JP2018136352A - Infrared defect detection system using ultrasonic wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce restrictions on an inspection object in an infrared defect detection system using ultrasonic waves that detects, by the infrared thermography method, a temperature change at a defect place by giving ultrasonic energy to the inspection object.SOLUTION: An infrared defect detection system 130 using ultrasonic waves includes: an ultrasonic vibration exciter for giving ultrasonic energy to a processing medium 140, i.e. a liquid state fluid medium; and an infrared thermography device 30 for taking an image of a temperature state of a surface of a channel pipe 128, i.e. an inspection object given ultrasonic energy by the processing medium 140 and displaying outer surface temperature distribution of the channel pipe 128.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an infrared defect detection system using ultrasonic waves, and in particular, provides infrared energy to an inspection object, and detects infrared defect using ultrasonic waves using detection of a state where heat is generated at a defective portion using infrared rays. About the system.

  As a method for detecting defects in a structure, there is known an ultrasonic flaw detection method in which ultrasonic waves are input to a structure and the presence or position of the defect is detected based on a reflected wave that is reflected back from the location of the defect. ing. Further, an infrared defect detection method is also used in which a heat flow is applied to the structure and a change in the state of the heat flow generated at the defect is detected by an infrared thermography apparatus.

For example, in Patent Document 1, as a method for evaluating a bonding interface between a sputtering target and a backing plate, when an object to be evaluated is immersed in water and its surface is subjected to ultrasonic scanning, the scanning speed is about 15 to 30 cm. It is stated that the scanning time is about 30 to 60 minutes for an object of 1,000 cm ² as ² / min. In contrast, when the object is immersed in a water bath and heated or cooled at a water temperature, the flow of thermal energy at the bonding interface is imaged with an infrared camera, and the imaging screen is analyzed and evaluated. It is stated that the imaging time of an object of 1,000 cm ² is about 1 to 500 s at 100 frames / s. As described above, the infrared defect detection method requires means for applying a heat flow, but can detect a wide range of defects at a much higher speed than the ultrasonic flaw detection method.

  In recent years, the Sonic-IR method has been used which has the advantages of a wider detection range and shorter inspection time than the ultrasonic flaw detection method, but does not require the application of heat flow to the structure. The Sonic-IR method is a method in which when ultrasonic energy is applied to an inspection object, friction occurs at a defective portion and the temperature of the portion increases due to frictional heat. This is a defect detection method that inputs temperature and outputs temperature distribution by infrared rays. Hereinafter, the Sonic-IR method is referred to as “infrared defect detection method using ultrasonic waves”, and the defect detection system using the Sonic-IR method is referred to as “infrared defect detection system using ultrasonic waves”.

  For example, in Patent Document 2, an ultrasonic vibrator of an ultrasonic vibration generator is used as a table roller as a crack diagnosis device for diagnosing the state of cracks at the neck portions at both ends of a table roller used in a rolling line of a steel plant. A configuration is disclosed in which a temperature change generated on the surface of the neck portion is detected by using an infrared thermography device by pressing with a predetermined pressing force. Here, the steel cooling water protection cover that covers the upper part of the neck at both ends of the table roller hinders the imaging of the infrared camera. Therefore, the reflector reflects the temperature change on the surface of the neck portion opposite to the cooling water protection cover. And detecting the tip of the ultrasonic transducer to match the shape of the table roller.

Special table 2007-531817 JP 2013-92489 A

  In the infrared defect detection method using ultrasonic waves, an ultrasonic wave is input to the inspection object, and as described in Patent Document 2, an ultrasonic transducer is pressed against the inspection object. If the pressing force is increased so that the ultrasonic energy is transmitted well, the inspection object may be damaged depending on the rigidity. In the case of an inspection object having a curved surface, as described in Patent Document 2, an ultrasonic transducer having a shape that conforms to the curved surface must be prepared. As described above, the infrared defect detection method using ultrasonic waves is limited in the shape and rigidity of the inspection object.

  An object of the present invention is to provide an infrared defect detection system using ultrasonic waves that can reduce application restrictions on an inspection object.

  An infrared defect detection system using ultrasonic waves according to the present invention includes an ultrasonic vibration device that applies ultrasonic energy to a liquid fluid medium that is in contact with a gap following the shape of an inspection object, and a liquid flow An infrared thermography device that images the temperature state of the surface of an inspection object to which ultrasonic energy is applied from a conductive medium and displays the surface temperature distribution of the inspection object as a measurement result, and has a pipe shape The ultrasonic vibration device applies ultrasonic energy to the liquid fluid medium in the pipe of the pipe that is the inspection object, and the infrared thermography device determines the temperature state of the outer peripheral surface of the pipe that is the inspection object. The surface temperature distribution of the inspection object is displayed as a measurement result after imaging.

  In the infrared defect detection system using ultrasonic waves according to the present invention, the liquid fluid medium preferably contains any one of water, fats and oils, and alcohols as a main component.

  Further, in the infrared defect detection system using ultrasonic waves according to the present invention, the pipe of the inspection object is a part of a plant apparatus, and is a pipe for a flow path of a liquid processing medium used in the plant apparatus. The ultrasonic vibration device is an ultrasonic wave having a frequency higher than the frequency at which the flow speed of the liquid processing medium fluctuates with respect to the liquid processing medium flowing in the pipe of the inspection object. It is preferable to provide energy.

  In the infrared defect detection system using ultrasonic waves according to the present invention, the liquid fluid medium may contain various additives.

  With the above-described configuration, the infrared defect detection system using ultrasonic waves applies ultrasonic energy to a liquid fluid medium that is in contact with the object to be inspected following the shape of the object to be inspected, and the ultrasonic energy is supplied from the liquid fluid medium. Is imaged, and the surface temperature distribution of the inspection object is displayed as a measurement result. Therefore, defect detection can be easily performed on the inspection object regardless of the shape of the inspection object, even if the inspection object has low rigidity. Further, for an inspection object having a pipe shape, ultrasonic energy is applied to the liquid fluid medium in the pipe and the temperature state of the outer peripheral surface of the pipe is examined with an infrared thermography apparatus. Thereby, defect detection can be performed regardless of the inner shape, outer shape, bending, or the like of the pipe.

  In the infrared defect detection system using ultrasonic waves, the liquid fluid medium may be mainly composed of any one of water, fats and oils, and a specially shaped jig for detecting defects. Etc. are unnecessary.

  Further, in the infrared defect detection system using ultrasonic waves, the pipe of the inspection object may be a flow path pipe for a liquid processing medium used in a plant apparatus. In that case, ultrasonic energy having a frequency higher than the frequency at which the flow rate of the liquid processing medium flowing in the pipe of the pipe to be inspected fluctuates is applied. Thereby, defect detection can be performed at the actual plant site regardless of the inner shape, the outer shape, the bending, or the like of the pipe.

  In the infrared defect detection system using ultrasonic waves, the liquid fluid medium may contain various additives. For example, cutting oil or cutting water containing a cutting additive, water containing antifreeze, water or oil added with a rust preventive can be used as they are.

It is a figure which shows the structure of the infrared defect detection system using the ultrasonic wave of reference embodiment. Here, the example which detects peeling of the heat resistant sprayed coating from the base material part in the turbine blade with the heat resistant sprayed coating was shown. It is a figure which shows the example which detects the fatigue crack which extended from the notch of the test object in the infrared defect detection system using an ultrasonic wave. 2A is a perspective view of an inspection object in an initial state, FIG. 2B is a perspective view of the inspection object when repeatedly bent, and FIG. 2C is a perspective view of FIG. It is a figure which shows the corresponding surface temperature distribution, (d) is a figure which shows the surface temperature distribution corresponding to (b), (e) is the fatigue crack which extended from the notch in the sectional view of (d). FIG. It is a figure which shows the example which detects the defect of the inspection target spot-welded in the infrared rays defect detection system using an ultrasonic wave. In FIG. 3, (a) is a diagram showing spot welding, (b) is a diagram showing an inspection object subjected to spot welding, and (c) is a diagram showing a surface temperature distribution corresponding to (a). (D) is a diagram showing a surface temperature distribution corresponding to (b), and (e) is a cross-sectional view of the defect portion detected in (d). It is a figure which shows the modification of the infrared rays defect detection system using the ultrasonic wave of reference embodiment described in FIG. In the infrared defect detection system using the ultrasonic wave of the reference embodiment, in order to immerse a part of the inspection object in a liquid fluid medium, it is a diagram showing an example of raising and lowering the medium bathtub with respect to the inspection object is there. It is a figure which shows the example which performs the defect detection of a container-shaped test target object in the infrared rays defect detection system using the ultrasonic wave of reference embodiment. It is a figure which shows the example which performs the defect detection of the pipe for flow paths of the liquid processing medium used for a plant apparatus in the infrared defect detection system using the ultrasonic wave of embodiment which concerns on this invention. In the infrared defect detection system using the ultrasonic wave of reference embodiment, it is a figure which shows the example which performs the defect detection of the test object arrange | positioned immersed in the medium bath filled with the liquid fluid medium. Fig.8 (a) is sectional drawing in a medium bathtub, (b) is a figure which shows arrangement | positioning of the infrared thermography apparatus etc. which are arrange | positioned on the outer side of a medium bathtub.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following, the case of a metal as the material of the inspection object will be described. However, a material that causes friction at a defective portion when ultrasonic energy is applied, for example, plastic, ceramic, rubber, or the like may be used. Further, it may be deformed when an external force is applied. For example, in addition to an object with low rigidity, an elastic body, a viscoelastic body, or the like such as a leaf spring or a coil spring may be used.

  The shapes, dimensions, materials, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of an infrared defect detection system using ultrasonic waves. In the following description, the same elements are denoted by the same reference symbols in all the drawings, and redundant description is omitted.

  FIG. 1 is a diagram illustrating a configuration of an infrared defect detection system 10 using ultrasonic waves according to a reference embodiment. Hereinafter, the infrared defect detection system 10 using ultrasonic waves is referred to as the defect detection system 10 unless otherwise specified. An infrared defect detection system using various ultrasonic waves described below with reference to FIG. 4 is also called a defect detection system unless otherwise specified.

  FIG. 1 shows an inspection object 8 that is not a component of the defect detection system 10 but has a curved surface shape. FIG. 1A is an overall configuration diagram, and FIG. 1B is a cross-sectional view of a defective portion in the inspection object 8. The inspection object 8 is a turbine blade with a heat-resistant sprayed coating in which the entire outer surface of the wing-shaped base member 6 is coated with the heat-resistant sprayed coating 7.

  The defect detection system 10 immerses a part of the inspection object 8 in water 18 stretched in the ultrasonic water tank 12, applies ultrasonic energy to the inspection object 8 through the water 18, and the surface of the inspection object 8. In this system, the temperature distribution is imaged by the infrared thermography device 30 and the presence / absence of a defect, its position, its size, and the like are detected from the image data.

  The ultrasonic water tank 12 is a large ultrasonic cleaning tank having a size of about 1 to 2 m in length and width and a depth of about 1 m. The ultrasonic water tank 12 is configured by integrating a medium bathtub 14 having a bathtub space filled with water 18 and an ultrasonic vibration device 16 disposed at the bottom of the medium bathtub 14.

  The medium bathtub 14 can be a metal large container. Surface treatment such as enameling may be performed.

  The ultrasonic vibration device 16 is an ultrasonic vibration source that applies ultrasonic energy to the water 18. The ultrasonic vibration device 16 is connected to an ultrasonic oscillator, which is a function generator that outputs an ultrasonic wave having an arbitrary frequency and an arbitrary amplitude, and an ultrasonic wave generator through an appropriate signal line, and outputs an ultrasonic wave to the outside. It consists of a sound wave vibrator. In the example of FIG. 1, a plurality of ultrasonic transducers are fixedly installed on the outer bottom surface of the medium bathtub. As the oscillation frequency, maximum output, and the like of the ultrasonic vibration device 16, those according to the specifications of the defect detection system 10 are used. For example, the oscillation frequency can be determined from the type and size of the defect to be detected. Defect types include peeling defects, crack defects, cavity defects, and the like. The maximum output can be appropriately changed depending on the size of the medium bathtub 14 and the amount of water 18 filled in the bathtub space. As an example, the oscillation frequency ranges from several hundred Hz to several tens kHz, and the maximum output ranges from several hundred W to several tens kW. For example, an ultrasonic oscillator having an oscillation frequency of about 40 kHz and a maximum output of about 0.5 kW is used.

  The water 18 is a liquid fluid medium, and is an ultrasonic energy transmission material that transmits the ultrasonic energy output from the ultrasonic vibration device 16 to the inspection object 8. Here, tap water is used as the water 18 which is a liquid fluid medium. Even if it is other than tap water, it can be used as an ultrasonic energy transmission material in the defect detection system 10 as long as it is a liquid fluid medium that contacts the inspection object 8 in conformity with the outer shape without gaps.

  As the liquid fluid medium, for example, a liquid mainly composed of any one of water, fats and oils, and alcohols can be used even if it is other than the water 18 which is tap water. In a general ultrasonic flaw detection method, creamy glycerin or the like may be applied between the tip of the ultrasonic transducer and the surface of the inspection object in order to reduce transmission loss of ultrasonic energy. Done. In this case, the cream-like medium is applied by locally applying the medium to the tip of the ultrasonic transducer, and in a natural state, following the outer shape of the inspection object 8 without contact with a gap. It is a concept different from immersion. Therefore, it is not included in the liquid fluid medium here, except that the medium bath is filled with a large amount of glycerin having a low viscosity and a part of the inspection object is buried therein.

  The liquid fluid medium may contain various additives. For example, cutting fluid or cutting water containing a cutting additive, water containing antifreeze, water or oil added with a rust inhibitor can be used as the liquid fluid medium.

  By using water 18 that is a liquid fluid medium as an ultrasonic energy transmission material, ultrasonic energy can be applied to the inspection object 8 through the water 18, so that the inspection object 8 has a complicated shape. There are no restrictions on the shape. Moreover, there is no restriction | limiting with respect to rigidity, without applying big pressing force which the test target object 8 deform | transforms.

  Water 18 may fill medium tub 14 at an appropriate water level. As an appropriate water level, about 50 to 80% of the depth of the medium bathtub 14 is good.

  The holding device 22 is a device that holds the inspection object 8 by immersing it in the water 18 of the medium bathtub 14. The holding device 22 adjusts the height so that one end side of the inspection object 8 is immersed in the water 18, and fixes and holds the other end portion in the space above the water 18. The holding device 22 includes a fixing unit 24 that fixes the other end of the inspection object 8 and a height adjusting unit 26 that adjusts the height of the fixing unit 24. The water surface 20 is shown in FIG.

  The fixing part 24 is a holding means that gently fixes the other end of the inspection object 8 to such an extent that the inspection object 8 does not move even when the water surface 20 undulates. The degree to which the inspection object 8 does not move means that the temperature state detection by the infrared thermography device 30 is not hindered. Specifically, the low frequency vibration below the frame rate that is the data transfer speed of the infrared thermography device 30. Is acceptable. The loose fixing means holding the inspection object 8 so as not to be damaged. As the fixing portion 24, for example, a clip in which a cushion material is provided at a grip portion, a double-sided adhesive sheet, or the like can be used. When the inspection object 8 is made of a material that can be gripped by a magnetic force, a magnet may be used as the fixing portion 24 and the inspection object 8 may be suspended from the medium bathtub 14 by a magnetic force.

  The height adjusting unit 26 adjusts the height of the fixing unit 24 so that one end side of the inspection object 8 is positioned below the water surface 20 of the water 18, and immerses a part of the inspection object 8 in the water 18. When the immersion amount is small, the ultrasonic energy is not sufficiently transmitted through the water 18, and when the immersion amount is large, the detectable region of the infrared thermography device 30 is narrowed. Therefore, the immersion amount is preferably about 5 to 20% of the entire height of the inspection object 8.

  The infrared thermography device 30 is a temperature distribution measuring device for the inspection object 8 and also a defect detection device for the inspection object 8. The infrared thermography device 30 includes an infrared camera 32 and an analysis display device 34 that converts detection data captured by the infrared camera 32 into a temperature distribution and displays the result as a measurement result. Here, the infrared camera 32 and the analysis display device 34 are separately configured as the infrared thermography device 30, but this may be a device in which the camera, the arithmetic device, and the image monitor are integrated.

  The number of pixels of the infrared camera 32, the imaging frame rate, the temperature resolution, and the like are in accordance with the specifications of the defect detection system 10. For example, the number of pixels of the infrared camera 32 can be determined by the minimum size of the defect to be detected, the distance from the infrared camera 32 to the inspection object 8, and the like. In addition, the imaging frame rate can be determined from the specification of the inspection time. The temperature resolution can be determined based on the type and size of the defect to be detected. For example, the number of pixels of the infrared camera 32 ranges from tens of thousands to hundreds of thousands of elements, the imaging frame rate ranges from several Hz to several hundreds Hz, and the temperature resolution ranges from several tens of mK to several hundreds of mK. The imaging frame rate is a frequency lower by about two to three digits than the oscillation frequency of the ultrasonic vibration device 16. For example, an infrared thermography apparatus 30 having about 200,000 elements of the infrared camera 32, an imaging frame rate of about 100 Hz, and a temperature resolution of about 25 mK is used.

  As the analysis display device 34, a personal computer having a display can be used. The analysis display device 34 has a function of converting detection data captured by the infrared camera 32 into image display data converted into a temperature distribution, and a function of displaying the converted image display data on a display as temperature distribution data. The analysis display device 34 may be connected to the ultrasonic vibration device 16 using an appropriate interface circuit to control the operation of the ultrasonic vibration device 16. In FIG. 1, a temperature distribution diagram 36 of the inspection object 8 is displayed on the display of the analysis display device 34.

  In the temperature distribution diagram 36 of the inspection object 8, it is shown that a portion 38 having a locally high temperature appears in an annular shape. The periphery of this portion 38 is a peeling defect portion. FIG. 1B is a cross-sectional view of the portion 38 of the inspection object 8. The inspection object 8 is a turbine blade with a heat-resistant sprayed coating in which the entire outer surface of the wing-shaped base member 6 is coated with a heat-resistant sprayed coating 7. It is a place. In FIG.1 (b), peeling has arisen on the single side | surface side of the base material part 6. FIG. The defective portion is divided into a portion 4 in which a cavity is generated between the turbine blade 6 and the heat-resistant sprayed coating 7 and a portion 5 in which a slight gap is generated around the portion 4.

  The defect detection system 10 detects a temperature change that occurs due to friction generated at a defect location by ultrasonic waves. The difference between the part 4 where the cavity is generated and the part 5 where the slight opening gap is generated is the size of the opening gap at the interface between the base material portion 6 and the heat-resistant sprayed coating 7. In the defect detection system 10, the gap interval between defects in which friction occurs varies depending on the physical properties of the material, but, for example, is about several μm. When a defect having a gap interval sufficiently larger than about several μm is called an opening defect, the opening defect has an air layer or a vacuum layer at the defect interface, and friction does not occur. Further, when a gap interval sufficiently smaller than about several μm is called a closed defect, even if the closed defect has almost no gap between the interfaces and friction occurs, the temperature rises below the temperature resolution of the infrared thermography device 30 and is detected. Can not. Therefore, the defect detection system 10 can detect a portion having an opening gap with a gap interval of several μm at the boundary between the opening defect and the closing defect.

  In the example of FIG. 1B, since the portion 4 where the cavity is generated is an opening defect, the temperature rise due to friction does not occur. Further, since the outer side of the portion 5 where the slight gap is generated is a closed defect, the temperature rise due to friction hardly occurs. The temperature increase due to friction can be detected only in the portion 5 where a slight gap of several μm is generated, and the portion surrounding the portion 4 where the cavity is generated by the peeling is annularly surrounded. As described above, in the case of a peeling defect, a portion 38 having a high temperature appears in a ring shape around the portion 4 where the cavity is generated by the peeling. A region surrounded by this portion 38 is a portion where a cavity is generated by peeling. In this way, the position and size of the peeling defect are detected in the defect detection system 10.

  Since the inspection object 8 in FIG. 1 has a curved outer shape, if a general Sonic-IR method is to be applied, an ultrasonic transducer having a tip shape adapted to the curved outer shape is required. . Further, since the peeling defect in the inspection object 8 occurs at the interface between the base material portion 6 and the heat-resistant sprayed coating 7, even if an ultrasonic transducer having an appropriate tip shape is prepared, a general Sonic- In the IR method, it is necessary to input ultrasonic energy enough to generate frictional heat, and it is necessary to press the ultrasonic vibrator against the inspection object 8 with a considerably large pressing force. If the ultrasonic vibrator is pressed against the inspection object 8 with such a large pressing force, the heat-resistant sprayed coating 7 may be peeled off or cracked. If the pressing force is reduced, the ultrasonic energy is not sufficiently transmitted to the inspection object 8, and defect detection becomes insufficient. If a general infrared flaw detection method is to be applied, means for forming an appropriate heat flow on the inspection object 8 having a curved outer shape is required.

  On the other hand, in the defect detection system 10 in FIG. 1, ultrasonic energy is applied to the water 18 that is a liquid fluid medium that contacts the inspection object 8 without a gap following the shape of the inspection object 8. The temperature state of the surface of the given inspection object 8 is imaged and the surface temperature distribution of the inspection object 8 is displayed. Therefore, even if the inspection object 8 has a curved surface shape or the rigidity of the heat-resistant sprayed coating 7 is low, it is possible to easily detect the peeling defect of the inspection object 8.

  2 and 3 are diagrams showing examples of defect detection other than the peeling defect using the defect detection system 10. FIG. 2 shows an example in which a fatigue crack that has developed from a notch in an inspection object having a curved surface shape is detected. FIG. 3 shows an example of detecting a defect of an inspection object obtained by spot welding thin plates having low rigidity.

  2A is a perspective view of an inspection object in an initial state, FIG. 2B is a perspective view of the inspection object when repeatedly bent, and FIG. 2C is a perspective view of FIG. It is a figure which shows the corresponding surface temperature distribution, (d) is a figure which shows the surface temperature distribution corresponding to (b), (e) is the enlarged view of (d), and the fatigue crack which propagated from the notch FIG.

  An inspection object 40 in FIG. 2 is a fatigue test piece composed of a test piece main body 42 having a curved shape and a notch 44 provided in the test piece main body 42. The inspection object 40 becomes an inspection object 43 whose outer shape is partially plastically deformed as shown in FIG. 2B by applying a predetermined repeated bending. However, visually, no defect is visually recognized on the inspection object 43.

  2C and 2D are diagrams showing temperature distributions obtained using the defect detection system 10 described in FIG. FIG. 2C shows the temperature distribution of the inspection object 40 in the initial state of FIG. 2A, and no local temperature rise is detected. FIG. 2D shows the temperature distribution of the inspection object 41 after the repeated bending load shown in FIG. 2B, and a locally high temperature portion 46 is detected at the tip of the notch 44. The periphery of the portion 46 is a defect portion where a fatigue crack is caused by repeated bending loads.

  FIG. 2E is an enlarged view of a portion 46 of the inspection object 41. The defective part is a part where a crack extending from the notch 44 is generated, a part 48 which is connected to the notch 44 and the crack is opened considerably large, a part 50 where the crack is slightly opened, and a crack. The fissure is divided into portions 52 that are hardly open.

  In the example shown in FIG. 2 (e), the portion 48 where the cracks are considerably opened is the opening defect described with reference to FIG. Further, the portion 52 where the crack is hardly opened is the closing defect described with reference to FIG. A temperature increase due to friction can be detected only at a portion 50 where a slight opening having a gap interval of several μm is formed, and a portion slightly separated from the notch 44. Accordingly, “opening considerably large” means a gap opening larger than several μm, and “almost no opening” means a gap opening of less than several μm. A specific numerical value of several μm can be set in advance based on the physical properties of the inspection object 8, inspection specifications, or the like. In this way, in the case of a fatigue crack defect that propagates from the notch 44, a locally high temperature portion 46 appears at a location slightly away from the notch 44. A fatigue crack defect occurs on the line connecting the notch 44 and the portion 46. In this manner, the defect detection system 10 detects the position and approximate size of the fatigue crack defect.

  In FIG. 3, (a) is a diagram showing spot welding, (b) is a diagram showing an inspection object subjected to spot welding, and (c) is a diagram showing a surface temperature distribution corresponding to (a). (D) is a diagram showing a surface temperature distribution corresponding to (b), and (e) is a cross-sectional view of the defect portion detected in (d).

  In FIG. 3A, spot welding is performed using a pair of welding terminals 54 and 56 and a welding power source 58 that supplies a welding power pulse between the welding terminals 54 and 56. Here, two thin plates 62 and 64 are shown as the spot welding object 60. In spot welding, two thin plates 62 and 64 are overlapped, the welding terminal 54 is assigned to the thin plate 62 side, the welding terminal 56 is assigned to the thin plate 64 side at a position opposite to this, and the welding terminal 54 is supplied from the welding power source 58. , 56, a welding power pulse is applied, and the thin plate 62 and the thin plate 64 are integrated at the welding point 66. FIG. 3B is a diagram showing the inspection object 61 integrated by welding, and no defects due to spot welding are visually recognized.

  3C and 3D are diagrams showing temperature distributions obtained using the defect detection system 10 described in FIG. FIG. 3C shows the temperature distribution of the spot welding object 60, and no local temperature rise is detected. FIG. 3D shows the temperature distribution of the inspection object 61 after spot welding shown in FIG. 3B, and the annular portions 70 and 72 having locally high temperatures are detected at locations corresponding to the welding locations 66. . The annular portions 70 and 72 are separated from each other, and the annular portions are doubled. The periphery of the annular portions 70 and 72 is a defective portion caused by spot welding.

  FIG. 3E is a cross-sectional view of the annular portions 70 and 72 of the inspection object 61. As shown in FIG. 3E, the two thin plates 62 and 64 are connected and integrated by an annular portion 80. The annular portion 80 is a portion corresponding to a welding point 66 in which the two thin plates 62 and 64 are integrated by spot welding. A gap 82 outside the annular portion 80 is a portion where the two thin plates 62 and 64 are not spot welded, and is a portion outside the welded portion 66.

  When spot welding is normally performed, the portion where the two thin plates 62 and 64 are connected and integrated becomes the same circular shape portion as the welded portion 66 and does not become the annular portion 80. In FIG.3 (e), spot welding is not perfect and the clearance gap 84 has arisen in the center part of the part corresponding to 64 of a welding location.

  The gaps 82 and 84 are the opening defects described with reference to FIG. There is a region where a slight opening is generated at the boundary of the annular portion 80 in contact with the gap 82, and similarly, there is a region where a slight opening is also generated at the boundary of the gap 84 which is in contact with the annular portion 80. In the gaps 82 and 84 which are opening defects, no friction is generated between the thin plates 62 and 64. At the annular boundary that contacts the gap 82 on the outer peripheral side of the annular portion 80 and the annular boundary that contacts the gap 84 on the inner peripheral side of the annular portion 80, a slight opening of several μm is generated, and the temperature rise due to friction occurs here. Detected.

  In FIG. 3D, the annular portion 70 having a locally high temperature is a portion of an annular boundary that contacts the gap 82 on the outer peripheral side of the annular portion 80, and another annular portion 72 inside the annular portion 70 is This is the portion of the annular boundary that contacts the gap 84 on the inner peripheral side of the annular portion 80. As described above, in the case of a defect that occurs in the weld spot 66 of the spot welding of the thin plates 62 and 64, the annular spots 70 and 72 that are locally high in temperature appear in the weld spot 66. Even if the spot welding is normally performed, the annular portion 70 appears. In this manner, the defect detection system 10 detects the welding spot 66 of spot welding and the position and size of the defect.

  In FIG. 1, the inspection object 8 is suspended by the holding device 22 so as to be immersed in the water 18 that is a liquid fluid medium filled in the medium bath 14. In the method of applying ultrasonic energy to the inspection object 8 via a liquid fluid medium, other means may be more convenient depending on the shape of the inspection object. Various methods for applying ultrasonic energy to the inspection object 8 through the liquid fluid medium will be described with reference to FIGS.

  The defect detection system 11 of the reference embodiment shown in FIG. 4 is a modification of the defect detection system 10 of FIG. The defect detection system 11, like the defect detection system 10, moves the inspection object 8 up and down in the ± Z direction with respect to the medium bathtub 14 fixedly placed on the floor 2. The configuration of is different. The ultrasonic vibration device has a configuration in which a waterproof ultrasonic transducer 17 is connected to an ultrasonic oscillator with a waterproof signal line, and the waterproof ultrasonic transducer 17 is thrown and fills the medium bathtub 14. It is immersed in water 18 which is a liquid fluid medium to be installed. The ultrasonic oscillator is provided at a suitable location outside the medium bath 14. By setting it as such a structure, a general container can be used as the medium bathtub 14. Furthermore, an outdoor pool or a dock yard can be used as a medium accommodation space. Thereby, it becomes easy to set a boat, a ship, etc. as a test subject.

  In the defect detection system 100 of the reference embodiment shown in FIG. 5, in order to immerse a part of the inspection object 98 in the water 18 that is a liquid fluid medium, the medium bath 102 is set to ± with respect to the inspection object 98. This is a method of moving up and down in the Z direction. A large truss that is a large structure is shown as the inspection object 98. The relative position with respect to the medium tub 102 is determined and the inspection target 98 is held so that at least a part of the inspection target 98 is immersed in the water 18 that is a liquid fluid medium filled in the medium tub 102. . As the holding device 104 for holding, a fixing unit 106 that fixes the inspection object 98 at a certain height position with respect to the floor surface, and an elevating unit 108 that raises and lowers the medium bathtub 102 in the ± Z direction are used. A hydraulic jack is used as the lifting unit 108. A lifting motor may be used instead of the hydraulic jack.

  When the inspection object 98 is large and the entire infrared inspection object 98 cannot be imaged when the infrared camera 32 of the infrared thermography apparatus 30 is fixed, the infrared camera 32 is moved along the X direction which is the longitudinal direction of the inspection object 98. It is preferable to be movable. On the display of the analysis display device 34 of the infrared thermography device 30, a temperature distribution diagram 110 of the inspection object 98 is displayed, and a portion 112 having a locally high temperature is shown.

  As described above, in the defect detection system 100 shown in FIG. 5, the inspection object 98 is a large structure, and the medium bathtub 102 is moved in the ± Z direction rather than the inspection object 98 is moved in the ± Z direction. Used when it is easier.

  FIG. 6 is a diagram showing a defect detection system 120 that performs defect detection of a container-like inspection object 118 as a reference embodiment. An example of the container-shaped inspection object 118 is the medium bathtub 14 described with reference to FIGS. The inside of the container that is the inspection object 118 is filled with water 18 that is a liquid fluid medium. The ultrasonic vibration device is the same as that described with reference to FIG. 4, and the ultrasonic vibrator 17 that applies ultrasonic energy to the water 18 is a throwing type installed in the inner space of the container that is the inspection object 118. A waterproof type is used.

  The infrared camera 32 of the infrared thermography device 30 is disposed outside the container that is the inspection object 118 and images the temperature state outside the container that is the inspection object 118. In order to capture an image over the entire outer periphery of the inspection object 118, it is preferable that the infrared camera 32 be movable along the outer periphery of the inspection object 118. Alternatively, the inspection object 118 may be rotated with the infrared camera 32 as a fixed position. In that case, the inspection object 118 is preferably rotated slowly so that the water 18 filled in the container which is the inspection object 118 does not wave.

  On the display of the analysis display device 34 of the infrared thermography device 30, a temperature distribution diagram 122 of the inspection object 118 is displayed, and a location 124 where the temperature is locally high is shown.

  As described above, the defect detection system 120 shown in FIG. 6 is convenient when the inspection object 98 is a container that can fill the water 18 that is a liquid fluid medium.

  FIG. 7 is a diagram showing a defect detection system 130 that detects defects in the flow path pipe 128 of the liquid processing medium used in the plant apparatus. FIG. 7A is a diagram illustrating the entirety of the defect detection system 130 in the plant apparatus, and FIG. 7B is a diagram illustrating a cross section of the infrared thermography apparatus 30 and the flow path pipe 128 to be inspected in the defect detection system 130. It is.

  In FIG. 7, as the plant apparatus, the processing medium 140 is temporarily stored in the first tank 134 from the processing medium supply pipe 132, and is transferred to the second tank 138 from the first tank 134 using the flow path pipe 128 including the delivery pump 136. An example of sending out was shown. The inspection target is a flow path pipe 128 through which the processing medium 140 flows. The processing medium 140 corresponds to a liquid fluid medium to which ultrasonic energy is applied.

The ultrasonic vibration device for applying ultrasonic energy to the processing medium 140 is the same as that described with reference to FIGS. 4 and 6, and the ultrasonic vibrator 17 for applying ultrasonic energy to the water 18 is provided inside the first tank 134. A throw-in and waterproof type installed in the space is used. The oscillation frequency f _US of the ultrasonic vibration device is set to a frequency higher than the frequency at which the flow rate of the liquid processing medium 140 flowing in the pipe of the flow path pipe 128 fluctuates. One of the causes of fluctuations in the flow rate of the processing medium 140 is pulsation caused by the delivery pump 136. With this pulsation frequency as f _P , f _US > f _P is set. For example, a pulse frequency _{f P} as 60 _{Hz, f US} is set to several kHz or more several tens of times the frequency side higher than _{f P.}

  The infrared camera 32 of the infrared thermography device 30 is disposed outside the flow path pipe 128 that is an inspection object, and images the temperature state of the outer surface of the flow path pipe 128. In order to capture an image over the entire length of the flow path pipe 128 from the first tank 134 to the second tank 138, it is preferable that the infrared camera 32 be movable along the laying direction of the flow path pipe 128. On the display of the analysis display device 34 of the infrared thermography device 30, a temperature distribution diagram 144 of the flow path pipe 128 that is an object to be inspected is displayed, and a location 146 where the temperature is locally high is shown.

  As described above, the defect detection system 130 shown in FIG. 7 applies ultrasonic energy to the processing medium 140, so that the inner shape of the flow path pipe 128, the outer shape, the bending, etc. Defect detection can be performed on site.

  FIG. 8 is a diagram illustrating a defect detection system 150 that performs defect detection of an inspection object 148 that is immersed in a medium bath 152 filled with water 18 that is a liquid fluid medium, as a reference embodiment. It is. Examples of such an inspection object 148 include pipes in the reactor containment vessel, various partition walls, and cooling water pipes in the condenser. FIG. 8A is a cross-sectional view of the medium bathtub 152, and FIG. 8B is a diagram illustrating the arrangement of the infrared thermography device 154 and the like arranged outside the medium bathtub 152.

  Up to FIG. 7, the infrared thermography apparatus is used to detect a defect in a portion of the inspection object that is not immersed in water, but in FIG. 8, it is immersed in the water 18 of the inspection object 148. Detect defects in the part. Infrared rays are not absorbed by the atmosphere, but are absorbed by water 18. Therefore, even if the infrared camera 32 is immersed in the water 18 and the water 18 is between the infrared camera 32 and the inspection object 148, the infrared camera 32 cannot detect infrared rays from the inspection object 148.

  Therefore, in the defect detection system 150 of FIG. 8, a waterproof infrared thermography device 154 is used. The waterproof infrared thermography device 154 includes a waterproof infrared camera device 156 that is disposed so as to be immersed in the water 18 in the medium bath 152, and an analysis display device 34 that is disposed outside the medium bath 152. Is done. The waterproof infrared camera device 156 includes a waterproof case 158 in which the infrared camera 32 is housed, and a waterproof signal line 160 connected to the infrared camera 32 and drawn out of the medium bathtub 152. The waterproof signal line 160 is pulled out of the medium bathtub 152 and then connected to a non-waterproof general signal line 161 drawn from the analysis display device 34.

  The waterproof case 158 includes a waterproof casing 159, an imaging window 162 attached to the waterproof casing 159, and an overhanging frame body 164 that projects to the outer periphery of the imaging window 162. The waterproof casing 159 and the imaging window 162 are connected in a waterproof structure, and the internal space defined by the waterproof casing 159 and the imaging window 162 is an airtight and liquid-tight space in which the infrared camera 32 is disposed. . The imaging lens of the infrared camera 32 is disposed so as to face the imaging window 162. The waterproof housing 159 is provided with a waterproof bush through which the waterproof signal line 160 drawn from the infrared camera 32 passes.

  The imaging window 162 is made of a transparent body that does not absorb infrared rays. As the imaging window 162, a sapphire glass plate can be used. As a waterproof structure between the waterproof casing 159 and the imaging window 162, a structure in which the inner wall surface of the waterproof casing 159 and the outer peripheral surface of the imaging window 162 are caulked with silicone resin, and the inner wall surface of the waterproof casing 159 and imaging are performed. A structure or the like in which an elastic waterproof ring is disposed between the outer peripheral surface of the window 162 and the like can be used. A caulking process may be further performed with a taper screw structure between the inner wall surface of the waterproof casing 159 and the outer peripheral surface of the imaging window 162.

  The overhang frame 164 is a part that surrounds the outer periphery of the imaging window 162 in an annular shape. The outside of the imaging window 162 is a side facing the water 18 on the opposite side with the side facing the infrared camera 32 as the inside. The ring may be an annular ring, a polygonal ring, or the like. The overhang frame 164 has a function of forming a space 166 surrounded by the overhang frame 164, the imaging window 162, and the inspection object 148 when the waterproof housing 159 faces the surface of the inspection object 148. Have

  A gas supply port 168 that opens to face the space 166 of the waterproof casing 159 is located outside the medium bathtub 152 via a gas flow path 169 provided in the waterproof casing 159, a check valve 170, and a gas supply tube 172. Connected to the pressurized gas supply 174 arranged. A compressor can be used as the pressurized gas supply source 174.

  The gas supply port 168 jets and supplies the pressurized gas supplied from the pressurized gas supply source 174 to the space 166. As a result, the water 18 in the space 166 is pushed out to the outside of the overhanging frame 164 so that the space 166 is a gas-only space that does not absorb infrared rays. The check valve 170 is provided so that a gas having a gas pressure equal to or higher than the water pressure of the medium bathtub 152 at a position facing the infrared camera 32 is ejected from the gas supply port 168. For example, when the position for detecting the defect of the inspection object 148 is 10 m at the water depth of the medium bathtub 152, the water pressure at that position is about 1 atm higher than the atmospheric pressure, and therefore higher than the water pressure from the gas supply port 168. A gas having a gas pressure of about 2 atm or more is ejected. Since a bias pressure can be set for the check valve 170, for example, when the bias pressure is about 0.2 atm, a gas having a gas pressure of about 2.2 atm is ejected from the gas supply port 168.

  When the inspection object 148 is fixed in the medium bathtub 152, it does not move due to the gas pressure of the gas ejected from the gas supply port 168, so that the ejection flow rate from the gas supply port 168 can be increased. When the ejection flow rate is sufficiently high, the water 18 in the space 166 can be excluded outside the projecting frame 164 without bringing the projecting frame 164 into contact with the inspection object 148. Therefore, the overhang frame 164 does not have to be an elastic body and can be a simple annular plate member. When there is a possibility that the inspection object 148 moves due to the gas pressure of the gas ejected from the gas supply port 168, the ejection flow rate from the gas supply port 168 cannot be increased so much. As described above, the water 18 in the space 166 is pushed out to the outside of the overhanging frame 164 while being pressed against the inspection object 148.

  When the inspection object 148 is not firmly fixed in the medium bath 152 and may move with the gas pressure of the gas ejected from the gas supply port 168, means for temporarily fixing the inspection object 148 is provided. It is good to use. For example, a temporary suction disk or the like may be provided on the surface of the inspection object 148 so that the temporary suction disk is fixed during the defect measurement. A vacuum suction board, a magnet suction board, etc. can be used as a temporary suction board. When the back side of the inspection object 148 can be pressed and held, an appropriate pressing and holding device is used to hold and hold the opposite side of the inspection object 148 from the side that receives the gas ejected from the gas supply port 168. It may be.

  A camera support member 176 attached to extend upward from the ceiling portion of the waterproof housing 159 is a pillar member that supports the waterproof case 158 so as to be movable in the medium bathtub 152. FIG. 8 shows the X, Y, and Z directions orthogonal to each other. The Z direction is a direction parallel to gravity, the upper direction is the upper direction along the Z direction, and the water depth direction is the lower direction along the Z direction. The X direction is a direction in which the distance between the waterproof case 158 and the inspection object 148 is increased or decreased. The camera support member 176 can be moved by an arbitrary amount of movement in each of the X direction, the Y direction, and the Z direction by a moving device provided outside the medium bathtub 152, and thereby the imaging range of the infrared camera 32 can be inspected. A scan can be made along the surface of the object 148.

  The waterproof ultrasonic transducer 17 is an ultrasonic vibration source that is immersed in the water 18 and applies ultrasonic energy to the water 18. The waterproof ultrasonic transducer 17 is connected to an ultrasonic oscillator 182 provided outside the medium bath 152 via a waterproof signal line 180. The vibrator support member 184 attached to extend upward from the waterproof ultrasonic vibrator 17 is a pillar member that supports the waterproof ultrasonic vibrator 17 so as to be movable in the medium bath 152. The vibrator support member 184 can be moved by an arbitrary amount of movement at least in the Z direction by a moving device provided outside the medium bathtub 152, thereby waterproofing ultrasonic vibration in accordance with the imaging position of the infrared camera 32. The child 17 can be moved.

  The vibrator support member 184 may move independently of the camera support member 176, or may move in conjunction with the movement of the camera support member 176. In the latter case, the waterproof ultrasonic transducer 17 and the waterproof infrared camera device 156 can always be in a predetermined positional relationship, and the ultrasonic energy applied to the inspection object 148 is almost the same. The imaging range of the infrared camera 32 can be scanned along the surface of the inspection object 148.

  In the defect detection system 150, the defect detection of the inspection object 148 that is immersed and arranged in the medium bath 152 filled with the water 18 is performed as follows. Ultrasonic energy is applied to the water 18 from the ultrasonic transducer 17 disposed so as to be immersed in the medium bath 152 filled with the water 18, and ultrasonic energy is applied to the inspection object 148 via the water 18. Then, the camera support member 176 is appropriately moved so that the waterproof infrared camera device 156 is brought close to the surface of the inspection object 148 in the medium bath 152 filled with water 18. At that time, the temperature state of the surface of the inspection object 148 is imaged through the imaging window 162 of the waterproof case 158 while ejecting gas from the gas supply port 168 to exclude the water 18 in the space 166. The imaged data is transmitted to the analysis display device 34 provided outside the medium bathtub 152 via the waterproof signal line 160. The analysis display device 34 displays the surface temperature distribution of the inspection object 148 on the display as a measurement result.

  In FIG. 8, a temperature distribution diagram 186 of the inspection object 148 is displayed on the display, and a location 188 where the temperature is locally high is shown. By appropriately moving the camera support member 176, the waterproof infrared camera device 156 can be scanned along the surface of the inspection object 148 in the medium bathtub 152, and thereby into the medium bathtub 152 filled with the water 18. Defect detection can be performed over the entire surface of the inspection object 148 that is immersed and arranged.

  In the example of FIG. 8, since the inspection object 148 extends in the Z direction in the water 18, the imaging direction of the infrared camera device 156 is set to face the X direction substantially perpendicular to the YZ plane. By providing the camera support member 176 with an imaging direction changing unit that can arbitrarily change the imaging direction of the infrared camera device 156, the imaging direction of the infrared camera device 156 can be set to an arbitrary direction as well as the X direction. By doing in this way, it can respond appropriately when the inspection object 148 extends horizontally in the water 18 or when the inspection object 148 has an inclined surface in the water 18. As such an imaging direction changing unit, a combination of a suitable bevel gear mechanism and a small motor can be used.

  2 floor surface, 4, 5 (of defective part), 6 base material part (of turbine blade with heat-resistant sprayed coating), 7 heat-resistant sprayed coating, 8, 40, 41, 43, 61, 98, 118, 148 10, 11, 100, 120, 130, 150 (infrared using ultrasonic waves) defect detection system, 12 ultrasonic water tank, 14, 102, 152 medium bathtub, 16 ultrasonic vibration device, 17 (waterproof type ) Ultrasonic vibrator, 18 water (which is a liquid fluid medium), 20 water surface, 22,104 holding device, 24,106 fixing unit, 26 height adjusting unit, 30 infrared thermography device, 32 infrared camera, 34 Analysis display device, 36, 110, 124, 144, 186 Temperature distribution diagram, 38, 46, 112, 124, 146, 188 (locally high temperature) location, 42 Test piece body 44 Notch, 48 Portion where the crack is opened considerably (opening defect), 50 Portion where the crack is slightly opened, 52 Portion where the crack is hardly opened (closing defect), 54, 56 Welding terminal, 58 welding power source, 60 spot welding object, 66 welding location, 62, 64 thin plate, 70, 72 annular location, 80 annular portion, 82, 84 clearance, 108 elevating part, 128 channel pipe, 132 treatment Medium supply pipe, 134 first tank, 136 delivery pump, 138 second tank, 140 processing medium, 154 waterproof infrared thermography device, 156 waterproof infrared camera device, 158 waterproof case, 159 waterproof casing, 160, 180 Waterproof signal line, 161 signal line, 162 imaging window, 164 overhang frame, 166 space, 168 gas supply port, 69 the gas flow path, 170 a check valve, 172 gas supply tube, 174 pressurized gas supply source, 176 a camera support member, 182 ultrasonic generator, 184 transducer support member.

Claims (4)

An ultrasonic vibration device that applies ultrasonic energy to a liquid fluid medium that contacts the inspection object without a gap following the shape of the inspection object;
An infrared thermography device that images the temperature state of the surface of an inspection object to which ultrasonic energy is applied from a liquid fluid medium and displays the surface temperature distribution of the inspection object as a measurement result;
With
For inspection objects having a pipe shape,
The ultrasonic vibration device
Applying ultrasonic energy to the liquid fluid medium in the pipe of the pipe to be inspected,
Infrared thermography device
An infrared defect detection system using ultrasonic waves, characterized in that the temperature state of the outer peripheral surface of a pipe that is an inspection object is imaged and the surface temperature distribution of the inspection object is displayed as a measurement result. In the infrared defect detection system using the ultrasonic wave according to claim 1,
An infrared defect detection system using ultrasonic waves, characterized in that the liquid fluid medium mainly contains any one of water, fats and oils, and alcohols. In the infrared defect detection system using the ultrasonic wave according to claim 1,
The pipe of the inspection object is a part of a plant apparatus, and is a pipe for a flow path of a liquid processing medium used in the plant apparatus,
The ultrasonic vibration device
Ultrasonic energy having a frequency higher than the frequency at which the flow speed of the liquid processing medium fluctuates is applied to a liquid processing medium flowing in a pipe of an inspection target. Infrared defect detection system using ultrasound. In the infrared defect detection system using the ultrasonic wave according to claim 2 or 3,
An infrared defect detection system using ultrasonic waves, wherein the liquid fluid medium contains various additives.

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