JP2934352B2 - Ultrasonic inspection method and apparatus for friction welding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and an apparatus used for quality control and quality assurance of a pressure-welded interface of a material or a product manufactured by friction welding, and more particularly, to an inspection method and apparatus using ultrasonic waves. TECHNICAL FIELD The present invention relates to a method and an apparatus for ultrasonically inspecting a friction welding material for inspecting a bonding state of a member.

[0002]

2. Description of the Related Art Friction welding using the energy of frictional heat has high mechanical strength of a joint, does not require a welding rod or a solvent, does not require special beveling, has high energy efficiency, and is a welded object. High accuracy in shape and dimensions, joining of dissimilar metals is possible, saving materials, reducing man-hours,
Because of its features such as short welding time, high working efficiency, automatic welding and high reliability, it is widely applied to many mechanical parts including automobile parts.

For example, when this method is applied to the joining of carbon steels, if the welding is performed under the conditions of high friction pressure and short friction time, the austenite temperature near the friction surface (A ₁ transformation point)
The portion heated above has a crystal grain size of 10 to 50 μm.
, And a stable joint surface can be obtained. Also, unlike other welding (arc welding, gas welding, etc.), this joint does not have a melted or solidified portion, so slag entrainment, generation of pores, shrinkage cracking at the time of solidification, and the like are hardly observed.

However, when a general steel material or a dissimilar material is joined by friction welding, a defect may be generated at or near the joint, and it is determined by visual observation or the like that there is a defect in the external region. Can not do.

Therefore, a vertical flaw detection method using ultrasonic waves is used as a means for easily inspecting these defects and other abnormalities. As shown in FIGS. 2 and 3, the defect inspection by the vertical flaw detection method uses one end face of the friction welding material 101, and applies a longitudinal ultrasonic wave to the probe 102 through a couplant such as oil. CRT 1 is captured by an A scope (DC amplitude display) by catching a reflected wave which is reflected by the defect 104 (macro defect) and the bottom surface 105 of the press-welding material.
This is a method of checking the presence or absence of the reception sound pressure of the defect echo F appearing between the transmission pulse T and the bottom surface echo B from the display of 07 (FIG. 3).

As a method for solving the above-mentioned problem, a defect inspection method using a two-probe (reflection or transmission) method of a water immersion method has been proposed. In this inspection method, as shown in FIG. 4, a probe 108a transmitting ultrasonic waves 110 and a probe 108b receiving ultrasonic waves 110 are arranged at predetermined positions, and the presence or absence of a defect echo F is checked by the same flaw detector 109 as described above. It is. (Fig. 5)

[0007]

However, in the former defect inspection by the vertical flaw detection method, cracks or unclamped portions at the valleys of the burrs 106 remaining during the friction welding shown in FIG. Macro defects (0.5 mm or more) that can be observed with a microscope having a magnification of several tens of times, such as those shown in FIG.
There is a problem that micro defects (0.1 mm or less) such as gap defects and inclusions cannot be inspected. That is, in this conventional inspection method, since the probe 102 is brought into contact with the friction welding material 101, there is a problem that the true contact area is not always constant on a practical surface. Therefore, when ultrasonic waves are incident on the end face of the friction welding material 101, the diameter of the friction welding material 101 is sufficient compared to the diameter of the probe (the diameter of the friction welding material 101 is three times or more the diameter of the probe). If it is not large, ultrasonic waves are reflected on the side surface of the friction welding material, so-called mode conversion occurs, and a delayed echo and a pseudo echo are generated, which makes it difficult to detect a defect.
As a result, an inspection error such as an abnormality in the destructive test result despite the presence of the defect echo or an abnormality in the destructive test result without the defect echo occurs.

In the latter two-immersion probe method, unlike the reflection method (using one probe), the transmission method (probe 2) is used.
Probe 1) in the axial direction of the friction welding material 111.
08a and 108b need to be scanned. At this time, when the probe 108a is scanned to the right, the pressing interface 11
Probe 108 to receive the transmitted wave defect signal from
b needs to be scanned to the left, the probes 108a,
It is difficult to always set the positional relationship of 108b constant, and there is a problem in that a complicated device configuration must be used in order to reliably obtain the ultrasonic transmission signal and the reception signal in three dimensions.

On the other hand, recently, the control technology of the friction welding machine has been improved, and the defects to be inspected such as burrs, cracks and macro unbonded parts are not micro defects but macro defects as described above. And it has come to the level. In other words, even higher quality is required for friction welding materials than in the past, and a higher level of soundness is required, such as the strength of the welded part being higher than the base metal strength and not breaking at the welded interface. Have been. Such a request,
In order to guarantee non-destructive, that is, ultrasonic, it is more urgent to establish a strict inspection technique for internal defects for defects in a micro region.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems of the prior art, and have conducted various systematic experiments. As a result, the present invention has been accomplished.

(Object of the Invention) It is an object of the present invention to provide a method and an apparatus for ultrasonically inspecting a friction welding material capable of simultaneously detecting a macro defect and a micro defect inside the friction welding material.

It is another object of the present invention to provide an inspection method and an inspection apparatus which make a pass / fail judgment based on the inspection result and can assure quality such as pressure contact strength.

The present inventors have focused on the following with respect to the above-mentioned problems of the prior art. In other words, the defects generated at the friction welding interface to be inspected by the present invention include precipitates generated by joining of dissimilar metals and micro defects generated by coarsening of crystal grains, and the like. We focused on the point that it is essential to identify the degree and the like more accurately.

Therefore, in order to satisfy the above conditions,
By actively using forest-like echoes, which had previously been considered unnecessary noise as it affected echoes from defects in inspections using ultrasonic waves and made flaw detection difficult, and by using a convergent beam to scan finely It has been found that the presence of the echo is related to a bonding defect, that is, a microdefect caused by the coarsening of the crystal grain. Therefore, from the information indicating the defect of the portion including the forest-like echo included in the backscattered wave due to the change of the structure such as the coarsening of the crystal grains from the vicinity of the friction welding portion, the micro defect and the macro defect inside the friction welding material are determined. The present invention has been achieved by focusing on solving the above-mentioned conventional problem by detection.

[0015]

[Means for Solving the Problems]

(Structure of the first invention) In the ultrasonic inspection method for a friction welding material according to the first invention, the convergence point of the ultrasonic beam from the ultrasonic probe to the friction welding material is determined at a predetermined position inside the friction welding material. And obliquely incident so as to detect backscattered waves from a defect existing inside the friction welding material, and detect an internal defect from information indicating a defect including a forest-like echo included in the backscattered wave. It is characterized by doing.

(Structure of the Second Invention) An ultrasonic inspection apparatus for a friction welding material according to the second invention is an apparatus for inspecting a defect including a micro defect inside the friction welding material using an ultrasonic wave. An ultrasonic probe, disposed at a predetermined position with respect to the friction welding material to be inspected, so that a convergence point is a predetermined position inside the friction welding material, and the ultrasonic probe Inspection wave supply means arranged so that the ultrasonic beam emitted from the probe is obliquely incident to the axial direction of the friction welding material, the ultrasonic beam emitted from the inspection wave supply means,
Beam scanning position control means for controlling the position of the friction welding material and / or the inspection wave supply means so that a predetermined position inside the friction welding material is scanned in a circumferential direction and / or an axial direction; A defect signal detecting means for detecting a backscattered wave including a forest-like echo among the beams in which the ultrasonic beam emitted from the inspection wave supplying means is scattered by a defect existing inside the friction welding material; and the defect signal. An arithmetic processing means for detecting an internal defect of the friction welding material from an internal defect signal of the friction welding material including a forest echo output from the detecting means, and accurately detecting a defect including a micro defect inside the friction welding material. Is detected.

[0017]

The mechanism by which the ultrasonic inspection method and apparatus for a friction welding material of the present invention exhibit excellent effects is not necessarily clear yet, but is considered as follows.

(Function of the First Invention) In the ultrasonic inspection method for a friction welding material according to the first invention, first, an ultrasonic beam from an ultrasonic probe is converged on the friction welding material so that the convergence point is set to the friction welding material. When the light is incident obliquely so as to be at a predetermined position inside the (object), the light is reflected and reflected by the sound velocity difference between the object and the couplant at the interface between the object and the couplant (a liquid such as water).
Refraction occurs and the transmitted beam produces scattered waves from the defect. That is, as illustrated in FIG. 6, the vicinity of the pressure-welded interface of the friction-welded material is affected by frictional heat, and the crystal orientation of the structure has anisotropy. This anisotropy changes the speed of sound of the ultrasonic waves, causing a difference in acoustic impedance at the crystal grain boundaries. The transmitted beam is partially reflected by a difference in the local acoustic impedance of the grain boundary and becomes a scattered wave.
This scattered wave has information corresponding to the tissue state.
Next, this scattered wave, that is, a backscattered wave from a defect existing inside the friction welding material is detected. Conventionally, in an inspection using ultrasonic waves, a forest-like echo has been considered as unnecessary noise because it affects a defect echo from a single defect and makes flaw detection difficult. However, in the present invention, the forest-like echo from the minute area is positively used, and is detected as information indicating a defect of the friction welding portion including the forest-like echo. Next, an internal defect including a micro defect and / or a macro defect of the friction welding material is detected from information indicating a defect including a forest echo included in the backscattered wave.

(Function of the Second Invention) The ultrasonic inspection apparatus for friction welding material according to the second invention is an apparatus for inspecting a defect including a micro defect inside the friction welding material by using ultrasonic waves. It comprises a wave supply unit, a beam scanning position control unit, a defect signal detection unit, and an arithmetic processing unit. The inspection wave supply means has an ultrasonic probe disposed at a predetermined position with respect to a friction welding material (test object) to be inspected, and has a convergence point within a predetermined range inside the friction welding material. And the ultrasonic beam emitted from the ultrasonic probe is obliquely incident on the friction welding member in the axial direction. Further, the beam scanning position control means controls the friction so that the ultrasonic beam emitted from the inspection wave supply means scans a predetermined position inside the friction welding material in a circumferential direction and / or an axial direction. The position of the pressure welding material and / or the inspection wave supply means is controlled. Irradiated from the test wave supply means, when the ultrasonic beam whose irradiation position is controlled by the beam scanning position control means is incident on the subject, at the interface between the subject and the couplant at the interface between the subject and the couplant. Reflection and refraction occur due to the difference in sound speed, and scattered waves from defects occur due to the transmitted beam. Next, in the defect signal detection means, among the beams scattered by the defect existing inside the friction welding material, a forest-like echo which has conventionally been regarded as noise which affects the echo from the defect and makes flaw detection difficult. And outputs as an internal defect signal of the friction welding material. Next, in the arithmetic processing means,
An internal defect of the friction welding material is detected from an internal defect signal of the friction welding material including a forest echo output from the defect signal detecting means. Thereby, a defect including a micro defect inside the friction welding material can be accurately detected.

[0020]

【The invention's effect】

(Effect of the First Invention) According to the ultrasonic inspection method of the friction welding material of the first invention, it is possible to simultaneously and accurately detect a macro defect and a micro defect inside the friction welding material.

(Effect of the Second Invention) The ultrasonic inspection device for a friction welding material of the second invention can simultaneously detect a macro defect and a micro defect inside the friction welding material, and can detect the defect. It can be specified accurately.

[0022]

【Example】

In the following, the invention (specific examples) which further embodies the first invention and the second invention will be described.

The backscattered wave from the minute area to be detected in the present invention is, as exemplified by the A scope in FIG. 7, an echo T from the sample surface and a forest echo F (a plurality of echoes F are used here). (Defined as a forest-like echo F). In the forest-like echo F, since the inspection object of the present invention is in the friction welding state of the friction welding material, the thickness in the vicinity of the welding interface of the portion is as thin as several mm, and the other areas are in a state close to the base material. However, since the target area of the forest-like echo is different from other areas, it is limited to a small area. Since this area is an area to be inspected (received) for the friction welding interface, a situation arises in which the gate width can be reduced and a plurality of echo components can be detected.

In the present invention, it is preferable that the test wave supply means comprises a plurality of ultrasonic probes having different frequency bands. Thus, even when the kind of the material and the size of the friction welding material are different, it is possible to easily cope with the case.

Further, the defect signal detecting means has means for performing a correlation process on the detected internal defect signal to remove noise, and an arithmetic processing means converts the signal output from the defect signal detecting means into a digital signal processing signal. Signal conversion means for converting the count value into a echo pulse count value, and dividing the count value into sound pressure echo levels at predetermined intervals of a received sound pressure and quantifying the count to indicate the degree and / or position of internal defects in the friction welding material The internal defect output signal output from the arithmetic processing means, and the information of the knowledge base indicating the relationship between the number of echo pulses and the press-fitting strength prepared in advance, It is preferable to determine the pass / fail of the test object based on the comparison result.

An embodiment of the present invention will be described below.

[0028] The ultrasonic inspection apparatus of the first embodiment the first embodiment will be described with reference to FIG. 1, FIGS. 8 to 13. Ultrasonic inspection apparatus 10 of the present invention
Are inspection wave supply means 20 and beam scanning position control means 3
0, defect signal detecting means 40, arithmetic processing means 50,
It comprises a display means 60 and an inspection water tank 90.

The inspection wave supply means 20 includes a linear convergence type ultrasonic probe 21 which also serves as a transmission / reception and also serves as a defect signal detection means 40, and an unnecessary sound wave fitted to the tip of the probe 21. And a collimator 22 to be removed. Ultrasonic probe 21
The ultrasonic wave irradiated in the side direction of the friction welding member 80 as the object is converged linearly by the position of the probe 21 and the collimator 22 (FIG. 9), and the object is observed in the cross-sectional direction. The convergence point is arranged at the central axis point of 80 (FIG. 8). At this time, in order to obtain a convergence point on the central axis shown in FIG. 8, the ultrasonic beam convergence point determination jig 23 having a thin wire also serving as a tailstock for supporting and fixing the subject 80 shown in FIG. Perform by using. The ultrasonic probe 21 has a frequency of 15 MHz, an incident angle of an ultrasonic beam from the probe of 18.9 degrees, and a refraction angle of 4
It is arranged so as to form a transverse wave of 5 degrees.

The beam scanning position control means 30 includes a computer section 31, a controller section 32, and a motor section 33.
And a mechanical scanner unit 36. The computer unit 31 determines the position of the friction welding member 80 and / or the position of the test wave supplying means 20 based on the information indicating the position of the friction welding material 80.
And a control amount for controlling the position of the test wave supply means 20 and outputs the result to the controller 32.

The controller unit 32 controls the synchronization of the electric system, and includes an IC for interrupting the I / O and the CPU, an A / D converter, a D / A converter (both not shown), and the like. Based on the control signal output from the unit 31, the electric power supplied to the motor for controlling the position of the friction welding material 80 and the position of the inspection wave supplying means 20 is adjusted. The motor unit 33 includes a friction welding material 80 based on the electric power output from the controller unit 32.
And a first motor 3 for continuously variably controlling the rotation angle of the control shaft so that the position of the inspection wave supply means 20 is set at a predetermined position.
31 and a second motor 332, each of which is provided with an encoder (not shown) for position detection.

The mechanical scanner unit 36 is configured to
Turntable 36 for holding and rotating the subject 80
1 and a probe holding means 36 for holding the ultrasonic probe 21
2 and five axes (X, Y, Z, θ, R). The turntable 361 is driven to rotate by the first motor 331 to rotate the subject 80, and the probe holding means 362 is driven by the second motor 332 to move the position of the probe 21 to the axis of the subject 80. Move in the direction. Thus, the friction welding material and / or the ultrasonic beam irradiated from the inspection wave supplying means 20 are scanned in a predetermined position inside the friction welding material in a circumferential direction and / or an axial direction. The position of the inspection wave supply means is controlled.

The defect signal detecting means 40 is composed of the linear convergent ultrasonic probe 401 (21) which has both transmitting and receiving functions and also functions to detect a defect signal, and a digitally controlled ultrasonic flaw detector. 402. The ultrasonic probe 40
1 detects a backscattered wave including a forest-like echo among the beams in which the ultrasonic beam emitted from the inspection wave supply means 20 is scattered by a defect existing inside the friction welding material, and detects the detection signal. Is output. The digitally controlled ultrasonic flaw detector 402 amplifies the detection signal output from the ultrasonic probe 401 and outputs an internal defect signal of the friction welding material including a forest echo to the arithmetic processing means 50, A signal including the internal defect is analog-displayed on a CRT (not shown) of the flaw detector 402. Also, the digitally controlled ultrasonic flaw detector 402 and the ultrasonic probe 21
The timing of the pulse repetitive transmission is controlled via the computer unit 501.

The arithmetic processing means 50 arithmetically processes the internal defect signal of the friction welding material including the forest echo outputted from the defect signal detecting means 40 and digitally outputs the degree of the internal defect of the friction welding material. The computer section 31 of the beam scanning position control means 30 is also used (50
1). The computer unit 501 quantifies the degree of the internal defect by the arithmetic processing shown in the flowchart of FIG. The computer unit 501 determines the timing of the pulse repetition transmission of the digitally controlled ultrasonic flaw detector 402 and the ultrasonic probe 21 and the turntable 3.
Synchronous control with the control of the controller 32 that controls the rotation of the probe 61 and the movement of the probe holding means 362 is performed.

The display means 60 is a means for displaying the degree of the internal defect of the subject output from the arithmetic processing means 50, and comprises a CRT monitor 601 and a printer 602.

The test water tank 90 contains water as a couplant in the water tank, and the test wave supply means 20 (401) for both transmission and reception, and the mechanical scanner section 34 of the beam scanning position control means 30. Is stored in the water. Further, a pump 901 and a filter 902 for purifying water are provided so that dust and the like in the couplant are not an unnecessary scattering source.

Next, using this ultrasonic inspection apparatus 10,
The vicinity of the pressure contact portion of the friction welding material 80 was inspected by a single scan.

First, a specimen 80 was prepared by friction welding a round bar (S45C) having a diameter of 10 mm and a length of 220 mm. Next, the subject 80 was attached and held on the turntable 361 of the mechanical scanner unit 36.

Next, an ultrasonic wave is transmitted / received to / from a predetermined position of the subject 80 by the inspection wave supply means 20 disposed at a predetermined position. FIG. 10 shows a scanning region of the ultrasonic beam. As shown in FIG. 10, a region indicated by oblique lines after the convergence point of the ultrasonic beam (see also FIG. 8) was set as a detection target. Next, a reception signal of the ultrasonic backscattered wave is transmitted by the ultrasonic probe 401 (test wave supply means 20) and the digitally controlled ultrasonic flaw detector 402, and the output signal is processed by the computer 501. did. The transmission and reception of the ultrasonic wave are performed by the flaw detector 402 and the ultrasonic probe 21.
Is repeated at 2.339 kHz, and one point of echo data is recorded for every one degree of rotation of the subject 80. At this time, the rotation speed of the turntable 361 was 389.8 rpm, and the movement of the ultrasonic probe 21 was 0.125 mm / in the Y-axis direction in FIG.
One rotation (360 points) is performed, and the entire scanning area is 1 in the Y-axis direction.
By moving 2 mm, the total number of echo data points 34,
560 points were obtained.

The time control of the ultrasonic probe 21 pulse repetition transmission / reception signal is performed by the digital control type ultrasonic flaw detector 40.
2 and the computer unit 501, and the control of the position of the test wave supply unit 20 and the position of the subject 80 are performed via the controller unit 32 by the amount of movement and the number of rotations of the probe holding unit 362 and the turntable 361 which are respectively held. ,
Each synchronization control is performed by the computer 501.

Here, the inspection condition setting and arithmetic processing performed in the computer unit 501 and the digitally controlled ultrasonic flaw detector 402 will be described in detail with reference to the flowchart shown in FIG.

First, the 5-axis mechanical scanner unit 36
The origin of (X, Y, Z, θ, R) is set (P1). That is, the reference origin of the X, Y, and Z axes of the probe holding means 362, the reference origin of the horizontal rotation (θ-axis) axis, and the reference origin of the rotation (R-axis) axis of the turntable 361 are set.

Next, a scanner operation condition input is input (P2). That is, X is set to the optimal water distance between the subject 80 and the test wave supply means 20 (the distance at which the convergence point is formed at the central axis of the subject 80), Y is set to the axial scanning distance of the subject 80, Z is set to the central axis of the subject 80, θ is set to the incident angle of the test wave supply means 20, and R is set to the test wave supply means 2.
A scan pitch and scan length of 0 were set.

Next, the echo detection conditions were input (P
3). That is, a frequency of 15 MHz is selected from the plurality of test wave supply units 20. After the process of P3 is completed, the subject 80 is disposed at a predetermined position.

Next, a gain fluctuation check is performed (P
4). That is, the current gain state of the digital ultrasonic flaw detector 402 is digitally output, and it is checked whether the current gain state is within the set range.

Next, the position of the reference echo is measured and the gate position is set (P5). That is, the reference echo position between the test wave supply means 20 and the subject 80 is measured, and the gate position inside the subject 80 is set.

Next, synchronous scan data is collected (P
6). That is, 34,560 by ultrasonic beam scanning.
Get the echo data of a point.

Next, noise removal processing is performed (P7).
That is, of the echo data obtained in P6, 2
Those that are continuous over a point (one or more at a scanning pitch or more) are treated as echo data, and one point is regarded as electrical noise or the like and is removed from the echo data.

Next, echo pulse counting is performed (P8).
That is, the total number of data obtained by the noise processing of P7 is counted.

Next, the echo height is output and displayed (P
9). That is, based on the data obtained by the noise processing of P7, those having five or more predetermined thresholds are classified into five stages of received sound pressure levels, and the number is classified into a CRT monitor 6
01 is displayed.

Next, an echo image is displayed (P10). That is, the area scanned by the inspection wave supply means 20 is displayed two-dimensionally on the CRT monitor 601 based on the data obtained at P8, and a pseudo echo image is obtained.

Next, the echo data for the sample axial position 0.5 mm interval is divided into specific regions and quantified, and echo image quantification processing is performed (P11). That is, the P
Based on the data (34,560 points) obtained in Step 6, the sample is divided into 24 points (12 / 0.5 = 24) in the direction of the sample axis, and 1,440 points (34,560 / 24) =
1,440).

Next, the number of the MAX echo height is displayed (P12). That is, the echo data divided by P11 is performed in all divided areas according to the processing of P9, and the obtained number is displayed on the CRT monitor 601.

Next, the images shown in FIGS. 12 and 13 are displayed on the CRT monitor 601 of the display means as data processed by the processing means 50, and the data is printed on paper by the printer 602.

Here, the echo height displayed on the CRT monitor 601 is (P9), the echo image (P10), MA
Based on the X echo height (P12) and one or two or more of the print results, pass / fail determination of the subject is performed (P12).
13).

FIG. 12 is a view showing the test results of the subject 80 obtained by the processes of P9 and P10. Macro defect was added to 0.05
It can be seen that there are many micro-defects generated during the production of a material of about 0.1 mm or during friction welding. FIG.
3 is a diagram showing a result obtained by quantifying the result shown in FIG. 12 with a five-step threshold value of the detected echo image obtained by the processing of P12. From this, it is possible to quantify the echo at the position in the sample axial direction, It can be seen that a defect at the position in the sample axial direction can be specified.

As is clear from the above, the distribution of defects near the friction welded portion can be known from the echo image shown in FIG. 12, and the quantification of the echo image shown in FIG. Since it is possible to identify defects and compare numerical values between specimens, based on this quantified data,
The pass / fail of the subject can be determined by comparing the knowledge base information indicating the relationship between the number of echo pulses prepared in advance and the pressure contact strength. This pass / fail judgment can be automatically performed by computer processing using the computer unit 501 or the like.

Second Embodiment

Using an apparatus similar to the ultrasonic inspection apparatus of the first embodiment, an ultrasonic inspection was performed on a friction welding material as a subject by a cylinder division scanning method. Hereinafter, a description will be given focusing on differences from the first embodiment.

As shown in FIG. 14, the scanning of the ultrasonic beam is performed by dividing the object 80 into six parts from the outermost peripheral part to the central part, and dividing the area into a plurality of cylindrical parts by the first cylindrical part. An echo image similar to that shown in the embodiment is displayed. Incidentally, the data capacity is 34.56 Kbytes in the first embodiment, but is 2 in this embodiment.
It was about 6.36 Kbytes, which is about 6 times.

FIG. 15 is a flowchart showing the procedure for setting the inspection conditions and performing the arithmetic processing in the computer unit 501 and the digitally controlled ultrasonic flaw detector 402 in this embodiment.

First, P21 to P23 are performed in the same manner as P1 to P3 of the first embodiment. In this process, the conditions for the above-mentioned six-division ultrasonic irradiation were input. Next, the subject 80 is disposed at a predetermined position. Next, P24 is performed in the same manner as P4 in the first embodiment.

Next, in the same manner as the steps P5 to P8 and P9 to P10 in the first embodiment, the steps P25 to P28 and P29 to P30 are cylindrically formed on the subject 80 as described above. In order to divide the ultrasonic waves, the ultrasonic irradiation positions were changed six times, and six types of echo images were obtained.

Next, the six types of echo images obtained above were combined to obtain an echo image (superpose) containing one piece of fine scanning information (P31).

The results obtained from this example are shown in FIGS. 16 to 21 are echo images corresponding to Nos. 21 to 26 in the scanning region of the ultrasonic beam shown in FIG. The test object used in the present example has friction welding conditions worse than usual, and it can be seen that many echoes estimated as micro defects are detected from the position of the welding interface. Further, the distribution state of the detected echoes was confirmed in many places on the outer peripheral portion (No. 21 and No. 22) of the subject. In addition, as a result of performing a cutting observation test in the friction welding joint cross section, the distribution state of the detected echo obtained according to the present example is in good correspondence with the distribution state of the micro defects observed by the test. Was confirmed.

FIG. 22 shows the six types of echo images (No. 21).
-No. 26). As is clear from FIG. 22, since it is dense scanning information including six times the data capacity as compared with the result of the first embodiment, the frictional welding condition from the welding interface generated when the welding condition is worse than usual is considered. Micro defects will be detected densely. Therefore, by using the cylinder division scanning method of the second embodiment, it is possible to analyze in detail the state of the micro defects relating to those having a poor friction welding state.

Third Embodiment

Five kinds of friction welding materials having different friction welding conditions were prepared, and the ultrasonic inspection according to the present invention was performed using the same apparatus as the ultrasonic inspection apparatus of the first embodiment. Further, a strength evaluation test of the friction welding material was performed, and a comparison with a result of an ultrasonic inspection was performed.

First, a specimen 80 obtained by friction welding a round bar (S45C) having a diameter of 10 mm and a length of 220 mm was prepared. At this time, the friction welding conditions include the friction pressure (P1: kgf / mm ² ) and the upset pressure (P2: kgf / mm ² ) of the friction welding cycle, and the upset amount (total deviation; U:
mm), and five conditions were set (sample numbers: 31 to 35).

Next, the subject 80 was mounted and held on the turntable 361 of the mechanical scanner unit 36, and an ultrasonic inspection was performed in the same manner as in the first embodiment.

FIG. 23 shows a flowchart of the inspection condition setting and calculation processing performed in the computer unit 501 and the digitally controlled ultrasonic flaw detector 402.

First, P41 to P43 are performed in the same manner as P1 to P3 of the first embodiment. Next, the subject 80 is disposed at a predetermined position. Next, P4 to P1 of the first embodiment.
Steps P44 to P50 were performed in the same manner as the step 0.
In P49 and P50, the respective results are displayed on the CRT monitor 601.

Next, at P51, based on the total number of echo pulses obtained at P48, pass / fail of the subject was determined according to the following pass / fail criterion stored in the computer unit 501. In P51, the result of the pass / fail judgment is displayed on the CRT monitor 601. 1) Total number of echo pulses ≤ 10,000 → passed 2) Total number of echo pulses> 10,000 → rejected

Next, the subject was exchanged, and
The process of P51 was performed, and echo images of five types of subjects and pass / fail results were obtained.

Next, as a result obtained, an echo image and a pass / fail judgment result were output from the printer 602. The echo images are shown in FIGS. 24 to 28, and the pass / fail judgment results are shown in FIG. 29 (sample numbers: 31 to 35). In the drawing, “○” indicates “the result of the pass / fail judgment is passed”, and “×” indicates “failed”.

Next, a press-contact strength test was performed on the five types of test objects. The result is shown in FIG. In the fracture site, sample numbers 31 to 33 were base materials, and sample numbers 34 and 35 were press-contact portions. FIG. 30 also shows the result of the pass / fail judgment. In the drawing, “○” indicates “the result of the pass / fail judgment is passed”, and “×” indicates “failed”. In addition, as in the above-described example, as a result of performing a cutting observation test in the friction welding joint cross section, the pass / fail result obtained in this example was determined from the distribution of micro defects observed by the test. It was confirmed that it matched the pass / fail result.

As is apparent from FIG. 30, the inspection result obtained by the ultrasonic inspection apparatus of this embodiment is consistent with the evaluation based on the evaluation test result usually performed.

Fourth Embodiment

Two types of friction welding materials having different friction welding conditions were prepared and subjected to ultrasonic inspection.

First, as a subject, φ20 mm × length 3
One obtained by friction welding a 00 mm round bar (S45C) was prepared. At this time, the friction welding conditions were changed as follows: the friction pressure (kgf / mm ² ), the upset pressure (kgf / mm ² ), and the upset amount (mm) of the friction welding cycle were changed, and the friction welding conditions were relatively good (sample number). : 41) and the condition (sample number: 42) that a part is friction-welded.

Next, using the same ultrasonic inspection apparatus as in the above embodiment, the subject was attached to and held on the turntable 361 of the mechanical scanner unit 36, and the subject was subjected to an ultrasonic inspection.

FIG. 31 shows a flowchart of the inspection condition setting and calculation processing performed in the computer unit 501 and the digitally controlled ultrasonic flaw detector 402.

First, in the same manner as in the above embodiment, P61 to P
Perform 63. In addition, as a scanner operation condition of P62,
It was set so that the entire data of the friction welding interface could be collected. Next, the subject 80 is disposed at a predetermined position. Then
Steps P64 to P70 were performed in the same manner as in the above embodiment. In P69 and P70, the respective results are displayed on the CRT monitor 601. Note that P70
The echo image displayed on the monitor 601 in FIG. 10 is magnified 10 times and corresponds to the cross section of the friction welding interface of the subject.

Next, the number of echo pulses per unit cell is calculated (P71). That is, the echo image obtained in the above 70 is divided into a lattice of 1 cm in length and width, the data of P8 corresponding to each of the divided areas is counted, and the counted value is divided by the area of the corresponding part to obtain a unit. Calculate the number of echo pulses per grating.

Next, the joining state of the friction welding interface is determined (P72). That is, based on the number of echo pulses per unit lattice obtained in P71, the computer 501
The joint state of the subject is determined in seven stages according to the tissue state determination criteria shown in FIG.

Next, the obtained judgment result is displayed on a monitor (P73). That is, the determination result is displayed on the CRT monitor 601 by displaying the pattern on the corresponding grid using the display pattern shown in FIG. Next, the result was printed by the printer 602. The results obtained are shown in FIG.
Are shown in FIG. 34, respectively.

Next, as a result of an observation test of each cut surface of the friction-welded interface of the test object, the judgment result obtained in this example was judged from the distribution of micro defects observed by the test. It was confirmed that the results agreed well with the judgment results.

As is clear from the above, it can be seen that the inspection result obtained by the ultrasonic inspection apparatus of the present embodiment is consistent with the evaluation based on the evaluation test result usually performed. In addition, the apparatus and method of the present embodiment can not only determine the presence of a micro abnormal structure but also accurately determine the state of a defect from macro defects such as cracks to micro results such as coarse crystal grains, gap defects and inclusions. You can see that it can be done. Further, in the present embodiment, a second knowledge base indicating the relationship between the tissue state and the friction welding condition is further constructed, and based on the second knowledge base and the information indicating the obtained tissue state, the optimum friction is determined. The pressure contact condition can also be calculated.

Fifth Embodiment

A friction welding material made of a dissimilar metal was prepared, and the ultrasonic inspection according to the present invention was performed using the same apparatus as the ultrasonic inspection apparatus of the first embodiment.

First, two kinds of round rods of φ10 mm × length 220 mm (heat-resistant steel and stainless steel) were used as the subject 80.
Was prepared by friction welding. Next, a solution treatment of the friction welding material was performed. At this time, three types of solution treatment temperatures were used: 1000 ° C. (sample No. 51), 1050 ° C. (sample No. 52), and 1100 ° C. (sample No. 53).

Next, the subject 80 was attached to and held on the turntable 361 of the mechanical scanner unit 36, and an ultrasonic inspection was performed in the same manner as in the first embodiment.

Of the results obtained by the ultrasonic examination,
FIG. 35 shows the relationship between the total number of echo pulses and the solution treatment temperature.
Shown in From FIG. 35, as the solution treatment temperature increases,
It can be seen that the total number of echo pulses has increased. Moreover, the total number of echo pulses sharply increases from the processing temperature of 1050 ° C. or higher. In addition, as a result of conducting a cut surface observation test of each friction welding interface of the test object, it was observed that the precipitates significantly increased at the treatment temperatures of 1050 ° C. and 1100 ° C. From this, it was confirmed that the result obtained in the present example was in good agreement with the judgment result judged from the distribution of micro defects observed in the cut surface observation test.

From the above, it is understood that the precipitates among the micro defects can be accurately inspected by the present ultrasonic inspection apparatus and method.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an ultrasonic inspection apparatus used in a first embodiment of the present invention.

FIG. 2 is an explanatory view schematically showing a conventional ultrasonic inspection apparatus and method.

FIG. 3 is a diagram showing a test result obtained by the conventional ultrasonic testing device of FIG. 2, and is a diagram showing a relationship between a received sound pressure and time.

FIG. 4 is an explanatory view schematically showing another conventional ultrasonic inspection apparatus and method.

5 is a diagram showing an inspection result obtained by the conventional ultrasonic inspection apparatus in FIG. 4, and is a diagram showing a relationship between a received sound pressure and time.

FIG. 6 is an explanatory diagram for explaining a state of a pressure contact interface of a friction pressure contact member.

FIG. 7 is a diagram illustrating a forest-like echo obtained by the ultrasonic inspection apparatus according to the specific example of the present invention, and is a diagram illustrating a relationship between received sound pressure and time (distance).

FIG. 8 is an explanatory view showing an ultrasonic inspection apparatus used in the first embodiment of the present invention and explaining the arrangement of a part of the ultrasonic inspection apparatus. Cross section).

FIG. 9 is an explanatory view showing the ultrasonic inspection apparatus used in the first embodiment of the present invention and explaining the arrangement of a part of the ultrasonic inspection apparatus, and is an arrangement view of the friction welding material as viewed from the side of the sample.

FIG. 10 is an explanatory diagram illustrating an ultrasonic beam scanning area of the ultrasonic inspection apparatus used in the first embodiment of the present invention.

FIG. 11 is a flowchart illustrating the ultrasonic inspection apparatus used in the first embodiment of the present invention and illustrating inspection conditions and arithmetic processing performed in the computer unit and the ultrasonic flaw detector.

FIG. 12 is a diagram showing inspection results of the first embodiment of the present invention;
FIG. 7 is a diagram illustrating a printer output result of an echo image by a single scan.

FIG. 13 is a diagram showing inspection results of the first embodiment of the present invention;
It is a figure which shows the quantification display result of an echo image.

FIG. 14 is an explanatory diagram illustrating an ultrasonic inspection method according to a second embodiment of the present invention, and illustrating a method for scanning a cylinder divided by an ultrasonic beam.

FIG. 15 is a flowchart illustrating inspection conditions and arithmetic processing performed in a computer unit and an ultrasonic flaw detector used in the second embodiment of the present invention.

FIG. 16 is a diagram showing inspection results according to the second embodiment of the present invention;
It is a figure showing an output result of an echo image of ultrasonic beam scanning conditions No. 21.

FIG. 17 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image under the ultrasonic beam scanning condition No. 22.

FIG. 18 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image under the ultrasonic beam scanning condition No. 23.

FIG. 19 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image under the ultrasonic beam scanning condition No. 24.

FIG. 20 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image under the ultrasonic beam scanning condition No. 25.

FIG. 21 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image under the ultrasonic beam scanning condition No. 26.

FIG. 22 is a diagram showing inspection results according to the second embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image including fine scanning information obtained by combining echo images of ultrasonic beam scanning conditions No. 21 to No. 26.

FIG. 23 is a flowchart showing an ultrasonic inspection apparatus used in the third embodiment of the present invention, showing inspection conditions and arithmetic processing performed by a computer unit and an ultrasonic flaw detector.

FIG. 24 is a diagram showing inspection results of the third embodiment of the present invention.
FIG. 14 is a diagram showing an output result of an echo image of sample number 31.

FIG. 25 is a diagram showing inspection results of the third embodiment of the present invention.
FIG. 14 is a diagram showing an output result of an echo image of sample number 32.

FIG. 26 is a diagram showing inspection results according to the third embodiment of the present invention;
FIG. 14 is a diagram showing an output result of an echo image of sample number 33.

FIG. 27 is a diagram showing inspection results of the third embodiment of the present invention.
FIG. 14 is a diagram showing an output result of an echo image of sample number 34.

FIG. 28 is a diagram showing inspection results of the third embodiment of the present invention.
FIG. 14 is a diagram showing an output result of an echo image of sample number 35.

FIG. 29 is a diagram showing inspection results of the third embodiment of the present invention;
It is a figure showing an output result of pass / fail judgment.

FIG. 30 is a diagram showing a relationship between an ultrasonic inspection result and an evaluation test result of a subject according to the third embodiment of the present invention, and is a diagram showing a relationship between the total number of echo pulses and the pressure contact strength of the subject. .

FIG. 31 is a flowchart showing inspection conditions and arithmetic processing performed in a computer unit and an ultrasonic flaw detector used in the fourth embodiment of the present invention.

FIG. 32 is a diagram showing a criterion for determining the tissue state of the friction welding interface in the knowledge base used in the fourth embodiment of the present invention.

FIG. 33 is a diagram showing inspection results of the fourth embodiment of the present invention.
FIG. 14 is a diagram illustrating an output result of a determination result of a sample number 41.

FIG. 34 is a diagram showing inspection results of the fourth embodiment of the present invention;
FIG. 14 is a diagram illustrating an output result of a determination result of a sample number 42.

FIG. 35 is a diagram showing inspection results of the fifth embodiment of the present invention.
It is a figure which shows the relationship between the total number of echo pulses and the solution treatment temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Ultrasonic inspection apparatus 20 ... Inspection wave supply means 30 ... Beam scanning position control means 40 ... Defect signal detection means 50 ... Arithmetic processing means 60 ... Display means 80 ... Subject 90 ・ ・ ・ Test tank

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takaaki Baba 2-1-1 Toyota-cho, Kariya-shi, Aichi Examiner, Toyoda Automatic Loom Works, Ltd. Inspector Shigeru Iino (56) References JP-A-4-95870 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (4)

(57) [Claims] 1. An ultrasonic beam from an ultrasonic probe is obliquely incident on a friction welding material so that a convergence point is at a predetermined position inside the friction welding material, and the ultrasonic beam is applied to the inside of the friction welding material. An ultrasonic inspection method for a friction welding material, comprising: detecting a backscattered wave from a defect existing in the backscattered wave; and detecting an internal defect from information indicating a defect including a forest echo included in the backscattered wave. 2. An apparatus for inspecting a defect including a micro defect inside a friction welding material by using an ultrasonic wave, comprising: an ultrasonic probe; The ultrasonic beam emitted from the ultrasonic probe is oblique to the axial direction of the friction welding material so that the convergence point is located at a predetermined position inside the friction welding material. Inspection wave supply means disposed so as to be incident on the frictional welding member, and an ultrasonic beam emitted from the inspection wave supply means scans a predetermined position inside the friction welding material in a circumferential direction and / or an axial direction. Beam scanning position control means for controlling the position of the friction welding material and / or the inspection wave supplying means, and the ultrasonic beam emitted from the inspection wave supplying means exists inside the friction welding material. Forest of the beam scattered by the defect Signal detecting means for detecting a backscattered wave including a shape echo, and an operation for detecting an internal defect of the friction welding material from an internal defect signal of the friction welding material including a forest-like echo output from the defect signal detecting means. An ultrasonic inspection system for a friction welding material, comprising a processing means, wherein a defect including a micro defect inside the friction welding material is accurately detected. 3. An ultrasonic inspection system for a friction welding material according to claim 2, wherein said inspection wave supply means comprises a plurality of ultrasonic probes having different frequency bands. 4. The defect signal detecting means has means for correlating the detected internal defect signal to remove noise, and the arithmetic processing means performs digital signal processing on the signal output from the defect signal detecting means. Signal converting means for converting the count value into a echo pulse count value, and dividing the count value into sound pressure echo levels at predetermined intervals of the received sound pressure and quantifying the count to indicate the degree and / or position of internal defects of the friction welding material. Comparing the internal defect output signal output from the arithmetic processing means with knowledge base information indicating the relationship between the number of echo pulses and the press-fitting strength, 3. The ultrasonic inspection system for a friction welding material according to claim 2, wherein the pass / fail of the test object is determined based on the comparison result.