is a flowchart showing the processing flow of the ultrasonic flaw detection method according to this embodiment. As shown in Fig. 5, the ultrasonic flaw detection method according to this embodiment includes a termination determination process S110, a temperature acquisition process S112, a temperature determination process S114, an inspection process S116, a movement process S118, an inspection object sound speed calculation process S120, a delay line sound speed calculation process S122, a delay line temperature calculation process S124, and a temperature adjustment process S126. Each process will be described below.

[0044] [End Determination Process S110] The control unit 212 determines whether or not the inspection of the predetermined inspection range has been completed. As a result, if it is determined that the inspection of the inspection range has not been completed (NO in S110), the control unit 212 proceeds to the temperature acquisition process S112. On the other hand, if it is determined that the inspection of the inspection range has been completed (YES in S110), the control unit 212 ends the ultrasonic flaw detection method.

[0045] [Temperature Acquisition Process S112] The control unit 212 acquires the temperature Tt of the test object T detected by the first temperature detection unit 150. Then, the control unit 212 moves the process to a temperature determination process S114.

[0046] [Temperature Determination Process S114] The control unit 212 determines whether the temperature Tt of the inspection object T acquired in the temperature acquisition process S112 is within a reference temperature range. As a result, if it is determined that the temperature Tt is within the reference temperature range (YES in S114), the control unit 212 proceeds to the inspection process S116. On the other hand, if it is determined that the temperature Tt is not within the reference temperature range (NO in S114), the control unit 212 proceeds to the inspection object sound speed calculation process S120.

[0047] [Inspection process S116] The control unit 212 controls the transmission unit 122 of the probe 120 to transmit ultrasonic waves from the transmission unit 122. The control unit 212 also analyzes the ultrasonic waves received by the reception unit 124 to detect the presence or absence of defects at the target position P and in the vicinity of the target position P. The control unit 212 then proceeds to a movement process S118.

[0048] [Movement Process S118] A movement mechanism (not shown) moves the probe 110 from the first position where the inspection process S116 was performed this time to a second position. The second position is a position different from the first position, and is a position where the shortest distance between the weld line WL of the welded portion WR and the probe 110 is the set distance SD. Then, the control unit 212 returns the process to the end determination process S110.

[0049] [Inspection object sound velocity calculation process S120] The control unit 212 refers to the inspection object sound velocity information stored in the memory unit 214 and calculates the sound velocity Vt of the inspection object T when the temperature Tt of the inspection object T is the temperature Tt acquired in the temperature acquisition process S112. Then, the control unit 212 proceeds to the delay material sound velocity calculation process S122.

[0050] [Delay Line Sound Velocity Calculation Process S122] The control unit 212 calculates the sound velocity Vw of the delay line 130 using the following formula (1): Vw = Vt × sin θI / sin θR (1) In the above formula (1), Vw is the sound velocity of the delay line 130, and Vt is the sound velocity of the test object T. Also, in the above formula (1), θI is the angle of incidence θi at the reference temperature (see FIG. 1), and θR is the angle of refraction θr at the reference temperature (see FIG. 1). The angle of incidence θI and the angle of refraction θR are set in advance by experiment, simulation, etc. Then, the control unit 212 proceeds to the delay line temperature calculation process S124.

[0051] [Delay Material Temperature Calculation Process S124] The control unit 212 refers to the delay material sound velocity information stored in the memory unit 214 and calculates the target temperature Tw, which is the temperature of the delay material 130 when the sound velocity Vw of the delay material 130 is calculated in the delay material sound velocity calculation process S122. Then, the control unit 212 proceeds to the temperature adjustment process S126.

[0052] [Temperature Adjustment Process S126] The control unit 212 performs feedback control on the temperature adjustment mechanism 140 so that the temperature of the delay material 130 detected by the second temperature detection unit 152 becomes the target temperature Tw calculated by the delay material temperature calculation process S124. Then, when the temperature of the delay material 130 detected by the second temperature detection unit 152 becomes the target temperature Tw calculated by the delay material temperature calculation process S124, the control unit 212 shifts the process to the inspection process S116.

[0053] As described above, the ultrasonic flaw detection device 100 according to this embodiment is equipped with a temperature adjustment mechanism 140 that adjusts the temperature of the delay material 130, and controls the temperature adjustment mechanism 140 based on the sound velocity information of the test object, the sound velocity information of the delay material, and the temperature Tt of the test object T.

[0054] When the temperature Tt of the test object T changes from the reference temperature, the sound velocity Vt of the ultrasonic wave in the test object T changes from the sound velocity Vt at the reference temperature, and the refraction angle θr becomes different from the refraction angle θR at the reference temperature. As a result, even if an inspection is performed by placing the probe 110 at a set distance SD determined based on the refraction angle θR, the ultrasonic wave will be irradiated at a position different from the target position P, and the target position P cannot be inspected. Therefore, if the installation position of the probe 110 is changed from the set distance SD in accordance with the refraction angle θr that has changed in response to the temperature change of the test object T, the ultrasonic wave can be irradiated at the target position P, but the propagation distance of the ultrasonic wave from the probe 120 to the target position P will change. This changes the degree of ultrasonic attenuation, resulting in a problem of reduced inspection accuracy.

[0055] For this reason, in the past, the mounting angle of the probe was changed or multiple delay lines with different sound velocities were used depending on the temperature Tt of the test object T. However, the conventional technology that includes a mechanism for changing the mounting angle of the probe has a problem in that the device becomes large-scale. Furthermore, the conventional technology that uses multiple delay lines has a problem in that the operator is forced to perform the cumbersome task of replacing the delay lines.

[0056] Therefore, the ultrasonic flaw detection apparatus 100 according to this embodiment controls the temperature adjustment mechanism 140 based on the temperature Tt of the object to be inspected T to adjust the temperature of the delay material 130, change the sound velocity Vw of the delay material 130, and change the incident angle θi, thereby propagating the ultrasonic waves transmitted by the probe 120 to the target position P. As a result, the ultrasonic flaw detection apparatus 100 according to this embodiment can inspect the target position P while maintaining the installation position of the probe 110 at the set distance SD, even if the temperature of the object to be inspected T changes, with a simple configuration that simply changes the temperature of the delay material 130. Therefore, the ultrasonic flaw detection apparatus 100 according to this embodiment can avoid changes in the degree of ultrasonic attenuation and prevent a decrease in inspection accuracy. Furthermore, the ultrasonic flaw detection apparatus 100 according to this embodiment can inspect the target position P simply by adjusting the temperature of the delay material 130, thereby eliminating the need to prepare multiple delay materials with different sound velocities and the need to replace the delay materials.

[0057] Furthermore, the ultrasonic flaw detection apparatus 100 according to this embodiment includes a second temperature detection unit 152 that detects the temperature of the delay line 130, and the control unit 212 performs feedback control on the temperature adjustment mechanism 140 based on the temperature of the delay line 130 detected by the second temperature detection unit 152. This allows the ultrasonic flaw detection apparatus 100 according to this embodiment to set the temperature of the delay line 130 to the target temperature Tw of the delay line 130 associated with the delay line sound speed information. Therefore, the ultrasonic flaw detection apparatus 100 according to this embodiment can propagate the ultrasonic waves transmitted by the probe 120 to the target position P with high accuracy.

[0058] Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above-described embodiments. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0059] For example, in the above embodiment, the second temperature detection unit 152 of the ultrasonic flaw detection apparatus 100 is a temperature sensor. However, the configuration of the second temperature detection unit 152 is not limited as long as it can detect the temperature of the delay line 130. For example, the second temperature detection unit 152 may be a probe different from the probe 120, having a transmitter with a transducer for transmitting ultrasonic waves and a receiver with a transducer for receiving ultrasonic waves. In this case, the second temperature detection unit 152 is preferably provided in the delay line 130, and the transmitter of the second temperature detection unit 152 transmits ultrasonic waves perpendicular to the interface IF between the delay line 130 and the test object T. Then, for example, the second temperature detection unit 152 calculates the speed of sound Vw of the delay line 130 based on the time from transmitting the ultrasonic waves to receiving the ultrasonic waves reflected at the interface IF and the thickness of the delay line 130 (the length in the Z-axis direction in FIG. 1 ), and calculates the temperature of the delay line 130 based on the speed of sound Vw.

[0060] In the temperature adjustment process S126 of the above embodiment, the control unit 212 performs feedback control on the temperature adjustment mechanism 140 so that the temperature of the delay material 130 detected by the second temperature detection unit 152 becomes the target temperature Tw calculated in the delay material temperature calculation process S124. However, in the temperature adjustment process S126, the control unit 212 may control the temperature adjustment mechanism 140 so that the temperature of the delay material 130 becomes within a target temperature range including the target temperature Tw. The target temperature range is a temperature range including the target temperature Tw. For example, the target temperature range is a range of the target temperature Tw ± 25°C.

[0061] In the above embodiment, the ultrasonic flaw detection apparatus 100 includes the second temperature detection unit 152. However, the ultrasonic flaw detection apparatus 100 does not necessarily need to include the second temperature detection unit 152. For example, the control unit 212 may refer to the test object sound velocity information and the delay line sound velocity information and perform open control on the temperature adjustment mechanism 140 based on the temperature Tt of the test object T detected by the first temperature detection unit 150. In this case, the control unit 212 may, for example, start the operation of the temperature adjustment mechanism 140 in the temperature adjustment process S126, adjust the temperature adjustment capacity of the temperature adjustment mechanism 140, and proceed to the inspection process S116 after a predetermined fixed time has elapsed. The fixed time is the time from the start of operation of the temperature adjustment mechanism 140 until the target temperature Tw is reached, and is determined in advance. Alternatively, the control unit 212 may start the operation of the temperature adjustment mechanism 140 in the temperature adjustment process S126, maintain the temperature adjustment capacity of the temperature adjustment mechanism 140 constant, and proceed to the inspection process S116 after a predetermined variable time has elapsed. The fluctuation time is determined in advance based on the time required to reach the target temperature Tw according to a certain temperature adjustment capability of the temperature adjustment mechanism 140 .

[0062] In the above embodiment, the memory unit 214 of the control device 210 pre-stores the test object sound velocity information and the delay line sound velocity information. However, the memory unit 214 of the control device 210 does not necessarily have to store the test object sound velocity information and the delay line sound velocity information. For example, the control device 210 may control the temperature adjustment mechanism 140 based on the target temperature Tw of the delay line 130 acquired in response to an operator's operation input to an operation unit (not shown). In this case, the operator may calculate the target temperature Tw based on the temperature Tt of the test object T detected by the first temperature detection unit 150.

[0063] In the above embodiment, the control unit 212 refers to the test object sound velocity information and the delay line sound velocity information and controls the temperature adjustment mechanism 140 based on the temperature of the test object T detected by the first temperature detection unit 150. However, the control unit 212 may control the temperature adjustment mechanism 140 based on the temperature of the test object T detected by the first temperature detection unit 150 without referring to the test object sound velocity information and the delay line sound velocity information. For example, the control unit 212 may operate the temperature adjustment mechanism 140 when the temperature of the test object T detected by the first temperature detection unit 150 is different from a reference temperature.

[0064] The probe 120 may also be disposed inside the delay material 130 .

[0065] The probe 120 may also be an array probe including a transmitter having a plurality of transducers and a receiver having a plurality of transducers, thereby enabling the target position P to be suitably inspected even when the temperature of the inspection object T changes significantly.

[0066] In the above embodiment, the ultrasonic flaw detection apparatus 100 controls the temperature adjustment mechanism 140 so that ultrasonic waves are transmitted to the target position P. However, the ultrasonic flaw detection apparatus 100 may control the temperature adjustment mechanism 140 to change the transmission position of ultrasonic waves. This allows the ultrasonic flaw detection apparatus 100 to inspect various locations simply by controlling the temperature adjustment mechanism 140, without changing the installation position. For example, the ultrasonic flaw detection apparatus 100 can scan and inspect the weld line WL of the welded portion WR simply by controlling the temperature adjustment mechanism 140, without changing the installation position.

[0067] The present disclosure can contribute, for example, to Goal 12 of the Sustainable Development Goals (SDGs), "Ensure sustainable consumption and production patterns."

[0068] 100: Ultrasonic flaw detector 120: Probe 130: Delay material 140: Temperature adjustment mechanism 150: First temperature detection unit 152: Second temperature detection unit 212: Control unit 214: Storage unit

Claims

1. An ultrasonic flaw detection device comprising: a probe that transmits ultrasonic waves into the interior of an object to be inspected and receives ultrasonic waves reflected from within the object to be inspected; a delay material disposed between the probe and the object to be inspected; a temperature adjustment mechanism that adjusts the temperature of the delay material; a first temperature detection unit that detects the temperature of the object to be inspected; and a control unit that controls the temperature adjustment mechanism based on the temperature of the object to be inspected detected by the first temperature detection unit.

2. The ultrasonic flaw detection device of claim 1, wherein the control unit refers to inspection object sound speed information indicating the relationship between the speed of sound and temperature of the inspection object, and delay material sound speed information indicating the relationship between the speed of sound and temperature of the delay material, and controls the temperature adjustment mechanism based on the temperature of the inspection object detected by the first temperature detection unit.

3. The ultrasonic flaw detection device described in claim 2, wherein the control unit: refers to the inspection object sound speed information, and calculates the sound speed of the inspection object from the temperature of the inspection object detected by the first temperature detection unit; calculates the sound speed of the delay material based on the sound speed of the inspection object; refers to the delay material sound speed information, and calculates a target temperature of the delay material from the sound speed of the delay material; and controls the temperature adjustment mechanism based on the target temperature.

4. An ultrasonic flaw detection device as described in claim 2 or 3, further comprising a memory unit for storing in advance the inspection object sound velocity information and the delay material sound velocity information.

5. An ultrasonic flaw detection device as described in claim 1 or 2, further comprising a second temperature detection unit that detects the temperature of the delay material, and the control unit performs feedback control on the temperature adjustment mechanism based on the temperature of the delay material detected by the second temperature detection unit.

6. An ultrasonic flaw detection method, comprising: detecting the temperature of an object to be inspected; transmitting ultrasonic waves into the interior of the object to be inspected; and adjusting the temperature of a delay material disposed between the object to be inspected and a probe that receives ultrasonic waves reflected from inside the object to be inspected, based on the detected temperature of the object to be inspected.

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