JPS62254052A - Ultrasonic flaw detection of joint - Google Patents

Abstract

PURPOSE:To enable simultaneous detection of a defect at the center and on the surface across the thickness, by detecting a defect at a joint using a probe in alternate operations of a tandem type flaw detection and a single probe type flaw detection at a proper cycle. CONSTITUTION:In the flaw detection of material to be inspected, defects are detected at the center thereof across the thickness with a probe 27 in a tandem mode. In a single probe mode, a probe 29 is controlled in scanning by an operation control means 28to detect flaws on the entire press-fit surface of the material being inspected across the thickness. Here, according to an operation command signal from an operation time setting means 22, a flaw detection mode selection means 23 controls the work to operate the tandem mode system 24 and the single probe mode system 25 alternately at a proper cycle. This enables simultaneous flaw detection at the center and on the surface of the material being inspected across the thickness, thereby making the flaw detection work simple and efficient.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an ultrasonic flaw detection method for joints, which detects defects in joints such as pressure welds and welds. This invention relates to an ultrasonic flaw detection method for joints that can efficiently detect flaws in the direction perpendicular to the flaw detection surface that exist in the center of the thickness of a J11i inspection material, and flaws that exist on the surface and in the vicinity of the surface.

[Conventional technology]

As this type of ultrasonic flaw detection method, it is common to use a -probe method to detect flaws on the entire surface of a pressure welded part or a welded part. Fourth
The figure shows an example of an angle probe that searches for a pressure contact surface using the one-probe method. This is exactly the same even if the material to be inspected is a welded part. That is, in this flaw detection method, when searching the entire pressure contact surface of a material to be inspected, the scanning method differs somewhat depending on the form of the material to be inspected. For example, as shown in Fig. 4, when the side surface (of the plate thickness) of the material to be inspected 1 is used as the pressure contact surface 2, the bevel probe 3 is scanned in the direction of the arrow (A) shown in the figure, that is, in the front-rear direction. A sound wave beam 4 is transmitted and the entire area of the pressure contact surface 2 is ti21n by a direct reflection method. In addition, when the material to be inspected 1 is plate-shaped, the angle probe 3 can be repeatedly scanned in the left-right direction and the front-back direction while maintaining a state parallel to the pressure contact surface 2 of the material to be inspected 1. , an ultrasonic beam 4 is transmitted over the entire area of the press-contact surface 2 of the material 1 to be inspected, and the entire area of the press-contact surface 2 is inspected for flaws. Furthermore, when the inspected material 1 is cylindrical, the inspected material 1
After fixing, flaw detection is performed by scanning the oblique probe 3 in the circumferential direction and in the forward direction in the same manner as in the case of the plate shape. Of course, various combinations can be considered, such as scanning the bevel probe 3 in the front and back direction while rotating the cylindrical inspected material 1, or vice versa, but the essential difference is not that much. do not have. In addition, if necessary, perform the same +S scan as in Fig. 4 from the opposite side of the pressure contact surface 2, or perform the opposite side (
In some cases, scanning is performed from the back side of the plate.

On the other hand, in the super wave automatic probing method, in order to cover the entire area of the pressure welding surface 2 in the thickness direction of the material 1 to be inspected, multiple r1
Although one probe may be used, the following explanation will be limited to the case where one probe is used to simplify the explanation. As for the probe, the thickness and geometric shape of the pressure contact surface 2 of the material 1 to be inspected.

The most suitable probe for flaw detection is used, taking into account the dimensions, the type, shape, size, and location of the defect to be detected. Usually, when the material 1 to be inspected is steel, the frequency is 2 to 5 M.
Hz, vibrator dimensions 10x10.20x20. Refraction angle 4
5°, 60°, 70°, etc. (35° to 40° in special cases)
°) things are used.

Next, FIG. 5 is a diagram in which artificial flaws such as seeds and warts for sensitivity calibration are provided on the material 1 to be inspected.
, the same figure (1)) shows the horizontal hole flaw 6, and the same figure (c) shows the drill hole flaw 7 (horizontal hole flat bottom surface) in the central part of the i thickness. In the case of the slit flaw 5 shown in FIG.
~12.5%, and the slit depth does not affect ultrasonic flaw detection, but some standards require it to be less than twice the slit depth.

Slab 1 - The quality is formed to be about 25 to 5 Qmm.

In the case of the horizontal hole flaw 6 in the same figure (b), the position of the horizontal hole flaw is, for example, 1/2. It is.

On the other hand, in the case of the drill hole flaw 7 shown in FIG. 6(e), the diameter of the small hole flaw is generally about 2φ to 5.6φ. Therefore, when various artificial flaws 5.6.7 as described above are provided, after adjusting the sensitivity of the ultrasonic flaw detection device using such artificial flaws 5.6.78, the entire pressure contact surface of the inspected material 1 is We are conducting flaw detection. Incidentally, FIGS. 6 and 7 are experimental examples using the one-probe method, of which FIG. 6 shows an experimental test piece, and FIG. 7 shows the experimental method for other numbers.

In other words, a 3.2φ notrile hole flaw 7, depth Q, 55111 x width 1.0 III is made on the test piece 11 according to the dimensions shown in the diagram.
A slit flaw 5 of 11×length 251011 is provided, and the probe is, for example, 2Z10×10A40. A45゜A60
．． 5Z10X10A35. A40. A45°A60. A
70 etc., as shown in Fig. 7, the EDM notch flaw is 0.5.
This is an example in which the echo height is measured using the triangular reflection method (c) to a drill hole flaw of 0.758 using the direct reflection method (b) by S as a reference. Fig. 8 is a diagram showing the experimental results, and there is a difference of 12 dB or more between the 3.2φ drill hole flaw 7 and the slit flaw 5. When used as an artificial flaw for sensitivity a adjustment, the drill hole flaw 7 in the center of the plate thickness becomes undetectable. This means that defects on the front and back surfaces of the board (including those in the vicinity) can be detected, but defects in the center of the thickness of the pressure weld to be inspected cannot be detected.

On the other hand, the thickness of the plate is different from that shown in Fig. 6, and the center part of the plate has a depth of 0.5 mm x @1. Prepare a test piece 11 (Fig. 9) with a length of 250 ms and a slit bottom flaw 5, and use a probe of 5ZlOxlOA37 to form a slit with EDM notch flaws 1 and O8 as a reference according to Fig. 10. 1]-height and beam path of the bottom surface flaw 5, results as shown in FIGS. 11 and 12 were obtained. 10th
Figure (a) shows a single reflection method, Figure cb> shows a triangular reflection method, and Figure (C) shows one used as a reference. As is clear from this experimental result, the echo height for the slit bottom flaw 5 shown in FIG. 9 is, for example, 13.5 to 24. - The probe 1 method cannot detect defects in the center of the wall thickness, and there is no significant difference in detection sensitivity even if the defect depth (slit width) changes.

Therefore, as a means to solve the problem of defects in the central part of the plate thickness, it is necessary to adopt the tandem system shown in FIG. 13.

In this tandem method, a tandem probe 12 having a transmitting transducer 12a and a receiving transducer 12b is installed at a predetermined position on the surface material, and an ultrasonic beam is transmitted from the transmitting transducer 12a. This is a method for detecting flaws by transmitting a wave, for example, reflecting it at the flat bottom of a drill hole provided in the center of the plate thickness, and further reflecting it at the bottom of the material to be inspected, and receiving the reflected echo obtained by the receiving transducer 12b. However, since this tandem method may not detect defects on the plate thickness surface, we used a test piece similar to the test piece used in the experiment shown in Figure 6, and a 5Z5x10A4.5 tandem probe. 12 and 5Z1 similar to those used in the experiments in Figure 11.
Using 0X10A37 normal angle probe 3 (actually measured 39°)! ! ! When investigating the degree of sensitivity, when the tandem probe 12 was used and the sensitivity was adjusted with the drill hole flaw 7 with a horizontal flat bottom of 3.2φ, the slit flaw 5 became low at -27.5<18, and conversely, the slit flaw 5 When the sensitivity is adjusted using the flaw 5, the drill hole flaw 7 with the flat bottom of the horizontal hole becomes as low as -30.5 dB. This means that when the tandem method is adopted, defects in the center of the pressure contact surface of the inspected material can be detected, but defects on the plate surface cannot be detected.

[Problem that the invention seeks to solve]

Therefore, as mentioned above, when using the -probe method, it is difficult to detect defects in the center of the plate thickness, while when using the tandem method, defects at the plate surface and near the surface are difficult to detect. It is difficult to detect defects in the ultrasonic flaw detection Ii! same.

Feeling! Since it is necessary to perform i-adjustment and ultrasonic flaw detection twice each, the work becomes complicated and the efficiency of flaw detection decreases, which is a major problem when flaw detection is performed in a production line.

The present invention has been made in view of the above-mentioned circumstances, and enables simultaneous detection of defects in the center of the plate thickness and defects on the surface of the plate thickness.
The object of the present invention is to provide an ultrasonic flaw detection method for joints that can simplify flaw detection work and improve the efficiency of flaw detection.

[Means for solving problems]

According to the ultrasonic flaw detection method for joints according to the present invention, in the ultrasonic flaw detection method for joints that detects joints such as pressure welds and welds, at least a At least one probe having an S transducer and a receiving transducer is installed, and this probe is alternately used at an appropriate period to perform tandem method detection Ill and single probe method probing 111! 1 to detect defects in the joint.

[Effect]

Therefore, by using one or more of the above means, a probe having at least a transmitting 1III transducer and a receiving transducer installed at a predetermined position of a material to be inspected having a joint part can be used for example in a tandem type deep depth probe. Since the operation is controlled as
The tandem method and single probe method are used to perform flaw detection on the inspected material in one scan! It is possible to simultaneously detect defects in the central part of two thicknesses, the surface thereof, and the vicinity of the surface.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic block diagram of a flaw detection apparatus to which the method of the present invention is applied, and FIG. 2 is a diagram showing the configurations of a single probe method and a tandem method. In these figures 2
Reference numeral 1 denotes a detector (!1.lI meter) which gives required control signals to each component, receives and outputs signals of flaw detection results, and includes an operating time setting means 22 and a probe (n).
A method selection means 23 is connected. This operation time setting means 22 is composed of, for example, a timer, an inverter, a pulse generator, a frequency divider, and other logic circuits as necessary.
The operating time is set in the timer or pulse generator manually or automatically directly or via the control unit 21, and an operating command signal is output based on this setting operation 11HFII. The flaw detection method selection means 23 is constituted by a changeover switch, and performs flaw detection by alternately selecting the tandem method system 24 and the one-probe method system 25 for a predetermined time based on the U operation command signal from the operation time setting means 22. Control unit 2
1 and controls the operation of each prefecture 24.25.

The tandem type system 24 has an operation control means 26 for transmitting and receiving excitation signals and a tandem type probe 27, and the probe 27 is connected to the test chamber 31 during sensitivity adjustment and detection. On the other hand, the probe 27 is installed as shown in FIG. On the other hand, the -probe method system 25 transmits/receives excitation and other signals and scans in a predetermined direction.Dimension operation control means 28!3 and one-probe method probe 29 For example, as shown in FIG. 2(b), a slit flaw 33 is provided on the test piece 31, and the test piece 3
The probe 29 having a transmitting/receiving vibrator 29a and a receiving fi vibrating spindle 29b is installed on the surface opposite to the sulin 1 flaw 3311'l of No. 1, and the operation control means 28 moves the probe 29 between The drive is controlled to perform forward and backward scanning. 3
0 is the CR7 display section.

Therefore, in the flaw detection device as described above, the operation time is set in the operation time setting means 22, and each test piece 3
Probes 27 and 29 are attached to each of the predetermined devices of 1.
When the probe is installed, the first step is to give a command to start operation from the search department 21, adjust the sensitivity using the one-probe system 25, and then continue with the tandem system. An example will be described in which the sensitivity is adjusted using the flaw detection controller 24.When the flaw detection control section 21 outputs an operation start command signal, the operation time setting means 22 receives the operation command signal and selects the selection command signal. The flaw detection method) selection means 23 selects the −probe 7 method system 25 during the operation setting time.
f m Connected to the ib control unit 21 side. Thereafter, a control signal is given from the flaw detection system section 1 21 to the operation control means 28, and as a result, the operation control means 2B
is excited, and an ultrahigh wave beam is transmitted from the vibrator 29a.

This ultrasonic beam is propagated through the test piece 31, reflected by the slit flaw 33, and returned as a reflector. This reflected echo is sent to the CRT display section 30 via the detection bomb control section 21, and the reflected echo from the slit flaw 33 is displayed (FIG. 3(a)). The sensitivity of this reflected echo is adjusted by adjusting it to a specified height.

- After sensitivity adjustment using the probe method, sensitivity 1 using the tandem method
m [Perform adjustment. This sensitivity adjustment is performed by the operating time setting means 2.
A selection command signal is output from 2, and in response to this, the ring type selection means 23 connects the tandem type system 24 to the 1111 section 21 for flaw detection. At this time, when the operation control means 26 receives a control signal from the probe 1 control section 21, each vibrator 27a, 27
When the ultrasonic beam b is excited, an ultrasonic beam is transmitted from the transmitting transducer 27a. This L3 sound beam is propagated through the test piece 31, reflected at the flat bottom of the horizontal drill hole 32, further reflected at the bottom of the test piece 31, and the receiving transducer 27b receives the reflected echo from the flat bottom of the horizontal drill ball. do. Then, the reflected echo (e) shown in FIG. 3(b) is displayed on the CR, T display section 30 km, 1'j, and the reflected echo is adjusted to a specified height, and the sensitivity adjustment is performed. It will be done. In addition, in the above sensitivity adjustment, test piece 31
Naturally there is a quality of contact between the and the probe 27.29, but
It is omitted here. Also, for flaw detection purpose? ! !
The shape of the test question.

It goes without saying that sensitivity may be reduced depending on dimensions, surface roughness, etc.

And it feels like it's north! After performing the first adjustment, the pressure contact surface of the test material is searched. For example, assuming that the slit flaw 33 and the horizontal drill hole 32 are the pressure contact surface of the test material, the same adjustment as the above-mentioned adjustment is performed. Just follow the steps.

By the way, when detecting flaws in the material to be inspected, in the tandem method, as shown in the figure, by setting the end of the probe 27 at the 0 point of the 21i<(a>), the central part of the plate wave inspection material in the thickness direction is detected. In addition, in the case of the -probe method, if the probe 29 is controlled by the operation control means 26 so that it can scan within the range A-8 shown in FIG. 2(b), It is possible to search 111' for the entire pressure contact surface in the thickness direction of the material to be inspected. Then, such operation control is predetermined)! Flaw detection is performed from step 1, which is repeated in the i1 stage. Therefore, as is clear from the above points, using one operation control means 26 and one probe 27, the exploration method selection means 23 receives the operation command signal from the operation time setting means 22, for example. By selecting the tandem type ring tube and installing the 1'2 probe 27 at point tC shown in FIG. In response to the operation command signal, the flaw detection method selection means 23 selects the single probe method (U), and the probe 27 is selected as shown in FIG.
), the ultrasonic beam is sent while scanning from point A to point B, and the flaw detection operation is carried out (j). can be performed simultaneously in one scan. Therefore, tandem method and single probe method can be used for flaw detection using one probe. Sensitivity adjustment can also be performed using the same configuration. Of course, for flaw detection of the material to be inspected, it is also possible to use a structure in which the tandem method system 24 and the one-probe method system 25 are divided in advance as shown in FIG. good.

J5, when the material to be inspected is cylindrical, defects can be detected by scanning the probe in the axial direction while rotating the material to be inspected. The amount of movement of the probe may be less than or equal to the effective beam width of the probe (-6 dB). In addition, in the case of a plate-shaped material to be inspected, scan parallel to the tangential line, scan in the width direction, and then move by the effective beam width in the direction C-8 perpendicular to the tangential surface and move 1 earth contact ( By scanning in the 12th row, it is possible to cover all of the contact surfaces.

Note that the present invention is not limited to the above embodiments.

For example, when recording the flaw detection results, it is sufficient to connect a recording device to the depth control section 21, and also connect the recording device to the flaw detection control section 21.
If an alarm device is connected, an alarm can be generated when the reflected echo exceeds a predetermined level, and the defective part of the inspected material can be marked by the alarm.

Further, one ultrasonic beam generally has two transducers, but it is also possible to provide three transducers or more.

(Effects of the Invention) As described above, according to the present invention, a probe having at least a transmitting vibration vJ'f- and a receiving vibrator is installed at a predetermined position of a material to be inspected, and a tandem method is used. If the probe is operated based on illt[I and the probe is scanned υ1111 based on the one-probe method, flaw detection using the one-probe f-method and tan- 1 I'm method detection (m) can be performed simultaneously, making it possible to detect flaws in the central part of the thickness of the material to be inspected and on the surface of the plate, as well as flaw detection work 1!!! Rating and flaw detection work It is possible to provide an ultrasonic flaw detection method for joints that can efficiently perform the following steps.

[Brief explanation of drawings]

Figures 1 to 3 are shown to explain one embodiment of the method of the present invention. Figure 1 is a schematic configuration diagram of a search mix to which the method of the present invention is applied, and Figure 2 is a tandem system. Figure 3 is a diagram explaining the configuration of the one-probe method; Figure 3 is a diagram showing the display state of reflected echoes in the tandem method and the one-probe method;
12 to 12 are diagrams for explaining the conventional one-probe method, and FIG. 4 shows the pressure measurement by the one-probe method. Figure 5 shows various types of artificial flaws vAJ3 and its detection configuration, Figure 6 shows test specimens for experiment, Figure 7 explains the experimental method, Figure 8 shows the experiment. Characteristic diagram showing the results,
Figures 9 through 12 are diagrams illustrating an experimental example using a test piece with a thickness different from Figure 6, and Figure 13 is a diagram showing a flaw detection configuration using a tandem method. 21...Flaw detection control section, 22...Operation time setter 11
．． 23... Flaw detection method selection means, 24... Tandem method thread, 25...-probe method system, 26.28... Operation control 3114-12° 27.29... Probe, 27a
...Transmission transducer, 27b...Reception tIiii1
1st child, 29a...Sentence for communication and reception, 31...Examination Ha, 32.33...Flaws. Applicant's agent Patent attorney Suzu )・■ Takehiko Figure 1 3'1 (a) (a) Go53N (b) Figure 5 Figure 7 Figure 8 Figure 9 (e) Thrime height (ITITI) --- Pickpocket/1・Height m11) ---Figure 11

Claims (1)

[Claims] In an ultrasonic flaw detection method for joints that detects joints such as pressure welds and welds, at least one transducer having at least a transmitting transducer and a receiving transducer is placed at a predetermined position of the material to be inspected having the joint. A joint part characterized in that a probe is installed, and the operation of the probe is controlled alternately in tandem method flaw detection and -probe method flaw detection at appropriate intervals to detect defects in the joint part. Ultrasonic flaw detection method.