Structure evaluation method, structure evaluation device, and structure evaluation program

Abstract

Provided are a structure evaluation method, a structure evaluation device, and a structure evaluation program with which it is possible to distinguish between diffracted X-rays generated for each region and evaluate respective structures. A structure evaluation method performed by measuring diffracted X-rays transmitted through a sample includes a step for simultaneously irradiating a plurality of regions of a large sample S11 in a single-crystal state with a white X-ray R11, and a step for detecting a diffracted X-ray produced by the irradiation. A measurement composed of the series of steps is performed a plurality of times. In at least one of the plurality of measurements, a slit 11 that selectively passes only a diffracted X-ray produced in a specific region among a plurality of regions C11, C12 irradiated with the X-ray is arranged on the back side of the large sample S10. Diffracted X-rays produced in the plurality of regions C11, C12 of the large sample S10 are each detected by using the slit 11, and the structure is evaluated for each of the regions.

Description

Structural evaluation method, structural evaluation device, and structural evaluation program

[0001] The present invention relates to a structure evaluation method, a structure evaluation apparatus, and a structure evaluation program for measuring diffracted X-rays transmitted through a sample.

[0002] X-ray diffraction is a well-known method for measuring damage in components used under high-temperature, high-load environments. Damage diagnosis methods for nickel-based superalloys have advanced rapidly in recent years, and it is now possible to perform non-destructive testing of thick metal materials, even deep within them, using high-energy X-rays.

[0003] Patent Document 1 discloses a method for diagnosing sample degradation by placing a sample so that the damage direction is parallel to the surface of a sample holder, measuring a diffraction spot image obtained by the reflection Laue method for a single-crystal sample with a two-dimensional detector, and calculating the full width at half maximum (FWHM) in the damage direction. This method eliminates the need for complicated procedures and enables measurement and analysis in a laboratory.

[0004] In response to this, Patent Document 2 discloses a method for irradiating a single crystal sample with a thin beam of white X-rays, calculating a coefficient that correlates with the variance of the intensity distribution in a specific direction in the resulting diffraction spot, and identifying the state of damage to the sample from the coefficient. For example, in the case of a nickel-based superalloy, such as a turbine blade for thermal power generation, that has a thermal barrier coating with a thickness of 100 μm or more formed thereon, the damage to the single crystal sample can be measured without removing the thermal barrier coating.

[0005] Meanwhile, a technique using a slit to focus diffracted X-rays is known. Patent Document 3 discloses a method in which, since diffracted X-rays are generated from a wide range when X-rays are incident on a thin film at a small angle, a slit is provided at the center of a goniometer to block part of the diffracted X-rays and extract only the diffracted X-rays from a narrow irradiation range. By limiting the generation position of the diffracted X-rays, the generation position of the diffracted X-rays is spread, preventing the diffracted X-rays from becoming broad.

[0006] Patent Document 4 discloses a method for blocking part of the diffracted X-rays with a slit and extracting only the diffracted X-rays from a narrow irradiation range, since diffracted X-rays are generated from multiple locations during transmission measurement of a thick sample. This is also a method for preventing the diffracted X-rays from becoming broad.

[0007] Japanese Patent No. 7093929 Japanese Patent Application Laid-Open No. 2023-140749 Japanese Patent Application Laid-Open No. 2017-223539 Japanese Patent Application Laid-Open No. 2012-7935

[0008] As described above, a method for measuring damage in components used under high-temperature, high-load conditions using X-ray diffraction has been proposed. However, when a Laue image of a thick metal material is obtained using X-rays, it is difficult to determine the exact location of the diffraction spot. For example, damage to the rotor blades of turbines used in thermal power generation can spread from a specific location, making it necessary to measure the degree of damage in each region.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a structural evaluation method, a structural evaluation device, and a structural evaluation program that can distinguish between diffracted X-rays generated in each region and evaluate each structure.

[0010] (1) In order to achieve the above-mentioned object, the structural evaluation method of the present invention is a structural evaluation method performed by measuring diffracted X-rays that have passed through a sample, and includes the steps of simultaneously irradiating white X-rays onto multiple regions of a large single-crystal sample and detecting the diffracted X-rays generated by the irradiation. The measurement consisting of the series of steps is performed multiple times, and in at least one of the multiple measurements, a slit is placed on the back side of the large sample that selectively passes only diffracted X-rays generated from a specific region among the multiple regions irradiated with the X-rays, and the diffracted X-rays generated in each of the multiple regions of the large sample are detected using the slit, and the structure is evaluated for each region.

[0011] (2) Furthermore, in the structural evaluation method described in (1) above, the multiple measurements are performed using multiple types of slits, each of which allows diffracted X-rays from a different region among the multiple regions to pass through.

[0012] (3) Furthermore, in the structural evaluation method described in (1) or (2) above, the diffraction X-ray data detected in the multiple measurements are compared to extract diffraction spot data for each region, and the structure is evaluated for each region using the extracted data.

[0013] (4) Furthermore, in the structural evaluation method described in any one of (1) to (3) above, the damage state is identified for each region of the large sample from a coefficient related to the variance of the intensity distribution in a specific direction in the diffraction spot of the detected diffracted X-rays.

[0014] (5) Furthermore, in the structural evaluation method described in (4) above, the damage life consumption rate is calculated for each region of the large sample from the half-width of the diffraction spot.

[0015] (6) Furthermore, in the structural evaluation method described in (1) or (2) above, the slit is formed in a disk or annulus, and the slit is arranged so that the main surface is perpendicular to the irradiation direction of the white X-rays and the center of the disk or annulus coincides with the central axis of the white X-rays.

[0016] (7) Furthermore, in the structural evaluation method described in (6) above, the large sample is formed of a Ni-based superalloy material having a dendritic structure in a single crystal state, and the slit is characterized in that the outer diameter of the disk or the inner diameter of the ring is designed according to the diffraction angle of the diffracted X-rays.

[0017] (8) Furthermore, in the structural evaluation method described in any one of (1) to (7) above, the large sample is characterized in that it consists of an abdominal portion and a dorsal portion sandwiching a hollow portion, and the specific region is the abdominal portion or the dorsal portion.

[0018] (9) Furthermore, the structural evaluation device of the present invention is a structural evaluation device that uses measurement data of diffracted X-rays that have passed through a sample, and is equipped with a data extraction unit that extracts data on the diffraction spots for each region by comparing the diffracted X-ray data obtained by performing multiple measurements in which white X-rays are irradiated simultaneously on multiple regions of a large single-crystal sample, and a damage state identification unit that identifies the damage state for each region using the extracted data, characterized in that in at least one of the multiple measurements, a slit is placed on the back side of the large sample that selectively allows only diffracted X-rays generated from a specific region to pass through, out of the multiple regions irradiated with the X-rays, and measurement data obtained is used.

[0019] (10) Furthermore, the structural evaluation program of the present invention is a structural evaluation program that uses measurement data of diffracted X-rays that have passed through a sample, and has a computer execute the following processes: extracting data on diffraction spots for each region by comparing the diffracted X-ray data obtained by performing multiple measurements in which white X-rays are irradiated simultaneously on multiple regions of a large single-crystal sample; and identifying the damage state for each region using the extracted data; and is characterized in that, in at least one of the multiple measurements, measurement data obtained by placing a slit on the back side of the large sample that selectively allows only diffracted X-rays generated from a specific region among the multiple regions irradiated with the X-rays to pass through is used.

[0020] 1 is a schematic side view showing an embodiment of X-ray diffraction measurement of a large hollow sample using a disk-shaped slit. (a) to (c) are enlarged views showing the diffraction region of the abdomen and the diffraction region of the back, respectively, and a front view showing the disk-shaped slit. (b) to (c) are schematic side views showing an embodiment of X-ray diffraction measurement of a large hollow sample using a circular slit. (a) to (c) are enlarged views showing the diffraction region of the abdomen and the diffraction region of the back, respectively, and a front view showing the circular slit. (c) are schematic side views showing an embodiment of X-ray diffraction measurement of a large solid sample using a large-diameter disk-shaped slit. (a) to (c) are front views showing a small-diameter disk-shaped slit, a large-diameter disk-shaped slit, and a small-hole circular slit, respectively. (c) is a schematic view showing the configuration of a structural evaluation system according to the present invention. (c) is a block diagram showing the configuration of a structural evaluation device according to the present invention. (d) is a flowchart showing a structural evaluation method according to the present invention. (e) is a perspective view showing the configuration of an experimental X-ray diffraction device. (f) is a schematic view showing the diffraction region of the abdomen and major diffraction lines. (f) is an image showing a diffraction pattern generated by the abdomen. (g) is an intensity profile in the 2θ direction of a specific diffraction spot. 1 is a schematic diagram showing the diffraction region and major diffraction lines of the dorsal region. 2 is an image showing a diffraction pattern produced by the dorsal region. 3 is a schematic diagram showing the diffraction region and major diffraction lines of the abdominal and dorsal regions. 4 is an image showing a diffraction pattern produced by the abdominal and dorsal regions. 5 is an intensity profile in the 2θ direction of a specific diffraction spot. 6 is a schematic diagram showing the diffraction region and major diffraction lines of the abdominal and dorsal regions. 7 is an enlarged view of the diffraction region of the abdominal and dorsal regions. 8 is an image showing a diffraction pattern produced by the abdominal region. 9 is an intensity profile in the 2θ direction of a specific diffraction spot. 10 is a schematic diagram showing the diffraction region, annular slits, and major diffraction lines of the abdominal and dorsal regions. 11 is an enlarged view of the diffraction region and annular slits of the abdominal and dorsal regions. 12 is an image showing a diffraction pattern produced by the dorsal region. 13 is a schematic diagram showing the diffraction region and major diffraction lines of the abdominal region. 14 is an image showing a diffraction pattern produced by the abdominal region. 15 is a schematic diagram showing the diffraction region and major diffraction lines of the dorsal region. 16 is an image showing a diffraction pattern produced by the dorsal region. 17 is a schematic diagram showing the diffraction region and major diffraction lines of the dorsal region. 18 is an image showing a diffraction pattern produced by the dorsal region. 19 is an intensity profile in the 2θ direction of a specific diffraction spot. 19 is a schematic diagram showing the diffraction region and major diffraction lines of the abdominal and dorsal regions. 1 shows an image of the diffraction patterns produced by the abdominal and dorsal parts, and an intensity profile in the 2θ direction of a specific diffraction spot.1 is a schematic diagram showing the diffraction regions of the abdominal and dorsal regions, a disk-shaped slit, and a major diffraction line; FIG. 2 is an enlarged view of the diffraction regions of the abdominal and dorsal regions and a disk-shaped slit; FIG. 3 is an image showing a diffraction pattern generated by the abdominal region; FIG. 4 is a schematic diagram showing the diffraction regions of the abdominal and dorsal regions, a circular slit, and a major diffraction line; FIG. 5 is an enlarged view of the diffraction regions of the abdominal and dorsal regions and a circular slit; FIG. 6 is an image showing a diffraction pattern generated by the dorsal region; FIG. 7 is an intensity profile in the 2θ direction of a specific diffraction spot;

[0021] Next, an embodiment of the present invention will be described with reference to the drawings. To facilitate understanding of the description, the same reference numerals are used to designate the same components in the drawings, and duplicated descriptions will be omitted.

[0022] [Principle] In this invention, a special slit is placed that selectively transmits diffracted X-rays according to the diffraction region, and white X-rays are irradiated onto a large sample (e.g., a thick metal material) with a single-crystal dendritic structure (transmission Laue method). Within the single-crystal sample, wavelengths are selected according to the respective combinations of interplanar spacing and diffraction angle, and diffracted X-rays are generated in each diffraction region. The transmitted diffracted X-rays are either blocked by the slit or pass through the slit. The diffracted X-rays that reach the detector are then measured to identify the diffraction region that generated the diffraction spot. The detector is a two-dimensional detector.

[0023] The slit is preferably made of a material that can adequately absorb and block diffracted X-rays, such as lead, but is not limited to lead. The slit is preferably formed in the shape of a disk or ring, with its main surface perpendicular to the direction of white X-ray irradiation, its center aligned with the central axis of the white X-ray, and positioned immediately behind the large sample. This allows selective passage or blocking of diffracted X-rays from each region along the irradiation direction. Note that "immediately behind" refers to a position that is tangent or nearly tangent to the dorsal surface of the large sample in the direction of white X-ray propagation. For convenience, the incident side of the large sample onto which the white X-rays are incident is referred to as the "ventral side," and the exit side of the transmitted X-rays is referred to as the "dorsal side." The slit described above refers to a component positioned to block unwanted X-rays and obtain X-rays of interest, and may also be referred to as a "block" in light of its function.

[0024] The term "single crystal state" refers to a state in which a material is formed of a single crystal or coarse crystal grains. In other words, the term "single crystal state" refers to a state in which a sample is formed of a single crystal or coarse crystal grains in which the X-ray beam diameter can be shaped to irradiate a portion of the single crystal or a single coarse crystal grain within the material. The principle will be explained below with reference to a specific example.

[0025] (Hollow Sample) First, we will explain the case where X-ray diffraction measurement is performed using a disk-shaped slit 11. Fig. 1 is a side view schematic diagram showing an aspect of X-ray diffraction measurement of a large hollow sample S10 using a disk-shaped slit 11. Figs. 2(a) to 2(c) are enlarged views showing the diffraction regions of the abdominal portion S11 and the dorsal portion S12, and front views showing the disk-shaped slit 11, respectively.

[0026] The large single-crystal sample S10 has a belly portion S11 forming a concave portion and a back portion S12 forming a convex portion. The large sample S10 is positioned with the belly portion S11 facing the X-ray irradiation side and the back portion S12 facing the X-ray detection side (hereinafter, in all examples, the belly side refers to the X-ray irradiation side and the back side refers to the detector side). A space is formed inside the belly portion S11 and the back portion S12. As a result, the large sample S10 consists of the belly portion S11 and the back portion S12, which sandwich a hollow portion. Either the belly portion S11 or the back portion S12 is a specific region through which the slit passes diffracted X-rays. For example, if a disk-shaped slit S11 is used, the diffracted X-rays generated in the belly portion S11 will pass through. Figure 1 shows a cross section of the large sample S10.

[0027] The large sample S10 is a rotor blade sample made of a Ni-based superalloy having a hollow single-crystal dendritic structure, and its cross section is shown parallel to the direction of irradiation with white X-rays in Fig. 1. The large sample S10 is positioned so that the direction of this cross section coincides with the 100 crystal plane.

[0028] When a direct beam R11 of white X-rays is irradiated onto the large sample S10, the direct beam R11 is incident on the abdominal region S11. Diffracted X-rays R14 are generated in the X-ray irradiated portion (diffraction region) of the abdominal region S11, pass through the back region S12, and are detected by the detector 140. Figure 2(a) shows an enlarged view of the diffraction region of the abdominal region S11 by enlarging the circular region C11 shown in Figure 1.

[0029] The direct beam R12 that has passed through the abdomen S11 passes through the air and is incident on the back S12. The direct beam R13 that has passed through the back S12 passes through the disk-shaped slit 11. Diffracted X-rays are also generated in the X-ray irradiated area (diffraction region) of the back S12, but the disk-shaped slit 11 blocks these diffracted X-rays. These diffracted X-rays are blocked by the disk-shaped slit 11. The dashed line in the figure indicates hypothetical diffracted X-rays V15 that would be generated if they were not blocked by the disk-shaped slit 11.

[0030] Figure 2(b) shows an enlarged view of the circular region C12 shown in Figure 1. As shown in Figure 2(b), diffracted X-rays R14 pass through the disk-shaped slit 11 without hitting it, while diffracted X-rays generated in the diffraction region of the back portion S12 hit the disk-shaped slit 11 and are blocked (virtual diffracted X-rays V11). Figure 2(c) is a front view showing the disk-shaped slit 11. The dashed circle B12 indicates the outer diameter of the annular slit 12, which will be described later. The disk-shaped slit 11 shown in Figures 1 and 2(b) is a side cross-sectional view. The diffracted X-rays R14 that reach the detector 140 are detected as diffraction spots.

[0031] Next, X-ray diffraction measurement is performed on the hollow large sample S10 using the annular slit 12. Figure 3 is a side view schematic showing the X-ray diffraction measurement of the hollow large sample S10 using the annular slit 12. Figures 4(a) to 4(c) are enlarged views showing the diffraction regions of the abdominal portion S11 and the dorsal portion S12, and a front view showing the annular slit 12, respectively. Figure 3 shows a cross section of the large sample S10.

[0032] When a direct beam R11 of white X-rays is irradiated onto the large sample S10, the direct beam R11 is incident on the abdominal portion S11. Diffracted X-rays R14 are generated in the X-ray irradiated portion (diffraction region) of the abdominal portion S11, pass through the back portion S12, and are detected by the detector 140. Figure 4(a) shows an enlarged view of the diffraction region of the back portion S12 by enlarging the circular region C21 shown in Figure 3.

[0033] The direct beam R12 that has passed through the abdomen S11 passes through the airspace and is incident on the back S12. The direct beam R13 that has passed through the back S12 passes through the central hole 12a of the annular slit 12. Diffracted X-rays R15 are generated in the X-ray irradiated portion (diffraction region) of the back S12 and pass through the hole 12a of the annular slit 12.

[0034] Figure 4(b) shows an enlarged view of the circular region C22 shown in Figure 3. As shown in Figure 4(b), diffracted X-ray R14 is blocked by the annular slit 12 (virtual diffracted X-ray V14). Diffracted X-ray R15 generated in the diffraction region of the back portion S12 passes through the annular slit 12. Figure 4(c) is a front view showing the annular slit 12. The annular slit 12 has a hole 12a in the center. The annular slit 12 shown in Figures 3 and 4(b) is a side cross-sectional view. The diffracted X-ray R15 that reaches the detector 140 is detected as a diffraction spot.

[0035] As described above, the structure of the abdominal portion S11 of the hollow large-sized sample S10 can be evaluated by measuring the diffraction beam passing through the disk-shaped slit 11. Also, the structure of the dorsal portion S12 can be evaluated by measuring the diffraction beam passing through the annular slit 12. Specifically, the damage life consumption rate can be calculated for each region, and the damage state can be confirmed.

[0036] In this way, multiple measurements can be performed using multiple types of slits that allow diffracted X-rays from different regions of the multiple regions to pass through, thereby enabling the structure of the different regions to be evaluated using the diffracted X-rays that have passed through each slit.

[0037] In hollow samples, it is possible that the dorsal and ventral regions have different structures. Compared to solid samples (described later), hollow samples allow for easy separation of the diffraction lines from the dorsal and ventral regions by using a slit. This allows for measurement of specific regions without comparing diffracted X-ray data detected through multiple measurements.

[0038] (Solid Sample) Next, the case where X-ray diffraction measurement of a large solid sample S20 is performed using various slits will be described. Fig. 5 is a side view schematic diagram showing an aspect of X-ray diffraction measurement of a large solid sample S20 using a large-diameter disk-shaped slit 32.

[0039] The large, solid sample S20 in a single crystal state has an abdominal portion S21 forming a concave portion, an intermediate portion S22, and a back portion S23 forming a convex portion. In other words, there is no space between the abdominal portion S21 and the back portion S23, and the intermediate portion S22, which is a sample in a single crystal state, is filled in between.

[0040] When the large sample S20 is irradiated with a direct beam R21 of white X-rays, the direct beam R21 is incident on the abdominal portion S21. Diffracted X-rays R23 are generated in the X-ray irradiated portion (diffraction region) of the abdominal portion S21. The diffracted X-rays R23 pass through the middle portion S22 and the back portion S23 and are detected by the detector 140.

[0041] The direct beam that has passed through the abdominal region S21 is incident on the middle region S22 and further on the back region S23. Diffracted X-rays are generated in the X-ray irradiated areas (diffraction regions) of the middle region S22 and the back region S23, but the disk-shaped slit 32 blocks these diffracted X-rays. The disk-shaped slit 32 shown in FIG. 5 is a side cross-sectional view. The direct beam R21 that has passed through the back region S23 is transmitted through the disk-shaped slit 32. The direct beam R22 that has passed through the disk-shaped slit 32 is detected by the detector 140.

[0042] The dashed lines in the figure indicate hypothetical diffracted X-rays V24 and V25 when not blocked by the disk-shaped slit 32. The diffracted X-ray R23 that reaches the detector 140 is detected as a diffraction spot due to the nostril S21.

[0043] The large-diameter disk-shaped slit 32 is used to measure diffracted X-rays from the abdomen S21, and similar measurements are then performed using the small-diameter disk-shaped slit 31 and the small-hole annular slit 33. The dashed circle B33 indicates the outer diameter of the annular slit 33, which will be described later. Figures 6(a) to 6(c) are front views showing the small-diameter disk-shaped slit 31, the large-diameter disk-shaped slit 32, and the small-hole annular slit 33, respectively.

[0044] In the measurement using the small-diameter disk-shaped slit 31, diffracted X-rays generated in the diffraction regions of the abdominal portion S21 and the middle portion S22 pass through the disk-shaped slit 31 and are detected by the detector 140. At this time, diffracted X-rays generated in the diffraction region of the dorsal portion S23 are absorbed and blocked by the disk-shaped slit 31.

[0045] By comparing the diffraction spots generated by the diffracted X-rays generated in the diffraction region of the abdominal portion S21 with those detected when a large-diameter disk-shaped slit 32 is used, the diffraction spots generated by the diffracted X-rays generated in the diffraction region of the intermediate portion S22 can be identified.

[0046] For example, when identifying diffraction spots in the middle part by comparison, the diffraction spots of the middle and abdomen parts are compared with the diffraction spots of only the abdomen part. Then, diffraction spots corresponding to the diffraction spots of only the abdomen part can be removed as diffraction spots of the abdomen data. In this case, only peaks with similar average half-widths of the diffraction spots can be removed.

[0047] It is also possible to compare the average half-width obtained from the diffraction peaks at the abdomen with the average half-width of the remaining diffraction peaks that do not correspond to the diffraction spots at the abdomen, and remove only diffraction spots with similar average half-widths. However, if the average half-width obtained from the diffraction peaks at the abdomen and the average half-width of the remaining diffraction spots (including the diffraction spots at the middle parts) that do not correspond to the diffraction spots at the abdomen are almost the same, removing the diffraction peaks at the abdomen will not significantly affect the results of the analysis of the damage state. If there is no significant difference in the half-widths of the diffraction peaks at the abdomen and the middle parts, there is little problem in using data that includes both the data at the abdomen and the middle parts.

[0048] In measurements using the small-hole annular slit 33, diffracted X-rays generated in the diffraction region of the dorsal portion S23 pass through the hole 33a of the annular slit 33 and are detected by the detector 140. On the other hand, diffracted X-rays generated in the diffraction regions of the abdominal portion S21 and the middle portion S22 are absorbed and blocked by the annular slit 33.

[0049] In this way, by using multiple slits, it becomes possible to independently select diffraction data from the abdominal, middle, and dorsal regions. Here, the explanation is limited to three diffraction regions, but in practice, more diffraction regions may be set and the diameter of the circular slit may be gradually increased. Similarly to the measurement of three diffraction regions, by selecting diffracted X-rays while capturing the characteristics of the diffraction regions and diffraction spots, it is also possible to determine the average half-width of the diffraction spots from a specific diffraction region. In other words, two or four or more regions may be distinguished.

[0050] In the above example, three slits are used to identify the diffracted X-rays from each region, but the diffracted X-rays from each region may also be identified using data measured with two slits and no slits. By comparing the diffracted X-ray data detected in multiple measurements, diffraction spot data for each region can be extracted, and the extracted data can be used to evaluate the structure of each region. Diffraction spots generated from specific regions can also be identified and the structure of the region can be evaluated using a combination of data acquired in measurements without using a slit and data acquired in measurements with a slit.

[0051] In addition to the above combinations, a large annular slit that allows the diffracted X-rays from the middle portion S22 and the back portion S23 to pass through can also be used. In either case, a combination of slits is used that allows the diffracted X-rays from each region to be distinguished by comparison. As described above, a slit is used in at least one measurement, and the structure of each region can be evaluated by comparing the diffracted X-rays detected in multiple measurements.

[0052] In the above examples, the shape of the slit is a disk or annulus, but the shape is not limited to these as long as it passes or blocks the diffraction rays of the diffraction angle to be detected. For example, it may be a sphere or a sphere with a hole. Furthermore, the combination of slits is not limited to the above examples.

[0053] [Target Sample] The large sample is preferably formed of a Ni-based superalloy material with a dendritic structure in a single crystal state, and the slit has an outer diameter of a disk or an inner diameter of a ring designed according to the diffraction angle of the diffracted X-rays. This is particularly effective when applied to, for example, turbine blades for thermal power generation. This is also particularly effective when the large sample is hollow. In this case, information from the region on the X-ray irradiation side of the large sample and the region on the detector side can be efficiently separated. Note that metal materials with a dendritic structure in a single crystal state are composed of numerous dendritic subgrains with a diameter of approximately several hundred μm.

[0054] In thermal power plants, generators are equipped with multiple turbine stages arranged in a row depending on the purpose. Nickel-based superalloys are used for the turbine blades (moving blades) of three to four stages, which are particularly exposed to high-temperature environments. Directionally solidified or single-crystal blades are particularly used for the first and second stage turbine blades. The directionally solidified material used for such turbine blades is made of nickel-based superalloys and is formed into rods several millimeters wide in a single crystal state.

[0055] The subgrains of nickel-based superalloys are composed of a composite material consisting of a nickel solid solution matrix (γ phase (gamma phase)) and a nickel-based intermetallic compound precipitate phase (γ' phase (gamma prime phase)) forming a single crystal. The γ phase has an fcc structure with a face-centered cubic lattice of Ni atoms. The γ' phase has a cubic superlattice structure in which atoms at each corner of the face-centered cubic lattice are replaced by Al or Ti atoms.

[0056] In nickel-based superalloys, countless γ' phase clusters are regularly arranged in three dimensions, and a network structure of γ phase surrounds each γ' phase cluster, forming a single crystal. Although it is a composite material consisting of different phases, the orientation of each phase is consistent. In this way, in nickel-based superalloys, the γ' phase is coherently dispersed within the γ phase, forming a single crystal state.

[0057] For example, when a nickel-based superalloy is used for a turbine blade, centrifugal force causes the turbine blade to stretch in the

[001] direction of the subgrains. This stretching direction is the damage direction. Then, in the process leading up to fracture due to damage deformation, etc., the regular arrangement of the single crystal state is disturbed. The direction and degree of this disorder of the arrangement are expressed as the damage direction and damage degree. Note that the damage state refers to the damage degree and damage direction.

[0058] When a single-crystal base material is irradiated with white X-rays, so-called Laue spots appear as diffraction spots. When a single-crystal base material is not deformed at all, Laue spots appear with a circular periphery. As the base material deforms, the periphery of the Laue spots changes from a circular shape to an ellipse, and the major axis of the ellipse elongates. For example, when evaluating damage in a nickel-based superalloy, disturbances in the crystal structure of the γ and γ' phases are observed as broadening of the diffraction peaks of the diffraction planes within the crystal. In this way, the coefficient related to the dispersion of the diffraction spots corresponds to the coefficient of damage in the nickel-based superalloy, allowing the damage state of the turbine blade to be identified and the remaining life of the turbine blade to be estimated.

[0059] [Principle of damage measurement] A sample is irradiated with white X-rays using the Laue method. The white X-rays are preferably a fine beam. A fine beam refers to a beam size equivalent to the crystal grain size (including subgrain grain size) to be irradiated with X-rays. When white X-rays are irradiated onto a subgrain where damage has occurred, diffracted X-rays are generated by crystallites whose orientation varies within the subgrain and whose lattice spacing has slightly widened, resulting in a diffraction peak with a large half-value width.

[0060] When X-rays are incident so that the direction parallel to the intersection of the lattice plane and the diffraction plane along which the X-rays are diffracted coincides with the direction of crystal damage, the change in the half-width of the diffraction peak due to damage is greatest. Therefore, when evaluating the degree of damage in a metallic material with a dendritic structure in a single crystal state, the degree of damage can be evaluated most efficiently based on the spread of the diffraction spot oriented parallel to or close to the damage direction. In single crystal or polycrystalline samples, the half-width of the diffraction spot is affected by the thickness of the sample, making it difficult to evaluate the crystallinity from the spread of the half-width. For the above reasons, it is preferable that the sample be a metallic material with a dendritic structure.

[0061] [Structural Evaluation System] A system used for structural evaluation will be described. FIG. 7 is a schematic diagram showing the configuration of a structural evaluation system 100. The structural evaluation system 100 includes an X-ray diffraction device 110 and a processing device 150 (structural evaluation device). The X-ray diffraction device 110 is a device used for measurements to detect diffraction spots. The processing device 150 is a device that mainly identifies the state of damage from the detected diffraction spots. The X-ray diffraction device 110 and the processing device 150 are preferably connected so that they can send and receive information, whether wired or wireless. The processing device 150 may also be located on the cloud.

[0062] [X-ray Diffraction Apparatus] The following describes the basic configuration of the X-ray diffractometer 110. The X-ray diffractometer 110 includes an X-ray irradiation unit 120, a sample holder 130, a position adjustment mechanism 135, and a detector 140. Although not shown in Fig. 7, when a slit is used, it is installed on the rear side immediately behind the sample S0.

[0063] The X-ray irradiation unit 120 includes a main body 121 and a collimator 122, and generates white X-rays to irradiate the sample S0. The main body 121 includes a housing, an X-ray source, and an X-ray shielding window. The X-ray source preferably uses a finely focused X-ray target to generate a thin beam of white X-rays. The X-rays pass through the X-ray shielding window and are emitted to the outside.

[0064] The collimator 122 has a collimator body and a shielding cover, and can form a narrow beam of X-rays. The shielding cover is preferably made of, for example, lead. It is preferable to use the collimator 122 to adjust the beam size to match the size of the subgrains of the sample. Two pieces of information, the degree of damage to the sample and the direction of the damage, can be simultaneously evaluated from the diffraction spots. The direction in which the damage occurs can be identified from the extension direction of the detected diffraction spots.

[0065] The sample holder 130 can be mounted with a sample as a measurement target to be irradiated with white X-rays, and can be fixed by adjusting its position to the X-ray irradiation position. The sample holder 130 is configured so that its angular position can be adjusted in three axes by a position adjustment mechanism 135, as shown in FIG.

[0066] The position adjustment mechanism 135 makes it possible to adjust the angle of the lattice plane of the sample relative to the irradiated white X-rays. The angular position of the sample can be adjusted by a motor or the like in response to a control signal from the processing device 150. Incident X-rays R1 emitted from the X-ray irradiation unit 120 are diffracted by the sample S0 to generate diffracted X-rays R2, which generate multiple diffraction spots in space.

[0067] The position adjustment mechanism 135 can adjust the angle of the X-ray incidence axis from the X-ray irradiation unit 120 so that the diffracted X-rays are incident on the detector 140. The position adjustment mechanism 135 can also adjust the tilt of the sample holder 130.

[0068] The lattice planes of the sample S0 are the lattice planes of the single crystal of the base material. The incident X-rays are diffracted by the sample, generating multiple diffraction spots in space. The positions at which the diffraction spots occur are determined according to the lattice planes present in the sample S0.

[0069] The detector 140 generates an electrical signal according to the intensity of the X-rays incident on the detection surface, thereby detecting the diffraction spots generated by the sample S0. The detector 140 is preferably a two-dimensional detector in order to easily detect the shape of the diffraction spots, and specifically, an imaging plate or a semiconductor detector can be used.

[0070] The position of the X-ray direct beam DB1 is 2θ = 0. The angle of the detector 140 with respect to the sample S0 is represented by β, and the angle of incidence of the X-rays with respect to the sample S0 is represented by α. The angle of incidence α and the angle β of the detector 140 are usually fixed, and none of the X-ray irradiation unit 120, the sample holder 130, and the detector 140 are moved during measurement.

[0071] 8 is a block diagram showing the configuration of the processing device (structural evaluation device) 150. The processing device 150 can be configured as a device equipped with a CPU and memory, such as a PC, and controls the X-ray diffraction device 110 and processes detected data by executing a program. The processing device 150 includes a position adjustment unit 151, a data extraction unit 153, a coefficient calculation unit 155, a damage state identification unit 156, and a storage unit 157.

[0072] The processing device 150 is connected to an input device 160 and an output device 170. The input device 160 is a device that accepts input from a user, such as a mouse, a touch panel, or a keyboard. The output device 170 is a device such as a display or a printer.

[0073] The processing device 150 processes data and controls the device in response to input of positional information of the X-ray irradiation unit 120, the sample holder 130, and the detector 140, input of instructions from the user, and input of measurement results from the detector 140. The processing device 150 outputs the identified damage state in the sample as a result of the structural evaluation. It may also output an image of the captured diffraction spot and the direction in which the peak shape is to be viewed.

[0074] The position adjustment unit 151 adjusts the arrangement of the detector 140 relative to the X-ray irradiation unit 120 based on the input information. This makes it possible to adjust the angle of the incident X-rays from the X-ray irradiation unit 120 so that the diffracted X-rays are incident on the detector 140. Specifically, the position adjustment unit 151 adjusts the position angle of the detector 140 (such as the φ angle) and the angle of the X-ray irradiation unit 120.

[0075] Furthermore, the position adjustment unit 151 can adjust the tilt of the sample holder 130 via the position adjustment mechanism 135. Note that the X-ray irradiation unit 120 may be fixed and the positions of the sample holder 130 and the detector 140 may be adjusted.

[0076] The data extraction unit 153 extracts diffraction spot data for each region by comparing the diffracted X-ray data obtained by performing measurements multiple times in which white X-rays are irradiated simultaneously on multiple regions of a large single-crystal sample.

[0077] The coefficient calculation unit 155 analyzes the diffraction peak in the 2θ direction to determine the extent of the broadening of the base of the diffraction peak. Specifically, based on the detected data of the diffraction spot, it calculates a coefficient that correlates with the variance of the intensity distribution in a specific direction at the diffraction spot of the detected data. From this coefficient, the damage state can be identified for each region of the large sample.

[0078] The damage state of the sample can be identified from the coefficient of the dispersion of the intensity distribution in a specific direction in the diffraction spot. The coefficient of the dispersion of the intensity distribution of the diffraction spot is preferably the half-width of the peak in the specific direction. The half-width means the peak width at half the height of the peak.

[0079] The damage state specifying unit 156 specifies the damage state of the sample from the calculated coefficient. To do so, it refers to a function supplied from the storage unit 157 and uses a calibration curve of a function between the coefficient that multiplies the variance of the intensity distribution in a specific direction in the diffraction spot and the damage life consumption rate. As the damage state of the sample, it is possible to calculate the damage life consumption rate calculated from the coefficient that multiplies the variance of the intensity distribution of the diffraction spot.

[0080] The calibration curve is obtained by plotting the damage life consumption rate against the half-width of each peak using a sample whose damage life consumption rate is known in advance, and drawing an approximate curve using the least squares method. This enables accurate and precise damage evaluation of each region in a non-destructive manner. In this case, unreliable data close to fracture can be ignored, and a linear approximation can be performed using only data on the damage life consumption rate between 0% and 50%, for example.

[0081] The memory unit 157 stores a coefficient related to the variance of the intensity distribution in a specific direction in a diffraction spot, which is prepared based on a standard sample, and a function of the damage life consumption rate. The memory unit 157 is referenced when evaluating damage to the sample. The memory unit 157 supplies the necessary functions as required in response to a request from the damage state specifying unit 156.

[0082] [Structural Evaluation Method] A method for evaluating the structure of a sample using the structural evaluation system 100 configured as described above will now be described. Fig. 9 is a flowchart showing the structural evaluation method. First, a large sample is placed on the sample holder 130, and the position of the large sample made of a single-crystalline material is adjusted so that the white X-ray beam is incident on the sample by the X-ray irradiation unit 120. A slit that passes diffracted X-rays from the target diffraction region is also positioned on the detector side (back side) immediately behind the large sample (step S01).

[0083] The slit is shaped according to the purpose. Examples of slit types include disk-shaped slits and annular slits. Note that measurements may be performed without a slit depending on the purpose. In at least one of the multiple measurements, a slit is placed on the back side of the large sample, selectively passing only diffracted X-rays generated from a specific region among the multiple regions irradiated with X-rays. By using a slit, diffracted X-rays generated in multiple regions of the large sample can be detected and the structure of each region can be evaluated.

[0084] It is preferable to determine the specific specifications of the slit in accordance with the energy of the X-rays to be transmitted. For example, when a 150 keV X-ray source is used, the X-ray absorption formula I=I ０ e －μｘ Using this formula, we can determine that the thickness of lead when the X-ray intensity decreases to 1 / e is approximately 0.4 mm (= x). The formula for X-ray absorption is ０ This indicates that when an X-ray of 1000 nm passes through an absorbing plate of thickness x cm with a linear absorption coefficient μ, the X-ray intensity is I.

[0085] μ = 22.8 (cm at 150 keV －１ ) for μx=1(I=I ０ / e), the lead thickness x can be determined. This is because the thickness of the absorbing plate when the X-ray intensity drops to 1 / e is usually set as the limit of the X-ray penetration distance. In other words, once the material is determined for a specific energy, the thickness required for X-ray absorption is determined. In addition, the diameter of the center of the slit is determined by considering the diffraction angles of the absorbed and unabsorbed diffracted rays relative to the thickness of the slit plate.

[0086] When placing a large sample, it is preferable to align the damage direction of the large sample with a direction parallel to the surface of the sample holder. For example, in the case of sample S0 cut from a turbine blade, the damage direction is from the center of rotation of the turbine toward the tip of the blade.

[0087] Next, a white X-ray beam is irradiated onto a large single-crystal sample, thereby irradiating multiple regions with the white X-ray simultaneously (step S02). Diffracted X-rays are generated from the multiple diffraction regions, and diffraction spots are detected by detector 140 (step S03). It is preferable to select a diffraction spot on the low-angle side where the X-ray intensity is relatively strong as the diffraction spot to be observed.

[0088] After aligning the detectors, the diffraction spots are detected while the instruments in each measurement system remain stationary. By using white X-rays, the detectors can be set at a low angle, and multiple high-intensity diffraction spots can be detected at a stationary position without rotating the instruments, regardless of the crystal orientation.

[0089] It is determined whether measurement of each region is complete (step S04), and if not, the process returns to step S01. This allows the measurement consisting of a series of steps to be performed multiple times. When performing step S01 in a loop, it may be necessary to position only the sample or the slit, as necessary. When measurement of each region is complete, diffraction spots arising from specific diffraction regions are extracted based on the obtained data (step S05). The extracted diffraction spots are then used to calculate the degree of damage to the corresponding diffraction regions (step S06).

[0090] When calculating the degree of damage, the shape of the diffraction spot is measured, the peak shape in the damage direction that indicates the state of damage is extracted from the shape, and the coefficient of dispersion is calculated by data processing. The direction in which the coefficient of dispersion is calculated is the 2θ direction. When the large sample is a turbine blade, it is preferable to measure the diffraction spot of the lattice plane parallel to its side surface.

[0091] Next, the damage assessment curve (master curve) stored in the memory unit 157 is read out, and the damage state of the sample is identified based on the coefficient related to the dispersion of the peak shape. Then, the remaining life of the sample can be estimated based on the damage state of the sample. The calculation results are output on a display, printer, etc. This completes the series of processes.

[0092] [Example] An experiment was conducted using a sample simulating an actual rotor blade. Fig. 10 is a perspective view showing the configuration of an X-ray diffraction apparatus 200 used for the experiment. The X-ray diffraction apparatus 200 includes an X-ray irradiation unit 120 and a detector 140. A sample S50 is placed between the X-ray irradiation unit 120 and the detector 140.

[0093] Sample S50 simulates a hollow sample. Sample S50 includes wood W10 and sample boards S51 and S52. Wood W10 is essentially 10 mm thick and has a recessed shape with an H-shaped horizontal cross section and a central thickness of 5 mm.

[0094] Sample plates S51 and S52 are two single-crystal Ni-based superalloy specimens with damage life consumption rates of 79% and 0%, respectively. Sample plate S51 is a 2 mm x 10 mm rectangle with a thickness of 1.5 mm. Sample plate S52 is a 10 mm x 10 mm square with a thickness of 1.5 mm. Sample plates S51 and S52 are supported by adhesive bonding to wood W10. The sample plate on the X-ray irradiation side is referred to as the belly, and the sample plate on the detector side is referred to as the back. Sample plate S51 was subjected to a tensile test in the longitudinal direction (001 crystal orientation direction).

[0095] A lead block with a diameter of 3 mm and a thickness of 2 mm was used as the disk-shaped slit, and a lead plate with a square shape of 11.5 mm x 11.5 mm and a hole with a diameter of 3 mm in the center was used as the annular slit.

[0096] The experiments were carried out under four conditions: irradiating only one of the samples with X-rays, placing the two samples in series with a 10 mm gap between them, and measuring the two samples in the same way with the front and back of the samples swapped. Diffraction images and diffraction peak profiles were obtained for each sample position.

[0097] (Embodiment 1) Samples with different damage life consumption rates (ventral side (79%) or dorsal side (0%)) (Experiment 1) (ventral side (79%) only, no slit) A sample plate S51 with a damage life consumption rate of 79% was placed on the X-ray incident side (ventral side), and diffraction spots were measured without a slit. Figure 11 is a schematic diagram showing the diffraction region and main diffraction lines of the abdomen. Figure 12 is an image showing a diffraction image M1 generated by the abdomen. A diffraction spot SP1 unique to sample plate S51 appears in the diffraction image M1. Figure 13 is the intensity profile in the 2θ direction of a specific diffraction spot SP1. The half-width of the diffraction spot SP1 is wide.

[0098] (Experiment 2) (Only the back side (0%), no slit) Sample plate S52 with a damage life consumption rate of 0% was placed on the detector side (back side) and the diffraction spots were measured without a slit. Figure 14 is a schematic diagram showing the diffraction region and main diffraction lines of the back side. Figure 15 is an image showing the diffraction image M2 generated by the back side. Diffraction spots are clearly visible in the diffraction image M2.

[0099] From (Experiment 1) and (Experiment 2), it can be seen that the half width of the diffraction spot of the sample plate with a high damage life consumption rate is larger than the half width of the diffraction spot of the sample plate with a low damage life consumption rate.

[0100] (Embodiment 2) Ventral (79%) and Dorsal (0%) Samples (Experiment 3) (Ventral (79%) and Dorsal (0%) Sides, No Slit) Sample plate S51 with a damage life consumption rate of 79% was placed on the X-ray incident side (ventral side), and sample plate S52 with a damage life consumption rate of 0% was placed on the detector side (dorsal side), and diffraction spots were measured without a slit. Figure 16 is a schematic diagram showing the diffraction regions and major diffraction lines of the ventral and dorsal regions. Figure 17 is an image showing diffraction image M3 generated by the ventral and dorsal regions. Diffraction spot SP3 corresponding to diffraction spot SP1 appears in diffraction image M3. Figure 18 shows the intensity profile in the 2θ direction of a specific diffraction spot SP3. The half-width of diffraction spot SP3 is wide.

[0101] (Experiment 4) (ventral side (79%) and dorsal side (0%), disc-shaped slit) Sample plate S51 with a damage life consumption rate of 79% was placed on the X-ray incident side (ventral side), and sample plate S52 with a damage life consumption rate of 0% was placed on the detector side (dorsal side). A lead block with a diameter of 3 mm and a thickness of 2 mm was used as the disc-shaped slit 51. Figure 19 is a schematic diagram showing the diffraction regions of the ventral and dorsal parts, the disc-shaped slit 51, and the main diffraction lines. Figure 20 is an enlarged view of the diffraction regions of the ventral and dorsal parts. Figure 21 is an image showing the diffraction image M4 generated by the ventral part. In the diffraction image M4, a diffraction spot SP4 corresponding to the diffraction spot SP1 (or SP3) appears. Furthermore, clear diffraction spots are no longer visible. Figure 22 shows the intensity profile in the 2θ direction of a specific diffraction spot SP4. The half-width of the diffraction spot SP4 is wide.

[0102] (Experiment 5) (ventral side (79%) and dorsal side (0%), annular slit) Sample plate S51 with a damage life consumption rate of 79% was placed on the X-ray incident side (ventral side), and sample plate S52 with a damage life consumption rate of 0% was placed on the detector side (dorsal side). An 11.5 mm × 11.5 mm square lead plate with a 3 mm diameter hole in the center was used as the annular slit 52. Figure 23 is a schematic diagram showing the diffraction regions of the ventral and dorsal regions, the annular slit, and the main diffraction lines. Figure 24 is an enlarged view of the diffraction regions of the ventral and dorsal regions and the annular slit. Figure 25 is an image showing the diffraction image M5 generated by the dorsal region. Diffraction spots are clearly visible in diffraction image M5.

[0103] In (Experiment 3), no slit was placed, so diffraction spots from both the ventral and dorsal sides were obtained. On the other hand, in (Experiment 4), a disk-shaped slit was placed, so diffraction spots with a large half-width were detected from the ventral sample plate, which has a high damage life consumption rate. Furthermore, in (Experiment 5), a circular slit was placed, so diffraction spots with a small half-width were detected from the dorsal sample plate, which has a low damage life consumption rate. Thus, as in (Experiment 4) and (Experiment 5), a slit may be used to extract only diffraction spots from a specific region, such as the dorsal or ventral region. Furthermore, by comparing (Experiment 3) with (Experiment 4) or (Experiment 3) with (Experiment 5), diffraction spots from specific regions may be extracted depending on the presence or absence of a single type of slit.

[0104] (Embodiment 3) Samples with different damage life consumption rates (ventral side (0%) or dorsal side (79%)) (Experiment 6) (ventral side (0%) only, no slit) Sample plate S52 with a damage life consumption rate of 0% was placed on the X-ray incident side (ventral side) and diffraction spots were measured. Figure 26 is a schematic diagram showing the diffraction region and main diffraction lines of the abdomen. Figure 27 is an image showing diffraction image M6 generated by the abdomen. Diffraction spots are clearly visible in diffraction image M6.

[0105] (Experiment 7) (Back side (79%) only, no slit) Sample plate S51 with a damage life consumption rate of 79% was placed on the detector side (back side) and the diffraction spots were measured. Figure 28 is a schematic diagram showing the diffraction region and main diffraction lines of the back side. Figure 29 is an image showing the diffraction image M7 generated by the back side. In the diffraction image M7, a diffraction spot SP7 unique to sample plate S51 appears. Figure 30 is the intensity profile in the 2θ direction of a specific diffraction spot SP8. The half-width of the diffraction spot SP7 is wide.

[0106] In (Embodiment 3), the positions of the ventral and dorsal samples were swapped compared to (Embodiment 1), and measurements were performed with the FWHM of the diffraction spot of the sample plate with a high damage life consumption rate still wider than the FWHM of the diffraction spot of the sample plate with a low damage life consumption rate.

[0107] (Embodiment 4) Ventral (0%) and Dorsal (79%) Samples (Experiment 8) (Ventral (0%) and Dorsal (79%), No Slit) Sample plate S52 with a damage life consumption rate of 0% was placed on the X-ray incident side (ventral side), and sample plate S51 with a damage life consumption rate of 79% was placed on the detector side (dorsal side), and diffraction spots were measured without a slit. Figure 31 is a schematic diagram showing the diffraction regions and major diffraction lines of the ventral and dorsal regions. Figure 32 is an image showing diffraction image M8 generated by the ventral and dorsal regions. Diffraction spot SP8 corresponding to diffraction spot SP7 appears in diffraction image M8. Figure 33 shows the intensity profile in the 2θ direction of a specific diffraction spot SP8. The half-width of diffraction spot SP8 is wide.

[0108] (Experiment 9) (Ventral side (0%) and dorsal side (79%), disc-shaped slit) Sample plate S52 with a damage life consumption rate of 0% was placed on the X-ray incident side (ventral side), and sample plate S51 with a damage life consumption rate of 79% was placed on the detector side (dorsal side), and a lead block with a diameter of 3 mm and a thickness of 2 mm was used as the disc-shaped slit 51. Figure 34 is a schematic diagram showing the diffraction regions of the ventral and dorsal parts, the disc-shaped slit, and the main diffraction lines. Figure 35 is an enlarged view of the diffraction regions of the ventral and dorsal parts and the disc-shaped slit. Figure 36 is an image showing the diffraction image M9 generated by the ventral part. Diffraction spots are clearly visible in the diffraction image M9.

[0109] (Experiment 10) (ventral side (0%) and dorsal side (79%), annular slit) Sample plate S52 with a damage life consumption rate of 0% was placed on the X-ray incident side (ventral side), and sample plate S51 with a damage life consumption rate of 79% was placed on the detector side (dorsal side). Figure 37 is a schematic diagram showing the diffraction regions of the ventral and dorsal parts, the annular slit, and the main diffraction lines. Figure 38 is an enlarged view of the diffraction regions of the ventral and dorsal parts and the annular slit. Figure 39 is an image showing the diffraction image M10 generated by the dorsal part. In the diffraction image M10, a diffraction spot SP10 corresponding to the diffraction spot SP7 appears. Figure 40 is the intensity profile in the 2θ direction of a specific diffraction spot SP10. The half-width of the diffraction spot SP10 is wider.

[0110] In (Experiment 8), no slit was placed, and diffraction spots from both the ventral and dorsal sides were obtained. On the other hand, in (Experiment 9), a disk-shaped slit was placed, and diffraction spots with narrow half-widths were detected from the ventral sample plate, which had a low damage life consumption rate. Furthermore, in (Experiment 10), a circular slit was placed, and diffraction spots with wide half-widths were detected from the dorsal sample plate, which had a high damage life consumption rate. Thus, as in (Experiment 9) and (Experiment 10), a slit may be used to extract only diffraction spots from a specific region, such as the dorsal or ventral region. Furthermore, by comparing (Experiment 8) with (Experiment 9) or (Experiment 8) with (Experiment 10), diffraction spots from specific regions may be extracted depending on the presence or absence of a single type of slit.

[0111] This application claims priority based on Japanese Patent Application No. 2024-99736 filed on June 20, 2024, and the entire contents of Japanese Patent Application No. 2024-99736 are incorporated by reference into this application.

[0112] DESCRIPTION OF SYMBOLS 11 Circular slit 12 Annular slit 12a Hole 31 Circular slit 32 Circular slit 33 Annular slit 33a Hole 51 Circular slit 52 Annular slit 100 Structural evaluation system 110 X-ray diffraction device 120 X-ray irradiation unit 121 Main body 122 Collimator 125 Housing 126 X-ray source 127 X-ray shield window 128 Collimator main body 129 Shielding cover 130 Sample holder 135 Position adjustment mechanism 140 Detector 150 Processing device (structural evaluation device) 151 Position adjustment unit 153 Data extraction unit 153 Data extraction unit 155 Coefficient calculation unit 156 Damage state identification unit 157 Memory unit 160 Input device 170 Output device 200 X-ray diffraction device DB1 Direct beam R11 Direct beam R12 Direct beam R13 Direct beam R14 Diffracted X-rays R15 Diffracted X-rays R2 Diffracted X-rays R21 Direct beam R22 Direct beam R23 Diffracted X-rays V11 Diffracted X-rays (virtual) V14 Diffracted X-rays (virtual) V15 Diffracted X-rays (virtual) V24 Diffracted X-rays (virtual) V25 Diffracted X-rays (virtual) S0 Sample S10 Large sample S11 Abdomen S12 Dorsal S20 Large sample S21 Abdomen S22 Middle S23 Dorsal S50 Sample S51 Sample plate S52 Sample plate SP1 Diffraction spot SP3 Diffraction spot SP4 Diffraction spot SP8 Diffraction spot SP9 Diffraction spot SP12 Diffraction spot

Claims

1. A structural evaluation method performed by measuring diffracted X-rays transmitted through a sample, comprising the steps of: simultaneously irradiating multiple regions of a large single-crystal sample with white X-rays; and detecting the diffracted X-rays generated by said irradiation; wherein the measurement consisting of said series of steps is performed multiple times; and during at least one of said multiple measurements, a slit is placed on the back side of the large sample that selectively passes only diffracted X-rays generated from a specific region out of the multiple regions irradiated with the X-rays; and the diffracted X-rays generated in each of the multiple regions of the large sample are detected using said slit, and the structure is evaluated for each region.

2. A structural evaluation method according to claim 1, wherein the measurements are carried out using a plurality of types of slits that each pass diffracted X-rays from a different one of the plurality of regions.

3. A structural evaluation method according to claim 1 or claim 2, characterized in that the diffraction X-ray data detected in the multiple measurements is compared to extract diffraction spot data for each region, and the structure is evaluated for each region using the extracted data.

4. A structural evaluation method according to claim 1 or 2, characterized in that the damage state is identified for each region of the large sample from a coefficient related to the variance of the intensity distribution in a specific direction in the diffraction spot of the detected diffracted X-rays.

5. A structural evaluation method according to claim 4, wherein the damage life consumption rate is calculated for each region of the large sample from the half-width of the diffraction spot.

6. A structural evaluation method according to claim 1 or claim 2, characterized in that the slit is formed in a disk or ring, the main surface of the slit is perpendicular to the irradiation direction of the white X-rays, and the center of the disk or ring is positioned so as to coincide with the central axis of the white X-rays.

7. A structural evaluation method according to claim 6, characterized in that the large sample is formed from a Ni-based superalloy material having a dendritic structure in a single crystal state, and the slit is designed such that the outer diameter of the disk or the inner diameter of the ring is designed according to the diffraction angle of the diffracted X-rays.

8. A structural evaluation method according to claim 1 or 2, characterized in that the large sample comprises a belly portion and a dorsal portion sandwiching a hollow portion, and the specific region is the belly portion or the dorsal portion.

9. A structural evaluation device that uses measurement data of diffracted X-rays that have passed through a sample, comprising: a data extraction unit that extracts diffraction spot data for each region by comparing the diffracted X-ray data obtained by performing multiple measurements in which white X-rays are irradiated simultaneously on multiple regions of a large single-crystal sample; and a damage state identification unit that identifies the damage state for each region using the extracted data, wherein the device uses measurement data obtained in at least one of the multiple measurements by placing a slit on the back side of the large sample that selectively allows only diffracted X-rays generated from a specific region out of the multiple regions irradiated with the X-rays to pass through.

10. A structural evaluation program that uses measurement data of diffracted X-rays that have passed through a sample, which causes a computer to execute the following processes: extracting data on diffraction spots for each region by comparing the diffracted X-ray data obtained by performing multiple measurements in which white X-rays are irradiated simultaneously on multiple regions of a large single-crystal sample; and identifying the damage state for each region using the extracted data; wherein the program uses measurement data obtained in at least one of the multiple measurements by placing a slit on the back side of the large sample that selectively allows diffracted X-rays generated from specific regions out of the multiple regions irradiated with the X-rays to pass through.

Images