JP7610467B2 - Metal fatigue evaluation device, method and program - Google Patents

Description

The present invention relates to a metal fatigue evaluation device, a metal fatigue evaluation method, and a metal fatigue evaluation program that use a diffraction ring to evaluate the degree of metal fatigue.

Evaluating the degree of metal fatigue is important and desirable because damage to equipment due to metal fatigue can lead to abrupt process shutdowns and accidents. Technology for evaluating the degree of metal fatigue is disclosed, for example, in Patent Document 1.

In this patent document, X-ray diffraction is performed on fatigued areas identified by observing the corroded areas due to the structural change to martensite, and the amount of change in the half-width of martensite and the amount of change in retained austenite are measured, and the degree of fatigue is calculated from the measurement results.

Generally, when the periodicity of a crystal is high, strong diffracted waves (Bragg reflected waves) are generated in a direction defined by the periodic interval and periodic direction. On the other hand, metal fatigue generates dislocations in the metal crystal, disrupting the periodicity of the metal crystal lattice. This causes the Bragg reflected waves to spread in the reflection direction, resulting in a change in the half-width of the diffracted waves (spread from the peak position). Therefore, it is presumed that the degree of metal fatigue can be evaluated by evaluating the half-width of the diffracted waves due to Bragg reflection in the crystal lattice, as in Patent Document 1.

JP 2009-41993 A

Therefore, X-ray diffraction was performed on each sample with fatigue damage of 0%, 10%, 30%, 50%, and 100% by fatigue testing, using CrKα X-rays at an incidence angle of 0 degrees, and the half-width of each diffraction ring was measured. As a result, the half-width of each diffraction ring was almost constant from damage degree 0% to 100%. This was considered to be due to the presence of a processing damage layer on the surface of each sample. For this reason, in order to expose the crystal of the base material, samples were created in which the processing damage layer on the surface was removed by electrolytic polishing (EP), and the half-width of the diffraction ring was measured in the same manner. As a result, it was confirmed that the half-width increased with increasing damage degree from 0% to 100%. Therefore, it was confirmed that the half-width of the diffraction ring contains information on fatigue damage.

However, the amount of change was approximately 11% from the initial value (half width at a damage level of 0%). It is presumed that the electrolytic polishing process captured the change in half width due to fatigue damage, but in a situation where measurement errors due to the measurement location are expected, a change of approximately 11% cannot be said to be a significant difference that allows accurate identification of the degree of fatigue damage, and there is room for improvement in the evaluation method for evaluating the degree of metal fatigue using X-ray diffraction.

The present invention has been made in consideration of the above circumstances, and its purpose is to provide a metal fatigue evaluation device, a metal fatigue evaluation method, and a metal fatigue evaluation program that can more appropriately evaluate the degree of metal fatigue.

As a result of various investigations, the inventors have found that the above object can be achieved by the present invention described below. That is, a metal fatigue evaluation device according to one aspect of the present invention is a device for determining an evaluation index representing the degree of metal fatigue in a metal evaluation object, and includes a data acquisition unit that acquires diffraction ring data representing an entire diffraction ring formed by irradiating the evaluation object with a beam having a diffracting property, and an index processing unit that determines, as the evaluation index, a uniformity index representing the degree of uniformity of peak intensity in the entire diffraction ring based on the diffraction ring data acquired by the data acquisition unit. Preferably, in the above-mentioned metal fatigue evaluation device, the data acquisition unit is an interface circuit that inputs and outputs data to and from an external device, and the external device is a storage medium that stores the diffraction ring data. Preferably, in the above-mentioned metal fatigue evaluation device, the data acquisition unit is an interface circuit that inputs and outputs data to and from an external device, and the external device is a drive device that reads data from a storage medium that records the diffraction ring data. Preferably, in the above-mentioned metal fatigue evaluation device, the data acquisition unit is a communication interface circuit that transmits and receives communication signals with an external device, and the external device is a server device that is connected to the communication interface circuit via a network and manages the diffraction ring data.

When the metal being evaluated is in its initial state, the number of crystal grains in the X-ray irradiated area is insufficient, resulting in a spotty diffraction ring; however, as metal fatigue progresses, the number of crystal grains increases due to the refinement of crystal grains (cell organization) accompanying dislocation proliferation, and it is believed that the diffraction ring becomes more uniform. In fact, as metal fatigue progresses, as described below, the diffraction ring becomes more uniform. The metal fatigue evaluation device determines a uniformity index that indicates the degree of uniformity of the peak intensity in the diffraction ring based on the diffraction ring data as an evaluation index that indicates the degree of metal fatigue, and therefore can more appropriately evaluate the degree of metal fatigue.

In another aspect, in the metal fatigue evaluation device described above, the index processing unit obtains, as the uniformity index, a standard deviation in the intensity distribution of the diffraction ring with respect to the azimuth angle.

This makes it possible to provide a metal fatigue evaluation device that determines the standard deviation in the intensity distribution of the diffraction ring with respect to the azimuth angle as the uniformity index, i.e., the evaluation index.

In another aspect, in the above-mentioned metal fatigue evaluation device, the data acquisition unit includes an irradiation unit that irradiates the beam, and an imaging unit that images an entire diffraction ring formed by irradiating the evaluation object with the beam by the irradiation unit, and generates diffraction ring data representing the entire diffraction ring. Preferably, in the metal fatigue evaluation device, the imaging unit includes an imaging plate.

This type of metal fatigue evaluation device generates and acquires diffraction ring data using a data acquisition unit, making it possible to evaluate metal fatigue at the site of the evaluation target.

Another aspect of the present invention is a metal fatigue evaluation method for determining an evaluation index representing the degree of metal fatigue in a metal evaluation object, and includes a data acquisition step of acquiring diffraction ring data representing the entire diffraction ring formed by irradiating the evaluation object with a beam having diffractive properties, and an index processing step of determining, as the evaluation index, a uniformity index representing the degree of uniformity of peak intensity throughout the entire diffraction ring based on the diffraction ring data acquired in the data acquisition step.

Another aspect of the metal fatigue evaluation program of the present invention is a program for obtaining an evaluation index representing the degree of metal fatigue in a metal evaluation object, and causes a computer to execute a data acquisition process for obtaining diffraction ring data representing the entire diffraction ring formed by irradiating the evaluation object with a beam having diffracting properties, and an index processing process for obtaining, as the evaluation index, a uniformity index representing the degree of uniformity of peak intensity throughout the entire diffraction ring based on the diffraction ring data obtained in the data acquisition process.

This metal fatigue evaluation method and metal fatigue evaluation program uses the diffraction ring data to determine a uniformity index that indicates the degree of uniformity of the peak intensity in the diffraction ring as an evaluation index that indicates the degree of metal fatigue, allowing for a more appropriate evaluation of the degree of metal fatigue.

The metal fatigue evaluation device, metal fatigue evaluation method, and metal fatigue evaluation program of the present invention can more appropriately evaluate the degree of metal fatigue.

1 is a block diagram showing a configuration of a metal fatigue evaluation device in an embodiment. FIG. 2 is a block diagram showing a configuration of an example of a data acquisition unit in the metal fatigue evaluation device. 10 is a diagram for explaining the state of change in the diffraction ring accompanying the progression of metal fatigue. FIG. FIG. 2 shows, as an example, a diffraction ring, the intensity distribution of said diffraction ring versus azimuthal angle, its mean value and its standard deviation. 4 is a flowchart showing an operation of the metal fatigue evaluation device. FIG. 1 is a diagram for explaining, as an example, the relationship between the degree of metal fatigue and the standard deviation of the strength distribution. FIG. 13 is a diagram for explaining the relationship between the degree of metal fatigue and the half-value width of a diffraction ring, as an example.

One or more embodiments of the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. Note that components with the same reference numerals in each drawing are the same components, and their description will be omitted as appropriate. In this specification, when referring to a general term, a reference numeral without a subscript is used, and when referring to an individual component, a reference numeral with a subscript is used.

The metal fatigue evaluation device in the embodiment is a device that determines an evaluation index that represents the degree of metal fatigue in a metal evaluation object. This metal fatigue evaluation device includes a data acquisition unit that acquires diffraction ring data that represents a diffraction ring formed by irradiating the evaluation object with a beam that has diffracting properties, and an index processing unit that determines, as the evaluation index, a uniformity index that represents the degree of uniformity of peak intensity in the diffraction ring based on the diffraction ring data acquired by the data acquisition unit. Such a metal fatigue evaluation device will be described in more detail below.

Figure 1 is a block diagram showing the configuration of a metal fatigue evaluation device in an embodiment. Figure 2 is a block diagram showing the configuration of an example of a data acquisition unit in the metal fatigue evaluation device. Figure 3 is a diagram for explaining the change in a diffraction ring with the progression of metal fatigue. Figure 4 is a diagram showing, as an example, a diffraction ring, the intensity distribution with respect to the azimuth angle of the diffraction ring, the average value, and the standard deviation.

The metal fatigue evaluation device D in the embodiment includes, for example, a data acquisition unit 1, a control processing unit 2, a memory unit 3, an input unit 4, an output unit 5, and an interface unit (IF unit) 6, as shown in FIG. 1.

The data acquisition unit 1 is connected to the control processing unit 2, and is a device that acquires diffraction ring data representing diffraction rings formed by irradiating a metal (including alloy) evaluation target with a beam having diffracting properties according to the control of the control processing unit 2. The data acquisition unit 1 is, for example, an interface circuit that inputs and outputs data to and from an external device, and the external device is, for example, a storage medium such as a USB (Universal Serial Bus) memory or an SD card (registered trademark) that stores the diffraction ring data. Alternatively, for example, the data acquisition unit 1 is an interface circuit that inputs and outputs data between an external device, and the external device is a drive device that reads data from a recording medium, such as a CD-ROM (Compact Disc Read Only Memory), a CD-R (Compact Disc Recordable), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a DVD-R (Digital Versatile Disc Recordable), on which the diffraction ring data is recorded. Alternatively, for example, the data acquisition unit 1 is a communication interface circuit that transmits and receives communication signals to and from an external device, and the external device is a server device that is connected to the communication interface circuit via a network (WAN (Wide Area Network, including a public communication network)) or LAN (Local Area Network) and manages the diffraction ring data. Note that when the data acquisition unit 1 is an interface circuit or a communication interface circuit, the data acquisition unit 1 may also be used as the IF unit 6 (i.e., the IF unit 6 may be used as the data acquisition unit 1).

In this embodiment, the data acquisition unit 1 includes an irradiation unit that irradiates the beam, and an imaging unit that images a diffraction ring formed by irradiating the evaluation object with the beam by the irradiation unit, and generates diffraction ring data representing the diffraction ring.

More specifically, as shown in FIG. 2, the data acquisition unit 1 includes a high-voltage power supply 11, a cooling unit 12, a control unit 13, an X-ray irradiation unit 14, and an imaging unit 15.

The high-voltage power supply 11 is a device that supplies a high voltage for accelerating the electron beam to the X-ray irradiation unit 14. The cooling unit 12 is a device that cools the X-ray irradiation unit 14. The control unit 13 is a device that controls the operation of the entire data acquisition unit 1. The control unit 13 may also serve as the control unit 21 (described later) that is functionally configured in the control processing unit 2.

The X-ray irradiation unit 14 includes an X-ray generator that generates X-rays by colliding an electron beam with a target, and an X-ray irradiation tube that irradiates the generated X-rays as a thin X-ray beam to the evaluation object Ob. The X-ray generator is, for example, an X-ray tube (vacuum tube) that accelerates an electron beam with high voltage and causes it to collide with an anode to generate CrKα characteristic X-rays. The X-ray irradiation tube is, for example, a pinhole collimator that narrows the generated X-rays into a thin parallel beam and irradiates it.

The angle (irradiation angle) between the surface of the evaluation object Ob and the X-ray beam can be set in the range above 0° and below 180°, but for example, 30° to 45° (or -30° to -45°) is desirable. An irradiation angle of 90° has a special meaning and is suitable for determining the so-called shear stresses τxz and τyz. An irradiation angle of -30° to -45° is suitable for determining the so-called stress σz.

The diameter of the irradiated X-ray beam may be smaller than 1-2 mm, for example, smaller than a few hundred microns.

Here, an example will be described in which X-rays are used as a beam (diffracted light) that has the property of diffracting toward the evaluation object Ob, but beams that have the property of diffraction are not limited to X-rays and include electromagnetic waves (including visible light, ultraviolet light, and gamma rays), neutron beams, electron beams, etc.

The imaging unit 15 is a device that images a diffraction ring formed by irradiating the evaluation object Ob with a beam by the X-ray irradiation unit 14, and generates diffraction ring data representing the diffraction ring. The imaging unit 15 is configured, for example, with a so-called imaging plate. This imaging plate utilizes the phenomenon of photostimulable fluorescence. In general, a film coated with a photostimulable phosphor is exposed to X-rays, and the amount of fluorescence generated by irradiating the exposed film with laser light is measured. The fluorescence emits light with an amount of light corresponding to the amount of exposure to X-rays, so an X-ray image can be obtained by measuring the amount of light emitted.

Returning to FIG. 1, the input unit 4 is connected to the control processing unit 2 and is a device that inputs various commands, such as a command to start the evaluation, and various data required for operating the metal fatigue evaluation device D, such as the name of the evaluation target to be evaluated by the metal fatigue evaluation device D (e.g., serial number, etc.), to the metal fatigue evaluation device D, and is, for example, a plurality of input switches, a keyboard, a mouse, etc., each assigned with a specific function. The output unit 5 is connected to the control processing unit 2 and is a device that outputs commands and data input from the input unit 4, diffraction rings represented by the diffraction ring data acquired by the data acquisition unit 1, and evaluation indices calculated by the metal fatigue evaluation device D, in accordance with the control of the control processing unit 2, and is, for example, a display device such as a CRT display, LCD (liquid crystal display device), or organic EL display, or a printing device such as a printer.

The IF unit 6 is connected to the control processing unit 2 and is a circuit that inputs and outputs data to and from, for example, an external device according to the control of the control processing unit 2, such as an interface circuit for RS-232C, which is a serial communication method, an interface circuit using the Bluetooth (registered trademark) standard, and an interface circuit using the USB standard. The IF unit 6 may also be a communication interface circuit that transmits and receives communication signals to and from an external device, such as a data communication card or a communication interface circuit conforming to the IEEE 802.11 standard.

The memory unit 3 is connected to the control processing unit 2 and is a circuit that stores various predetermined programs and various predetermined data according to the control of the control processing unit 2. The various predetermined programs include, for example, a control processing program, which includes a control program that controls each of the parts 1, 3 to 6 of the metal fatigue evaluation device D according to the function of each part, and an index processing program that obtains a uniformity index that represents the degree of uniformity of the peak intensity in the diffraction ring as an evaluation index based on the diffraction ring data acquired by the data acquisition unit 1. The various predetermined data include data necessary for executing each of these programs, such as the diffraction ring data. Such a memory unit 3 includes, for example, a ROM (Read Only Memory) that is a non-volatile memory element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable non-volatile memory element, and the like. The storage unit 3 includes a RAM (Random Access Memory) that serves as a so-called working memory for the control processing unit 2, which stores data generated during execution of the specified program. The storage unit 3 may also include a hard disk device capable of storing large amounts of data in order to store relatively large amounts of learning data.

The control processing unit 2 is a circuit that controls each of the units 1, 3 to 6 of the metal fatigue evaluation device D according to the function of each unit, and determines an evaluation index that represents the degree of metal fatigue in the evaluation target. The control processing unit 2 is configured, for example, with a CPU (Central Processing Unit) and its peripheral circuits. In the control processing unit 2, a control unit 21 and an index processing unit 22 are functionally configured by executing the control processing program.

The control unit 21 controls each of the parts 1, 3 to 6 of the metal fatigue evaluation device D according to the function of each part, and is responsible for controlling the entire metal fatigue evaluation device D.

The index processing unit 22 calculates a uniformity index representing the degree of uniformity of the peak intensity in the diffraction ring as an evaluation index based on the diffraction ring data acquired by the data acquisition unit 1.

Figure 3 shows, as an example, the change in the diffraction ring with the progression of metal fatigue. In Figure 3, X-ray diffraction was performed on each sample with fatigue damage of 0% (damage), 10% (damage), 30% (damage), 50% (damage), and 100% (damage), with CrKα X-rays incident at an angle of 0 degrees, and the diffraction ring images obtained as a result are shown. A fatigue testing machine with a normal vibration load was used for the tensile test, and the number of cycles at the time of breakage was set to a damage degree of 100% (damage degree), and the damage degrees of 0% (damage degree), 10% (damage degree), 30% (damage degree), and 50% (damage degree) are the ratio of the number of cycles to this. As an example, the sample is a steel pipe material of a general standard used for boiler pipes. The upper row of Figure 3 shows the diffraction ring images of each sample that has not been subjected to electrolytic polishing, and the lower row shows the diffraction ring images of each sample that has been subjected to electrolytic polishing. From left to right, the diffraction ring images are of samples with damage levels of 0% (planar), 10% (planar), 30% (planar), 50% (planar), and 100% (planar).

Looking at Figure 3 from left to right, it can be seen that the diffraction rings change from an initial spotty shape in which the peak intensity varies at each circumferential position to a shape in which the peak intensity becomes approximately uniform at each circumferential position as metal fatigue increases. Comparing this change with the results of TEM (transmission electron microscope) observations (not shown), it is inferred that the process in which numerous fine cell structures are formed due to dislocation proliferation accompanying the accumulation of fatigue damage is related to the change in the diffraction rings to become uniform.

In general, when there are a sufficient number of crystal grains in the X-ray irradiation area, a uniform diffraction ring is obtained. The results shown in Figure 3 are presumably due to the fact that in the initial state, the number of crystal grains in the X-ray irradiation area was insufficient, resulting in a spotty diffraction ring shape, but the number of crystal grains increased due to the refinement of the crystal grains (cell organization) associated with dislocation proliferation, which contributed to the uniformity of the diffraction ring. In evaluation methods using X-ray diffraction, including residual stress measurement, it is recommended that the average crystal grain size of the sample be 30 μm or less to avoid a decrease in measurement accuracy. Compared to this guideline, the ferrite grain size in the initial state of the sample in Figure 3 is as large as 50 to 60 μm, which is in the coarse category in terms of X-ray diffraction measurement, and is consistent with the above consideration.

From the above, it can be concluded that the phenomenon of the diffraction ring becoming uniform due to the accumulation of fatigue damage is caused by two factors: first, microstructural refinement due to dislocation proliferation (cell structure formation), and second, a change in the orientation of the microstructural structure. The unevenness of the diffraction ring is considered to be a physical quantity that succinctly represents the change in the microstructural structure, and the uniformity index, which indicates the degree of uniformity of the peak intensity in the diffraction ring, can be used as a new evaluation index to indicate the degree of metal fatigue.

The uniformity index (=evaluation index) may be, for example, the difference between the maximum peak intensity and the minimum peak intensity with respect to the azimuth angle of the diffraction ring, the change in the half-width of the peak, etc., but in this embodiment, the standard deviation of the intensity of the peak of the diffraction ring with respect to the azimuth angle is used as the uniformity index. An example is shown in FIG. 4. FIG. 4A shows a diffraction ring, and FIG. 4B shows the intensity distribution (peak intensity at each position in the circumferential direction of the diffraction ring) with respect to the azimuth angle α in the diffraction ring shown in FIG. 4A, its average value μ and its standard deviation σ. The horizontal axis of FIG. 4B is the azimuth angle α [deg] from 0° to 360°, and the vertical axis is the diffraction intensity (Diffraction Intensity [counts]). The azimuth angle α is the angle from the baseline in the circumferential direction of the diffraction ring in a clockwise direction, when the baseline (Baseline) passing through the center position O of the diffraction ring is set as the reference 0°, as shown in FIG. 4A. When the standard deviation σ as the uniformity index (= evaluation index) is relatively large, the peak intensity at each position in the circumferential direction of the diffraction ring varies, and metal fatigue is relatively small. On the other hand, when the standard deviation σ is relatively small, the peak intensity at each position in the circumferential direction of the diffraction ring is approximately uniform (the variation is small), and metal fatigue is relatively large.

The control processing unit 2, memory unit 3, input unit 4, output unit 5, and IF unit 6 can be configured, for example, by a desktop, notebook, tablet, or other type of computer. If the data acquisition unit 1 is an interface circuit or a communication interface circuit, the IF unit 6 can also be used as the data acquisition unit 1, so the metal fatigue evaluation device D, including the data acquisition unit 1, can be configured by a computer.

Next, the operation of this embodiment will be described. Figure 5 is a flowchart showing the operation of the metal fatigue evaluation device.

When the metal fatigue evaluation device D configured in this way is powered on, it initializes the necessary parts and starts its operation. In the control processing unit 2, a control unit 21 and an index processing unit 22 are functionally configured by executing the control processing program.

When a command to start the evaluation is input, in FIG. 5, the metal fatigue evaluation device D first acquires and stores diffraction ring data from the data acquisition unit 1 (S1). More specifically, in this embodiment, the data acquisition unit 1 irradiates the evaluation object Ob with an X-ray beam from the X-ray irradiation unit 14 under the control of the control unit 13, images the diffraction ring with the imaging unit 15 under the control of the control unit 13, and generates diffraction ring data representing the diffraction ring. The data acquisition unit 1 then outputs this diffraction ring data to the control processing unit 2.

Next, the metal fatigue evaluation device D uses the index processing unit 22 of the control processing unit 2 to determine and store the uniformity index as an evaluation index for the evaluation object Ob (S2). More specifically, in this embodiment, the index processing unit 22 determines the standard deviation σ in the intensity distribution of the diffraction ring with respect to the azimuth angle α as the uniformity index, i.e., the evaluation index.

Then, the metal fatigue evaluation device D causes the control processing unit 2 to output the standard deviation σ as the evaluation index from the output unit 5, and ends this process (S3). Note that, if necessary, the evaluation index may be output from the IF unit 6 to an external device.

Figure 6 is a diagram for explaining, as an example, the relationship between the degree of metal fatigue and the standard deviation of the strength distribution. The horizontal axis of Figure 6 is the degree of fatigue damage (Fatigue damage N/Nr [%]), and the vertical axis is the standard deviation (non-uniformity [counts]). Figure 7 is a diagram for explaining, as an example, the relationship between the degree of metal fatigue and the half-width of the diffraction ring. The horizontal axis of Figure 7 is the degree of fatigue damage (Fatigue damage N/Nr [%]), and the vertical axis is the half-width (Average FWHM [deg]).

For comparative examples, the half-widths of the diffraction rings obtained by X-ray diffraction using CrKα X-rays incident at an angle of 0 degrees for each sample (untreated samples) with fatigue damage of 0%, 10%, 30%, 50%, and 100% were approximately constant from 0% to 100%, as shown by ● in Figure 7. This is thought to be due to the presence of a processing damage layer on the surface of each sample, as described above. For each sample (treated samples) with each degree of damage in which the processing damage layer on the surface was removed by electrolytic polishing (EP), the half-widths of the diffraction rings obtained by similar X-ray diffraction were confirmed to increase with the increase in the degree of damage from 0% to 100%, as shown by ■ in Figure 7. Therefore, it was confirmed that the half-width of the diffraction ring contains information on fatigue damage. However, as mentioned above, the change was about 11% from the initial value to the final value. It is presumed that the electrolytic polishing process captured the change in half-width associated with fatigue damage, but in a situation where measurement errors due to the measurement location are expected, it cannot be said that the change of about 11% is a significant difference that allows accurate identification of the degree of fatigue damage.

In contrast, FIG. 6 shows the standard deviation as the evaluation index obtained by the metal fatigue evaluation device D in this embodiment for each sample of each damage level similar to the comparative example described above. ● in FIG. 6 shows the results of each non-electrolytically polished sample, and ■ in FIG. 6 shows the results of each electrolytically polished sample. From FIG. 6, it can be confirmed that the standard deviation σ decreases with increasing damage level and the non-uniformity decreases (the uniformity increases) for both the non-electrolytically polished sample and the electrolytically polished sample. The rate of decrease is a maximum of -71 [%] from the initial value in the case of the non-electrolytically polished sample, and a maximum of -83 [%] from the initial value in the case of the electrolytically polished sample, and therefore is sufficiently large compared to the change range when the half-width of the comparative example is used as the evaluation index. The variation due to the measurement position is a maximum of 21 [%] at a damage level of 0 [%] for the electrolytically polished sample, and although there is room for improvement, even taking this variation into account, the change in the evaluation index due to fatigue damage can be identified. The rate of change in the evaluation index due to fatigue damage is approximately 70 to 90%, and it can be a useful evaluation index for evaluating metal fatigue.

As described above, the metal fatigue evaluation device D in the embodiment and the metal fatigue evaluation method and metal fatigue evaluation program implemented therein calculate a uniformity index that indicates the degree of uniformity of the peak intensity in the diffraction ring based on the diffraction ring data as an evaluation index that indicates the degree of metal fatigue, thereby enabling a more appropriate evaluation of the degree of metal fatigue.

The metal fatigue evaluation device D, metal fatigue evaluation method, and metal fatigue evaluation program generate and acquire diffraction ring data using the data acquisition unit 1, making it possible to evaluate metal fatigue at the site of the evaluation target.

According to this embodiment, a metal fatigue evaluation device D can be provided that determines the standard deviation σ in the intensity distribution of the diffraction ring with respect to the azimuth angle α as the uniformity index, i.e., the evaluation index.

In order to express the present invention, the present invention has been described above adequately and sufficiently through the embodiments with reference to the drawings. However, it should be recognized that a person skilled in the art can easily modify and/or improve the above-mentioned embodiments. Therefore, unless the modification or improvement implemented by a person skilled in the art is at a level that deviates from the scope of the claims described in the claims, the modification or improvement is interpreted as being included in the scope of the claims.

D Metal fatigue evaluation device 1 Data acquisition unit 2 Control processing unit 11 High voltage power supply 12 Cooling unit 13, 21 Control unit 14 X-ray irradiation unit 15 Imaging unit 22 Index processing unit

Claims (5)

A metal fatigue evaluation device that calculates an evaluation index that represents a degree of metal fatigue in a metal evaluation object, comprising:
a data acquisition unit that acquires diffraction ring data representing an entire diffraction ring formed by irradiating the evaluation object with a beam having a diffractive property;
and an index processing unit that calculates, as the evaluation index, a uniformity index that indicates a degree of uniformity of peak intensity over the entire diffraction ring based on the diffraction ring data acquired by the data acquisition unit.
Metal fatigue evaluation device. The index processing unit calculates a standard deviation in the intensity distribution of the diffraction ring with respect to the azimuth angle as the uniformity index.
The metal fatigue evaluation device according to claim 1 . The data acquisition unit is
an irradiation unit that irradiates the beam;
an imaging unit that captures an image of an entire diffraction ring formed by irradiating the evaluation object with the beam by the irradiation unit, and generates diffraction ring data representing the entire diffraction ring;
The metal fatigue evaluation device according to claim 1 or 2. A metal fatigue evaluation method for determining an evaluation index representing a degree of metal fatigue in a metal evaluation object, comprising the steps of:
a data acquisition step of acquiring diffraction ring data representing an entire diffraction ring formed by irradiating the evaluation object with a beam having a diffractive property;
and an index processing step of determining, as the evaluation index, a uniformity index representing a degree of uniformity of peak intensity over the entire diffraction ring based on the diffraction ring data acquired in the data acquisition step.
Metal fatigue evaluation method. A metal fatigue evaluation program for determining an evaluation index representing a degree of metal fatigue in a metal evaluation object, comprising:
On the computer,
a data acquisition step of acquiring diffraction ring data representing an entire diffraction ring formed by irradiating the evaluation object with a beam having a diffractive property;
an index processing step of determining, as the evaluation index, a uniformity index representing the degree of uniformity of peak intensity over the entire diffraction ring based on the diffraction ring data acquired in the data acquisition step;
A metal fatigue evaluation program to carry out the above.