JP7629334B2 - Ultrasonic inspection method for welds - Google Patents

Description

The present invention relates to an ultrasonic inspection method for inspecting welds using ultrasonic waves, and in particular to an ultrasonic inspection method capable of measuring the length of unwelded areas.

Generally, ultrasonic testing is widely used in various industrial fields as a non-destructive testing method for detecting internal defects in objects under test. Defect detection using ultrasonic testing is carried out by utilizing the phenomenon in which ultrasonic waves are reflected by defects.

In defect detection using ultrasonic testing, an ultrasonic probe that transmits and receives ultrasonic waves is placed on the surface of the object being inspected, ultrasonic pulses are transmitted from the ultrasonic probe, and the reflected waves (also called reflected echoes) are received by the ultrasonic probe. The received reflected waves are then subjected to signal processing to determine whether or not there are any internal defects in the object being inspected.

There are two types of welding for welded structures: "full penetration welding," in which the metal completely penetrates the base material in the thickness direction, and "partial penetration welding," in which the metal penetrates only partway through. With "partial penetration welding," however, unwelded areas remain. In the case of structures in which stress is applied to the welded areas, the static strength and fatigue strength change depending on the unwelded length of the unwelded areas relative to the base material.

Therefore, there is a demand to check the unwelded length after welding. As a method for measuring the unwelded length using ultrasonic testing, for example, the technology described in JP 2004-333387 A (Patent Document 1) (hereinafter referred to as the prior art) is known.

The conventional technology described in Patent Document 1 introduces ultrasonic waves into the slit, which is the remaining welded portion in the weld. Then, as a means of determining whether the weld is good or bad based on the reflected waves from the slit, data is created in advance from an artificial defect test specimen that is the same as the actual product, and based on this data, the optimal inspection position of the ultrasonic probe for determining the slit height is determined and measured, thereby obtaining highly accurate measurement values.

As a specific means for achieving this, multiple artificially defective test specimens with slits of different heights are created in advance, and multiple echo heights are measured for each of these test specimens when an ultrasonic probe is moved toward, away from, and moved from a specific position toward the slit. The echo height measurement results at multiple positions for each of these test specimens are then digitized, and from among this data, the reference data for a test specimen with a slit of a height that serves as the criterion for determining whether a weld is good or bad is used to determine the measurement position of the probe at a portion where a difference between the data values from other test specimens and the reference data values is clearly evident.

Furthermore, master data is created by extracting the echo height of each test piece at this measurement position, and then the echo height of the slit part at the probe measurement position is measured for the welded part of the actual product to be inspected, and the measured echo height of this actual product is compared with the master data to judge whether the weld condition is good or bad.

JP 2004-333387 A

However, the conventional technology described in Patent Document 1 requires the preparation of a test specimen in advance to obtain master data for comparison. In addition, although it can determine whether the welding condition is good or bad, it cannot calculate the unwelded length, which makes it difficult to use.

The objective of the present invention is to provide an ultrasonic inspection method for welds that does not require the preparation of master data and can measure the unwelded length of unwelded parts with high accuracy.

In order to solve the above problem, the present invention is characterized in that ultrasonic waves are incident obliquely from a first incident position of a first ultrasonic probe at a first refraction angle to a welded metal portion and an unwelded portion at the same position, and ultrasonic waves are incident obliquely from a second incident position different from the first incident position of a second ultrasonic probe at a second refraction angle different from the first refraction angle, and the unwelded length of the unwelded portion is measured from the first reflected wave based on the first ultrasonic probe and the second reflected wave based on the second ultrasonic probe.

According to the present invention, there is no need to prepare master data, and the unwelded length of the unwelded portion can be measured with high accuracy.

1 is a configuration diagram showing a configuration of an ultrasonic flaw detection device according to the present invention. FIG. 4 is a flowchart showing a procedure for setting inspection conditions in the present invention. FIG. 1 is a cross-sectional view showing a cross section of a welded structure having an unwelded portion when no welding deformation occurs according to the design. FIG. 1 is a cross-sectional view showing a cross section of a welded structure having an unwelded portion in which actual welding deformation has occurred. FIG. 4 is an explanatory diagram showing an ultrasonic wave path in an unwelded portion where no welding deformation shown in FIG. 3 occurs. 5 is an explanatory diagram showing an ultrasonic wave path in an unwelded portion where the welding deformation shown in FIG. 4 occurs; FIG. 1 is a top view showing an arrangement of a welded structure and two ultrasonic probes according to a first embodiment of the present invention; 8 is an explanatory diagram illustrating an ultrasonic path of the first ultrasonic probe shown in FIG. 7 . FIG. 8 is an explanatory diagram illustrating an ultrasonic path of the second ultrasonic probe shown in FIG. 7 . FIG. 8 is an explanatory diagram showing an example of a setting screen for setting inspection conditions for the first ultrasonic probe shown in FIG. 7 . FIG. 8 is an explanatory diagram showing an example of a setting screen for setting inspection conditions for the second ultrasonic probe shown in FIG. 7 . FIG. 8 is an explanatory diagram showing an example of a setting screen for setting common inspection conditions for the first ultrasonic probe and the second ultrasonic probe shown in FIG. 7 . FIG. FIG. 11 is a flow chart showing a procedure for measuring the unwelded length. 8 is an explanatory diagram showing an example of flaw detection images of the first ultrasonic probe and the second ultrasonic probe shown in FIG. 7 and a measurement screen for measuring the unwelded length using these images. FIG. FIG. 11 is an explanatory diagram showing a welded structure according to a second embodiment of the present invention, the arrangement of an ultrasonic probe in this example, and an ultrasonic path. FIG. 11 is an explanatory diagram showing a welded structure according to a third embodiment of the present invention, the arrangement of an ultrasonic probe in this example, and an ultrasonic path. FIG. 17 is a configuration diagram showing a positioning jig for the ultrasonic probe shown in FIG. 16 . FIG. 13 is an explanatory diagram showing a welded structure according to a fourth embodiment of the present invention and the arrangement of an ultrasonic probe in this example. 19 is an explanatory diagram illustrating the arrangement of the ultrasonic probe and the ultrasonic path illustrated in FIG. 18 . FIG. 13 is an explanatory diagram showing a welded structure according to a fifth embodiment of the present invention and the arrangement of an ultrasonic probe in this example. 21 is an explanatory diagram illustrating the arrangement of the ultrasonic probe and the ultrasonic path illustrated in FIG. 20. FIG.

The following describes in detail an embodiment of the present invention with reference to the drawings. However, the present invention is not limited to the following embodiment, and the scope of the present invention includes various modifications and applications within the technical concept of the present invention.

The ultrasonic inspection method for welded joints according to the first embodiment of the present invention will be described in detail with reference to Figures 1 to 14.

Figure 1 shows the overall configuration of an ultrasonic flaw detection device in a first embodiment of the present invention. As shown in the figure, the ultrasonic flaw detection device is composed of an array-type ultrasonic probe 10 that irradiates ultrasonic waves on the inspection object Smp, an ultrasonic flaw detection control unit 11, and a display unit 12 that has the function of displaying the flaw detection image and the function of setting the flaw detection conditions.

The ultrasonic flaw detection control unit 11 is composed of a calculation unit 13 that has the function of setting the phase and intensity of the incident wave from the ultrasonic probe 10 and the function of detecting unwelded parts from the intensity and propagation time of the reflected wave from the ultrasonic probe 10, a delay time control unit 14 that controls the delay time of the incident wave from the calculation unit 13, a pulser 15 for generating the incident wave based on a control signal from the delay time control unit 14, a receiver 16 that receives the reflected wave from the ultrasonic probe 10, and a data collection unit 17 that collects and stores the intensity, propagation time, etc. based on the reflected wave from the receiver 16.

The array-type ultrasonic probe 10 is basically composed of multiple piezoelectric vibration elements that generate ultrasonic waves and receive ultrasonic waves returned from the inspection object Smp, and is placed on the inspection surface of the inspection object Smp. Then, ultrasonic waves (incident waves) are generated by a drive signal supplied from the ultrasonic inspection control unit 11, and the reflected waves that appear as the waves propagate through the inspection object Smp are detected, and the reflected waves are input to the ultrasonic inspection control unit 11.

The ultrasonic flaw detection control unit 11 causes the ultrasonic probe 10 to transmit (incident waves) and receive (reflected waves) ultrasonic waves, and for this purpose includes the above-mentioned calculation unit 13, delay time control unit 14, pulser 15, receiver 16, and data collection unit 17. The pulser 15 supplies a drive signal to the ultrasonic probe 10, and the ultrasonic probe 10 receives the reflected waves generated by this and sends them to the receiver 16.

At this time, the calculation unit 13 controls the delay time control unit 14, the pulser 15, the receiver 16, and the data collection unit 17, and drives them so as to obtain the required operation. First, it controls both the timing of the drive signal output from the delay time control unit 14 and the pulser 15 and the input timing of the received signal by the receiver 16, thereby functioning to obtain the operation of the ultrasonic probe 10 using the phased array method.

The operation of the phased array method using the array-type ultrasonic probe 10 is to control the focal depth and incident angle (refractive angle) of the ultrasonic waves to transmit incident waves and receive reflected waves, thereby supplying reflected wave signals from the receiver 16 to the data collection unit 17.

The data collection unit 17 processes the reflected wave signals supplied and stores them as data necessary for calculations in the calculation unit 13. The calculation unit 13 synthesizes the waveforms obtained by the ultrasonic probe 10 according to the delay time, images the waveforms for each ultrasonic incident angle, supplies them to the display unit 12, and displays them as flaw detection images.

Next, the condition settings for measuring the unwelded length using ultrasonic testing will be explained with reference to Figures 2 and 10 to 12. Figures 10 to 12 show the setting screens corresponding to the condition setting steps shown below.

First, the frequency, element size, element pitch, number of elements, as well as the refraction angle (detection range), focal length, number of simultaneous excitations, and sound speed required for coordinate calculation of the ultrasonic probe to be used are determined in advance using design information, etc. Then, based on this, the settings shown in Figs. 10 to 12 are executed on the screen of the display unit 12 in accordance with the conditions determined in the detection condition setting block 20 of the ultrasonic flaw detector shown in Fig. 2. Note that in this embodiment, since two ultrasonic probes are used, two "setting tags" (condition setting 1, condition setting 2) are provided in Figs. 10 and 11.

As shown in condition setting tags 1 and 2 in Figures 2, 10 and 11, in step S20, the probe to be used for flaw detection is selected. In step S21, the material constant (sound speed) of the inspection object is set. In step S22, the number of elements to be excited simultaneously in the array-type ultrasonic probe 10 is set. In step S23, the flaw detection range, i.e., the maximum and minimum values of the refraction angle (or linear scanning range), is set. Also, the fineness (pitch) of the flaw detection is set. In step S24, the focal depth of the ultrasonic waves (flaw detection distance) is set. In step S25, the ultrasonic capture path length is set.

As shown in the "setting tag" (condition setting 3) in Figures 2 and 12, in step S26, the pulse voltage related to the strength of the ultrasound is set. In step S27, the pulse width related to the frequency of the ultrasound is set. In step S28, the number of bursts related to the number of times ultrasound is generated is set. In step S29, the base gain, preamplifier gain, and digital gain of the ultrasound sensitivity (gain) are set. Also, the display mode, etc. are set.

Next, we will explain the issues with "partial penetration welding." Figures 3 and 4 show cross sections of a welded structure. Figure 3 shows a cross section of a welded structure with an unwelded part where no welding deformation has occurred in the design, and Figure 4 shows a cross section of a welded structure with an unwelded part where actual welding deformation has occurred.

In this example, as shown in Figure 3, base material A21 (cylinder) and base material B22 (cylinder) are welded in the shape of a "R-groove". At this time, the weld metal 23 does not reach the back side (inner circumference) of base material B22, and the design allows for an unwelded portion (also known as a notch) 24. However, in reality, as shown in Figure 4, base material B22 shrinks due to thermal contraction and deforms by pushing base material A21 inward, causing the shape of unwelded portion 24 to change from the designed shape.

As shown in Figure 5, consider the case where an array-type ultrasonic probe 25 is placed on the surface of the base material B22 and the unwelded portion 24 is inspected by sector scanning. Note that this case is targeted at the configuration in Figure 3, and is a design configuration.

The ultrasonic path 100 reaches the unwelded boundary (the boundary between the weld metal 23 and the unwelded portion 24) 24a, where it is reflected and returns to the ultrasonic probe 25. Similarly, the ultrasonic path 101 reaches the unwelded end portion (the end portion on the inner circumference side of the unwelded portion 24) 24c, where it is reflected and returns to the ultrasonic probe 25.

On the other hand, the ultrasonic path 102 reaches the unwelded intermediate portion 24b (partway through the unwelded portion 24) and is reflected and does not return to the ultrasonic probe 25. As a result, both ends of the unwelded portion 24 can be grasped, and the unwelded length can be determined.

However, as described above, in reality, as shown in Figure 6, the base material B22 shrinks due to thermal contraction during welding, pushing into and deforming the base material A21. As a result, the propagation path of the ultrasonic waves changes.

For example, ultrasonic path 103 reaches unwelded boundary 24a, is reflected, and returns to ultrasonic probe 25. Similarly, ultrasonic path 104 reaches unwelded end 24c, is reflected, and returns to ultrasonic probe 25. Furthermore, ultrasonic path 105 reaches unwelded intermediate portion 24b and is reflected, but may return to ultrasonic probe 25 because the shape (angle) of unwelded portion 24 has changed from the design shape. As a result, both ends of unwelded portion 24 cannot be grasped, and the unwelded length cannot be determined.

In this embodiment, as shown in Figures 7 to 9, we propose a method in which ultrasonic waves are incident on a welded metal part 23 and an unwelded part 24 at the same position from multiple incident positions (different positions) and multiple refraction angles (different angles) based on the angle beam inspection method, and reflected waves are detected for each incident position and refraction angle.

More specifically, this embodiment is characterized in that ultrasonic waves are incident obliquely from a first incident position of the first ultrasonic probe 25a at a first refraction angle to the weld metal 23 and the unwelded portion 24 at the same position, and ultrasonic waves are incident obliquely from a second incident position different from the first incident position of the second ultrasonic probe 25b at a second refraction angle different from the first refraction angle, and the unwelded length of the unwelded portion is measured from the first reflected wave based on the first ultrasonic probe and the second reflected wave based on the second ultrasonic probe.

In FIG. 7, a first ultrasonic probe 25a is positioned farther from the weld metal 23 in the direction of the axis (C) of the base material B22, and a second ultrasonic probe 25b is positioned closer to the weld metal 23, and ultrasonic inspection is performed on the weld metal portion 23 and the unwelded portion 24 at the same position. Note that the weld metal portion 23 and the unwelded portion 24 at the same position are not specific positions, but are a concept of an area (the same area) that has a spread that is subjected to ultrasonic inspection.

The first ultrasonic probe 25a and the second ultrasonic probe 25b are configured as separate probes and stored in a single housing, and can be handled as a single ultrasonic probe 25.

The first ultrasonic probe 25a and the second ultrasonic probe 25b are arranged side by side along the axis (C), and each of the ultrasonic probes 25a and 25b emits ultrasonic waves at an oblique angle toward the weld metal 23. This method of incidence is well known.

Here, as shown in Figures 8 and 9, the ultrasonic wave incidence position of the first ultrasonic probe 25a is set to a position farther from the weld metal 23 than the ultrasonic wave incidence position of the second ultrasonic probe 25b, and the refraction angle (θa) of the ultrasonic wave of the first ultrasonic probe 25a is set to a larger angle than the refraction angle (θb) of the ultrasonic wave of the second ultrasonic probe 25b. Note that the refraction angle is a refraction angle known in the field of ultrasonic flaw detection.

In this way, by always checking whether a reflected wave is detected regardless of the incident position and refraction angle, as described below, it is possible to determine from the two detected reflected waves whether the reflected wave is from the boundary 24a between the welded portion (welded metal 23) and the unwelded portion 24, the end 24c of the unwelded end portion, or the middle portion 24b of the unwelded portion 24. As a result, it becomes possible to accurately measure the unwelded length of the unwelded portion 24.

Specifically, as shown in FIG. 8 (first measurement mode), ultrasonic path 107 from first ultrasonic probe 25a reaches unwelded boundary 24a, then is reflected and returns to first ultrasonic probe 25a. Similarly, ultrasonic path 108 reaches unwelded end 24c, then is reflected and returns to first ultrasonic probe 25a. Furthermore, ultrasonic path 109 reaches unwelded intermediate portion 24b and is reflected, but because the angle of unwelded portion 24 has changed from the design shape, it may return to first ultrasonic probe 25a. This is as explained in FIG. 6.

In contrast, as shown in FIG. 9 (second measurement mode), ultrasonic path 110 from second ultrasonic probe 25b reaches unwelded boundary 24a, is reflected, and returns to ultrasonic probe 25b. Similarly, ultrasonic path 111 reaches unwelded end 24c, is reflected, and returns to second ultrasonic probe 25b. On the other hand, ultrasonic path 112 reaches unwelded intermediate portion 24b, is reflected at this portion, but does not return to second ultrasonic probe 25b. As a result, both ends of unwelded boundary 24a and unwelded end 24c of unwelded portion 24 can be grasped, and the unwelded length of unwelded portion 24 can be obtained.

Next, we will explain the calculation process of the reflected waves detected by the above-mentioned method. This calculation process of the reflected waves is performed by the calculation unit 13 shown in Figure 1, but the conditions and instructions for this calculation process can be set on the screen provided in the display unit 12.

For example, a graphical user interface or the like can be used, which allows the measurement flow of the unwelded length shown in FIG. 13 to be executed. Note that this is an example in which two ultrasonic probes 25a and 25b are used, as in the first embodiment.

First, in step S30, the inspection conditions for the two ultrasonic probes (probe 1 and probe 2) are set. This setting is the same as that shown in the inspection condition setting block 20 in Figure 2.

Next, in step S31, two ultrasonic probes are placed on the welded structure to be inspected. The ultrasonic probe placement positions are determined in advance in consideration of the design information of the "groove" and other factors, and are sufficient for flaw detection so that the areas where the unwelded end 24c and unwelded boundary 24a shown in Figures 8 and 9 exist are included. The ultrasonic probe 25 is then placed at the determined locations.

Next, in step S32, ultrasonic testing is performed using a linear scan. In this ultrasonic testing, the first ultrasonic probe 25a performs testing to collect reflected wave data, and then the second ultrasonic probe 25b performs testing to collect reflected wave data. This allows each reflected wave to be collected individually.

Next, in step S33, a flaw detection image is obtained based on the reflected waves acquired by the scan. Furthermore, in step S34, the flaw detection images obtained by the first ultrasonic probe 25a and the second ultrasonic probe 25b are compared.

Next, in step S35, the reflected waves from the unwelded boundary 24a and the unwelded end 24c are extracted, and finally, in step S36, the unwelded length is measured from the coordinates of the extracted reflected waves from the unwelded boundary 24a and the unwelded end 24c.

Figure 14 shows an example of a flaw detection image display. The left side of the screen shows a flaw detection image Dpa acquired by the first ultrasonic probe (probe 1) 25a, and the right side of the screen shows a flaw detection image Dpb acquired by the second ultrasonic probe (probe 2) 25b. This makes it easy to determine the difference in reflected waves depending on the flaw detection position.

If the frequencies are set to be the same, the reflected waves from the first ultrasonic probe 25a and the second ultrasonic probe 25b cannot be obtained simultaneously, so the reflected waves from the first ultrasonic probe 25a are obtained first, and then the reflected waves from the second ultrasonic probe 25b are obtained. The data on these reflected waves is stored in the data collection unit 17 shown in FIG. 1.

The calculation unit 13 can determine the unwelded length of the unwelded portion 24 from the data of the reflected waves from the first ultrasonic probe 25a and the data of the reflected waves from the second ultrasonic probe 25b stored in the data collection unit 17.

In Figure 14, the flaw detection image Dpa on the left shows the cross-sectional shape of the flaw detection area of the welded structure (as shown in Figures 3 and 4, where the deformed parts are shown by dashed lines in Figure 4) and the ultrasonic paths of the incident and reflected waves, and similarly, the flaw detection image Dpb on the right shows the cross-sectional shape of the flaw detection area of the welded structure and the ultrasonic paths of the incident and reflected waves. If necessary, it is also possible to display the ultrasonic probe as shown by the dashed lines.

Furthermore, a "scale" indicating length is displayed on the X-axis (horizontal axis) and Y-axis (vertical axis) of the display screen. Superimposed on this "scale", grid lines 200a, 201a along the Y-axis are displayed on the flaw detection image Dpa, and grid lines 200b, 201b along the Y-axis are displayed on the flaw detection image Dpb.

Furthermore, grid lines 202a, 202b, and 203 aligned along the X-axis are displayed on the flaw detection images Dpa and Dpb. Then, image processing is performed so that echoes of unwelded parts are displayed in the areas where these grid lines intersect.

In the flaw detection screens Dpa and Dpb in FIG. 14, the echo regions Eh-1 and Eh-2 show the echo regions from the unwelded boundary 24a. Furthermore, the echo regions Ehc-1 and Ehc-2 show the echo regions from the unwelded end 24c. Furthermore, the echo region Ehb-1 shows the reflected wave from the unwelded intermediate portion 24b. However, in the flaw detection screen Dpb, the echo region corresponding to the unwelded intermediate portion 24b does not appear in the flaw detection image acquired by the second ultrasonic probe 25b.

Then, on the screen, for example, using the mouse pointer Mp, the position of the echo area can be identified by moving each grid line over the echo area. In FIG. 14, the grid line 200a indicates the lateral position of the echo area from the unwelded boundary 24a.

Since both images acquired by ultrasound probe 25a (probe 1) and ultrasound probe 25b (probe 2) have echo regions Eh-1 and Eh-2, respectively, grid line 200b indicating the lateral position of echo region Eh-2 can be made to move in synchronization with grid line 200a.

Similarly, the mouse pointer Mp is used to identify the echo position from the unwelded end 24c. In FIG. 14, the grid lines 201a indicate the echo region Ehc-1 from the unwelded end 24c in the flaw detection image acquired by the ultrasonic probe 25a (probe 1).

Grid line 201b indicates echo region Ehc-2 from unwelded end 24c in the flaw detection image acquired by ultrasonic probe 25b (probe 2). As described above, grid line 201a and grid line 201b can also be made to move synchronously.

Similarly, the vertical positions of the unwelded boundary 24a and the unwelded end 24c are identified by grid lines 202a, 202b, and 203. The coordinates on the screen can be converted to actual distances using the speed of sound, so the unwelded length can be found by this process. The found length can then be displayed on the screen, as shown in Figure 14. These calculations can be easily performed by the calculation unit 13.

In addition, since the echo area is not a point but has a certain extent, it is possible to provide a function that automatically moves the grid lines to the peak position of the echo area using an image processing technique such as peak search when the mouse pointer Mp is moved near the echo area.

Thus, in this embodiment, ultrasonic waves are incident obliquely from a first incident position of a first ultrasonic probe at a first refraction angle on a welded metal portion and an unwelded portion at the same position, and ultrasonic waves are incident obliquely from a second incident position different from the first incident position of a second ultrasonic probe at a second refraction angle different from the first refraction angle, and the unwelded length of the unwelded portion is measured from the first reflected wave based on the first ultrasonic probe and the second reflected wave based on the second ultrasonic probe. This allows the unwelded length of the unwelded portion to be measured with high accuracy.

Next, a second embodiment of the present invention will be described with reference to FIG. 15. This second embodiment is characterized in that it uses a large array-type ultrasonic probe 25c, rather than two separate ultrasonic probes 25a and 25b as shown in FIG. 7. The ultrasonic probe 25c is formed by dividing a plurality of ultrasonic transducers into two groups, a first ultrasonic probe 25a and a second ultrasonic probe 25b.

The array type (Ultrasonic Phased Array) makes it possible to change the refraction angle and focus of ultrasonic waves by changing the timing (delay time) of transmission from multiple ultrasonic transducers inside. These two probes are controlled by the ultrasonic flaw detection control unit 11 to achieve the same operation and function as when the two ultrasonic probes 25a and 25b described above are used.

The operation of the ultrasonic probe 25c is the same as in the first embodiment, so a description thereof will be omitted here. This embodiment provides the effects of easy installation and easy handling.

Next, a third embodiment of the present invention will be described with reference to Figures 16 and 17. In this third embodiment, instead of using two separate ultrasonic probes 25a, 25b as shown in Figure 7, as shown in Figure 16, one ultrasonic probe 25a shown in solid lines approaches or moves away from the weld metal 23 at the same position, like the ultrasonic probe 25a shown in dashed lines.

This allows the first measurement mode using the first ultrasonic probe 25a in FIG. 7 and the second measurement mode using the second ultrasonic probe 25b to be performed with a single ultrasonic probe 25a.

In this way, it is possible to achieve the same operation and function as if two ultrasonic probes were used. Note that the operation of this ultrasonic probe 25a is the same as in the first embodiment, so a description thereof will be omitted here.

Figure 17 shows a probe positioning jig 31 for moving the ultrasonic probe 25a, and the width (W) is determined to allow the ultrasonic probe 25a to slide and move. The length (L) is determined to obtain the positioning relationship shown in Figure 7. This allows the ultrasonic probe 25a to be accurately positioned before and after movement. Also, because only one ultrasonic probe 25a is required, the cost of the ultrasonic flaw detection device can be prevented from increasing.

Next, a fourth embodiment of the present invention will be described with reference to Figs. 18 and 19. In this fourth embodiment, as shown in Fig. 7, the transmission and reception of ultrasonic waves are not performed by a single ultrasonic probe 25a or ultrasonic probe 25b, but rather, as shown in Figs. 18 and 19, the transmission and reception are separated.

In FIG. 18, ultrasonic probe 25at is an ultrasonic probe dedicated to transmission, and ultrasonic probe 25ar is an ultrasonic probe dedicated to reception. Similarly, ultrasonic probe 25bt is an ultrasonic probe dedicated to transmission, and ultrasonic probe 25br is an ultrasonic probe dedicated to reception. Therefore, in operation, ultrasonic probe 25at and ultrasonic probe 25ar are paired, and ultrasonic probe 25bt and ultrasonic probe 25br are paired.

The ultrasonic waves transmitted from ultrasonic probe 25at are reflected and received by ultrasonic probe 25ar. Similarly, the ultrasonic waves transmitted from ultrasonic probe 25bt are reflected and received by ultrasonic probe 25br. The operation of ultrasonic probe 25d is the same as in the first embodiment, so a description thereof will be omitted here. This can increase the sensitivity of ultrasonic probe 25d.

The ultrasonic probes 25at and 25ar, and the ultrasonic probes 25bt and 25br are configured as four separate probes and stored in a single housing, and can be handled as a single ultrasonic probe 25d.

Next, a fifth embodiment of the present invention will be described with reference to Figs. 20 and 21. This fifth embodiment is characterized in that it uses two large array-type ultrasonic probes 25et and 25er, rather than four separate ultrasonic probes 25at, 25ar, 25bt, and 25br as shown in Fig. 18. As shown in Fig. 15, ultrasonic probes 25et and 25er are formed by dividing a plurality of ultrasonic transducers into two groups to form ultrasonic probe 25at and ultrasonic probe 25bt, and similarly ultrasonic probe 25ar and ultrasonic probe 25br.

The ultrasonic waves transmitted from ultrasonic probe 25at are reflected and received by ultrasonic probe 25ar. Similarly, the ultrasonic waves transmitted from ultrasonic probe 25bt are reflected and received by ultrasonic probe 25br. In this embodiment, the operation of ultrasonic probe 25e is the same as in the first embodiment, so a description thereof will be omitted here.

In this embodiment as well, the sensitivity of the ultrasonic probe 25d can be increased, the installation work can be simplified, and the handling can be simplified.

The present invention is not limited to the above-mentioned embodiments, but includes various modified examples. The above-mentioned embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment.

11... ultrasonic flaw detector, 12... display unit, 13... calculation unit, 14... delay time control unit, 15... pulsar, 17... receiver, 17... data collection unit, 21... base material A, 22... base material B, 23... weld metal, 24a... unwelded boundary portion, 24b... unwelded intermediate portion, 24c... unwelded end portion, 25... ultrasonic probe, 31... probe positioning jig, 100-112... ultrasonic path.

Claims (7)

For weld metal and unwelded parts in the same position of a welded structure,
an ultrasonic wave is incident obliquely at a first refraction angle from a first incident position of a first ultrasonic probe, and a first reflected wave is received;
an ultrasonic wave is obliquely incident from a second incident position different from the first incident position of a second ultrasonic probe at a second refraction angle different from the first refraction angle, and a second reflected wave is received;
An ultrasonic inspection method for welded parts, characterized in that a first inspection image based on the first reflected wave of the first ultrasonic probe and a second inspection image based on the second reflected wave of the second ultrasonic probe are compared to extract an unwelded boundary and an unwelded end of the unwelded part, and an unwelded length of the unwelded part is measured from the extracted unwelded boundary and unwelded end . 2. The method for ultrasonically inspecting a welded portion according to claim 1,
2. A method for ultrasonically inspecting a welded portion, comprising the steps of: detecting a position of the welded portion by ultrasonically inspecting the welded portion; detecting a position of the welded portion by ultrasonically inspecting the welded portion; 3. The method for ultrasonically inspecting a welded portion according to claim 2,
2. The ultrasonic inspection method for welds, wherein the first ultrasonic probe and the second ultrasonic probe are formed by dividing a plurality of ultrasonic transducers of an array type ultrasonic probe into two groups. For weld metal and unwelded parts at the same position of a welded structure,
A first measurement mode is executed in which an ultrasonic wave is obliquely incident at a first refraction angle from a first incident position of the ultrasonic probe and a first reflected wave is received;
a second measurement mode is executed in which an ultrasonic wave is obliquely incident from a second incident position different from the first incident position of the ultrasonic probe at a second refraction angle different from the first refraction angle, and a second reflected wave is received;
An ultrasonic inspection method for welded parts, characterized in that a first inspection image based on the first reflected wave received in the first measurement mode and a second inspection image based on the second reflected wave received in the second measurement mode are compared to extract an unwelded boundary and an unwelded end portion of the unwelded part, and the unwelded length of the unwelded part is measured from the extracted unwelded boundary and unwelded end portion . The ultrasonic inspection method for a welded portion according to claim 4,
4. The ultrasonic inspection method for welded parts, wherein the ultrasonic probe has both an ultrasonic transmission function and a reflected wave reception function. For weld metal and unwelded parts in the same position of a welded structure,
an ultrasonic wave is incident obliquely at a first refraction angle from a first incident position of a first ultrasonic probe for transmission;
receiving a first reflected wave by the first ultrasonic probe for transmission with a first ultrasonic probe for reception corresponding to the first ultrasonic probe for transmission;
an ultrasonic wave is obliquely incident from a second incident position different from the first incident position of a second ultrasonic probe for transmission at a second refraction angle different from the first refraction angle;
receiving a second reflected wave by the second transmitting ultrasonic probe with a second receiving ultrasonic probe corresponding to the second transmitting ultrasonic probe;
An ultrasonic inspection method for welded parts , characterized in that a first inspection image based on the first reflected wave measured by the first receiving ultrasonic probe and a second inspection image based on the second reflected wave measured by the second receiving ultrasonic probe are compared to extract an unwelded boundary and an unwelded end portion of the unwelded part, and an unwelded length of the unwelded part is measured from the extracted unwelded boundary and unwelded end portion . 7. The method for ultrasonically inspecting a welded portion according to claim 6,
The first transmitting ultrasonic probe and the second transmitting ultrasonic probe are formed by dividing a plurality of ultrasonic transducers of an array type ultrasonic probe into two groups,
The ultrasonic inspection method for welds, characterized in that the first receiving ultrasonic probe and the second receiving ultrasonic probe are formed by dividing a plurality of ultrasonic transducers of the array type ultrasonic probe into two groups.

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