JP2004028762A - Method and device for ultrasonic flaw detection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for ultrasonic flaw detection for obtaining a flaw detection result with high sensitivity and accuracy for all times independent of an atmospheric temperature at the time of flaw detection. <P>SOLUTION: In the method for ultrasonic flaw detection, a contact medium 8 is applied to a surface of an inspected body A, and an ultrasonic probe 1 transmitting/receiving an ultrasonic wave is pressed against the contact medium 8 so as to detect flaws in the inspected body A. In a state where the contact medium 8 has a temperature higher than a temperature at the time of detecting the crack, the contact medium 8 having the high temperature is applied to the surface of the inspected body A, and the ultrasonic probe 1 is pressed against the contact medium with the high temperature. In a state where the contact medium 8 has a temperature lower than the temperature at the time of being applied to the inspected body A and being pressed by the ultrasonic probe 1, the ultrasonic probe 1 performs the crack detection of the inspected body A. A device for ultrasonic flaw detection for use in the method is also provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides an ultrasonic flaw detection method for applying a couplant to the surface of a test object, pressing an ultrasonic probe for transmitting and receiving ultrasonic waves against the couplant, and performing flaw detection on the test object, and The invention relates to an ultrasonic flaw detector used to carry out the method.
[0002]
[Prior art]
In flaw detection using an ultrasonic probe, the sensitivity of the ultrasonic probe is closely related to the viscosity of the couplant, but conventionally, no special consideration was given to the viscosity of the couplant. It is a fact.
[0003]
[Problems to be solved by the invention]
That is, it is known that the ultrasonic probe has higher sensitivity as the viscosity of the couplant is higher, and has higher sensitivity as the thickness of the couplant is thinner. However, when the viscosity of the couplant increases, it is difficult to reduce the film thickness by pressing the ultrasonic probe against the couplant, and conversely, when the viscosity is reduced to reduce the film thickness, the ultrasonic probe There is a contradiction that the sensitivity of the device decreases.
However, conventionally, no special consideration has been given to this point, and the viscosity of the couplant has been dependent on the ambient temperature at the time of flaw detection. There is a drawback that a flaw detection result cannot be obtained.
In particular, among ultrasonic waves, a transverse wave generally referred to as “SH wave” is a transverse wave parallel to the surface of the object to be inspected, and is generally used in an SH wave ultrasonic probe that transmits and receives SH waves. Since the machine oil, water, glycerin and the like cannot be used as a couplant, and a couplant having a higher viscosity is required, the above-mentioned disadvantages are remarkable.
[0004]
The present invention focuses on such a conventional problem, and its object is to provide an ultrasonic flaw detection method capable of always obtaining highly sensitive and accurate flaw detection results without being affected by the ambient temperature at the time of flaw detection. And an ultrasonic flaw detector.
[0005]
[Means for Solving the Problems]
A feature of the invention according to claim 1 is that a couplant is applied to the surface of the object to be inspected, and an ultrasonic probe for transmitting and receiving ultrasonic waves is pressed against the couplant to perform flaw detection of the object to be inspected. An ultrasonic flaw detection method, wherein in a state where the temperature of the couplant is higher than that at the time of flaw detection execution, a couplant having a higher temperature is applied to the surface of the test object, and When an ultrasonic probe is pressed, and the temperature of the couplant is lower than when applied to the object to be inspected and when the ultrasonic probe is pressed, the ultrasonic probe detects the flaw of the object to be inspected. Where to run.
[0006]
According to the characteristic configuration of the first aspect of the present invention, there is provided an ultrasonic flaw detection method in which an ultrasonic probe is pressed against a couplant to perform flaw detection on an object to be inspected. In other words, in the state where the viscosity of the couplant is low, the low-viscosity couplant is applied to the surface of the test object, so that the couplant is familiar with the surface of the test object and has a low viscosity. Since the ultrasonic probe is pressed against this, the thickness of the couplant can be reduced as desired.
Then, in a state where the temperature of the couplant is lower than the time of application to the test object and the time of pressing the ultrasonic probe, that is, in a state where the viscosity of the couplant is high, the ultrasonic probe detects the flaw of the test object. Is performed, flaw detection with high sensitivity becomes possible.
As a result, the flaw detection result can always be obtained with high sensitivity without being influenced by the ambient atmosphere temperature, even if the ultrasonic probe is an ultrasonic probe for SH waves.
[0007]
The characteristic configuration of the invention according to claim 2 is the ultrasonic flaw detection method, wherein the temperature of the couplant is lower at the time of application to the test object and at the time of pressing the ultrasonic probe. The flaw detection of the inspection object is performed while scanning the ultrasonic probe.
[0008]
According to the characteristic configuration of the invention of claim 2, the ultrasonic flaw detection method described above, wherein the ultrasonic wave is applied in a state where the temperature of the couplant is lower than the time of application to the test object and the time of pressing the ultrasonic probe. Since flaw detection of the inspection object is performed while scanning the probe, efficient flaw detection is possible.
That is, the ultrasonic probe is scanned in a state where the viscosity of the couplant is high. However, since the scanning is performed after the thickness of the couplant is reduced as described above, the thin film is relatively easily formed. Scanning can be performed while maintaining the thickness, and thus efficient inspection can be performed while maintaining high sensitivity and accurate inspection.
[0009]
The characteristic configuration of the invention according to claim 3 is that the ultrasonic probe that transmits and receives ultrasonic waves, the couplant storage unit that stores the couplant, and the couplant in the couplant storage unit are covered with the ultrasonic probe. An ultrasonic flaw detector having a supply means for supplying a gas to an inspection object, the apparatus having a temperature adjusting means for adjusting the temperature of the couplant.
[0010]
According to the characteristic configuration of the invention of claim 3, the ultrasonic probe for transmitting and receiving ultrasonic waves, the couplant storage portion for storing the couplant, and the ultrasonic probe for the couplant in the couplant storage portion. An ultrasonic flaw detector having a supply unit for supplying a material to be inspected and an object to be inspected, which is provided with a temperature adjusting unit for adjusting the temperature of the couplant, and if necessary, the couplant is provided by the temperature adjusting unit. Can be applied to the surface of the object to be inspected, or the ultrasonic probe can be pressed against the surface of the object to be inspected. Can be made as thin as desired. Then, if necessary, the temperature of the couplant can be lowered and its viscosity increased by its temperature adjusting means, and the ultrasonic probe can perform flaw detection on the object to be inspected. This makes it possible to always obtain a highly sensitive and accurate flaw detection result without being influenced by the ambient temperature, even if the flaw detection is performed by the SH wave ultrasonic probe.
[0011]
According to a fourth aspect of the present invention, in the ultrasonic flaw detector, the temperature adjusting means is provided on the ultrasonic probe.
[0012]
According to the characteristic configuration of the invention of claim 4, in the ultrasonic flaw detector, since the temperature adjusting means is provided in the ultrasonic probe, if necessary, the ultrasonic probe The viscosity of the couplant can be increased or decreased in the part to adjust as desired.
[0013]
According to a fifth aspect of the present invention, in the ultrasonic flaw detector, the temperature adjusting means is provided in the couplant storage portion.
[0014]
According to the fifth aspect of the present invention, in the above ultrasonic flaw detector, since the temperature adjusting means is provided in the couplant storage part, if necessary, the contact in the couplant storage part is provided. By adjusting the viscosity of the medium, the contact medium can be supplied between the ultrasonic probe and the test object, and when the viscosity of the contact medium is reduced, the ultrasonic probe The supply of the couplant can be performed smoothly.
In particular, as described above, the temperature adjusting means is provided in the ultrasonic probe, and in addition, in the case where the temperature adjusting means is also provided in the couplant storage section, while smoothly supplying the couplant to the ultrasonic probe, It becomes possible to adjust the viscosity of the couplant at the ultrasonic probe portion as desired.
[0015]
A feature configuration of the invention according to claim 6 is an ultrasonic flaw detector having an ultrasonic probe for transmitting and receiving an ultrasonic wave, wherein the ultrasonic probe is provided between the ultrasonic probe and the object to be inspected. There is a temperature adjusting means for adjusting the temperature of the couplant interposed therebetween.
[0016]
According to the characteristic configuration of the invention of claim 6, there is provided an ultrasonic flaw detector having an ultrasonic probe for transmitting and receiving an ultrasonic wave, wherein the ultrasonic probe comprises the ultrasonic probe and the object to be inspected. In this case, the viscosity of the couplant is adjusted by adjusting the temperature of the couplant by means of the temperature adjuster as necessary. Adjustment is possible, and therefore, even with flaw detection using the SH wave ultrasonic probe, a highly sensitive and accurate flaw detection result can always be obtained without being affected by the surrounding ambient temperature.
[0017]
A feature of the invention according to claim 7 is the ultrasonic flaw detector, wherein the temperature adjusting means is a Peltier element.
[0018]
According to the characteristic configuration of the invention of claim 7, in the above ultrasonic flaw detector, since the temperature adjusting means is a Peltier element, it is easy to assemble to the couplant storage portion or the ultrasonic probe, Moreover, the temperature of the couplant can be freely adjusted to be higher or lower only by changing the direction of the supply current to the Peltier element.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of an ultrasonic flaw detection method and apparatus according to the present invention will be described with reference to the drawings.
In the flaw detection method and device according to the present invention, among the ultrasonic waves, a transverse wave generally called “SH wave”, that is, an ultrasonic probe for SH wave that transmits and receives a transverse wave parallel to the surface of the test object is used. As shown in FIG. 1 and FIG. 2, the ultrasonic probe for SH wave 1 is a probe main body 4 having a transducer 2 for transmitting an SH wave and receiving the reflected wave. The probe surface of the probe main body 4 on the object to be inspected is formed in an arc shape along the peripheral surface of the stainless steel tube A as the object to be inspected.
[0020]
An arc-shaped acrylic resin layer 5 along the peripheral surface of the stainless steel tube A is disposed on the probe surface side of the probe main body 4 with a space having a thickness t of about 10 μm. A contact space 6 for a couplant having a thickness t of about 10 μm is formed on the side of the probe surface, and the storage space 6 is provided with a flexible tube 7 as a supply means, for example, a Sonicoat SHN. A couplant container 9 is connected as a couplant storage unit for storing a highly viscous couplant 8 such as -B25 (manufactured by Nichiai Acetylene Co., Ltd.).
Temperature adjustment means for adjusting the temperature of the couplant 8 supplied and stored in the storage space 6 in a state adjacent to the couplant storage space 6 on the probe surface side of the probe body 4. The probe-side Peltier element 10 is disposed, a lead wire 11 for power supply is connected to the Peltier element 10, and a lead wire 12 for a temperature sensor for detecting the temperature of the couplant 8 is also provided. Is provided.
[0021]
As shown in FIG. 3, the couplant container 9 is formed of an aluminum cylindrical body having an outlet 14 with an opening / closing mechanism 13 at one end, and a pressing plate 15 and a spring 16 at the other end. Then, the couplant 8 is pushed out toward the outlet 14 via the pressing plate 15 by the elastic force of the spring 16, and the couplant 8 in the couplant container 9 is transferred through the flexible tube 7 to the supersonic wave. The ultrasonic probe 1 is configured to be supplied into the storage space 6.
A container-side Peltier device 17 as a temperature adjusting means for adjusting the temperature of the couplant 8 housed in the container 9 is provided on the outer peripheral portion of the couplant container 9. The outer peripheral portion is covered with a heat insulating material 18.
A lead wire 19 for power supply is also connected to the container-side Peltier element 17, and a lead wire 20 for a temperature sensor for detecting the temperature of the couplant 8 is provided. The leads 19 and 20 and the leads 11 and 12 on the side of the SH wave ultrasonic probe 1 are connected to a control device 21 for controlling the entire apparatus.
[0022]
Next, a flaw detection method for flaw detection of the stainless steel tube A using this apparatus will be described.
When the control device is turned on, the temperature of the couplant 8 in the couplant 9 is measured based on a signal from the temperature sensor lead 20 connected to the couplant 9 and the power supply lead. An electric current is supplied to the container-side Peltier element 17 via 19, and for example, the couplant 8 is heated by the container-side Peltier element 17 and maintained at an appropriate temperature, that is, a relatively low viscosity.
Thereafter, the SH probe 1 is brought into contact with the peripheral surface of the stainless steel tube A as an object to be inspected by an artificial operation to open and close the opening / closing mechanism 13 of the couplant container 9. The couplant 8 is supplied to the storage space 6 of the SH wave ultrasonic probe 1 via the flexible tube 7 and applied to the surface of the stainless steel tube A.
[0023]
Also on the side of the SH wave ultrasonic probe 1, the temperature of the couplant 8 is measured based on the signal from the temperature sensor lead wire 12, and at the same time, the probe is connected via the power supply lead wire 11. A current is supplied to the side Peltier element 10, and the couplant 8 in the storage space 6 of the SH wave ultrasonic probe 1 is maintained at a relatively high temperature.
In a state where the temperature of the couplant 8 is relatively high, the SH wave ultrasonic probe 1 is artificially pressed against the surface of the stainless steel tube A, so that the probe surface of the probe main body 4 is made of the stainless steel tube A. In contact with the surface, a layer of the couplant 8 having a thickness t of about 10 μm is interposed between the surface of the acrylic resin layer 5 and the surface of the stainless steel tube A.
[0024]
Thereafter, the couplant 8 in the storage space 6 is cooled by the probe-side Peltier element 10, and has a relatively lower temperature than when the stainless steel tube A is applied and when the SH wave ultrasonic probe 1 is pressed. In other words, the vibrator 2 is vibrated and emits ultrasonic waves, and the vibrator 2 receives the reflected wave in a state where the viscosity is maintained at a high level and the couplant 8 in the storage space 6 is maintained at a high viscosity. Thus, the flaw detection of the stainless steel tube A is performed, and the flaw detection result is stored in the control device 21 and displayed on the display as needed.
Then, in a plurality of places of the stainless steel tube A, the necessary flaw detection is performed by repeating this operation several times, or, if possible, in a state where the temperature of the couplant 8 in the storage space 6 is relatively low, A necessary flaw detection is executed by artificially scanning the SH wave ultrasonic probe 1. If the amount of the couplant 8 in the storage space 6 becomes insufficient during the scanning, the probe is passed through the flexible tube 7. The couplant 8 is automatically replenished from the couplant container 9.
[0025]
[Another embodiment]
(1) In the above embodiment, the flaw detection method according to the present invention relates to a method for supplying the couplant 8 to the storage space 6 of the SH wave ultrasonic probe 1 and automatically applying the couplant 8 to the surface of the stainless steel tube A. As shown, the couplant 8 having a relatively high temperature is artificially applied to the surface of the stainless steel tube A, and the ultrasonic probe 1 for SH wave is pressed against the couplant 8 having the high temperature. The probe 8 can be cooled by the probe-side Peltier element 10 provided in the wave ultrasonic probe 1, or the flaw detection can be performed after natural cooling.
[0026]
(2) In the above embodiment, the flaw detector according to the present invention has been described as a probe having one vibrator 2 for transmitting and receiving, as the SH wave ultrasonic probe 1. The present invention can be applied to a probe having a transmitting transducer and a receiving transducer separately, and further comprising only an SH wave ultrasonic probe having only a transmitting transducer and only a receiving transducer. Also, the present invention can be applied to an ultrasonic probe for SH waves.
Further, the example in which the SH wave ultrasonic probe 1 and the couplant material container 9 are separately formed and connected by the flexible tube 7 is shown. 9, the Peltier elements 10 and 17 are shown as an example of the temperature adjusting means, but the temperature adjusting means may be replaced with another temperature adjusting device.
[0027]
(3) In the above embodiment, the stainless steel tube A is shown as an example of the inspected object. However, the inspected object targeted by the flaw detection method and the flaw detection apparatus according to the present invention is not limited to the stainless steel tube A. The present invention can be applied to various articles such as metal plates and rods as well as various metal tubes, and the transmitted and received ultrasonic waves are not limited to the “SH wave”. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing the entire ultrasonic flaw detector. FIG. 2 is a cross-sectional view of an SH wave ultrasonic probe. FIG. 3 is a cross-sectional view of a couplant container.
DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 7 Supply means 8 Coupling medium 9 Coupling medium storage part 10, 17 Peltier element A as temperature adjusting means

Claims (7)

An ultrasonic flaw detection method for applying a couplant to the surface of a test object, pressing an ultrasonic probe for transmitting and receiving ultrasonic waves against the couplant, and performing flaw detection of the test object,
In a state where the temperature of the couplant is higher than that at the time of the flaw detection, the couplant having the higher temperature is applied to the surface of the test object, and the ultrasonic probe is pressed against the couplant having the higher temperature. ,
An ultrasonic flaw detection method in which the ultrasonic probe performs flaw detection on the object under test when the temperature of the couplant is lower than when applied to the object to be tested and when the ultrasonic probe is pressed. In a state where the temperature of the couplant is lower than the time of application to the object to be inspected and the time of pressing of the ultrasonic probe, flaw detection of the object to be inspected is performed while scanning the ultrasonic probe. 2. The ultrasonic flaw detection method according to 1. An ultrasonic probe for transmitting and receiving ultrasonic waves, a couplant storage section for storing the couplant, and a supply unit for supplying the couplant in the couplant storage section between the ultrasonic probe and the test object An ultrasonic flaw detector having:
An ultrasonic flaw detector comprising a temperature adjusting means for adjusting the temperature of the couplant. The ultrasonic flaw detector according to claim 3, wherein the temperature adjusting means is provided on the ultrasonic probe. The ultrasonic flaw detector according to claim 3 or 4, wherein the temperature adjusting means is provided in the couplant storage portion. An ultrasonic flaw detector having an ultrasonic probe for transmitting and receiving ultrasonic waves,
An ultrasonic flaw detector wherein the ultrasonic probe includes a temperature adjusting means for adjusting a temperature of a couplant interposed between the ultrasonic probe and the test object. The ultrasonic flaw detector according to any one of claims 3 to 6, wherein the temperature adjusting unit is a Peltier element.

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