JPH08278297A - Reference flaw-detecting jig and ultrasonic flaw-detecting method using the jig - Google Patents

Abstract

PURPOSE: To simply and accurately detect the reflection echo from e reference hole of ϕ4×4 of a standard testpiece STB-A3. CONSTITUTION: A jig 1 has a guide 11 formed at the outer end face in the same shape ass the end face of a standard testpiece STB-A3 and extended obliquely to the longitudinal direction of the jig 1 and a scale indicating the horizontal distance from a reference defect and attached along the guide 11. The jig 1 is mounted on the upper or lower surface of the STB-A3 and so aligned that the end face of the STB-AC and the outer end face of the jig 1 become substantially in plane. The probe 2 of an ultrasonic flaw detector is brought into contact with the guide 11, moved to the scale position responsive to the refractive angle of the probe 2 with the scale as a measure, and an ultrasonic wave is transmitted. As long as the probe 2 is brought into contact with the guide 11, the wave from the probe 2 is emitted to the center of the reference defect, and hence the reflection echo from the reference defect can be effectively detected.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a standard test piece STB-A.
The present invention relates to a reference defect flaw detection jig used when performing an ultrasonic flaw detection test using No. 3.

[0002]

2. Description of the Related Art An ultrasonic flaw detector can detect flaws in a welded portion. The flaw detection result is usually displayed on the monitor with the detection time of the defect echo, that is, the defect position as the horizontal axis and the echo height (amplitude of the defect echo) as the vertical axis.

FIG. 5A shows a defect inside a weld and an ultrasonic probe of an ultrasonic flaw detector (hereinafter referred to as a probe).
FIG. 5B is a diagram showing the positional relationship with the, and FIG. 5B is a diagram in which the horizontal axis represents the beam path of the defect echo and the vertical axis represents the echo height. Figure 5
In (a), the position of the probe 2 (horizontal distance from the origin of flaw detection) is Y _P , the propagation distance of ultrasonic waves (beam path) is W _F ,
The horizontal distance between the origin of flaw detection and the defect (defect position) is Y _F , the defect depth is Z _F , and the refraction angle of the probe 2 is θ. In this case, the defect position Y _F is expressed by the equation (1) and the defect depth Z _F is expressed by the equation (2).

[0004]

[Formula 1] Y _F = Y _P −W _F · sin θ (1) Z _F = W _F · cos θ (2)

The echo height of the defect echo is proportional to the sound pressure of the ultrasonic waves reflected at the defect portion, and usually, the larger the defect, the higher the echo height. However, if the type of the probe 2 used and the sensitivity of the ultrasonic flaw detector are different, the echo height will be different even if flaw detection is performed on the same defect, and the size of the detected defect and the defect. It becomes impossible to objectively and accurately determine whether or not is within the criteria for determining pass / fail.

Therefore, JIS Z 3060 is a method of irradiating a reference defect having a predetermined size and shape with ultrasonic waves and evaluating the performance of the ultrasonic flaw detector by the echo height of the reflection echo from the reference defect. It is set.

6 and 7 are external views of standard test pieces used in JIS Z 3060. The standard test piece of FIG. 6 is STB-A2.
7 and the standard test piece in FIG. 7 is called STB-A3. A flat bottom hole (hereinafter referred to as a reference defect) 101 of φ4 × 4 is formed in each of the standard test pieces, and the reference hole 101 is generally used for performance evaluation of the ultrasonic flaw detector.

The STB-A3 is provided with two φ8 through holes 102 and 103 in addition to the φ4 × 4 reference defect 101, and these through holes 102 and 103 are mainly used for refracting the probe 2. Used for corner evaluation. Other, STB
The curved surface portion R of −A3 is also used for evaluation of the incident point of the probe 2. As described above, various performance evaluations can be performed by using the respective parts inside the STB-A3. In this specification, a case where the φ4 × 4 reference defect 101 is used as a reference defect will be described.

When performing the flaw detection test using the φ4 × 4 reference defect 101, the probe 2 of the ultrasonic flaw detector is placed on the upper surface or the lower surface of the STB-A2 or STB-A3 as shown in FIG. Then, from the probe 2 to the reference defect 1
The ultrasonic wave is emitted toward 01 and the reflection echo from the reference defect 101 is detected. The detected peak position of the reflected echo is displayed on the monitor of the ultrasonic flaw detector as shown in FIG.

The above work is performed by the probe 2 as shown in FIG.
Is moved in 0.5 skip units, and a line diagram as shown in FIG. 10 in which the peak positions of the reflection echo at each position are connected by a line is displayed on the monitor. In FIG. 10, H line is a line when sensitivity is not corrected, M line is a line when sensitivity is adjusted by −6 dB, L line is a line when sensitivity is adjusted by −12 dB, and U line is +6 dB when sensitivity is adjusted. The diagrams for each case are shown below. Each of these diagrams is called an echo height dividing line,
Further, the intervals between the diagrams are distinguished from each other as regions I to IV.

FIG. 11 is a defect classification diagram for classifying defects inside the object. The defect classification diagram shown in FIG. 11 is for classifying defects using the region to which the defect echo belongs and the plate thickness of the object as parameters. That is, it is specified in which of the regions I to IV in FIG. 11 the defect echo obtained by actually detecting the subject is detected, and the plate thickness of the subject is detected, and these regions and the plate thickness are used as parameters. The defects are classified into 1 to 4 categories. The larger the number, the larger the defect size.

In order to use the defect classification diagram of FIG. 11, it is necessary to prepare the echo section line of FIG. 10 as a pre-stage, and the echo section line is usually a standard test piece ST shown in FIG.
It is created using B-A2. However, STB-A2
Because of its large size and weight, STB-A3 is often used at work sites because of its small size, light weight, and excellent portability.

[0013]

On the other hand, the conventional STB-
There is no effective means for positioning the probe 2 on the A3, and as shown in FIG. 12, the ultrasonic wave transmitted from the probe 2 does not hit the reference defect 101, passes through the side thereof, and is reflected by the end face. , The reflected echo from the end face may be received by the probe 2.

However, STB-A3 has a standard defect 10
Since the distance between 1 and the end face is close to about 10 mm, it is difficult to distinguish whether the received reflected echo is reflected by the reference defect 101 or reflected by the end face, and the reflected echo from the end face is difficult to distinguish. May be erroneously detected as a reflection echo from the reference defect.

In order to avoid such a fear, the horizontal distance from the incident point of the probe 2 to the reference defect is usually measured using a scale or the like, and whether the obtained reflection echo is reflected by the reference defect. I was checking. However, since such confirmation is difficult and time-consuming for an unfamiliar operator, it requires a considerable amount of skill to detect flaws using the standard defect of STB-A3.

The object of the present invention is to provide a standard test piece STB-A3.
The object is to provide a reference defect jig that can easily and accurately detect the reflection echo from the φ4 × 4 reference hole.

[0017]

The present invention will be described with reference to FIG. 1 showing an embodiment. The present invention is mounted on the upper surface or the lower surface of a standard test piece STB-A3 having a reference defect 101 of φ4 × 4. A reference defect flaw detection jig that can be placed, and includes a guide portion 11 that defines the scanning direction of the ultrasonic probe 2.
In preparation for this, when ultrasonic waves are transmitted from the ultrasonic probe 2 in a state where the ultrasonic probe 2 is in contact with the guide portion 11, the transmitted ultrasonic waves are applied to the substantially central portion of the reference defect 101. As described above, by providing the guide portion 11 in an oblique direction with respect to the longitudinal direction of the jig 1, the above object is achieved. According to a second aspect of the present invention, in the reference defect jig according to the first aspect, the shape of the outer end surface of the jig 1 and the shape of the end surface of the STB-A3 are substantially the same, and the outer shape of the jig 1 is the same. Dimensions and ST
The external dimensions of B-A3 are substantially the same. The invention according to claim 3 is the jig for reference defects according to claim 1 or 2, wherein the STB-A3 from the reference defect 101 is used.
A graduation indicating the distance along the surface direction is provided along the guide portion 11. According to a fourth aspect of the present invention, in the reference defect jig according to the third aspect, two facing surfaces of the jig 1 can be placed on STB-A3, respectively.
The jig 1 is made of a transparent material so that the scale can be confirmed from the surface direction facing the surface placed on A3.
The invention according to claim 5 can be placed on the upper surface or the lower surface of the standard test piece STB-A3 having the φ4 × 4 reference defect 101, and defines the scanning direction of the ultrasonic probe 2. 11, an ultrasonic flaw detection method using a reference defect flaw detection jig having a shape substantially equal to the shape of the end surface of STB-A3 and having an outer dimension substantially equal to the outer dimension of the end surface of STB-A3. And the outer end surface of the jig 1 and ST
Align the end face of B-A3 with the end face so that the guide portion 1
The ultrasonic probe 2 is moved while making contact with the ultrasonic probe 2, and the ultrasonic probe 2 is positioned.
The above object is achieved by transmitting the ultrasonic wave toward No. 1 and performing the flaw detection test based on the result of receiving the ultrasonic wave reflected by the reference defect 101.

[0018]

In the invention described in claim 1, when the jig 1 is provided with the guide portion 11 that defines the scanning direction of the ultrasonic probe 2, the ultrasonic wave is applied to the guide portion 11 when performing the ultrasonic flaw detection test. Ultrasonic waves are transmitted from the ultrasonic probe 2 while the probe 2 is in contact. Further, by providing the guide portion 11 in an oblique direction with respect to the longitudinal direction of the jig 1, the ultrasonic waves transmitted from the ultrasonic probe 2 can be irradiated to the substantially central portion of the reference defect 101. In the invention according to claim 2, the shape of the outer end surface of the jig 1 and the shape of the end surface of the STB-A3 are made substantially equal, and the outer dimensions of the jig 1 and the STB-A3 are made substantially equal. The outer edge of the jig 1 and the STB-A
The end face of No. 3 and the end face of No. 3 can be aligned substantially flush with each other, and the flaw detection test is performed in this aligned state. Claim 3
In the invention described in 1), STB-A3 from the reference defect 101 is
A scale indicating the distance along the surface direction of, that is, the horizontal distance from the reference defect 101 is provided along the guide portion 11 to facilitate the positioning of the ultrasonic probe 2. In the invention according to claim 4, the flaw detection test can be carried out even if the jig 1 is placed on either the upper surface or the lower surface of the STB-A3. Make it possible to check the scale from the facing surface direction. According to the invention of claim 5,
Before performing the flaw detection test, first, the outer end surface of the jig 1 and the STB-
The end face of A3 is substantially flush with the position, and then the ultrasonic probe 2 is moved while being brought into contact with the guide portion 11 of the jig 1 and positioned at a predetermined position. Next, ultrasonic waves are transmitted from the ultrasonic probe 2 toward the reference defect 101, and the reference defect 1
The ultrasonic wave reflected by 01 is received, and a flaw detection test is performed based on the reception result.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used for the sake of easy understanding of the present invention. It is not limited to.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the reference defect jig according to the present invention will be described below with reference to FIGS. Figure 1 shows the standard test piece S
It is a figure which shows the shape of one Example of the jig | tool for reference defects used for the flaw detection test which used TB-A3. As shown in the figure, the jig 1 of the present embodiment has a substantially L-shaped transparent resin or the like (for example,
Acrylic plate), and the outer end surface of the jig 1 is S
The end face of TB-A3 is processed into the same shape, and the outer dimensions of the jig 1 and STB-A3 are made substantially equal.

The jig 1 has a guide portion 11 extending obliquely with respect to its longitudinal direction.
A scale 12 is attached along the line. This scale 12
The horizontal distance from the φ4 × 4 reference defect 101 on the standard test piece is shown in millimeters (mm). Further, numerical values are displayed at predetermined scale positions (15, 25, 30, 40, 50, 80 mm) so that the horizontal distance from the reference defect 101 can be immediately grasped.

The guide portion 11 defines the scanning direction of the probe (ultrasonic probe) 2 of the ultrasonic flaw detector (not shown), and the probe 2 scans forward and backward while being in contact with the guide portion 11. To be done. Further, when the jig 1 is aligned on the STB-A 3 and the ultrasonic wave is emitted in a state where the probe 2 is in contact with the guide portion 11, the central portion of the reference defect 101 is irradiated with the ultrasonic wave. As described above, the angle of the guide portion is adjusted in advance.

FIG. 2 is a diagram showing the relationship between the refraction angle of the probe 2 and the 0.5-skip and 1-skip horizontal distances. As shown, when the refraction angle of the probe 2 changes,
The 0.5 and 1 skip horizontal distances change accordingly. Therefore, by attaching the scale 12 to the jig 1 as shown in FIG. 1, it is possible to immediately set the skip position according to the refraction angle of the probe 2 used.

FIG. 3 is a view of the jig 1 shown in FIG. 1 placed on the lower surface of the STB-A3. FIG. 3 (a) is a side view and FIG. 3 (b) is a lower surface side. It is a figure. Hereinafter, a method of using the jig 1 of this embodiment will be described with reference to FIG.
Note that FIG. 3 shows an example in which defect detection is performed at one skip position using the probe 2 having a refraction angle of 70 degrees.

First, the jig 1 is placed on the lower surface of the STB-A3. At that time, the end surface of the STB-A3 and the outer end surface of the jig 1 are aligned so that they are substantially flush with each other. Then, the probe 2 is brought into contact with the guide portion 11 of the jig 1. As a result, the ultrasonic wave (dotted line in the figure) transmitted from the probe 2 is irradiated near the center of the φ4 × 4 reference defect 101.

Since the one-skip horizontal distance when the refraction angle of the probe 2 is 70 degrees is 82.4 mm as shown in FIG. 2, the probe 2 is moved to a graduation position near 82 mm and abutted on the guide portion 11. The probe 2 is scanned forward and backward while being in contact with each other to detect a defect echo, and the peak position of the defect echo is detected.

On the other hand, in the case of flaw detection at the 0.5 skip position, the jig 1 is turned upside down and placed on the upper surface of the STB-A3, and the scale position near 40.5 mm, which is the 0.5 skip horizontal distance. The probe 2 is moved to the position to detect the defect echo.

As described above, according to the present embodiment, the jig 1 provided with the guide portion 11 for guiding the scanning of the probe 2 is moved to the S position.
When the ultrasonic wave is transmitted from the probe 2 in a state where the ultrasonic wave is placed on the upper surface or the lower surface of the TB-A3 and the probe 2 is in contact with the guide portion 11, the ultrasonic wave is the standard defect 10 of the STB-A3.
Since the ultrasonic wave from the probe 2 is erroneously reflected by the end face of the STB-A3 because it is radiated to the substantially central portion of the No. 1, the conventional echo wave from the end face is erroneously detected. The problem goes away.

Since the scale 12 showing the horizontal distance from the reference defect 101 is provided along the guide portion 11, the probe 2 can be positioned easily and accurately. Further, even when the flaw detection test is performed using the probes 2 having different refraction angles, the skip position corresponding to each probe 2 can be set easily and accurately by using the scale 12 as a guide.

The jig 1 in FIG. 1 displays numerical values indicating the scale position at predetermined intervals, but a mark may be displayed at a predetermined skip position for each of a plurality of probes 2 having different refraction angles. . For example, in FIG. 4, the probe 2 has a refraction angle of 45.
Marks are added to the 0.5 skip horizontal distance position and the 1 skip horizontal distance position for each of degrees, 60 degrees, and 70 degrees. Specifically, when the refraction angle is 45 degrees, the black circle mark, when the refraction angle is 60 degrees, the black square mark,
When the refraction angle is 70 degrees, a black triangle mark is attached. By providing the marks as shown in the figure, the positioning of the probe 2 can be performed more easily.

[0031]

As described above in detail, according to the present invention, the jig is provided with the guide portion, and the ultrasonic probe is moved from the ultrasonic probe to the guide portion while the ultrasonic probe is in contact with the guide portion. When the sound wave is transmitted, the ultrasonic wave is irradiated to the substantially central portion of the reference defect on the STB-A3. Therefore, the reflected echo from the reference defect can be reliably detected, and the ultrasonic flaw detection test can be performed accurately. That is, unlike the conventional case, there is no possibility of erroneously detecting a reflection echo from the end face of STB-A3. Further, since the ultrasonic probe may be moved in a state of being in contact with the guide portion, the ultrasonic probe can be easily positioned, and thus the error in positioning can be reduced. Claim 2
According to the invention described in 1), the shape of the outer end surface of the jig and the STB
In order to make the shape of the end surface of -A3 equal and the outer dimensions of the jig and STB-A3 substantially equal,
It becomes easy to position the jig on B-A3. That is,
Since the outer end surface of the jig and the end surface of the STB-A3 may be placed so as to be substantially flush with each other, the jig can be positioned easily and accurately. According to the invention of claim 3, since the scale indicating the distance from the reference defect along the surface direction of the STB-A3, that is, the horizontal distance from the reference defect is provided along the guide portion, the scale is used as a guide. The ultrasonic probe can be positioned and the positioning error can be reduced. According to the invention described in claim 4, since the jigs can be placed on both the upper surface and the lower surface of the STB-A3, the flaw detection test can be performed in a plurality of different skip units. Further, since the jig is formed of a transparent material so that the scale can be confirmed even when the jig is turned upside down and placed, the jig can be placed on the upper surface or the lower surface of the STB-A3 with the same accuracy. The ultrasonic probe can be positioned.

[Brief description of drawings]

FIG. 1 is a view showing the shape of a jig of one example used in a flaw detection test using STB-A3.

FIG. 2. Probe refraction angle, 0.5 skip and 1
The figure which shows the relationship with a skip horizontal distance.

FIG. 3 is a diagram showing an example in which defect inspection is performed at one skip position using a probe having a refraction angle of 70 degrees.

FIG. 4 shows probe refraction angles of 45 °, 60 ° and 70 °.
The figure which shows the example which marked 0.5 skip and 1 skip horizontal distance position for each degree.

5A is a diagram showing a positional relationship between a defect inside a weld and a probe of an ultrasonic flaw detector, and FIG. 5B is a horizontal axis showing a defect echo detection time and a vertical axis showing an echo height. Fig.

FIG. 6 is an external view of a standard test piece STB-A2.

FIG. 7 is an external view of a standard test piece STB-A3.

FIG. 8 is a diagram showing a positional relationship between a standard test piece and a probe.

FIG. 9 is a diagram showing a defect flaw detection result displayed on a monitor.

FIG. 10 is a diagram in which peak positions of reflected echoes at respective probe positions are connected by a line.

FIG. 11 is a defect classification diagram for classifying defects inside a subject.

FIG. 12 is a diagram showing a state in which ultrasonic waves from a probe are displaced and reflected by an end surface.

[Explanation of symbols]

 1 jig 2 probe 11 guide part 12 scale

Claims (5)

[Claims] 1. A reference defect flaw detection jig that can be placed on the upper surface or the lower surface of a standard test piece STB-A3 having φ4 × 4 reference defects, wherein the jig is in the scanning direction of an ultrasonic probe. When the ultrasonic wave is transmitted from the ultrasonic probe in a state where the ultrasonic probe is in contact with the guide section, the transmitted ultrasonic wave is the reference. A reference defect flaw detection jig, wherein the guide portion is provided in an oblique direction with respect to the longitudinal direction of the jig so as to irradiate a substantially central portion of the defect. 2. The jig for reference defects according to claim 1, wherein the shape of the outer end surface of the jig and the shape of the end surface of the STB-A3 are substantially the same, and the outer dimensions of the jig and the S
A reference defect jig characterized in that the outer dimensions of TB-A3 are made substantially equal. 3. The jig for reference defects according to claim 1, wherein a scale indicating a distance from the reference defect along the surface direction of the STB-A3 is provided along the guide portion. Jig for reference defects. 4. The jig for reference defects according to claim 3, wherein two facing surfaces of the jig are mountable on the STB-A3, respectively, and a surface mounted on the STB-A3. A jig for reference defects, characterized in that the jig is made of a transparent material so that the scale can be confirmed from the facing surface direction. 5. A standard test piece STB-A3 having a φ4 × 4 standard defect is mountable on the upper surface or the lower surface of the standard test piece STB-A3, and has a guide portion for defining the scanning direction of the ultrasonic probe, and An ultrasonic flaw detection method using a reference defect flaw detection jig having a shape substantially equal to the shape of the end surface of STB-A3 and having an outer dimension substantially equal to the outer dimension of the end surface of STB-A3, comprising: The outer end face of the jig and the end face of the STB-A3 are aligned substantially flush with each other, and the ultrasonic probe is moved by bringing the ultrasonic probe into contact with the guide portion to position the ultrasonic probe, An ultrasonic flaw detection method using a reference defect jig, which transmits an ultrasonic wave toward the reference defect after completion of positioning and performs a flaw detection test based on a result of receiving the ultrasonic wave reflected by the reference defect.