JP2912159B2 - Method and apparatus for measuring ear ratio of rolled aluminum material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to ear measuring method and apparatus of the rolled aluminum material, for example aluminum
The completion degree of recrystallization beam hot-rolled sheet was non-destructive measurement, to a method and its apparatus for performing ear measurements upon this hot-rolled sheet deep drawing.

[0002]

2. Description of the Related Art For example, a cold rolled sheet as a raw material of an aluminum can is manufactured by cold rolling a hot rolled sheet. In order to manufacture a thin plate by this cold rolling, it is necessary to recrystallize a hot rolled plate. However, the temperature during hot rolling was low,
Alternatively, if the heat treatment is insufficient, the crystal becomes an uncrystallized state in which dislocations remain in the crystal. In this case, deformation becomes difficult, and cracks easily occur during cold rolling. Therefore, it is necessary to determine the completion of recrystallization of the hot rolled sheet. Conventionally, therefore, humans have polished the cross section of a rolled plate, etched it by corrosion, and observed the crystal grain shape with a microscope. In this case, the unrecrystallized material has a structure in which the crystals are elongated in a needle shape by rolling, but as recrystallization proceeds, the crystal grains have a thickness in the thickness direction. Using this, the number of needle-like crystals, which are unrecrystallized grains, is determined.
The quality of recrystallization was determined. Conventionally, the crystallinity of a rolled plate has been measured in this way. Further, when a thin plate of this rolled material is deep drawn by using a die and a punch to produce a cylinder, an uneven shape is formed at the end of the cylinder. The so-called ear ratio is used as the index. This is an amount obtained by standardizing the amount of unevenness by the average height of the cylinder (see FIG. 16). A positive ear ratio is when the ears are higher than the average height in a direction inclined at 45 ° to the rolling direction, and a negative ear ratio is when the ears in the direction inclined at 45 ° to the rolling direction are lower than the average height. Is defined. Conventionally, the measurement of the ear ratio has been based on the crystallinity measurement result of the rolled material by the above-described destructive test.

[0003]

The conventional methods for measuring the crystallinity and ear ratio of a rolled material as described above have the following problems. (1) Due to the destructive inspection, quick measurement was difficult. (2) Objective judgment could not be made because humans judged the degree of non-recrystallization. (3) Because the judgment is made in a small area that can be seen with a microscope,
The reliability of the measurement results was not sufficient. The present invention has been made in view of the above circumstances, rapidly performs crystalline measurement with objective and reliable, may perform ear measurements using a crystalline measurements of the rolled material A
It is an object of the present invention to provide a method and an apparatus for measuring an ear ratio of a rolled aluminum material.

[0004]

[0005]

[0006]

According to a first aspect of the present invention, there is provided a method of forming a focused ultrasonic wave at 0 °, 45 ° and 90 ° with respect to a rolling direction of a rolled aluminum material. From the direction, the light is incident on the surface of the rolled aluminum material at a predetermined angle, is diverged from the ultrasonic waves incident thereon, and is included in the ultrasonic wave propagating while being multiply reflected between the front and back surfaces of the rolled aluminum material. The multiple reflection waves having a predetermined refraction angle are respectively received, and the crystallinity of the aluminum rolled material is measured by the evaluation value φ obtained based on the propagation time of each of the received multiple reflection waves, Based on the measured crystallinity of the rolled aluminum material, the aluminum
Is configured as an ear measuring method of an aluminum rolled material for measuring the ear rate of beam rolled material. According to a second aspect of the present invention, the focused ultrasonic wave is set at 0 ° with respect to the rolling direction of the aluminum rolled material ,
Ultrasonic transmitting means for entering the surface of the rolled aluminum material at a predetermined angle from the directions of 45 ° and 90 °, and diverging from the incident ultrasonic waves,
Ultrasonic receiving means for receiving each multiple reflection waves in a predetermined refraction angle included in the propagating ultrasonic waves while being multiple-reflected between the front and back surfaces of the aluminum rolled material, the propagation time of the multiple reflection waves received respectively the Evaluation value obtained based on
and comprising a crystalline measuring means for measuring the crystallinity of the aluminum rolled material by phi, the ear rate measuring means for measuring the ear rate of the aluminum rolled material based on crystalline aluminum rolled material which is the measurement This is a device for measuring the ear ratio of a rolled aluminum material. Here, φ = (τL−τC) + (τN−τC) where τL: delay time in the rolling direction τC: delay time in a direction inclined by 45 ° with respect to the rolling direction τN: tilted by 90 ° with respect to the rolling direction The delay time in the direction of

[0007]

According to the first and second aspects of the present invention, the focused ultrasonic wave is first moved by 0 °, 45 ° with respect to the rolling direction of the rolled aluminum material.
ア ル ミ ニ ウ ム and 90 ° are incident on the surface of the rolled aluminum material at a predetermined angle. Multiple reflected waves having a predetermined refraction angle included in the ultrasonic waves diverging from the incident ultrasonic waves and propagating while being multiply reflected between the front and back surfaces of the rolled aluminum material are received. Based on the propagation time of each received multiple reflected wave
The crystallinity of the rolled aluminum material is measured by the evaluation value φ . In a material having a texture such as a rolled aluminum material, it is considered to be a mixture of a group of isotropic crystal grains in which crystals are randomly oriented and a group of single crystal grains having a specific orientation determined by the texture. The propagation speed of the ultrasonic wave is constant in the material of the crystal group of the isotropic crystal regardless of the propagation direction of the ultrasonic wave. On the other hand, in the material of a single crystal grain group having a specific orientation, the material exhibits a sound velocity anisotropy in which the sound speed changes depending on the propagation direction of the ultrasonic wave. This sound velocity anisotropy is equal to or greater than the number of main orientations of the texture , especially in the rolling direction for rolled aluminum.
On the other hand , the crystallinity of the material can be measured with high accuracy by determining the angles in directions of 0 °, 45 °, and 90 ° .

Furthermore, the ear rate of the aluminum rolled material is measured based on the crystallinity of the aluminum pressure <br/> rolled material was measured above. That is, since the crystallinity of the rolled aluminum material indicates a difference in texture of the material, the ear ratio can be easily measured based on the difference. As a result, rapidly, objectively yet a reliable aluminum rolled material
It is possible to obtain a method and an apparatus capable of performing ear measurements.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention. here,
Figure 1 is a schematic diagram showing a schematic configuration of the engagement Ru ear index measuring apparatus in an embodiment of the present invention, the arrangement of FIG. 2 probe unit, Fig. 3 is an explanatory diagram showing the diffusion of ultrasound, 4 FIG. 5 is a diagram showing a detected multiple reflection echo group, FIG. 5 is a diagram showing a change in reciprocal transmittance of ultrasonic waves with respect to an angle from a rolling direction, and FIG. 6 is a diagram showing a relationship between a distance between a plate and a probe and a delay time. FIG. 7, FIG. 7 is a pole figure of a recrystallized material and an unrecrystallized material, FIG. 8 is a (111) pole figure of a texture that can be produced in an aluminum plate, and FIG. 9 is (100) <001.
FIG. 10 is an explanatory view showing the sound velocity anisotropy of a single crystal, and FIG.
0) Explanatory diagram showing sound velocity anisotropy of <001> single crystal, FIG.
1 is an explanatory diagram showing the sound velocity anisotropy of a (123) <634> single crystal, FIG. 12 is a diagram showing a comparison result between a non-recrystallization ratio by a destructive test and a value measured by this apparatus, and FIG. FIG. 14 is a diagram showing the relationship between the ratio and the evaluation value of the sound velocity anisotropy, FIG. 14 is a diagram showing the relationship between the ear ratio and the evaluation value of the sound velocity anisotropy, and FIG. It is a figure showing a calculation result.

[0010] In the ear ratio measuring method according to the first invention, the measured ultrasonic wave is applied to the rolling direction of the aluminum rolled material with respect to the rolling direction.
方向, 45 ゜ and 90 ゜ are respectively incident on the surface of the rolled aluminum at a predetermined angle (step 1), and are diverged by the incident ultrasonic waves.
A multi-reflection wave having a predetermined refraction angle included in the ultrasonic wave propagating while being multi-reflected between the front and back surfaces of the rolled aluminum material is received (step 2), and based on the propagation time of the received multi-reflection wave. The evaluation value φ obtained by
) To measure the crystallinity of the rolled aluminum material (Step 3). Further, in the above step 3, the waveform of the multi-reflected wave previously obtained for the standard material having the same thickness as the rolled material is compared with the waveform of the received multi-reflected wave to obtain the propagation time. (Step 4). Further, in the above-mentioned step 3, the reflected waves of the respective incident ultrasonic waves on the surface of the rolled material are re-reflected by the re-reflection surface arranged substantially in parallel with the rolled material, so that at each of the reception points. Each of them is received, and the change of the propagation time of the multiple reflection wave due to the change of the interval between each of the incident points and the re-reflection surface is corrected using the respectively received re-reflection waves (step 5). May be. Further, the ear ratio of the rolled material is measured based on the measured crystallinity of the rolled material (step 6). The second invention is
An apparatus according to the method of the first invention. According to this, of the above steps, step 1 is performed by ultrasonic transmitting means,
Step 2 is executed by the ultrasonic wave receiving means, Step 3 is executed by the crystallinity measuring means, Step 4 is executed by the propagation time calculating means, Step 5 is executed by the correcting means, and Step 6 is executed by the ear ratio measuring means. Hereinafter, in this embodiment, the method of the first invention will be described in detail in the order of the steps 1, 2,..., The device configuration will be further embodied, and the basic principle thereof will also be described.

[Step 1] In FIGS. 1 and 2, first, a line focusing type ultrasonic probe 1 _a ,
Using the 1 _{b, 1} c _{(corresponding} to ultrasonic wave transmission unit in the second invention), A at the focal point of the ultrasonic wave by a known immersion method
Luminium hot rolled sheet 2 (corresponding to rolled aluminum ,
(Hereinafter, simply referred to as a hot rolled plate )). The focal points of the focusing probes 1 _a , 1 _b , and 1 _c are respectively matched to the incident point by the water immersion method, and oblique incidence conditions of about 20 ° (corresponding to a predetermined angle) with respect to the Z axis in the figure are selected. Then
The incident angle of the ultrasonic wave on the beam has a spread corresponding to the angle at which the terminals of the transducers of the ultrasonic probes 1 _a , 1 _b , and 1 _c are seen from each incident point. Observing this far enough,
In the hot rolled sheet 2, it is observed that a transverse wave diverging from each incident point propagates. This phenomenon can be easily understood from Snell's law, which is known to describe the refraction relationship of the ultrasonic wave incident on the dissimilar material (see FIG. 3). As described above, when the focal point coincides with the surface of the material, the position of the point where the ultrasonic wave is incident on the material can be limited, so that the position of the incident ultrasonic wave is limited, and as a result, the distance when converting to the sound velocity Information can be specified. By the way, when measuring the characteristics of a material by strictly measuring the speed of sound, a method of increasing the propagation time in the material and reducing the error due to the uncertainty of the distance is generally adopted to increase the measurement accuracy. . However, in this embodiment, the thin aluminum plate is used.
It is difficult to increase the distance because the velocity of the ultrasonic wave propagating obliquely is measured for the hot-rolled sheet 2 of FIG. Therefore,
It is particularly important to identify the location of the point of incidence of the ultrasound and to match the focal point to the point of incidence.

[Step 2] Next, the ultrasonic waves divergently radiated from each incident point propagate while being reflected multiple times between the front and back surfaces of the hot rolled sheet 2. the type of ultrasound probe 3 _a, 3 _b, 3 receives with _c (corresponding to the ultrasonic reception means). That is, in the case of reception, the position of the reception point can be specified by making the focal point coincide with the surface of the material, which is exactly the same as in the case of transmission. Then, a plurality of reflected echoes delayed by a time required by dividing the beam path determined by the number of multiple reflections by the speed of sound are observed. This observed echo is shown in FIG. In the figure, each echo is a hot rolled plate 2 which is a plate to be measured.
When the sound velocity has anisotropy in the propagation angle direction, an echo is observed after a delay time that reflects the anisotropy of the sound velocity in order to respond to ultrasonic waves propagated at different angles with respect to the sound velocity (see Table 1). Will be.

[Table 1]

[Step 3] A refraction angle of 20 ° is selected from a plurality of multiple reflection echoes of transverse waves having different orders of multiple reflection.
A reflected wave in the range of ６０60 ° (corresponding to a multiple reflected wave with a predetermined refraction angle) is extracted, and its propagation time is measured. by the way,
In the case of a hot-rolled aluminum sheet, when recrystallized, (100) <0 on the pole figure showing the orientation distribution of crystal grains contained in the material.
01> predominates, but in the non-recrystallized state, the (110) <001> texture predominates. This means that the degree of accumulation is somewhat lower than those of the two types of textures, but in the unrecrystallized state, (123) <634>
It is known that a texture exists. FIG. 7 shows a (111) pole figure measured by X-rays for the material before and after recrystallization, and FIG. 8 shows a pole figure for a material having a single texture. From this, it is easily understood that the above relationship exists before and after recrystallization. Materials with texture should be evaluated as a mixture of isotropic crystal grains with randomly oriented crystal grains and single crystals with a specific orientation determined by texture. Can be. In the material of the isotropic group,
The propagation speed of the ultrasonic wave does not depend on the propagation direction of the ultrasonic wave. On the other hand, the material of a crystal group having a specific orientation exhibits a sound velocity anisotropy in which the sound speed changes in the propagation direction, reflecting the direction dependence of the sound speed in a single-crystal aluminum plate. Using the calculation result of the sound velocity anisotropy of the ultrasonic wave propagation velocity in this single crystal, if the single crystal is oriented in the above-mentioned direction that appears in the recrystallization texture of the aluminum plate, The propagation angle with respect to the Z direction and the sound speed of the ultrasonic wave when the ultrasonic wave propagates in the cross section are set to 45 degrees with respect to the rolling direction (X direction) of the sheet, the direction orthogonal to the X direction (Y direction), and the X direction. FIG. 9 shows the results of pole figure display in three directions of inclination. However, transverse waves include ultrasonic waves having two types of sound velocities in the vibration direction. In the figure, only the components that are excited in the material when the ultrasonic probe is excited by the water immersion method are described. ing.

Further, in the material having the above-mentioned texture, it is considered that the velocity anisotropy of the single crystal and the sound velocity distribution of the isotropic material show anisotropy in which the degree of texture accumulation is mixed. . First, consider the case of recrystallization, which has a (100) <001> texture on the pole figure. (1
00) It is assumed that crystals having a <001> orientation are dispersed in a homogenous body by a certain ratio. Then, the sound speed in a certain direction in the plate indicates an intermediate value between the sound speed of the isotropic crystal and the sound speed of the (100) <001> component in the direction of interest. This value can be approximated by adding and averaging the mixture ratio. Therefore, when the ultrasonic wave is propagated in the XZ section,
If the speed of sound is expressed using the angle between the plate surface and the propagation direction as a parameter, the absolute value changes depending on the mixture ratio. In this case, anisotropy similar to FIG. 7 should be exhibited. Next, FIG.
Similarly to the recrystallization structure of the aluminum material (11)
FIG. 1 shows the results of pole figure display in three directions in the case of (0) <001> texture and (123) <634> texture.
0, shown in FIG. From these FIGS. 9 to 11, from the case of the recrystallized material and the case of the non-recrystallized material, the X direction, the Y direction, and the direction inclined by 45 ° with respect to the X direction, a total of three directions,
For example, a delay time when an ultrasonic wave is propagated in the XZ section direction inclined by 40 ° from the Z direction is obtained. This can be derived by dividing the propagation distance by the speed of sound. FIG. 12 shows the relationship between the delay time and the unrecrystallized rate extracted by the destructive inspection. From this figure, it can be seen that the delay time differs between the recrystallized material and the non-recrystallized material in each direction. Therefore, the degree of unrecrystallization can be evaluated by measuring the delay time of the multiple reflected waves in the direction inclined by 40 ° from the Z direction propagated in the respective directions.

Further, the delay time in the X direction is τL, the delay time in the direction inclined by 45 ° with respect to the X direction is τC, the delay time in the Y direction is τN, and the evaluation value φ of the unrecrystallized crystal is as follows. Define. φ = (τL−τC) + (τN−τC) (1) FIG. 13 shows the relationship between the evaluation value φ of unrecrystallized given by the above equation (1) and the unrecrystallized rate extracted by the destructive test. .
From this figure, it can be determined that recrystallization has occurred when the evaluation value of unrecrystallized is 45 nsec or more. Here, assuming that the distance between incident points of ultrasonic waves is L, the order of reflection is n, the plate thickness is t, and the sound speed is C, the delay time τ can be expressed by the following equation. τ = 4n√ (L / 4n) ² + t ² / C (2) From the above equation (2), it can be seen that the delay time τ is greatly different when the order n of reflection and the plate thickness t are different. Therefore, if the judgment is made based only on the delay time in one direction, the measurement accuracy is lowered. For this reason, in the present embodiment, the delay time in three directions is measured simultaneously for the same plate to be measured, and the relative time difference (the magnitude relationship of the delay times in the X direction, the Y direction, and the direction inclined at 45 ° with respect to the X direction) is measured. ) Are compared. In this case, since the plate thickness t is the same depending on the direction, there is no difference in the manner of changing the order n of reflection depending on the direction. Therefore, an error caused by a change in the thickness t within the tolerance is reduced, and the measurement accuracy is improved. In the measurement of the delay time τ, since the ultrasonic wave propagates while being reflected multiple times between the front and back surfaces of the plate, the propagation distance can be long, the sound speed in one direction is averaged, and the measurement dispersion is small. This also improves the measurement accuracy. The waveform actually received at this time is as shown in FIG. 4, but will be described in more detail. The order in the figure is the number of times the ultrasonic wave is reflected on the front and back surfaces of the plate. Reflection orders of 1 to 3 cannot be measured separately because the difference in propagation distance due to the order of reflection is small. However,
Reflection orders of order 4 and higher are measured separately. In the case where the order of reflection is 7th or higher, no observation is made, because the transmission / reception efficiency of ultrasonic waves incident at a small refraction angle is low.

[Step 4] In FIG. 4, it can be seen that the waveform changes depending on the order. Incidentally, as a method for accurately measuring the sound velocity, a method using a correlation with a predetermined reference waveform is known. However, if the waveforms are different, the measurement error of the propagation delay time decreases. Therefore, as a reference assumption, the correlation method is based on a waveform propagating in the XZ sectional direction inclined by 20 ° to 60 ° from the plate width direction (Z direction) of the recrystallized standard test specimen 4 of the same thickness. To obtain the delay time. Here, the angle 20
The reason why the measurement can be performed only in the range of ゜ to 60 ° is that as shown in FIG. 5, when the angle is 20 ° or less, the reciprocal passage rate of the shear wave is greatly reduced. .38 (see Figure 2.44 (b)). However, the notation of the angle is changed from that of the reference diagram for convenience of explanation.
Therefore, in this case, it is impossible to make a measurement unless the attenuation is too large and the angle is not more than 20 °. On the other hand, the angle 60
Above ゜, the longitudinal wave propagates simultaneously with the transverse wave, so it is difficult to separate from the longitudinal wave, and it is difficult to measure the angle unless the angle is less than 60 °. Therefore, measurement can be performed only in the range of angles of 20 ° to 60 °. As described above, the propagation time of the ultrasonic wave in the standard test article 4 is set in advance, and the propagation time can be accurately measured by using the correlation between the waveform and the measured waveform.

[Step 5] Further, FIG. 6 shows the hot rolled plate 2 and the ultrasonic probes 1 _a , 1 _b , 1
changing the distance between the _c indicating the delay time of the echo of the reflection plate 5 or these when measured. From the figure, it can be seen that the delay time of the ultrasonic wave reflected by the reflector 5 has a linear relationship with the distance between the plate and the probe. By utilizing this relationship, it is possible to correct errors caused by warpage of the plate to be measured. That is,
The difference in the delay time due to the change in the distance between the ultrasonic probes 1 _a , 1 _b , 1 _c and the hot rolled plate 2 is determined from the delay time from the reflection plate 5, whereby the echo propagating through the material is determined. The change in the delay time can be corrected. More specifically, the delay time from the reflector 5 is determined based on the delay time from the reflector 5 for a flat plate as a reference. In this case, although the incident ultrasonic wave is partially reflected on the plate surface, a reflecting plate 5 that reflects the reflected wave again in the direction of the hot rolled plate 2 is integrated with the probe in parallel with the hot rolled plate 2. Are arranged in a relationship. Thus, the ultrasonic probes 1 _a , 1 _b , 1 _c
The delay time can be measured more accurately by compensating for the change in the delay time of the multiple reflected wave due to the change in the distance between each input point of incidence and the reflection point due to the change in the distance between the sheet and the hot rolled sheet 2. be able to. In this embodiment, the ultrasonic probe 1
_a, as the oscillation frequency of the ₁ b, _{1 c,} it was used probe 10MHz high bandwidth. This is because the lower the frequency of the probe, the longer the wavelength, so that the separation of the delay time of the multiple reflected ultrasonic waves between the front and back surfaces of the plate becomes poor.
On the other hand, if the frequency is too high, the attenuation of the ultrasonic waves increases, and the propagation distance can be increased. For this reason, it is difficult to measure the delay time of a reflected wave having a large number of multiple reflections.
From such a viewpoint, it is necessary to use a frequency whose wavelength is approximately equal to the plate thickness and whose attenuation is small.

Next, the received ultrasonic waves in three directions, that is, the X direction, the Y direction, and the direction inclined at 45 ° with respect to the X direction, are converted into electric signals by the ultrasonic probes 3 _a , 3 _b , and 3 _c. Then, those signals are digitized by the digital oscilloscope 6 and stored in the memory 7 for use. The signal stored in the memory 7 is input to a computer 8, and a refraction angle of interest, for example, 40
遅 延 Extract the delay time of the ultrasonic wave propagating in the inclined section direction. An evaluation value of unrecrystallized is calculated from the result of the delay time in these three directions. This value is compared with a reference value (a value obtained by measuring the unrecrystallized sample using the same measurement method and calculating the evaluation value at each unrecrystallized rate). Derive the rate. Thus, the crystallinity of the hot rolled sheet 2 can be measured. Here is the calculator 8 serves crystalline measuring <br/> hand stage.

[Step 6] Further, the ear ratio of the hot-rolled sheet 2 is measured by comparing the crystallinity of the hot-rolled sheet 2 with the data previously stored in the file 9 by the computer 8 based on the measurement result. Here, consider aluminum materials. That is, since the sliding surface at the time of plastic working is the (111) plane on the pole figure, the ear ratio is determined by the texture. For example, in the (100) <001> texture, the (111) plane is oriented four times in the X direction.
Deformation in the direction inclined by 5 ° easily occurs. Therefore, the ear ratio in that direction increases, and in the (110) <001> texture, the ear ratio in the X direction increases. Here, the ear ratio is a positive ear ratio when the ear is higher than the average height in a direction inclined by 45 ° with respect to the X direction, and a negative ear ratio when the ear in the direction tilted with respect to the X direction is lower than the average height. It is defined as Therefore, the (110) <001> structure having a high unrecrystallized ratio has a positive ear ratio. On the other hand, the unrecrystallization ratio is low, and (100) <00.
1> As the texture develops, the ear rate becomes negative . As described above, the ear ratio is sensitive to the texture, and it can be estimated that the ear ratio can be evaluated if the texture is known. As described above, the aluminum material is composed of three main textures, but if the ratio can be evaluated, the ear ratio can be determined. Assuming that the sound velocity of a transverse wave propagating in a direction inclined by 20 ° to 60 ° with respect to the Z direction is CL, CC, and CN, respectively, the sound velocity in the X direction, the direction inclined by 45 ° with respect to the X direction, and the Y direction are CL, CC, and CN, respectively. Can be represented by the following three equations. CL = (1−r) × Cm + r1 × C1 + r2 × C2 + r3 × C3 (3) CC = (1−r) × Cm + r1 × C1 + r2 × C2 + r3 × C3 (4) CN = (1−r) × Cm + r1 × C1 + r2 × C2 + r3 × C3 (5) Here, Cm: sound velocity of an isotropic body C1-3: sound velocity of a single crystal in a direction of interest r1-3: ratio of a single crystal in a direction of interest r = r1 + r2 + r3. As described above, since the above three simultaneous equations can be established, the ratio of the three textures can be determined.

FIG. 14 shows the relationship between the evaluation value of the above-mentioned unrecrystallized crystal and the evaluation value of the ear ratio extracted by the destructive inspection.
From the figure, it can be seen that the evaluation value of the ear ratio and the evaluation value of the non-recrystallized are almost proportional. This shows that the ear ratio can be determined from the evaluation value of the non-recrystallized crystal. In other words, by this method, ultrasonic waves are propagated to the plate to be measured in the above three directions, the delay time is measured, and the evaluation value of the non-recrystallized is calculated, whereby the proportion of the three textures can be determined, and the ear ratio is determined. can do. In this way, the ear ratio can be measured. Here, the computer 8 plays a role of ear ratio measuring means. The input of the operation command and the output of the result are performed by the input / output device 10 connected to the computer 8. In the above embodiment, the digital oscilloscope 6 is used to collect the ultrasonic waveform.
In addition, although the delay time is calculated by the computer 8, a dedicated signal processing circuit may be used for actual use. Furthermore, it is considered that the above embodiment can be applied not only to measurement of the unrecrystallized ratio of an aluminum plate as a hot-rolled plate, but also to measurement of, for example, difference in texture of a steel plate. This can be easily understood from FIG. 15 showing the calculation result of the anisotropy of the sound velocity of the iron single crystal.

[0021]

The method and apparatus for measuring the ear ratio of a rolled aluminum material according to the present invention have the following effects because they are constructed as described above. In a material having a texture such as a rolled aluminum material, it is considered to be a mixture of a group of isotropic crystal grains in which crystals are randomly oriented and a group of single crystal grains having a specific orientation determined by the texture. The propagation speed of the ultrasonic wave is constant in the material of the crystal group of the isotropic crystal regardless of the propagation direction of the ultrasonic wave. On the other hand, in the material of a single crystal grain group having a specific orientation, the material exhibits a sound velocity anisotropy in which the sound speed changes depending on the propagation direction of the ultrasonic wave. The speed of sound anisotropy rolling direction
0 ° to 45 °, and by seeking <br/> Mel in the direction forming 90 °, it can be measured crystallinity of the aluminum rolled material with high accuracy. Furthermore, the based on the crystallinity of the thus be measured aluminum rolled material Arumini
Ear ratio of Um rolled material is measured. That is, the above aluminum
Since the crystallinity of the rolled material indicates the difference in the texture of the material, the ear ratio can be easily measured based on the difference. A As a result, quickly, objectively yet reliable
It is possible to obtain a method and an apparatus capable of measuring ear ratio of rolled luminium .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a crystallinity and ear ratio measuring apparatus according to one embodiment of the present invention.

FIG. 2 is a layout diagram of a probe unit.

FIG. 3 is an explanatory diagram showing diffusion of ultrasonic waves.

FIG. 4 is a diagram showing a detected multiple reflection echo group.

FIG. 5 is a diagram showing a change in reciprocal transmittance of ultrasonic waves with respect to an angle from a rolling direction.

FIG. 6 is a diagram showing a relationship between a distance between a plate and a probe and a delay time.

FIG. 7 is a pole figure of a recrystallized material and a non-recrystallized material.

FIG. 8 shows a texture (11) that can be formed in an aluminum plate.
1) Pole figure.

FIG. 9 is an explanatory diagram showing sound velocity anisotropy of a (100) <001> single crystal.

FIG. 10 is an explanatory diagram showing sound velocity anisotropy of a (110) <001> single crystal.

FIG. 11 is an explanatory diagram showing the sound velocity anisotropy of a (123) <634> single crystal.

FIG. 12 is a view showing a comparison result between a non-recrystallization rate by a destructive test and a value measured by the present apparatus.

FIG. 13 is a graph showing a relationship between a non-recrystallization ratio and an evaluation value of sound velocity anisotropy.

FIG. 14 is a diagram showing a relationship between ear ratio and evaluation value of sound velocity anisotropy.

FIG. 15 is a diagram showing a calculation result of anisotropy of a sound velocity for a single crystal of iron.

FIG. 16 is a view showing a deep drawing state of a thin plate and a processing result.

[Explanation of symbols]

_{1 a, 1 b, 1 c} ... focused ultrasonic probe (corresponding to ultrasonic wave transmission unit) 2 ... hot-rolled sheet (corresponding to the rolling _{member) 3 a, 3 b, 3} c ... focused ultrasonic feeler Element (corresponding to ultrasonic receiving means) 4 ... Standard test product (corresponding to reference material) 5 ... Reflector (corresponding to re-reflecting surface) 8 ... Computer (crystallinity measuring means, propagation time calculating means, correcting means, ear ratio (Equivalent to measuring means, etc.)

Continuation of the front page (72) Inventor Toshishi Yanai 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel, Ltd. Kobe Research Institute (72) Inventor Takeo Ogawa 1 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel, Ltd.Kobe Institute of Technology, Kobe Steel, Ltd. (72) Inventor Tsutomu Morimoto 1-5-5, Takatsukadai, Nishi-ku, Kobe, Hyogo, Japan Kobe Steel, Ltd.Kobe Institute of Technology, (56) References JP-A-2-236450 (JP, A) JP-A-2-296147 (JP, A) JP-A-2-210258 (JP, A) JP-A-1-301162 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (2)

(57) [Claims] 1. A focused ultrasound to 0 ° to the rolling direction of the aluminum rolled material, 45 °, and respectively incident from a direction forming a 90 ° inclined a predetermined angle to the surface of the aluminum rolled material, the respective incident diverged from ultrasonic waves, the Al
Receives multiple reflected waves of a predetermined refraction angle included in the ultrasonic wave propagating while being multiple reflected between the front and back surfaces of the rolled minium, and based on the propagation times of the received multiple reflected waves.
Measuring the crystallinity of the aluminum rolled material by an evaluation value φ obtained Te, aluminum pressure <br/> rolled material for measuring the ear rate of the aluminum rolled material based on crystalline aluminum rolled material which is the measurement Ear rate measurement method. Here, [phi] = ([tau] L- [tau] C) + ([tau] N- [tau] C) [tau] L: delay time in the rolling direction [tau] C: delay time in the direction inclined by 45 [ deg.] To the rolling direction [tau] N: inclined 90 [deg.] To the rolling direction. Delay time Wherein 0 ° focused ultrasound to the rolling direction of the aluminum rolled material, 45 °, and ultrasonic wave emitting means from a direction forming 90 ° incident respectively inclined at a predetermined angle to the surface of the aluminum rolled material If, diverged from ultrasonic waves above are respectively incident, the Al
Ultrasonic receiving means for receiving multiple reflected waves having a predetermined refraction angle included in the ultrasonic waves propagating while being multiply reflected between the front and back surfaces of the rolled minium, and based on the propagation times of the received multiple reflected waves.
A crystalline measuring means for measuring the crystallinity of the aluminum rolled material by an evaluation value φ obtained Te, ear measurement for measuring the ear rate of the aluminum rolled material based on crystalline aluminum rolled material which is the measurement And a means for measuring an ear ratio of a rolled aluminum material. Here, [phi] = ([tau] L- [tau] C) + ([tau] N- [tau] C) [tau] L: delay time in the rolling direction [tau] C: delay time in the direction inclined by 45 [ deg.] To the rolling direction [tau] N: inclined 90 [deg.] To the rolling direction. Delay time