JP2017181364A - Metal material evaluation method and evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal material evaluation method with which it is possible to evaluate a metal material with high accuracy irrespective of the surface condition of a sample.SOLUTION: A metal material evaluation method in an embodiment of the present invention includes: a first step for finding the relationship of a difference in lattice strains of small crystal grain and large crystal grain with a life consumption rate using a first metal material; a second step for finding a difference in lattice strains of small crystal grain and large crystal grain with regard to a second metal material of the same quality as the first metal material; and a third step for applying the difference in lattice strain found in the second step to the relationship found in the first step, and estimating the life consumption rate of the second metal material.SELECTED DRAWING: None

Description

  Embodiments described herein relate generally to a metal material evaluation method and an evaluation apparatus.

  Conventionally, lattice strain in crystal grains has been used in the evaluation of the lifetime consumption rate of metal materials. Specifically, first, using the first metal material, the relationship between the lattice strain in the crystal grains and the lifetime consumption rate is obtained. Separately, for the second metal material, the lattice strain in the crystal grains is measured. Then, the lattice strain of the second metal material is applied to the above relationship, and the lifetime consumption rate of the second metal material is obtained.

  The lattice strain can be obtained as follows. First, crystal orientations at a large number of measurement points set in a measurement region are measured by an EBSP (Electron Back-Scatter Diffraction Pattern) method.

  A large number of crystal orientations thus obtained are analyzed to obtain a lattice strain. As an analysis method, KAM (Carnel Average Mission), GAM (Grain Average Mission), IQ (Image Quality), and the like are used.

JP 2004-3922 A JP 2005-106486 A JP 2012-154891 A

  However, the crystal orientation measured by the EBSP method is easily affected by the surface state of the sample. Specifically, surface polishing is performed in the preparation of the sample, but such polishing tends to cause distortion on the surface of the sample. The measurement result of the crystal orientation is likely to change due to the strain generated on the surface.

  Since the lattice strain is obtained using the crystal orientation, it is easily affected by the change. In addition, the conventional evaluation method is easily affected by the change because the lattice strain obtained using the crystal orientation is basically related to the evaluation of the lifetime consumption rate and the like as it is. Specifically, the lattice strain required for the first metal material is likely to change. As a result, the relationship between the lattice strain and the lifetime consumption rate is likely to change. Further, the lattice strain required for the second metal material is likely to change. As a result, the result when applied to the above relationship is likely to change.

  The problem to be solved by the present invention is to provide a metal material evaluation method and an evaluation apparatus capable of evaluating a metal material with high accuracy regardless of the surface state of a sample.

The method for evaluating a metal material according to the embodiment includes a first step of obtaining a relationship between a lattice strain difference between a small crystal grain and a large crystal grain and a lifetime consumption rate using the first metal material; For the second metal material of the same quality as the metal material, the second step for obtaining the lattice strain difference between the small crystal grains and the large crystal grains and the relationship obtained in the first step are obtained in the second step. And a third step of fitting the lattice strain difference and estimating the lifetime consumption rate of the second metal material.
In addition, the metal material evaluation apparatus according to the embodiment is obtained using the first metal material, and stores the relationship between the lattice strain difference between the small crystal grains and the large crystal grains and the lifetime consumption rate or the deformation amount. A lattice distortion difference between a small crystal grain and a large crystal grain in a second metal material of the same quality as the first metal material is applied to the relationship stored in the memory unit, and the second metal material An estimation unit for estimating the lifetime consumption rate or the deformation amount.

  According to the metal material evaluation method and evaluation apparatus of the embodiment, by using the lattice strain difference between the small crystal grains and the large crystal grains, the metal material can be evaluated with high accuracy regardless of the surface state of the sample. Can do.

It is a figure explaining the calculation method of KAM. It is the figure which showed the evaluation apparatus of 3rd Embodiment. It is the figure which showed the evaluation apparatus of 4th Embodiment. It is the figure which showed the test piece for a creep test. It is the figure which showed the relationship between the average KAM (small crystal grain, large crystal grain) of Example 1, and a creep life consumption rate. It is the figure which showed the relationship between the average KAM difference of Example 1, and a creep life consumption rate. It is the figure which showed the relationship between the average KAM of the comparative example 1, and a creep life consumption rate.

  Hereinafter, modes for carrying out the present invention will be described.

(First embodiment)
The metal material evaluation method according to the present embodiment is a first step in which the first metal material is used to determine the relationship between the lattice strain difference between the small crystal grains and the large crystal grains and the lifetime consumption rate or the deformation amount. And the second step for obtaining the lattice strain difference between the small crystal grains and the large crystal grains for the second metal material of the same quality as the first metal material, and the relationship obtained in the first step is And a third step of estimating the lifetime consumption rate or the deformation amount of the second metal material by applying the lattice strain difference obtained in the step.

  In the present embodiment, the difference in lattice strain between the small crystal grains and the large crystal grains is used for estimating the lifetime consumption rate or the deformation amount. Thereby, the lifetime consumption rate or deformation amount of the second metal material can be estimated with high accuracy regardless of the surface state of the sample. Examples of the lifetime consumption rate include the lifetime consumption rate in creep (creep lifetime consumption rate). Examples of the deformation amount include a deformation amount in creep (creep deformation amount).

  Since the lattice strain difference between the small crystal grains and the large crystal grains changes so as to gradually decrease or increase according to the lifetime consumption rate or the deformation amount, it can be used for these estimations. Further, since the lattice strain difference between the small crystal grains and the large crystal grains does not change depending on the surface states of the first metal material and the second metal material, it can be estimated with high accuracy. Specifically, even if distortion caused by polishing is introduced into the surfaces of the first metal material and the second metal material, or noise caused by an evaluation apparatus based on the EBSP method is added, they are not detected by the EBSP method. These differences do not change because they act on both the small and large grains in the lattice strain being evaluated. Therefore, estimation can be performed with high accuracy.

<First step>
In the first step, the relationship between the lattice strain difference between the small crystal grains and the large crystal grains and the lifetime consumption rate or the deformation amount is obtained using the first metal material.

  As a 1st metal material, the metal material used for high temperature apparatuses, such as a turbine, is mentioned, for example. Specifically, iron, nickel, stainless steel, heat-resistant steel, nickel-base heat-resistant superalloy, and the like can be given. As the first metal material, a plurality of materials having different lifetime consumption rates or deformation amounts are usually used. The adjustment of the life consumption rate and the deformation amount can be performed by changing the processing conditions.

  The lattice strain difference can be obtained as a difference between the lattice strain of small crystal grains and the lattice strain of large crystal grains. The lattice strain of each crystal grain can be obtained using the crystal orientation. The crystal orientation can be determined by an EBSP (Electron Back-Scatter Diffraction Pattern) method.

  Usually, the crystal orientation can be obtained using OIM (ORIENTATION IMAGEING MICROSCOPY). According to OIM, crystal orientations of a large number of measurement points set in a measurement region can be obtained. The distance (step size) between the measurement points is often several μm or less, and the number of measurement points is tens of thousands to several millions depending on the measurement region.

  The lattice strain difference can be determined by using, for example, Karnel Average Misoration (KAM) or Grain Average Missoriation (GAM) determined from such crystal orientation.

When KAM is used, the lattice strain difference can be obtained as follows.
First, in a measurement region including a plurality of measurement points including small crystal grains and large crystal grains, for each measurement point, the crystal orientation of the crystal orientation of the measurement point and the crystal orientation of the measurement point adjacent thereto The difference is averaged to determine the average crystal orientation difference. Among these average crystal orientation differences, the measurement points included in the small crystal grains are averaged to obtain the average crystal orientation difference for the small crystal grains, and the measurement points included in the large crystal grains are averaged. Then, the average crystal orientation difference for large crystal grains is obtained. Then, the difference between the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains is obtained. Here, the average crystal orientation difference at each measurement point corresponds to KAM. Further, the difference between the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains corresponds to the lattice strain difference.

  Hereinafter, KAM will be specifically described.

  First, as shown in FIG. 1, an analysis section 10 is set in the measurement region. Here, the measurement region includes small crystal grains and large crystal grains. Each section is artificially determined, and the measurement area is divided by a regular hexagon. Each section corresponds to a measurement point.

  Next, a crystal orientation difference is calculated for the analysis section 10 and each of the first sections 11A to 11F adjacent to the periphery of the analysis section 10. For example, the crystal orientation differences are 2.1 °, 35.8 °, 34.5 °, 1.1 °, 1.6 °, and 1.8 °, respectively.

  As for these crystal orientation differences, those exceeding the threshold value are deleted as belonging to the grain boundary. For example, when the threshold is 5 °, 2.1 °, 1.1 °, 1.6 °, and 1.8 ° are effective values.

  KAM is obtained by averaging such effective values. Specifically, (2.1 ° + 1.1 ° + 1.6 ° + 1.8 °) /4=1.65.

  In addition, in order to improve the analysis accuracy, KAM is obtained using the crystal orientation difference between the second section 12 (12A, 12B) and the third section (not shown) as well as the first section 11. You can also.

  When KAM is used, the average crystal orientation difference for the small crystal grains can be obtained by averaging the KAMs whose measurement points are included in the small crystal grains. Hereinafter, what is obtained in this manner is referred to as an average KAM for small crystal grains. Similarly, the average crystal orientation difference for large crystal grains can be obtained by averaging the KAMs whose measurement points are included in the large crystal grains. Hereinafter, what is obtained in this way is referred to as an average KAM for large crystal grains.

  The difference between the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains is the difference between the average KAM for the small crystal grains and the average KAM for the large crystal grains (average KAM difference). Can be sought. That is, the difference (average KAM difference) between the average KAM for the small crystal grains and the average KAM for the large crystal grains is the lattice strain difference.

On the other hand, when GAM is used, the lattice strain difference can be obtained as follows.
First, in a measurement region including a plurality of measurement points including a small crystal grain and a large crystal grain, an average of the small crystal grains is obtained by averaging the crystal orientation difference between adjacent measurement points included in the small crystal grain. A crystal orientation difference is obtained, and an average crystal orientation difference for a large crystal grain is obtained by averaging the crystal orientation differences between adjacent measurement points included in the large crystal grain. Then, the difference between the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains is obtained.

  Here, the average crystal orientation difference for the small crystal grains corresponds to GAM for the small crystal grains, and the average crystal orientation difference for the large crystal grains corresponds to GAM for the large crystal grains. The difference between the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains can be obtained as a difference between the GAM for the small crystal grains and the GAM for the large crystal grains. That is, the difference between the GAM for the small crystal grains and the GAM for the large crystal grains is the lattice strain difference.

  Note that the lattice strain difference is not necessarily obtained using KAM or GAM. For example, the image quality may be obtained using Image Quality (IQ) or the like.

  The small crystal grains and the large crystal grains are preferably classified based on the grain size. That is, it is preferable to use a crystal grain having a grain size equal to or smaller than a reference value as a small crystal grain and a grain having a grain size exceeding the reference value as a large crystal grain. Since the particle size distribution varies depending on the individual metal material, the reference value is preferably set as appropriate according to the individual metal material. The grain size is a diameter of a circle having the same area as the crystal grain.

  The crystal grains are preferably classified into three types: small crystal grains, medium crystal grains, and large crystal grains. Lattice between large crystal grains and small crystal grains by discontinuing the lower limit value of the grain size for classifying large crystal grains and the upper limit value of the grain size for classifying small crystal grains, and providing intermediate crystal grains in between. The distortion difference becomes clearer.

  As for the grain size that classifies small crystal grains, medium crystal grains, and large crystal grains, a threshold value that makes the lattice strain difference between large crystal grains and small crystal grains clearer may be searched by trial and error. The total area of the grains, the total area of the medium crystal grains, and the total area of the large crystal grains may be set to be equal to each other. Thereby, the life consumption rate or the deformation amount can be estimated more easily and with high accuracy.

<Second step>
In the second step, the lattice strain difference between the small crystal grains and the large crystal grains is obtained for the second metal material that is the same quality as the first metal material.

  As the second metal material, the same material as the first metal material is used. As such a thing, the metal material used for high temperature apparatuses, such as a turbine, is mentioned, for example. Specifically, iron, nickel, stainless steel, heat-resistant steel, nickel-base heat-resistant superalloy, and the like can be given.

  As the second metal material, for example, a material cut out from a high-temperature device such as a turbine is used. If it is a general refractory metal material made by forging or rolling, a cutout size of about several mm × several mm is sufficient, and a measurement region of about 1 mm × 1 mm is sufficient. If the measurement region is too small, the number of crystal grains contained is reduced, and thus the variation in measurement results increases.

  The lattice strain difference can be obtained in the same manner as in the first step. For example, after obtaining the crystal orientation by EBSP, the average crystal orientation difference for the small crystal grains and the average crystal orientation difference for the large crystal grains are obtained, and the average crystal orientation difference for these small crystal grains and the average for the large crystal grains are determined. Find the difference from the crystal orientation difference.

  In obtaining the lattice distortion difference, KAM or GAM can be used. When KAM is used in the first step, it is preferable to use KAM in the second step. Further, when GAM is used in the first step, it is preferable to use GAM also in the second step. Note that IQ or the like may be used in obtaining the lattice strain difference.

<Third step>
In the third step, the lattice strain difference obtained in the second step is applied to the relationship obtained in the first step. The relationship obtained in the first step shows the relationship between the lattice strain difference between the small crystal grains and the large crystal grains and the lifetime consumption rate or the amount of deformation. Therefore, the relationship was obtained in the second step. By applying the lattice strain difference between the small crystal grains and the large crystal grains, the lifetime consumption rate or the deformation amount of the second metal material can be estimated.

  According to this embodiment, the life consumption rate or the deformation amount can be evaluated with high accuracy by utilizing the lattice strain difference between the small crystal grains and the large crystal grains.

(Second Embodiment)
The metal material evaluation method of the present embodiment includes a first step for obtaining a lattice strain difference between small crystal grains and large crystal grains in the metal material, and a lattice strain difference obtained in the first step as a reference value. A second step of comparing, and a third step of evaluating the lifetime consumption rate or the deformation amount by comparing with a reference value in the second step.

  In the present embodiment, the lattice strain difference between the small crystal grains and the large crystal grains in the metal material is obtained, and this lattice strain difference is compared with a reference value. That is, the lattice strain difference between the small crystal grains and the large crystal grains changes so as to gradually decrease or increase according to the lifetime consumption rate or the deformation amount. Therefore, by comparing this with the reference value, the life consumption rate or the deformation amount can be evaluated. That is, it is not necessary to create a strict relationship as in the first embodiment, and the lifetime consumption rate or the deformation amount can be evaluated easily and quickly.

<First step>
In the first step, a lattice strain difference between small crystal grains and large crystal grains in the metal material is obtained. The lattice strain difference between the small crystal grains and the large crystal grains can be obtained in the same manner as the lattice strain difference between the small crystal grains and the large crystal grains in the first embodiment.

<Second step>
In the second step, the lattice strain difference obtained in the first step is compared with a reference value. The reference value can be determined as appropriate based on experimental results, past experience, and the like. Examples of the reference value include 0. That is, the reference value can be set when there is no lattice strain difference between the small crystal grains and the large crystal grains.

  Usually, the lattice strain difference between the small crystal grains and the large crystal grains changes so as to gradually decrease or increase in accordance with the change in the lifetime consumption rate or the deformation amount. In general, the value of the lattice strain difference is switched from positive to negative or from negative to positive in a later region of the life or a region exceeding a certain amount of deformation.

  For this reason, by setting the reference value to 0, when the reference value is reached, it can be considered that it is in the later stage of the life or exceeds the certain amount of deformation. Therefore, it is not necessary to create a strict relationship as in the first embodiment, and the lifetime consumption rate or the deformation amount can be evaluated easily and quickly.

  According to this embodiment, by comparing the lattice strain difference between the small crystal grains and the large crystal grains with the reference value, it is possible to easily and quickly evaluate the life consumption rate or the deformation amount.

(Third embodiment)
FIG. 2 shows a metal material evaluation apparatus 20 according to the present embodiment. The evaluation device 20 according to the present embodiment includes a storage unit 21 and an estimation unit 22. The evaluation apparatus 20 of this embodiment is suitably used for implementing the evaluation method of the first embodiment.

  The storage unit 21 stores the relationship between the lattice strain difference between the small crystal grains and the large crystal grains and the lifetime consumption rate or the deformation amount. The above relationship is obtained using the first metal material. The storage unit 21 includes a storage device such as a semiconductor memory or a hard disk, for example.

  The estimation unit 22 applies the lattice strain difference between the small crystal grains and the large crystal grains in the second metal material of the same quality as the first metal material to the relationship stored in the storage unit 21, and Estimate life consumption rate or deformation.

  For example, a measurement unit 23 is connected to the storage unit 21 and the estimation unit 22.

  For example, the measurement unit 23 uses the first metal material to acquire the lattice strain difference between the small crystal grains and the large crystal grains. This lattice strain difference is sent to the storage unit 21 together with the lifetime consumption rate or the deformation amount. These are used to construct a relationship stored in the storage unit 21.

  Further, the measurement unit 23 acquires a lattice strain difference between the small crystal grains and the large crystal grains in the second metal material. This lattice strain difference is sent to the estimation unit 22 and is applied to the relationship stored in the storage unit 21. Thereby, the lifetime consumption rate or deformation amount of the second metal material is estimated.

  For example, an input unit 24 and a display unit 25 are connected to the estimation unit 22. The input unit 24 is provided for inputting instructions or data. The input unit 24 includes an input device such as a keyboard. The display unit 25 displays the estimation result in the estimation unit 22 and the like. The display unit 25 includes various display devices.

  According to the present embodiment, the evaluation method of the first embodiment can be implemented, and the life consumption rate or the deformation amount can be evaluated with high accuracy.

(Fourth embodiment)
FIG. 3 shows a metal material evaluation apparatus 30 according to this embodiment. The evaluation device 30 according to the present embodiment includes a measurement unit 31, a storage unit 32, and a comparison unit 33. The evaluation apparatus 30 of this embodiment is suitably used for implementing the evaluation method of the second embodiment.

  The measuring unit 31 acquires a lattice strain difference between a small crystal grain and a large crystal grain in the metal material. The storage unit 32 stores a reference value. The comparison unit 33 compares the lattice strain difference sent from the measurement unit 31 with the reference value stored in the storage unit 32.

  For example, an input unit 34 and a display unit 35 are connected to the comparison unit 33. The input unit 34 is provided for inputting instructions or data. The input unit 34 includes an input device such as a keyboard. The display unit 35 displays the comparison result in the comparison unit 33 and the like. The display unit 35 includes various display devices.

  According to this embodiment, the evaluation method of the second embodiment can be carried out, and the lifetime consumption rate or the deformation amount can be easily and quickly evaluated.

  Hereinafter, specific description will be given with reference to examples.

Example 1
As a metal material, Hastelloy (registered trademark) X, which is a solid solution strengthened Ni-base heat-resistant superalloy having a face-centered cubic structure, was prepared. This metal material was rolled to obtain a plate material having a thickness of 20 mm. Furthermore, as solution heat treatment, 1150 ° C., holding for 50 minutes, and gas fan cooling were performed.

  After the solution heat treatment, a test piece 40 for a creep test as shown in FIG. 4 was cut out. Here, the test piece 40 has a round bar shape in which the stress axis coincides with the rolling direction, and includes a parallel portion 41 and a pair of holding portions 42 arranged at both ends thereof. The parallel part 41 has a diameter of 6 mm and a gauge distance of 27.4 mm.

  Using such a test piece 40, the temperature and load were fixed, and the creep test was performed by changing the time. The temperature was 1123 K and the stress was 49 MPa. Thereby, the some test piece 40 from which a creep life consumption rate differs was produced. These test pieces 40 correspond to the first metal material in the first embodiment.

  After the creep test, a sample was cut out from the parallel portion 41 of each test piece 40 in a direction perpendicular to the rolling surface. This sample was embedded in a resin, polished with SiC paper and diamond paste, and then the surface was polished using colloidal silica. In addition, about what was fractured, it evaluated in the position about 5 mm away from the fracture surface.

  About these samples, the crystal orientation of each measurement point was calculated | required by EBSP. At this time, the measurement area was 1 mm × 1 mm. The step size (distance between adjacent measurement points) was 2.5 μm.

  Moreover, KAM of each measurement point was obtained from the crystal orientation of each measurement point. Here, the measurement grid was a hexagonal grid. Crystal orientation differences of 5 ° or more were excluded as corresponding to grain boundaries. In addition, measurement data having a coincidence index (CI) of less than 0.1 was excluded. CI relates to the reliability of measurement data.

  After that, among the above KAM, those whose measurement points were included in the small crystal grains were averaged to determine the average crystal orientation difference for the small crystal grains (average KAM for the small crystal grains). Similarly, among the above KAM, the measurement points included in the large crystal grains were averaged to determine the average crystal orientation difference for the large crystal grains (average KAM for the large crystal grains). Here, those having a particle size of 20 μm or less were defined as small crystal grains, and those having a particle diameter exceeding 35 μm were defined as large crystal grains.

  Note that the maximum diameter of the crystal grains in the measurement region is about 100 μm. The crystal grains were classified into three types: small crystal grains, medium crystal grains, and large crystal grains so that the total area of small crystal grains, the total area of medium crystal grains, and the total area of large crystal grains were almost equal to each other.

  FIG. 5 shows the relationship between the average KAM (small crystal grains, large crystal grains) thus determined and the creep life consumption rate. FIG. 6 shows the relationship between these differences (average KAM difference) and the creep life consumption rate. Note that the average KAM difference corresponds to a lattice distortion difference. The average KAM difference was defined as “average KAM for small crystal grains−average KAM for large crystal grains”.

  As is apparent from FIGS. 5 and 6, the average KAM difference gradually decreases as the creep life consumption rate increases. For this reason, the creep life consumption rate of this metal material can be estimated by obtaining and applying the average KAM difference of the metal material whose creep life consumption rate is unknown. This metal material corresponds to the second metal material in the first embodiment.

  Also, if distortion occurs on the surface of the sample during the adjustment process for evaluation by EBSP, the crystal orientation changes, for example, the average KAM (small crystal grains, as shown by arrows in FIG. 5). Large crystal grains) change. However, since the amount of change in these average KAMs (small crystal grains, large crystal grains) is basically the same, the average KAM difference, which is the difference between them, does not change. That is, the relationship between the average KAM difference and the creep life consumption rate shown in FIG. 6 does not change. For the same reason, the average KAM difference of the metal material applied to such a relationship does not change depending on the surface state of the sample.

  Thus, by using the difference in lattice strain between the small crystal grains and the large crystal grains, including the average KAM difference between the small crystal grains and the large crystal grains, the influence of the surface condition of the sample at any stage can be achieved. I will not receive it. Therefore, the creep life consumption rate and the like can be evaluated with high accuracy.

(Comparative Example 1)
In the same manner as in Example 1, the KAM at each measurement point was obtained. Thereafter, these KAMs were averaged to obtain an average KAM. That is, as in Example 1, KAM was averaged as it was without distinguishing between KAM for small crystal grains and KAM for large crystal grains, and an average KAM was obtained.

  FIG. 7 shows the relationship between the average KAM thus obtained and the creep life consumption rate. Since there is a certain relationship between the average KAM and the creep life consumption rate, the creep life consumption rate can be estimated even if the average KAM is used.

  However, when the average KAM is simply related to the creep life consumption rate, if a strain occurs on the surface of the sample, the crystal orientation changes, for example, as shown by the arrow in the figure, the average KAM is Change. That is, the relationship between the average KAM and the creep life consumption rate changes. Similarly, the average KAM of the metal material applied to such a relationship also changes due to the strain generated on the surface of the sample.

  Thus, when the average KAM is simply related to the creep life consumption rate, etc., there is a risk of being influenced by the surface condition of the sample at each stage. For this reason, it is not always possible to accurately evaluate the creep life consumption rate and the like.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Analysis division, 11 ... 1st division, 12 ... 2nd division, 20 ... Evaluation apparatus, 21 ... Memory | storage part, 22 ... Estimation part, 23 ... Measurement part, 24 ... Input part, 25 ... Display part, 30 ... Evaluation device, 31 ... Measurement part, 32 ... Storage part, 33 ... Comparison part, 34 ... Input part, 35 ... Display part, 40 ... Test piece, 41 ... Parallel part, 42 ... Holding part

Claims (10)

A first step of obtaining a relationship between a lattice strain difference between a small crystal grain and a large crystal grain and a lifetime consumption rate or a deformation amount using the first metal material;
A second step of obtaining a lattice strain difference between a small crystal grain and a large crystal grain for a second metal material having the same quality as the first metal material;
Applying the lattice strain difference obtained in the second step to the relationship obtained in the first step, and estimating the lifetime consumption rate or the deformation amount of the second metal material;
Evaluation method of metal material having   The method for evaluating a metal material according to claim 1, wherein a parent phase of the first metal material and the second metal material has a face-centered cubic structure. A first step of obtaining a lattice strain difference between a small crystal grain and a large crystal grain in a metal material;
A second step of comparing the lattice strain difference obtained in the first step with a reference value;
A third step of evaluating the lifetime consumption rate or the deformation amount by comparison with the reference value in the second step;
Evaluation method of metal material having   The metal material evaluation method according to claim 3, wherein a parent phase of the metal material has a face-centered cubic structure.   The metal material evaluation method according to claim 1, wherein the life consumption rate is a creep life consumption rate, and the deformation amount is a creep deformation amount.   The metal material evaluation method according to any one of claims 1 to 5, wherein a lower limit value of a particle size for classifying the large crystal grains and an upper limit value of a particle size for classifying the small crystal grains are not continuous. The lattice strain difference between the small crystal grains and the large crystal grains is
In the measurement region including the small crystal grains and the large crystal grains, and a plurality of measurement points are set, for each measurement point, the crystal orientation of the crystal orientation of the measurement point and the crystal orientation of the measurement point adjacent thereto Calculating the average crystal orientation difference by averaging the differences;
Among these average crystal orientation differences, the measurement points included in the small crystal grains are averaged to obtain an average crystal orientation difference for the small crystal grains, and the measurement points are included in the large crystal grains. Averaging the ones to determine the average crystal orientation difference for the large grains;
Determining a difference between an average crystal orientation difference for the small crystal grains and an average crystal orientation difference for the large crystal grains;
The method for evaluating a metal material according to claim 1, which is obtained through the process.   The method for evaluating a metal material according to claim 7, wherein the crystal orientation is obtained using backscattered electron diffraction. A storage unit that is obtained using the first metal material and stores a relationship between a lattice strain difference between a small crystal grain and a large crystal grain and a lifetime consumption rate or a deformation amount;
The lattice strain difference between the small crystal grains and the large crystal grains in the second metal material of the same quality as the first metal material is applied to the relationship stored in the storage unit, and the lifetime consumption rate of the second metal material Or an estimation unit for estimating a deformation amount;
An evaluation apparatus for metal materials. A measurement unit for acquiring a lattice strain difference between a small crystal grain and a large crystal grain in a metal material;
A storage unit for storing a reference value;
A comparison unit for comparing the lattice strain difference with the reference value;
An evaluation apparatus for metal materials.

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