JPH01158348A - Ultrasonic flaw detection equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an ultrasonic flaw detection apparatus used for nondestructively testing an object to be flawed, such as a turbine disk.

(Prior art) This type of ultrasonic flaw detection device that has already been proposed is
It is constructed as shown in the figure and FIG. 13.

That is, in FIGS. 12 and 13, a turbine rotor as the object W to be tested is mounted on a turbine shaft a. That is, the turbine disk W is formed of a hub W2 and a web W3, and a key W5 is placed in a key groove W4 formed in the hub W2.
are integrally fixed.

Therefore, when a defect (crack) W6 occurring in the key groove W4 as the object W to be tested is inspected by ultrasonic flaw detection using non-destructive testing, an ultrasonic probe is placed on the outer peripheral surface of the hub W2. This is done by placing them in contact.

That is, by emitting the ultrasonic beam B from the ultrasonic probe to the key groove W4, the reflected waves (reflected echoes) due to the tip of the defective portion W6 and the shape of the key groove W4 are detected by the ultrasonic probe. Receive at the receiver of the antenna.

Then, as shown in the graph of FIG. 13, the ultrasonic probe detects the defective part W6 at an echo level b1,
On the other hand, the shape of the keyway W4 detects the echo level b2 at a position shifted by the beam path difference Δg. Further, the defect depth is usually measured as d-6g based on the beam path difference Δg between the echo level bl and the echo level b2.

On the other hand, when the defect W6 occurring in the keyway W located directly below the web W3 of the object W to be tested is inspected by ultrasonic testing, it is carried out as shown in FIGS. 14 and 15. .

That is, a transmitting (transmitting) bevel probe C and a receiving probe d are arranged side by side on the outer periphery of the hub portion W2 located on both sides of the web W3.

Next, by transmitting the ultrasonic beam B from the transmitting angle probe C at an angle β, this ultrasonic beam B has an incident angle γ of approximately 45″ to the tip of the defective portion W6. Then, the reflected echo at the tip of the defective portion W6 is received by the receiving probe d.Furthermore, the transmitting probe C The receiving probe d is synchronously moved and inspected while moving the outer periphery of the hub portion W2 in the circumferential direction.

In this way, the transmitting probe C and the receiving probe d
By moving in the circumferential direction in synchronization with the keyway W4, the entire keyway W4 is inspected for flaws.

Therefore, the ultrasonic waveform data obtained from the ultrasonic beam B of the transmitting probe C and the receiving probe d is processed using a signal processing method with an algorithm called the ALOK method. It is designed to measure W6 and its dimensions.

In particular, as shown in FIG. 14, when the key W5 fitted in the keyway W4 is pressed against the keyway W4 by stress in the circumferential direction, the key W5 and the scale existing in the keyway W4 are affected. , key corner (key corner) C1,
Sometimes a pseudo echo is detected from C2, and the "orientation result" (also called measurement result) after signal processing of the ultrasonic waveform information detected in the state of this pseudo echo is as shown in Figure 15. , are located as indicators at positions corresponding to each key corner CI, C2.

Furthermore, even when there is no defective portion W6, each indication C+ is generated by the pseudo echo as described above.

Since C2 is to be located, there is a risk that even when there is no defect, it may be mistakenly detected as if there was a defect.

(Problems to be Solved by the Invention) As described above, the above-mentioned ultrasonic flaw detection means detects the influence of the keyway W, the key W5, the scale, etc. when inspecting for defects in the keyway W in the turbine disk as the object W to be tested. There is a risk of detecting a false echo that is received, and there is a problem that this false echo may be erroneously determined to be a defective part.

The present invention has been made in view of the above-mentioned circumstances, and is provided in an ultrasonic flaw detection apparatus for non-destructively testing an object to be tested. By transmitting and receiving data with different refraction angles for each probe of the sonic probe, you can distinguish between defective echoes and false echoes detected at the defective part, or remove false echoes to improve the quality of the defective part. An object of the present invention is to provide an ultrasonic flaw detection device that can accurately detect and measure the size of a defective part.

[Structure of the invention]

(Means for Solving the Problems and Their Effects) The present invention provides an ultrasonic flaw detection apparatus for non-destructively testing an object to be tested, in which a pair of scanners are provided around the outer periphery of the object to be tested in synchronization so as to be freely movable. , this one scanner is provided with a multi-ultrasonic probe for transmitting, which includes a first transmitting probe and a second transmitting probe, and the other scanner is equipped with a first receiving probe and a transmitting multi-ultrasonic probe. A receiving multi-ultrasonic probe equipped with a second receiving probe is provided, and the signals obtained by transmission and reception between the transmitting multi-ultrasonic probe and the receiving multi-ultrasonic probe are centrally processed. By switching the transmitting beams of the first transmitting probe and the second transmitting probe so as to be displayed on the display through the processing device, A/D converter, and signal processor, the defective portion of the object to be tested is detected. In addition to detecting the defects with high precision, the size of the defective portion is determined by 71gj.

(Embodiment) Hereinafter, an illustrated embodiment in which the present invention is applied to defect inspection of a fitting surface between a turbine disk and a rotor shaft and a keyway will be described.

It should be noted that the present invention will be described with the same reference numerals attached to the same constituent members as in the above-described specific example.

In FIG. 1, numerals 1 and 2 refer to the hub W of the object W to be tested.
A pair of scanners are provided so as to be freely movable so that a web W3 is sandwiched between the outer periphery of the scanner 1, and one of the scanners 1 is provided with a multi-ultrasonic probe 3 for transmission. The transmitting multi-ultrasonic probe 3 also includes a first transmitting probe 3a that transmits ultrasonic waves at an inclination angle of a probe refraction angle βi (γi) of about 40 to 50 degrees, and a A second transmitting probe 3b transmits ultrasonic waves at an inclination angle of a probe refraction angle βi (γi) of about 65 to 75 degrees.

3C, and the other scanner 2 is provided with a receiving multi-ultrasonic probe 4. Further, inside this receiving multi-ultrasonic probe 4, there is a first receiving probe 4a that receives ultrasonic waves at an inclination angle of a probe refraction angle βi (γi) of about 40 to 50 degrees, 65 to 75
Second reception probes 4b and 4c are provided which receive ultrasonic waves at an inclination angle of a probe refraction angle βi (γi) of approximately 1.5 degrees.

On the other hand, a scanner controller 5 is connected to both the scanners 1 and 2 through respective lead wires 6a and 6b, and this scanner controller 5 includes a central processing unit (C, P, U) 7 and a position detection unit. device 8 is connected. The transmitting multi-ultrasonic probe 3 and the receiving multi-ultrasonic probe 4 are connected to a multi-channel pulser-receiver group 9 via respective lead wires 10a and 10b. The pulsar receiver group 9 includes the central processing unit (C, P, U) 7 and A/
A D converter 11 is connected. Furthermore, the central processing unit 7 and the A/D converter 11 are provided with software that uses an algorithm called the ALOK method to convert the ultrasonic waveform data converted into digital values and the probe position information detected by the position detector 8. A built-in signal processor 12 is connected to the signal processor 12, and a display 13 for displaying the signal processing results is connected to the signal processor 12.

In particular, the first transmitting probe 3a and the first receiving probe 4
The incident angle of the ultrasonic beam B at a, that is, the probe refraction angle β
It has been experimentally confirmed that when i (γi) is, for example, 45 degrees, the sensitivity is maximum and the echo level shown in the graph of Figure 3 is shown, and the incident angle γi of this ultrasonic beam B is It has been experimentally confirmed that pseudo echoes are clearly detected at 45 degrees, but are not detected under the flaw detection condition where the incident angle γi is 70 degrees.

Also, as is clear from the graph in FIG. 3, the defective portion W6
The change in the reflected echo level from the incident angle of 71° is 45°.
At ~60＠, the echo level remains constant at a high level, but it decreases rapidly at an incident angle of γiζ of 60 degrees, and when the incident angle exceeds γ1-60 degrees, the reflected echo gradually increases, and around γiζ of 70 degrees, the echo level is sufficient to reflect. It has been confirmed that echoes can be detected.

As shown in the graph of FIG. 5, when the incident angle γiL is near 0'', defect detection is performed and defect echoes can be detected, but pseudo echoes are not detected.
! ? A probe with a probe refraction angle βi of 70″ is:
It can be used as a probe for identifying false echoes and defective echoes.

Next, as shown in FIG. 6 and FIG. When the surfaces are moved synchronously, as shown in FIG. 6, when there is a defect W6 on the object W to be tested, and as shown in FIG. 7, when there is no defect W6 on the object W to be tested, The transmitting probes 3b, 3c of the transmitting multi-ultrasonic probe 3 and the receiving probes 4b, 4 of the receiving multi-ultrasonic probe 4
If flaw detection is performed by transmitting ultrasonic beam B and receiving ultrasonic beam B, for example, when the entire keyway W4 is flaw-detected, each of the above-mentioned transmitting probes 3b, 3c and each receiving probe 1b, 4c. The relationship between the position and the path of the ultrasonic beam B is as shown in Fig. 8(a).
The results shown in (b) and (c) were obtained.

That is, in FIGS. 8(a), (b), and (c), the flaw detection results when there is a defect W8- in the keyway W are the flaw detection results obtained by the above-mentioned transmitting probe 3c and receiving probe 4c. In this case, pseudo echoes are detected in addition to defect corner echoes, defect edge echoes, and shape echoes.

In addition, in the case of flaw detection using the transmitting probe 3b and the receiving probe 4b for identifying pseudo echoes, defect corner echoes and shape echoes are detected, but pseudo echoes and defective edge echoes are not detected. As a final orientation result obtained by signal processing these two flaw detection data using an algorithm called the original ALOK method, the defect size d is determined as shown in FIG. 8(C).

On the other hand, as shown in FIG. 7, there is a defective part W in the keyway W4.
6 is absent, the flaw detection result is detected by the transmitting probe 3C for defect size measurement and the receiving probe 4C, and the pseudo echo is detected by the transmitting probe 3B for identifying pseudo echoes and the receiving probe 4C. No flaws are detected by the flaw detection using the probe 4b, and only the shape echo is detected at this time, so the signal is processed by the signal processor 12 as shown in FIG.
As shown in C), a "location result" can be obtained.

In this way, when inspecting for defects in a state where the keyway W4 is in contact with or pressed under various conditions, the incident angle γiζ7
Second transmitting probe 3c with flaw detection conditions near 0″
However, if flaw detection is performed using the second receiving probe 4b, defective echoes will be detected.

No false echoes are detected. Furthermore, the incident angle γi'-45' of the first transmitting probe 3a and the first receiving probe 4a, which detect defect edge echoes with high sensitivity, and the second transmitting probe 3b and the second By using it in combination with the receiving probe 4b, it is possible to measure the defect size with high precision, and therefore, appropriate defect inspection can be carried out.

Therefore, as shown in FIG. 1, by installing a pair of scanners 1 and 2 along the outer periphery of the hub W2 and moving them synchronously, the transmitting multi-ultrasonic probe of the one scanner 1 can be Refraction angle 4 from the first transmitting probe 3a of the instrument 3
By transmitting the 5° ultrasonic beam B, this ultrasonic beam B detects the defective part W6, and the defective echo is received by the first receiving probe 4a of the other scanner 2, which is transmitted through multiple channels. Pulsar receiver group 9-A/D converter 11
-Display on the display 13 via the signal processor 12.

On the other hand, the second transmitting probes 3b and 3c of the transmitting multi-ultrasonic probe 3 are switched to the second transmitting probes 3b and 3c.
, 3c, the ultrasonic beam B with a refraction angle of 70'' is detected, and the ultrasonic beam B detects the defective portion W6.
The defect echo is sent to the second receiving probe 4 of the other scanner 2.
The signal is received at 4c and 4c, and is displayed on the display 13 via the multi-channel pulser receiver group 9, the A/D converter 11, and the signal processor 12. At this time, these displays are displayed as shown in FIGS. 8(a), (b), and (c), as described above.

Next, FIGS. 9 and 11 show other embodiments of the present invention, in which an array type probe is used instead of the transmitting multi-ultrasonic probe 3 and the receiving multi-ultrasonic probe 4. This is what I did to my child.

That is, each shoe 14.15 is provided on the hub portion W2 so as to be in contact with each other and move synchronously, and each shoe 14.15 has a large number of transmitting transducers 16a in the transmitting array probe. 16 and a receiving array probe 17 having a large number of receiving transducers 17a, each transducer 16a, 16b, 17a, 17b has a refraction angle of 4.
By setting the angles to be 5° and 70°, highly accurate defect inspection can be performed.

In addition, each vibrator 16a of the above-mentioned array probe.

Although 16b, 17a, and 17b are shown in the circumferential direction of the hub portion W2, it goes without saying that they may be arranged side by side in the axial direction without changing the gist of the present invention.

On the other hand, in the present invention, as shown in FIG. 10, the object W to be tested is divided into two structures W7. The method shown in Fig. 11(a) can be applied to W8, and also to such an object W to be tested.
, (b) and (c), the defective portion can be detected.

〔Effect of the invention〕

As described above, according to the present invention, in the ultrasonic flaw detection apparatus for non-destructively testing the object W to be tested,
A pair of scanners 1 and 2 are provided on the outer periphery of the scanner so as to be able to travel freely in synchronization, and one of the scanners 1 is equipped with a first transmitting probe 3a.
and a second transmitting probe 3b, 3c is provided, and the other scanner 2 has a first transmitting probe 3b and a second transmitting probe 3b, 3c.
A receiving multi-ultrasonic probe 4 including a receiving probe 4a and second receiving probes 4b and 4c is provided, and the transmitting multi-ultrasonic probe 3 and the receiving multi-ultrasonic probe 4 are provided with a receiving probe 4a and a second receiving probe 4b, 4c. The signals obtained by the transmission and reception of the contactor 4 are sent to the central processing unit 7, A/
Since the information is displayed on the display 13 through the D converter 11 and the signal processor 12, it is possible not only to perform highly accurate measurements, but also to measure the defect size, thereby improving reliability. Has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the ultrasonic flaw detection device of the present invention, FIGS. 2 to 8 are diagrams for explaining the present invention in detail, and FIG.
11(a), (b), and (c) show other embodiments of the present invention, and FIGS. 12 to 15 show an already proposed ultrasonic flaw detection device. They are each line diagram. 1.2...Scanner, 3...Multi-ultrasonic probe for transmitting, 3a...1st transmitting probe, 3b, 3c...
・Second transmitting probe, 4... Receiving multi-ultrasonic probe, 4a... First receiving probe, 4b, 4c...
Second receiving probe. Applicant's representative Mr. Sato Figure 6 Figure 7 Figure 10 (a) Scratches caused by 3c (b) Deep depth caused by 3b (C) Test results Figure 1I Figure 15 Figure 14

Claims (1)

[Scope of Claims] 1. In an ultrasonic flaw detection device for non-destructively testing an object to be flawed, a pair of scanners is provided around the outer periphery of the object to be flawed so as to be movable in synchronization, and one of the scanners is provided with a first transmitter. A transmitting multi-ultrasonic probe including a transmitting probe and a second transmitting probe is provided, and the other scanner is equipped with a first receiving probe and a second receiving probe. A receiving multi-ultrasonic probe is provided, and the signals obtained by the transmission and reception between the transmitting multi-ultrasonic probe and the receiving multi-ultrasonic probe are sent to a central processing unit, an A/D converter, and the signal. An ultrasonic flaw detection device characterized by displaying information on a display through a processor. 2. The first transmitting probe and the first receiving probe have a probe refraction angle of about 40 to 50 degrees, and the second transmitting probe and the second receiving probe The ultrasonic flaw detection apparatus according to claim 1, wherein the probe has a refraction angle of about 65 to 75 degrees.