JP2013242202A - Ultrasonic inspection method and ultrasonic inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic inspection method and ultrasonic inspection apparatus capable of reducing a cost and shortening an inspection time.SOLUTION: An ultrasonic inspection method for inspecting the surface layer part and deep part of a subject 10 by using a double crystal angle probe 1 includes: propagating a longitudinal wave toward a longitudinal wave cross point Pin the surface layer part of the subject 10 by using the double crystal angle probe 1 and, at the same time, propagating a transverse wave toward a transverse wave cross point Pin the deep part of the subject 10; receiving a first reflection wave obtained by the reflection of the longitudinal wave against a defect when the defect exits in the longitudinal wave cross point P, receiving a second reflection wave obtained by the reflection of the transverse wave against a defect when the defect exists in the transverse wave cross point P, extracting a wave height peak value Hwithin the detection range of the first reflection wave and extracting a wave height peak value Hwithin the detection range of the second reflection wave with respect to acquired waveform data; and evaluating presence/absence of defects on the basis of the wave height peak values H, H.

Description

  The present invention relates to an ultrasonic inspection method and an ultrasonic inspection apparatus using a dual transducer oblique angle probe having a transmission transducer and a reception transducer.

  As one of the typical nondestructive inspection methods in the industrial field, an ultrasonic inspection method is known. In this ultrasonic inspection method, an ultrasonic wave (vibration) is transmitted (oscillated) by applying a voltage to a piezoelectric element (vibrator) having an electromechanical conversion function provided in an ultrasonic sensor (probe). This ultrasonic wave is propagated into the subject. Then, the ultrasonic wave is reflected by a defect or the like generated in the subject, the reflected wave is received by the piezoelectric element and converted into a voltage, and the acquired waveform data is recorded, graphed, or visualized to evaluate the defect or the like. .

  For example, when a structure such as a power plant is used as an inspection object (subject), an oblique angle probe method using an oblique angle probe is generally employed. In this oblique angle probe method, for example, a vibrator pedestal (in detail, for example, made of polystyrene or polyimide and called a wedge, wedge, shoe, or the like) is used to attach the vibrator to the subject. While being held so as to be inclined with respect to the surface, ultrasonic waves are refracted by utilizing the difference in acoustic impedance between the pedestal and the subject. Thereby, ultrasonic waves are propagated obliquely into the subject.

  Further, a method using a two-transducer oblique probe having a transmitting transducer and a receiving transducer is known in order to realize a high SN ratio inspection (see, for example, Non-Patent Document 1). As a comparative example, a case where a surface layer portion of a subject is inspected using a single transducer oblique angle probe having a transducer for transmission and reception will be described. In this case, detection of a reflected wave (defect signal) from a defect may be difficult due to the dead zone and multiple reflection noise. The dead zone is a time zone in which the transmission / reception transducer transmits ultrasonic waves (that is, a time zone in which vibration remains in the transmission / reception transducer itself), and is a time zone in which a defect signal cannot be received. The multiple reflection noise described here is noise generated by a reflected wave that is repeatedly reflected in the contact medium. Thus, if there are a transducer for transmission and a transducer for reception, such as a dual transducer oblique angle probe, it is possible to avoid the dead zone. In the dual transducer oblique angle probe, the detection range is a cross point between the propagation direction of the ultrasonic wave transmitted from the transmission transducer and the propagation direction of the reflected wave received by the reception transducer. By adjusting the distance of propagation through the contact medium, it is possible to make the multiple reflection noise out of the detection range and realize a high SN ratio inspection.

E.A.Ginzel, “Automated Ultrasonic Testing For Pipeline Girth Welds: A Handbook”, Olympus, January 2006, P.66

  In order to guarantee the soundness of the subject, an examination from the surface layer portion to the deep portion of the subject may be required. In such a case, for example, a method of preparing a probe for surface layer inspection and a probe for deep inspection is conceivable. Then, for example, the surface layer portion of the subject is inspected using the probe for surface layer inspection, and then the probe for surface layer inspection is replaced with a probe for deep portion inspection, and then the deep portion inspection is performed. Examine the depth of the subject using the probe for the test.

  However, in the above-described method, it is necessary to prepare a probe for surface layer inspection and a probe for deep inspection, which increases costs. In particular, if a two-element oblique angle probe is employed in order to realize a high SN ratio inspection, for example, a two-element oblique angle probe for surface layer inspection and a two-element oblique angle probe for deep inspection are used. Since it is necessary to prepare an angle probe, the cost increases. Further, in the above-described method, since the surface layer portion and the deep portion of the subject are not examined at the same time, the examination time becomes long.

  An object of the present invention is to provide an ultrasonic inspection method and an ultrasonic inspection apparatus capable of reducing cost and shortening inspection time.

  In order to achieve the above object, the present invention is an ultrasonic inspection method for inspecting a surface layer portion and a deep portion of a subject using a dual transducer oblique angle probe having a transmitting transducer and a receiving transducer. Then, using the two-element oblique angle probe, a longitudinal wave is propagated toward a longitudinal wave cross point set in the surface layer portion of the subject, and simultaneously, a transverse wave set in the deep portion of the subject When a transverse wave is propagated toward a cross point, when a defect exists at the longitudinal wave cross point, the first reflected wave reflected by the longitudinal wave at the defect is received, and a defect exists at the transverse wave cross point The second reflected wave reflected by the transverse wave due to the defect is received, and the first peak value in the first range preset based on the propagation path of the longitudinal wave is extracted from the acquired waveform data. And the propagation path of the transverse wave Based second crest peak value extracted in a preset second range was to evaluate the presence or absence of a defect based on the first and second crest peak.

  According to the present invention, it is possible to reduce costs and shorten inspection time.

It is the schematic showing the structure of the ultrasonic inspection apparatus in the 1st Embodiment of this invention. It is the top view and sectional drawing showing the principal part structure of the two vibrator oblique angle probe in the 1st Embodiment of this invention with a subject. It is a figure showing the waveform data screen in the 1st Embodiment of this invention. It is a flowchart showing the procedure of the ultrasonic inspection method in the 1st Embodiment of this invention. It is the top view and sectional drawing for demonstrating the specific example of the evaluation of the defect in the 1st Embodiment of this invention. It is a figure showing the waveform data screen in the 1st modification of this invention. It is sectional drawing showing a calibration test body. It is the schematic showing the structure of the ultrasonic inspection apparatus in the 2nd Embodiment of this invention. It is a top view showing as an example the scanning orbit of the two vibrator oblique angle probe in the 2nd embodiment of the present invention. It is a figure showing the reflected wave detection distribution screen in the 2nd Embodiment of this invention. It is a flowchart showing the procedure of the ultrasonic inspection method in the 2nd Embodiment of this invention. It is the top view and sectional drawing showing the principal part structure of the two vibrator oblique angle probe in the 2nd modification of this invention with a test object. It is sectional drawing showing the principal part structure of the dual vibrator oblique angle probe in the 3rd modification of this invention with a subject.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram illustrating a configuration of an ultrasonic inspection apparatus according to the present embodiment. FIG. 2A is a plan view illustrating the main structure of the dual transducer oblique angle probe according to this embodiment together with the subject, and FIG. 2B is a cross-sectional view.

  The ultrasonic inspection apparatus of the present embodiment includes a dual transducer oblique angle probe 1, a flaw detector 2, a waveform data processing unit 3, an input unit 4, and a display unit 5.

  The dual transducer oblique angle probe 1 includes a transmitting transducer 6, a receiving transducer 7, shoes 8A and 8B, and a sound insulating plate 9. The sound insulating plate 9 is provided between the transmitting vibrator 6 and the shoe 8A and the receiving vibrator 7 and the shoe 8B. As shown in FIG. 2B, the shoe 8A holds the transmitting vibrator 6 so as to be inclined with respect to the surface 10a of the subject 10 (a flat plate in the drawing). Similarly to the shoe 8A, the shoe 8B holds the receiving vibrator 7 so as to be inclined with respect to the surface 10a of the subject 10.

As shown in FIG. 2A, the transmitting transducer 6 and the receiving transducer 7 are connected in the direction connecting the probe 1 and cross points P _L and P _S described later (the horizontal direction in FIG. 2A). ) In parallel with each other, and in a substantially V shape. In other words, the transmitting vibrator 6 and the receiving vibrator 7 are arranged in a direction parallel to the predicted defect propagation direction (vertical direction in FIG. 2A).

Then, longitudinal waves transmitted from the transmitting transducer 6, and propagated through the shoe 8A, are incident at an incident angle theta ₁ to the surface 10a of the object 10. The incident angle theta ₁ is attitude angle of the transmitting transducer 6, i.e., is set by the inclination of the upper surface of the shoe 8A. Some of the longitudinal wave incident on the object 10 is refracted at the surface 10a of the object 10 and propagates a longitudinal wave refraction angle theta _L in a test sample 10. A part of the longitudinal wave incident on the subject 10 is mode-converted on the surface 10 a of the subject 10 and propagates into the subject 10 as a transverse wave having a refraction angle θ _S (where θ _S <θ _L ). To do. Therefore, the longitudinal wave is propagated toward the longitudinal wave cross point P _L set in the surface layer portion of the subject 10, and at the same time, the transverse wave is propagated toward the transverse wave cross point P _S set in the deep portion of the subject 10. It is supposed to let you. The “surface layer portion” is a portion located on the surface 10a side (upper side in FIG. 2B) from the middle of the thickness of the subject 10, and preferably, for example, when the thickness of the subject 10 is 20 mm. A portion up to a depth of 5 mm corresponding to 25% of the thickness is assumed. Further, the “deep part” is a part located on the opposite side (lower side in FIG. 2B) from the middle of the thickness of the subject 10, and preferably a part near the back surface 10 b.

Receiving transducer 7, for example, when the defect in the longitudinal wave cross point P _L is present, receiving a first reflected wave longitudinal wave reflected by the defect. That is, the longitudinal wave follows the propagation path R _L (specifically, the incident point P _I → the longitudinal wave cross point P _L → the emission point P _O ) in the subject 10, and then the emission angle θ ₂ (this embodiment). Then, the longitudinal wave of θ ₂ = θ ₁ ) propagates through the shoe 8B and is received by the receiving vibrator 7. Further, receiving transducer 7, for example, if a defect is present in the transverse cross point P _S, transverse at the defect receives the second reflected wave reflected. That is, the transverse wave follows the propagation path R _S (specifically, the incident point P _I → the transverse wave cross point P _S → the emission point P _O ) in the subject 10, and then undergoes mode conversion on the surface 10 a of the subject 10. Then, it propagates through the shoe 8B as a longitudinal wave having an emission angle θ ₂ and is received by the receiving vibrator 7.

For example, when the subject 10 is a flat plate, the longitudinal wave cross point P _L and the transverse wave cross point P _S coincide with each other when projected onto the surface 10 a of the subject 10. That is, longitudinal cross point _{P L} and transverse cross point _{P S,} although the Z coordinate is different _{(Z L} ≠ _Z S), X-coordinate (specifically, in FIGS. 2 (a) and the incident point _{P I} in the vertical direction exit point P _O intermediate corresponding to the position of) and Y coordinate (specifically, from the incident point P _I and the exit point P _O FIGS. 2 (a) has moved to and 2 (b) medium rightward by a distance L position ) Matches.

Furthermore, longitudinal cross point P _L is a point where the propagation direction of the first reflected wave received by the receiving transducer 7 and the propagation direction of the longitudinal waves transmitted from the transmitting transducer 6 intersect, actual Has an area (region) considering the spread of the longitudinal wave beam. Similarly, transverse cross point P _S is a at the point where the propagation direction of the second reflected wave received by the receiving transducer 7 and the propagation direction of the transverse waves and to mode conversion transmitted from the transmitting transducer 6 intersect In fact, it has an area (region) in consideration of the spread of the transverse wave beam.

The incident angle θ ₁ (and the emission angle θ ₂ ) will be described. The longitudinal cross point P _L and sets the surface of the subject 10, for setting a transverse cross point P _S deep into the subject 10, the longitudinal wave refraction angle theta _L is from 90 ° (longitudinal wave critical angle) The incident angle θ ₁ (and the outgoing angle θ ₂ ) is set so as to be smaller, preferably 70 ° or more. Specifically, for example, when the shoes 8A and 8B are made of polystyrene and the subject 10 is made of SUS, that is, the longitudinal wave sound speed V of the shoes 8A and 8B is about 2330 m / s, and the longitudinal wave sound speed V _L of the subject 10 is equal to A case where the velocity is about 5780 m / s and the sound velocity V _S of the subject 10 is about 3230 m / s will be described as an example. In this case, if the incident angle θ ₁ is set to 23.7 °, the longitudinal wave refraction angle θ _L = 85.6 ° and the transverse wave refraction are obtained from Snell's law (see the following equations (1) and (2)). The angle θ _S = 33.9 °. For example, if the incident angle θ ₁ is set to 22.3 °, the longitudinal wave refraction angle θ _L = 70.3 ° and the transverse wave refraction angle θ _S = 31.7 ° are obtained from Snell's law. Therefore, for example, if the incident angle θ ₁ is set within the range of 22.3 ° ≦ θ ₁ ≦ 23.7 °, the longitudinal wave refraction angle θ _L is within the range of 85.6 ° ≦ θ _L ≦ 70.3 °. The transverse wave refraction angle θ _S falls within the range of 33.9 ° ≦ θ _S ≦ 31.7 °.

θ _L = sin ⁻¹ (sin θ ₁ × V _L / V) (1)
θ _S = sin ⁻¹ (sin θ ₁ × V _S / V) (2)
The flaw detector 2 controls the transmission of ultrasonic waves in the two-transmission angle probe 1 and digitally converts the signal received by the receiving vibrator 7 to acquire waveform data. This waveform data (primary data) is expressed with time on the horizontal axis and peak value (amplitude) on the vertical axis.

Here, the length of the propagation path _{R L} of the longitudinal wave (path length) _{D L} is the length of the propagation path _{R S} of the transverse wave (path length) _{D S} less. In addition, since the longitudinal wave sound velocity V _L of the subject 10 is larger than the transverse wave sound velocity V _S of the subject 10, the detection time T _L (= D _L / V) of the first reflected wave reflected by the longitudinal wave cross point P _{L. L} ) is earlier than the detection time T _S (= D _S / V _S ) of the second reflected wave reflected at the transverse wave cross point P _S. Therefore, the first reflected wave and the second reflected wave are temporally separated. Therefore, data relating to the first reflected wave and data relating to the second reflected wave can be extracted from the waveform data based on the corresponding path length or detection time.

In the present embodiment, the waveform data processing unit 3 performs processing for extracting data relating to the first reflected wave and data relating to the second reflected wave from the waveform data based on the corresponding path. More specifically, first, waveform data (secondary data) is created by deleting initial data corresponding to the propagation time of longitudinal waves in the shoes 8A and 8B from the waveform data (primary data). The time on the horizontal axis of the waveform data (secondary data) is multiplied by the longitudinal wave sound velocity _VL of the subject 10 to convert it into a longitudinal wave path. A longitudinal waveguide range W _L (in other words, the first reflected wave) that is set in advance corresponding to the propagation path _RL of the longitudinal wave (specifically, in consideration of the area of the longitudinal wave cross point P _L ). The peak height value (maximum amplitude value) _HL in the detection range) is extracted. Further, the time on the horizontal axis of the waveform data (secondary data) is multiplied by the transverse wave speed of sound V _S of the subject 10 to be converted into a transverse wave path. Then, a predetermined range W _S (in other words, detection of the second reflected wave) corresponding to the propagation path R _S of the transverse wave (specifically, considering the area of the longitudinal wave cross point P _L ). crest peak value in the range) (amplitude maximum) H _S extracted.

As shown in FIG. 3, the display unit 5 displays a waveform data screen 11 that displays the above-described waveform data (secondary data) by taking a longitudinal wave path and a transverse wave path on the horizontal axis. Yes. The waveform data screen 11 displays the vertical waveguide range W _L and the horizontal waveguide range W _S described above, and also displays the peak height values H _L and H _S. The waveform data screen 11 displays threshold values T _L and T _S (not shown) set in advance for the peak height values H _L and H _S. In the present embodiment, the difference of the transverse wave (specifically, differences in reflection intensity) by, first at the first sensitivity and a transverse wave path length range W _S of the reflected wave in the range W _L as vertical waveguide 2 Since the detection sensitivities of the reflected waves are different, the thresholds T _L and T _S are set corresponding to the detection sensitivities. The waveform data screen 11 is a cross-point calculated by the waveform data processing section 3 P _L, the position of P _S (not shown) is also displayed.

  Next, the ultrasonic inspection method of this embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the procedure of the ultrasonic inspection method according to this embodiment.

First, in step 100, the flaw preparation stage, the operator, the reference point of the probe 1 (more specifically, for example, the incident point _{P I} and the exit point _{P O} and the middle) and cross point _P L, and _{P S} Are input by the input unit 4 and stored in the waveform data processing unit 3. Also, type propagation path of the longitudinal wave R _L as vertical waveguide corresponding to the range W _L and the threshold value T _L, the range W _S and threshold T _{S in} more vertical waveguide corresponding to the propagation path R _S of the transverse wave at the input unit 4, It is stored in the waveform data processing unit 3. These input values are obtained from the design values of the probe 1 or, for example, side drill holes 12A and 12B (artificial defects) are given to the depths (Z _L , Z _S ) of the longitudinal wave cross point and the transverse wave cross point. What is necessary is just to obtain | require experimentally using the made calibration test body 13 (refer FIG. 7 mentioned later). Thereafter, the operator places the probe 1 on the surface 10 a of the subject 10 and inputs the position of the probe 1 with the input unit 4. The waveform data processing unit 3 calculates the positions of the cross points P _L and P _S according to the position of the probe 1 input by the input unit 4.

In step 110, the operator inputs an instruction to start flaw detection using the input unit 4. The flaw detector 2 controls the two-element firing angle probe 1 in response to a flaw detection start instruction, and starts transmission of ultrasonic waves from the transmission vibrator 6. That is, the longitudinal wave is propagated toward the longitudinal wave cross point P _L set in the surface layer portion of the subject 10, and simultaneously, the transverse wave is propagated toward the transverse wave cross point P _S set in the deep portion of the subject 10. Let When there is a defect at the longitudinal wave cross point P _L , the first reflected wave reflected by the defect with the defect is received by the receiving vibrator 7, and when there is a defect at the transverse wave cross point P _S. The second reflected wave in which the transverse wave is reflected by the defect is received by the receiving vibrator 7. Then, the flaw detector 2 digitally converts the signal received by the receiving vibrator 7 to obtain waveform data.

Thereafter, the process proceeds to step 120, where the waveform data processing unit 3 performs predetermined processing on the waveform data (primary data) acquired by the flaw detector 2. Specifically, initial data corresponding to the propagation time of the longitudinal wave in the shoes 8A and 8B is deleted from the waveform data (primary data) to create waveform data (secondary data). The time that is the horizontal axis of the waveform data (secondary data) is converted into a vertical waveguide and a horizontal waveguide. Then, as the vertical waveguide in the range W _L to extract the crest peak value H _S in crest peak value H _L and transverse path length range W _S.

Thereafter, the process proceeds to step 130, where the display unit 5 displays the waveform data screen 11. This waveform data screen 11 displays waveform data (secondary data) together with the longitudinal waveguide range W _L , the lateral waveguide range W _S , and the peak height values H _L and H _S. The waveform data screen 11 displays the threshold _{T S} in respect thresholds _{T L} and crest peak value _{H S} for the crest peak value _{H L.} In addition, the waveform data screen 11 displays the positions of the cross points P _L and P _S calculated in step 100 described above.

Then, the process proceeds to step 140, and the operator evaluates the presence or absence of a defect based on the peak height values H _L and H _S displayed on the waveform data screen 11. Specifically, it is determined whether or not the peak height H _L is equal to or greater than the threshold value T _L to determine the presence or absence of the first reflected wave, and whether or not the peak height peak value H _S is equal to or greater than the threshold value T _S. And the presence or absence of the second reflected wave is determined. For example, when it is determined that there is a first reflected wave and no second reflected wave, a defect 14A (see FIGS. 5A and 5B) has occurred in the surface layer portion of the subject 10. evaluate. For example, when it is determined that there is no first reflected wave and there is a second reflected wave, it is evaluated that a defect 14B (see FIGS. 5A and 5B) has occurred in the deep portion of the subject 10. To do. Further, for example, when it is determined that the first reflected wave and the second reflected wave are present, a long defect 14C extending from the surface layer portion to the deep portion of the subject 10 (see FIGS. 5A and 5B). Evaluate that occurred. For example, when it is determined that the first reflected wave and the second wave wave are not present, it is evaluated that the surface layer portion and the deep portion of the subject 10 are not defective.

  In the present embodiment as described above, the dual transducer oblique angle probe 1 is used for both the surface layer inspection and the deep portion inspection. For example, the dual transducer oblique angle probe and the deep portion for surface layer inspection are used. The cost can be reduced as compared with the case of preparing a two-element oblique angle probe for inspection. Further, the ultrasonic inspection apparatus can be reduced in size. Further, since the surface layer portion and the deep portion of the subject 10 are inspected at the same time, the inspection time can be shortened.

In the above first embodiment, as shown in Figure 3 above, the first second detection sensitivity of the reflected wave in the detection sensitivity and transverse path length range W _S of the reflection wave in the range W _L as vertical waveguide In the above description, the waveform data is displayed while being different from each other. However, the present invention is not limited to this. That is, for example, as a second detection sensitivity of the reflected wave at the first sensitivity and a transverse wave path length range W _S of the reflected wave in the range W _L as vertical waveguide are the same, as the vertical waveguide range W _L or transverse path length the data in the range W _S after correction may be displayed waveform data. Such a modification will be described below.

In this modified example, the waveform data processing section 3, as in the second detection sensitivity of the reflected wave at the first sensitivity and a transverse wave path length range W _S of the reflected wave in the range W _L as vertical waveguide are the same, previously The set correction function (proportional coefficient) is multiplied by the data (crest value) in the range of the transverse waveguide _WS and corrected. Also, to extract a crest peak value H _S in the data shear path length range W _S corrected. Then, the display unit 5, as shown in Figure 6, displays the waveform data screen 11A for displaying waveform data and crest peak value H _S corrected by the waveform data processing section 3.

The correction function described above is, for example, a calibration specimen 13 in which the same side drill holes 12A and 12B (artificial defects) are given to the depths (Z _L , Z _S ) of the longitudinal wave cross point and the transverse wave cross point (see FIG. 7). ) To obtain in advance. In detail, the waveform data processing section 3 performs predetermined processing on the waveform data acquired side drilled holes 12A upon testing, as vertical waveguide extracts a crest peak value H _L in a range W _L. Further, it performs predetermined processing on the waveform data acquired side drilled hole 12B upon inspection, to extract the crest peak value H _S in transverse path length range W _S. Then, a ratio H _L / H _S between the peak height value H _L and the peak height value H _S is calculated and stored as a correction function (proportional coefficient).

In this modification, the detection sensitivity of the first reflected wave in the longitudinal waveguide range W _L is the same as the detection sensitivity of the second reflected wave in the horizontal waveguide range W _S , so that the thresholds T _L and T _S are Set to be the same.

  Also in the above modification, the same effect as the first embodiment can be obtained.

In the first embodiment and the modified example, the waveform data screens 11 and 11A display the waveform data (secondary data) as the vertical waveguide range W _L , the horizontal waveguide range W _S , and the peak height H _L , Although the case of displaying with H _S has been described as an example, instead of this, waveform data (primary data) is displayed together with the longitudinal waveguide range W _L and the horizontal waveguide range W _S and the peak height values H _L and H _S. May be. In such a case, the same effect as described above can be obtained.

In the first embodiment and the modification, the waveform data screens 11 and 11A have been described by way of example in which waveform data is displayed by taking the longitudinal wave path and the transverse wave path on the horizontal axis. Instead of this, waveform data may be displayed with time on the horizontal axis. Further, in the first embodiment and the modification, as the vertical waveguide range W _L is set in advance, the second reflected wave corresponding to the propagation path R _L of the longitudinal wave as the detection range of the first reflected wave Although the case where the shear wave path length range W _S corresponding to the propagation path R _S of the transverse wave as the detection range is set in advance has been described as an example, instead of those, the longitudinal wave propagation path R _L on basis of the first reflected wave The detection time zone may be set in advance, and the detection time zone of the second reflected wave may be set in advance based on the propagation path _{RS of the} transverse wave. Then, the waveform data processing section 3, to the waveform data, extracts the wave height peak value H _S in crest peak value H _L and the detection time period of the second reflected wave in the detection times of the first reflected wave. In such a case, the same effect as described above can be obtained.

  A second embodiment of the present invention will be described with reference to FIGS. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 8 is a schematic diagram showing the configuration of the ultrasonic inspection apparatus according to this embodiment. FIG. 9 is a plan view illustrating, as an example, the scanning trajectory of the dual transducer oblique angle probe in the present embodiment.

  The ultrasonic inspection apparatus of the present embodiment includes a dual transducer oblique probe 1, a scanner (scanning mechanism) 15, a flaw detector 2, a waveform data processing unit 3A, a reflected wave detection unit 16, an input unit 4, and a display unit. 5A. For example, as shown in FIG. 9, the scanner 15 scans the double vibration oblique probe 1 on the surface 10 a of the subject 10.

The waveform data processing unit 3A acquires the scanning position of the probe 1 from the scanner 15 and associates it with the waveform data acquired from the flaw detector 2. Then, the waveform data processing unit 3A calculates the positions of the cross points P _L and P _S for each scanning position of the probe 1. In addition, for each scanning position of the probe 1, a process for extracting data relating to the first reflected wave and data relating to the second reflected wave from the waveform data is performed. That is, for each scanning position of the probe 1, the peak height H _L in the longitudinal waveguide range W _L (or the detection time zone of the first reflected wave) and the horizontal waveguide range W _S (or the second reflected wave) extracting the crest peak value H _S in the detection time period). Then, the positions of the cross points P _L and P _S and the peak heights H _L and H _S acquired in this way are output to the reflected wave detection unit 16 in association with each scanning position of the probe 1.

The reflected wave detection unit 16 determines whether or not the peak height H _L is equal to or greater than the threshold value T _{L for} each scanning position of the probe 1 to determine the presence or absence of the first reflected wave and the peak height. It is determined whether or not the second reflected wave is present by determining whether or not the value H _S is equal to or greater than the threshold value T _S. Then, for example, when the wave height peak value H _L is the threshold value T _L or more, it is determined that there is first reflected wave, and stores in association with the position of the longitudinal cross point P _L corresponding to the detection information. For example, when the peak height H _S is equal to or greater than the threshold value T _S , it is determined that there is a second reflected wave, and the detected information and the position of the corresponding transverse wave cross point P _L are stored in association with each other.

As shown in FIG. 10, the display unit 5 </ b> A displays the reflected wave detection distribution screen 17 that displays the detection information of the first and second reflected waves described above. The reflected wave detection distribution screen 17 displays the first reflected wave detection information in a corresponding vertical direction in a two-dimensional coordinate system corresponding to the scanning region of the probe 1 (in other words, the surface 10a of the subject 10). by plotting at the position of the wave cross point P _L, and displays the detected distribution of the first reflected wave. Further, in the same two-dimensional coordinate system, the detection information of the second reflected wave, by plotting in a position corresponding transverse cross point P _S, which displays the detected distribution of the second reflected wave. The first reflected wave detection distribution and the second reflected wave detection distribution are displayed in different colors, for example, so that they can be distinguished from each other. Specifically, for example, the detection distribution of the first reflected wave is shown in red, the detection distribution of the second reflected wave is shown in blue, the detection distribution of the first reflected wave and the detection distribution of the second reflected wave. The overlapping part is shown in purple.

  Next, the ultrasonic inspection method of this embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing the procedure of the ultrasonic inspection method according to this embodiment.

First, in step 200, as a flaw detection preparation stage, the operator inputs the relative positional relationship between the reference point of the probe 1 and the cross points P _L and P _S with the input unit 4, and the waveform data processing unit 3A. Remember me. Also, as the vertical waveguide corresponding to the propagation path R _L of the longitudinal wave range W _{L (or} detection time period of the first reflected wave) or the threshold T _L, the propagation path R _S as vertical waveguide corresponding to the range W _S of transverse waves (or the first detection time period of the reflected wave) with or threshold T _S in input by the input unit 4, and stores the waveform data processing unit 3A. Thereafter, the operator places the probe 1 on the surface 10 a of the subject 10 and inputs scanning conditions such as an initial position, a movement amount, and a scanning region of the probe 1 through the input unit 4.

In step 210, the operator inputs an instruction to start flaw detection using the input unit 4. The scanner 15 scans the probe 1 under the scanning condition input by the input unit 4 in response to an instruction to start flaw detection. The flaw detector 2 controls the two-element firing angle probe 1 in response to a flaw detection start instruction, and starts transmission of ultrasonic waves from the transmission vibrator 6. That is, for each scan position of the probe 1, by propagating longitudinal waves toward the longitudinal wave crosspoint P _L which is set in the surface portion of the subject 10, which the set in a deep portion of the object 10 at the same time transverse waves toward the cross point P _S propagating a shear wave. When there is a defect at the longitudinal wave cross point P _L , the first reflected wave reflected by the defect with the defect is received by the receiving vibrator 7, and when there is a defect at the transverse wave cross point P _S. The second reflected wave in which the transverse wave is reflected by the defect is received by the receiving vibrator 7. Then, the flaw detector 2 digitally converts the signal received by the receiving vibrator 7 to obtain waveform data.

Thereafter, the process proceeds to step 220, where the waveform data processing unit 3A performs predetermined processing on the waveform data acquired by the flaw detector 2 for each scanning position of the probe 1 acquired from the scanner 15. That is, from the waveform data, the peak height H _L in the longitudinal waveguide range W _L (or the first reflected wave detection time zone) and the wave height in the horizontal waveguide range W _S (or the second reflected wave detection time zone). extracting the peak value _{H S.}

Thereafter, the process proceeds to step 230, and the reflected wave detection unit 16 determines whether or not the peak height value H _L is equal to or greater than the threshold value T _{L for} each scanning position of the probe 1 to determine whether there is a first reflected wave. And whether or not the peak height value H _S is equal to or greater than the threshold value T _S to determine the presence or absence of the second reflected wave. For example, when the wave height peak value H _L is the threshold value T _L or more, it is determined that there is first reflected wave, and stores in association with the position of the longitudinal cross point P _L corresponding to the detection information. For example, when the peak height H _S is equal to or greater than the threshold value T _S , it is determined that there is a second reflected wave, and the detected information and the position of the corresponding transverse wave cross point P _L are stored in association with each other.

  Thereafter, the process proceeds to step 240, and the display unit 5A displays the reflected wave detection distribution screen 17. The reflected wave detection distribution screen 17 is configured so that the first reflected wave detection distribution and the second reflected wave detection distribution can be distinguished from each other in a two-dimensional coordinate system corresponding to the scanning region of the probe 1. indicate.

  In step 250, the operator evaluates the presence or absence of a defect based on the first reflected wave detection distribution and the second reflected wave detection distribution displayed on the reflected wave detection distribution screen 17. Specifically, for example, in a region where there is a first reflected wave and no second reflected wave (in other words, a region where the detection distribution of the first reflected wave exists independently), the surface layer portion of the subject 10 It is evaluated that the defect 14A (see FIGS. 5A and 5B described above) has occurred. Further, for example, in a region where there is no first reflected wave and there is a second reflected wave (in other words, a region where the detection distribution of the second reflected wave exists independently), the defect 14B ( It is evaluated that the above-described FIG. 5A and FIG. 5B have occurred. Further, for example, a region where the first reflected wave and the second reflected wave are present (in other words, as shown by region A in FIG. 10, the detection distribution of the first reflected wave and the detection distribution of the second reflected wave are mutually It is evaluated that a long defect 14 </ b> C (see FIGS. 5A and 5B described above) that extends from the surface layer portion to the deep portion of the subject 10 occurs in a region that overlaps and partially overlaps. Further, for example, in a region where there is no first reflected wave and second wave wave, it is evaluated that no defect has occurred in the surface layer portion and the deep portion of the subject 10.

  In the present embodiment as described above, as in the first embodiment, the cost can be reduced and the inspection time can be shortened. In the present embodiment, the progress of a three-dimensional defect can be easily grasped.

In the second embodiment, the reflected wave detection distribution screen 17 has been described by taking an example in which the detection distribution of the first reflected wave and the detection distribution of the second reflected wave are each shown in a single color. Not limited to. That is, the color tone may be changed according to the magnitudes of the peak height values H _L and H _S. In such a case, the same effect as described above can be obtained.

Although not particularly described in the second embodiment, the display unit 5A may display the waveform data screen 11 linked to the reflected wave detection distribution screen 17. That is, for example, when arbitrary coordinates on the reflected wave detection distribution screen 17 (that is, the positions of arbitrary cross points P _L and P _S ) are selected, the waveform data screen 11 or 11A that displays the corresponding waveform data (the above-described figure). 3 or FIG. 6) may be displayed. In such a case, the same effect as described above can be obtained.

In the above description, the dual transducer oblique angle probe 1 has been described by taking an example in which the transmitting transducer 6 and the receiving transducer 7 are arranged in parallel. However, the present invention is not limited to this. As shown in FIG. 12A and FIG. 12B, the transmitting vibrator 6 and the receiving vibrator 7 may be arranged in series. At this time, although the incident angle θ ₁ and the outgoing angle θ ₂ are different from each other, they are set by the same method as described above. Further, the refraction angle theta _L2 of return propagation and refraction angle theta _L1 of the propagation forward of the longitudinal waves are different from each other, the refraction angle theta _S2 of backward propagation and refraction angle theta _S1 propagation forward of a transverse wave are different from each other, longitudinal cross point P _L and transverse cross point _{P S} is (in particular, FIG. 2 (a) and the distance _L 1, _{L 2} to FIG. 2 (b) medium rightward from the incident point _{P I)} Y coordinate well Z-coordinate are different . However, even in such a modification, the same effect as described above can be obtained.

Further, as shown in FIG. 13, the transmission vibrator 6 and the reception vibrator 7 may each employ an array type vibrator in which a plurality of vibration elements are arranged. The flaw detector 2, and a delay control ultrasound transmission timing of each transducer element, by shifting the respective timings, the incident angle theta ₁ may be variably controlled (sector scan). Specifically, for example, when the shoes 8A and 8B are made of polystyrene and the subject 10 is made of SUS, if the incident angle θ ₁ is variably controlled within a range of 22.3 ° ≦ θ ₁ ≦ 23.7 °, The longitudinal wave refraction angle θ _L varies within the range of 85.6 ° ≦ θ _L ≦ 70.3 °, and the transverse wave refraction angle θ _S varies within the range of 33.9 ° ≦ θ _S ≦ 31.7 °. . As a result, the longitudinal wave cross point P _L and the transverse wave cross point P _S can be changed in the depth direction (Z direction) to perform a more three-dimensional inspection. The waveguide range W _L (or the first reflected wave detection time zone), the horizontal waveguide range W _S (or the second reflected wave detection time zone), and the threshold values T _L and T _S are longitudinal wave cross points. it may be automatically set and changed in accordance with the change of the P _L and transverse cross point P _S. The correction function for correcting the waveform data may be automatically changed according to changes in the longitudinal wave cross point P _L and the transverse wave cross point P _S. Even in such a modification, the same effect as described above can be obtained.

DESCRIPTION OF SYMBOLS 1 2 transducer oblique angle probe 2 Flaw detector 3, 3A Waveform data processing part 5, 5A Display part 6 Transmitting vibrator 7 Receiving vibrator 10 Subject 16 Reflected wave detection part

Claims (10)

An ultrasonic inspection method for inspecting a surface layer portion and a deep portion of a subject using a dual transducer oblique angle probe having a transmission transducer and a reception transducer,
Using the dual transducer oblique angle probe, a longitudinal wave is propagated toward a longitudinal wave cross point set in the surface layer portion of the subject, and simultaneously, a transverse wave cross point set in the deep portion of the subject When a defect is present at the longitudinal wave cross point, a first reflected wave reflected by the defect is received at the longitudinal wave cross point, and when a defect is present at the transverse wave cross point, Receiving a second reflected wave reflected from the transverse wave by a defect;
For the acquired waveform data, the first peak value in the detection range of the first reflected wave set in advance based on the propagation path of the longitudinal wave is extracted, and set in advance based on the propagation path of the transverse wave Extracting the second peak height value in the detection range of the second reflected wave;
An ultrasonic inspection method, wherein the presence or absence of a defect is evaluated based on the first and second peak height values. The ultrasonic inspection method according to claim 1,
It is determined whether or not the first peak height value is greater than or equal to a first threshold value set in advance to determine the presence or absence of the first reflected wave, and the second peak height value is set in advance. Determining whether or not the second reflected wave is present by determining whether or not the second threshold value or more,
When it is determined that the first reflected wave is present and the second reflected wave is absent, it is evaluated that a defect has occurred in the surface layer portion of the subject, the first reflected wave is absent, and the second reflected wave is present. When it is determined that there is a wave, it is evaluated that a defect has occurred in the deep portion of the subject, and when it is determined that there is the first reflected wave and the second reflected wave, from the surface layer portion to the deep portion of the subject. Evaluating that the extended long defect has occurred, and evaluating that there is no defect in the surface layer portion and the deep portion of the subject when it is determined that the first reflected wave and the second wave are not present Ultrasonic inspection method characterized by. The ultrasonic inspection method according to claim 2,
The detection distribution of the first reflected wave and the detection distribution of the second reflected wave are displayed so as to be distinguishable from each other in a two-dimensional coordinate system corresponding to the scanning region of the two-transducer oblique angle probe. An ultrasonic inspection method characterized by the above. The ultrasonic inspection method according to claim 2,
An ultrasonic inspection method characterized by displaying the waveform data from which the waveform data or a part thereof has been deleted together with the first and second reflected wave detection ranges and the first and second peak height values. The ultrasonic inspection method according to claim 4,
Using a correction function for making the detection sensitivity of the first reflected wave in the detection range of the first reflected wave the same as the detection sensitivity of the second reflected wave in the detection range of the second reflected wave An ultrasonic inspection method comprising displaying the waveform data after correcting the data of the detection range of the first or second reflected wave in the waveform data. In the ultrasonic inspection method according to any one of claims 1 to 5,
The ultrasonic inspection method, wherein the dual transducer oblique angle probe includes the transmitting transducer and the receiving transducer arranged in parallel in a direction connecting the probe and the cross point. . An ultrasonic inspection apparatus for inspecting a surface layer portion and a deep portion of a subject using a dual transducer oblique angle probe having a transmission transducer and a reception transducer,
Using the dual transducer oblique angle probe, a longitudinal wave is propagated toward a longitudinal wave cross point set in the surface layer portion of the subject, and simultaneously, a transverse wave cross point set in the deep portion of the subject When a defect is present at the longitudinal wave cross point, the first reflected wave reflected by the defect is received when the defect is present at the longitudinal wave cross point, and the defect is present when the defect is present at the transverse wave cross point. A flaw detector that receives the second reflected wave reflected by the transverse wave at
For the waveform data acquired by the flaw detector, a first peak value in the detection range of the first reflected wave set in advance based on the propagation path of the longitudinal wave is extracted, and based on the propagation path of the transverse wave A waveform data processing unit for extracting a second peak height value in a detection range of a second reflected wave set in advance;
It is determined whether or not the first peak height value is equal to or greater than a first threshold value set in advance to determine the presence or absence of the first reflected wave, and the second peak height value is set in advance. A reflected wave detector that determines whether or not there is a second reflected wave by determining whether or not the second threshold value or more;
The detection distribution of the first reflected wave and the detection distribution of the second reflected wave are displayed so as to be distinguishable from each other in a two-dimensional coordinate system corresponding to the scanning region of the two-transducer oblique angle probe. An ultrasonic inspection apparatus comprising a display unit. An ultrasonic inspection apparatus for inspecting a surface layer portion and a deep portion of a subject using a dual transducer oblique angle probe having a transmission transducer and a reception transducer,
Using the dual transducer oblique angle probe, a longitudinal wave is propagated toward a longitudinal wave cross point set in the surface layer portion of the subject, and simultaneously, a transverse wave cross point set in the deep portion of the subject When a defect is present at the longitudinal wave cross point, the first reflected wave reflected by the defect is received when the defect is present at the longitudinal wave cross point, and the defect is present when the defect is present at the transverse wave cross point. A flaw detector that receives the second reflected wave reflected by the transverse wave at
For the waveform data acquired by the flaw detector, a first peak value in the detection range of the first reflected wave set in advance based on the propagation path of the longitudinal wave is extracted, and based on the propagation path of the transverse wave A waveform data processing unit for extracting a second peak height value in a detection range of a second reflected wave set in advance;
And a display unit for displaying the waveform data from which the waveform data or a part thereof has been deleted together with the first and second reflected wave detection ranges and the first and second peak height values. Ultrasonic inspection device. The ultrasonic inspection apparatus according to claim 8,
The waveform data processing unit makes the detection sensitivity of the first reflected wave in the detection range of the first reflected wave the same as the detection sensitivity of the second reflected wave in the detection range of the second reflected wave. Using the correction function for correcting the detection range data of the first or second reflected wave in the waveform data,
The ultrasonic inspection apparatus, wherein the display unit displays the waveform data corrected by the waveform data processing unit. The ultrasonic inspection apparatus according to any one of claims 7 to 9,
2. The ultrasonic inspection apparatus according to claim 2, wherein the dual transducer oblique angle probe includes the transmitting transducer and the receiving transducer arranged in parallel in a direction connecting the probe and the cross point. .

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