JP2019002908A - Inspection method of heat-resistant member - Google Patents

Abstract

A method for inspecting a heat-resistant member capable of accurately estimating the operating temperature of a steel material based on the state of the structure on the surface of the steel material. A method for inspecting a heat-resistant member obtains a relationship between an average particle size of precipitates having a first particle size or larger and a parameter relating to a use temperature and a use time of the heat-resistant material. An average particle size obtaining step for determining an average particle size of a precipitate having a particle size equal to or larger than a second particle size corresponding to the first particle size among the precipitates in the structure of the heat-resistant member to be inspected by measuring the relationship. And, based on the relationship acquired in the relationship acquisition step and the average particle size determined in the average particle size acquisition step, a use temperature parameter acquisition step for determining a parameter relating to the use temperature of the heat-resistant member to be inspected, Is provided. [Selection] Figure 2

Description

  The present disclosure relates to a method for inspecting a heat-resistant member.

In order to evaluate the life of steel materials used in high heat equipment such as boilers, estimation of the use temperature of the steel materials based on the state of the structure of the steel material surface is performed. For example, Patent Document 1 discloses a method of preliminarily determining the relationship between the average interparticle distance of precipitates and the temperature / time parameter, and estimating the operating temperature from the average interparticle distance of precipitates in the steel material to be inspected. ing.
Further, for example, in Patent Document 2, the relationship between the area ratio, the number density, or the average size, the operating time, and the operating temperature occupied by the precipitate in the unit area is obtained in advance, and the precipitate in the steel material to be inspected is the unit area. A method for estimating a use temperature from an area ratio, a number density, or an average size is disclosed.

JP-A-2015-125116 JP 2014-228196 A

However, when starting to use steel at high temperatures, the frequency of new precipitates increases at a short time after the start of use, so the average interparticle distance decreases, and then new precipitates are generated. As the frequency decreases, the average interparticle distance starts to increase. Therefore, in the method disclosed in Patent Document 1, there is a possibility that the use temperature estimated from the average interparticle distance of precipitates in the steel material to be inspected may not be uniquely determined.
In addition, when starting to use steel at a high temperature, at a certain time, there may be both precipitates that become coarser over time and precipitates that become smaller and disappear, so over time, There is a period in which no clear change in the area ratio, number density or average size occupied by the precipitates in the unit area is observed. Therefore, in the method disclosed in Patent Document 2, there is a risk that the estimation accuracy of the operating temperature is lowered.

  In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a method for inspecting a heat-resistant member capable of accurately estimating the use temperature of a steel material based on the state of the structure of the steel material surface.

(1) An inspection method for a heat-resistant member according to at least one embodiment of the present invention includes:
A relationship acquisition step of acquiring a relationship between an average particle size of precipitates having a first particle size or more among precipitates in the structure of the heat-resistant material and parameters regarding the use temperature and use time of the heat-resistant material;
An average particle size obtaining step for obtaining an average particle size of a precipitate having a particle size equal to or larger than the second particle size among the precipitates in the structure of the heat-resistant member to be inspected by measurement;
Based on the relationship obtained in the relationship obtaining step and the average particle size obtained in the average particle size obtaining step, a use temperature parameter obtaining step for obtaining a parameter relating to the use temperature of the heat-resistant member to be inspected,
Is provided.

According to the method of (1) above, the relationship acquisition for acquiring the relationship between the average particle size of the precipitates having the first particle size or more among the precipitates in the structure of the heat-resistant material and the parameters regarding the use temperature and the use time of the heat-resistant material. A process is provided. Therefore, in the acquired relationship, the influence of precipitates having a particle size less than the first particle size can be excluded. As a result, in the acquired relationship described above, the influence of newly generated precipitates and the influence of precipitates that disappear over time can be suppressed, so the acquired relationship is suitable for estimation of the operating temperature. It will be a thing.
In addition, according to the method of (1) above, the average particle size of precipitates having a particle size equal to or larger than the second particle size corresponding to the first particle size among the precipitates in the structure of the heat-resistant member to be inspected is measured. The required average particle diameter acquisition process is provided. Therefore, the influence of precipitates having a particle size less than the second particle size corresponding to the first particle size can be excluded from the average particle size of the precipitates in the structure of the heat-resistant member to be inspected obtained in the average particle size acquisition step. .
And according to the method of said (1), the parameter regarding the operating temperature of the heat-resistant member to be examined is calculated | required based on the relationship acquired in the relationship acquisition process, and the average particle diameter calculated | required by the average particle diameter acquisition process. A use temperature parameter acquisition step is provided. Thereby, since the parameter regarding the operating temperature of the heat-resistant member to be inspected can be obtained in a state in which the influence of the precipitate having a particle size less than the predetermined particle size is excluded, the estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

(2) In some embodiments, in the method of (1) above,
The first particle size is n micrometers;
The second particle size is the n micrometers.

  According to the method (2), the first particle size and the second particle size are both n micrometers. As a result, the selection criteria for determining whether or not the precipitates are to be calculated for the average particle diameter can be made uniform between the heat-resistant material and the heat-resistant member to be inspected, so that the estimation is based on the state of the structure of the surface of the heat-resistant member to be inspected. The estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

(3) In some embodiments, in the method of (1) above,
The first particle size is a particle size of an nth precipitate in order from a precipitate having a maximum diameter among precipitates in the structure of the heat-resistant material,
The second particle size is a particle size of the n-th precipitate in order from the largest-diameter precipitate among the precipitates in the structure of the heat-resistant member to be inspected.

According to the method of (3) above, the first particle size is the particle size of the nth precipitate in order from the largest diameter precipitate among the precipitates in the structure of the heat-resistant material, and the second particle size is It is a particle size of the n-th precipitate in order from the largest diameter precipitate among the precipitates in the structure of the heat-resistant member to be inspected. As a result, the first particle size and the second particle size can be made closer to each other, and therefore the selection criteria for whether or not the precipitates are to be calculated for the average particle size are aligned between the heat-resistant material and the heat-resistant member to be inspected. It is done. Therefore, it is possible to improve the estimation accuracy of the operating temperature of the heat-resistant member to be inspected, which is estimated based on the state of the structure of the surface of the heat-resistant member to be inspected.
In addition, if the size of the area where the precipitate is investigated in order to calculate the average particle size is approximately the same for the heat-resistant material and the heat-resistant member to be inspected, the precipitate used for calculating the average particle size is selected. In order to do this, it is only necessary to select n precipitates in order from the precipitate with the largest diameter, so that the precipitate used for calculating the average particle diameter can be easily selected. Therefore, it is possible to improve the working efficiency when investigating the precipitate in order to calculate the average particle diameter.

(4) In some embodiments, in the method of (1) above,
The first particle size is the particle size of the smallest precipitate in the precipitates included in the top n% of the particles having the largest particle size among the precipitates in the structure of the heat-resistant material,
The second particle size is a particle size of the smallest precipitate among the precipitates included in the upper n% number of particles having the largest particle size among the precipitates in the structure of the heat-resistant member to be inspected.

  According to the method of (4) above, the first particle size is the particle size of the smallest precipitate in the precipitates included in the number of the largest n% of the particles in the structure of the heat-resistant material, The second particle size is the particle size of the smallest precipitate among the precipitates included in the upper n% of the large particles among the precipitates in the structure of the heat-resistant member to be inspected. As a result, the selection criteria for determining whether or not the precipitates are to be calculated for the average particle diameter can be made uniform between the heat-resistant material and the heat-resistant member to be inspected, so that the estimation is based on the state of the structure of the surface of the heat-resistant member to be inspected. The estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

(5) In some embodiments, in any of the above methods (1) to (4),
The precipitate in the structure of the heat-resistant material includes at least a first type precipitate and a second type precipitate different in type,
The relationship acquisition step includes a first relationship between an average particle size of precipitates of the first particle size or more among the first type precipitates and parameters relating to a use temperature and a use time of the heat-resistant material, and the second type. The second relationship between the average particle size of the precipitates of the first particle size or more among the precipitates and the parameters relating to the use temperature and use time of the heat-resistant material is acquired.

According to the method of (5) above, the relationship acquisition step acquires the first relationship and the second relationship for the first type precipitate and the second type precipitate that are different in type. Thereby, parameters relating to the use temperature of the heat-resistant member to be inspected are obtained in the use temperature parameter acquisition step based on the first relation for the first type precipitates of different types and the second relation for the second type precipitates. Therefore, it is possible to further improve the estimation accuracy of the use temperature of the heat-resistant member to be inspected.
That is, by identifying the precipitate in the structure of the heat-resistant member to be inspected by using, for example, a scanning electron microscope, the first precipitate and the second precipitate in the structure of the heat-resistant member to be inspected in the average particle diameter acquisition step The average particle size of precipitates having a second particle size or more can be determined for each product by measurement. Then, in the use temperature parameter acquisition step, based on the first relationship acquired in the relationship acquisition step and the average particle size of the first precipitate obtained in the average particle size acquisition step, use of the heat-resistant member to be inspected The first parameter related to the temperature can be obtained, and the heat resistance of the inspection target is determined based on the second relationship obtained in the relationship obtaining step and the average particle size of the second precipitate obtained in the average particle size obtaining step. A second parameter relating to the operating temperature of the member can be determined.
Thereby, for example, the obtained first parameter and the second parameter are compared, and if there is no great difference between the values of the first parameter and the second parameter, the reliability of the values of the first parameter and the second parameter is high. Therefore, the estimation accuracy of the use temperature of the heat-resistant member to be inspected is increased.
Further, the estimation accuracy is increased by estimating the operating temperature of the heat-resistant member to be inspected based on the parameter that is considered to be more reliable with the first parameter and the second parameter.
Thus, according to the method of (5) above, the operating temperature of the heat-resistant member to be inspected based on the first relationship for the first type precipitates of different types and the second relationship for the second type precipitates. As described above, it is possible to further improve the estimation accuracy of the use temperature of the heat-resistant member to be inspected.

(6) In some embodiments, in any of the above methods (1) to (4),
The precipitate in the structure of the heat-resistant material includes at least a first type precipitate and a second type precipitate different in type,
In the relationship acquisition step, a third of the average particle diameter of the first particle size and the second particle size precipitate and the parameters relating to the use temperature and use time of the heat-resistant material. Get relationship.

According to the method of (6) above, the relationship acquisition step does not distinguish between the first type precipitates and the second type precipitates of different types, whether they are the first type precipitates or the second type precipitates. The third relationship is acquired. Thereby, since it becomes possible to obtain a parameter relating to the use temperature of the heat-resistant member to be inspected in the use temperature parameter acquisition step without distinguishing whether it is the first kind precipitate or the second precipitate, The operating temperature of the heat-resistant member to be inspected can be easily estimated.
That is, for example, even if the first precipitate and the second precipitate cannot be accurately distinguished in the structure of the heat-resistant member to be inspected, if it is determined whether it is the first precipitate or the second precipitate, In the average particle size acquisition step, the average particle size of the precipitates of the second particle size or larger can be obtained by measurement for the first precipitate and the second precipitate in the structure of the heat-resistant member to be inspected. And, in the use temperature parameter acquisition step, based on the third relationship acquired in the relationship acquisition step and the average particle size obtained in the average particle size acquisition step, a parameter relating to the use temperature of the heat-resistant member to be inspected. Can be sought.
By doing in this way, it becomes possible to obtain a parameter relating to the use temperature of the heat-resistant member to be inspected without distinguishing whether it is the first type precipitate or the second type precipitate. Thus, the use temperature of the heat-resistant member to be inspected can be easily estimated.

(7) In some embodiments, in the method of any one of (1) to (6), the relationship acquisition step includes acquiring the average particle diameter and the parameters used to acquire the relationship If the standard error with the relationship is outside the allowable range, the relationship is obtained again by changing the first particle size.

  According to the method of (7) above, if the standard error between the average particle size and parameters used to acquire the relationship and the acquired relationship is outside the allowable range, the relationship acquisition step is the first particle size. Since the above relationship is reacquired and the average particle diameter and parameters used for reacquiring the above relationship and the standard error between the above reacquired relationship can be reduced, The estimation accuracy of the use temperature of the heat-resistant member can be further improved.

(8) In some embodiments, in any of the methods (1) to (7), the heat-resistant material and the heat-resistant member to be inspected are made of high-strength austenitic steel.

  According to the above method (8), even when the frequency of occurrence of new precipitates increases in the high-strength austenitic steel shortly after the start of use, the precipitates having a predetermined grain size or more are included. Since the use temperature of the heat-resistant member can be estimated based on the average particle diameter, the use temperature estimation accuracy can be improved.

(9) An inspection method for a heat-resistant member according to at least one embodiment of the present invention includes:
Of the precipitates in the structure of the heat-resistant member to be inspected, the average particle size obtained by measuring the average particle size of the precipitates having a particle size equal to or larger than the second particle size corresponding to the first particle size of the precipitate in the structure of the heat-resistant material Diameter acquisition process;
Of the precipitates in the structure of the heat-resistant material, the relationship between the average particle size of the precipitates of the first particle size or more and the parameters related to the use temperature and the use time of the heat-resistant material, and the average particle size obtaining step And a use temperature parameter obtaining step for obtaining a parameter related to the use temperature of the heat-resistant member to be inspected based on the average particle diameter.

According to the method of (9) above, the average obtained by measuring the average particle size of precipitates having a particle size equal to or larger than the second particle size corresponding to the first particle size among the precipitates in the structure of the heat-resistant member to be inspected. A particle size acquisition step is provided. Therefore, the influence of precipitates having a particle size less than the second particle size corresponding to the first particle size can be excluded from the average particle size of the precipitates in the structure of the heat-resistant member to be inspected obtained in the average particle size acquisition step. .
And according to the method of said (1), the relationship between the average particle diameter of the precipitate of the 1st particle size or more among the precipitates in the structure of the heat-resistant material and the parameters relating to the use temperature and use time of the heat-resistant material, and A use temperature parameter obtaining step for obtaining a parameter relating to the use temperature of the heat-resistant member to be inspected based on the average particle size obtained in the average particle size obtaining step is provided. Thereby, since the parameter regarding the operating temperature of the heat-resistant member to be inspected can be obtained in a state in which the influence of the precipitate having a particle size less than the predetermined particle size is excluded, the estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

(10) In some embodiments, in the method of (9) above, from a plurality of standard samples having different heating temperatures and heating times, a precipitate having the first particle size or more among the precipitates in the structure of the heat-resistant material A relationship obtaining step of obtaining a relationship between the average particle diameter of the heat-resistant material and the parameters relating to the use temperature and use time of the heat-resistant material.

  According to the method of (10) above, since the relationship between the average particle size of the precipitates of the first particle size or more among the precipitates in the structure of the heat resistant material and the parameters relating to the use temperature and use time of the heat resistant material is obtained. In the acquired relationship, the influence of precipitates having a particle size less than the first particle size can be eliminated. As a result, in the acquired relationship described above, the influence of newly generated precipitates and the influence of precipitates that disappear over time can be suppressed, so the acquired relationship is suitable for estimation of the operating temperature. It will be a thing.

(11) In some embodiments, in any of the above methods (1) to (10),
Prior to the average particle diameter acquisition step, a hardness measurement step for measuring the hardness of the heat-resistant member to be inspected,
The operating temperature of the heat-resistant member to be inspected is estimated by inputting the hardness of the heat-resistant member to be inspected obtained in the hardness measurement step into the correlation between the hardness of the heat-resistant material and the operating temperature of the heat-resistant material. A service temperature estimation step,
Whether or not the average particle diameter acquisition step is necessary is determined based on the use temperature of the heat-resistant member to be inspected estimated in the use temperature estimation step.

  According to the above method (11), the operating temperature of the heat-resistant member to be inspected is estimated by a simple method of measuring the hardness of the heat-resistant member to be inspected, and a more detailed operating temperature is based on the estimated operating temperature. When it is determined that the estimation of the average particle size is necessary, the average particle size acquisition step can be performed. Accordingly, it is possible to reduce the time for estimating the use temperature of the heat-resistant member to be inspected and improve the estimation accuracy of the use temperature of the heat-resistant member to be inspected.

(12) In some embodiments, in the method of (11), a step of obtaining a correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material from a plurality of samples having different heating temperatures and heating times. Further prepare.

  According to the method of (12) above, the correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material can be acquired.

(13) In some embodiments, in the above method (11) or (12), the correlation is based on information on the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use time of the heat-resistant material. It is the relationship between the hardness of the said heat-resistant material extracted by the use time of the said heat-resistant member of the test object, and the use temperature of the said heat-resistant material.

  According to the method (13), the operating temperature of the heat-resistant member to be inspected can be immediately estimated from the hardness of the heat-resistant member to be inspected obtained by measurement and the above correlation.

(14) In some embodiments, in the method of (11) or (12), the correlation is based on information on the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use time of the heat-resistant material. It is the relationship between the hardness of the obtained heat-resistant material and the parameters relating to the use temperature and use time of the heat-resistant material.

  According to the above method (14), since the parameters relating to the use temperature and use time of the heat-resistant material are used, the use time of the heat-resistant member to be inspected is longer than the heating time of the sample prepared for obtaining the above correlation Even so, the operating temperature of the heat-resistant member to be inspected can be estimated.

  According to at least one embodiment of the present invention, the operating temperature of a steel material can be accurately estimated based on the state of the structure of the steel material surface.

It is a figure which shows schematic structure of a boiler. It is a flowchart which shows the schematic procedure of the inspection method of the heat-resistant member which concerns on some embodiment. It is a flowchart which shows an example of the schematic procedure of a relationship acquisition process. It is a graph which shows an example of the master curve in one embodiment. It is an example of the image obtained by observing the surface with a scanning electron microscope about the standard sample of austenitic stainless steel. It is a figure which shows an example of the TTP diagram of austenitic stainless steel. It is a flowchart which shows an example of the procedure in a master curve acquisition process. It is a flowchart which shows an example of the detailed acquisition procedure of a master curve. It is a flowchart which shows an example of the schematic procedure of an average particle diameter acquisition process. It is a flowchart which shows an example of the procedure of a use temperature parameter acquisition process. It is a flowchart which shows the schematic procedure of the inspection method of the heat-resistant member which concerns on other embodiment. It is a flowchart which shows the process in the use temperature estimation process based on hardness. It is a flowchart which shows the process in a correlation acquisition process. It is a figure which shows an example of the master data acquired at the master data acquisition process. It is a figure which shows the example of the master curve which shows the relationship between the hardness of a heat-resistant material, and the use temperature of a heat-resistant material, (a) is the hardness of the heat-resistant material extracted with the use time of 10,000 hours, for example, and the use temperature of a heat-resistant material (B) is an example of a master curve showing the relationship between the hardness of the heat-resistant material extracted during the use time of 80,000 hours and the use temperature of the heat-resistant material, for example. It is a flowchart which shows an example of the schematic procedure of a hardness measurement process. It is a figure which shows the example of the master curve which shows the relationship between the parameter regarding the hardness of a heat-resistant material, the use temperature of a heat-resistant material, and use time.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

FIG. 1 is a diagram illustrating a schematic configuration of a boiler 10.
The boiler 10 has a combustion furnace 12 and a flue 14 connected to the upper part of the combustion furnace 12.
The fire channel wall 16 of the combustion furnace 12 includes an evaporation pipe for heating water, and a superheater 18 for superheating steam is disposed at the upper part of the combustion furnace 12. A economizer 20 for preheating water is disposed below the flue 14. In addition, a reheater 22 for reheating the steam is disposed on the upper portion of the flue 14.

A burner 24 is attached to the combustion furnace 12, and pulverized coal and air as fuel are supplied to the burner 24. High-temperature exhaust gas generated by burning pulverized coal ejected from the burner 24 rises in the combustion furnace 12 and flows into the flue 14. The heat generated by the combustion is transmitted to the evaporation pipe of the fire channel wall 16, thereby heating the water. The heat of the exhaust gas is used to superheat the steam in the superheater 18, reheat the steam in the reheater 22, and preheat water in the economizer 20. The exhaust gas that has become low temperature flows into a denitration device provided downstream of the boiler 10, for example, and is purified.
The steam (main steam) superheated by the superheater 18 is supplied to, for example, the steam turbine 26 and used for power generation or the like.

FIG. 2 is a flowchart showing a schematic procedure of a heat-resistant member inspection method according to some embodiments.
The heat-resistant member to be inspected is, for example, a steel pipe constituting the superheater 18 and the reheater 22.

As shown in FIG. 2, the heat-resistant member inspection method includes a relationship acquisition step S10, an average particle size acquisition step S20, and a use temperature parameter acquisition step S30.
In the relationship acquisition step S10, the relationship between the average particle size of the precipitates having the first particle size or more among the precipitates in the structure of the heat-resistant material and the parameters regarding the use temperature and use time of the heat-resistant material is obtained.

In the average particle size acquisition step S20, the average particle size of precipitates of the second particle size or larger, which is the particle size corresponding to the first particle size, among the precipitates in the structure of the heat-resistant member to be inspected is obtained by measurement.
In the use temperature parameter acquisition step S30, based on the relationship acquired in the relationship acquisition step S10, the average particle size obtained in the average particle size acquisition step S20, and the usage time of the heat-resistant member to be inspected, The parameter regarding the use temperature of the heat-resistant member is obtained.
In addition, the particle diameter in some embodiments described below may be any one according to various definitions such as a long diameter, a short diameter, a biaxial average diameter, and a circle-equivalent diameter. For convenience of explanation, the following explanation simply refers to the particle diameter regardless of which definition is used.

(Relationship acquisition step S10)
Hereinafter, the relationship acquisition step S10 according to some embodiments will be described with reference to FIG. FIG. 3 is a flowchart illustrating an example of a schematic procedure of the relationship acquisition step S10.
In the relationship acquisition step S10, parameters relating to the average particle size of the precipitates having the first particle size or more among the precipitates in the structure of the heat-resistant material, the use temperature and the use time of the heat-resistant material, by the steps S101 to S110 described below. Is obtained as a master curve which is a correlation diagram between the average particle diameter and the parameter.
That is, in some embodiments, the master curve is a parameter (temperature / time parameter) relating to the average particle size of precipitates having a first particle size or larger among the precipitates in the structure of the heat-resistant material, the use temperature and the use time of the heat-resistant material. ) Is a correlation diagram with λ, for example, a graph as shown in FIG. FIG. 4 is a graph illustrating an example of a master curve according to some embodiments. As shown in FIG. 4, in the master curve C, for example, when the temperature / time parameter λ is taken on the horizontal axis and the average particle size of the precipitate is taken on the vertical axis, the relationship between the average particle size and the temperature / time parameter λ is taken. It is expressed as a curve showing.

Here, the temperature / time parameter λ is, for example, a Larson mirror parameter, where T (unit: K) is the temperature when the sample is heated (sample temperature), and t (unit: h) is the time during which the sample is heated. When the material constant of the sample is C, it is expressed by the following formula (1).
λ = T × (C + log (t)) / 1000 (1)

  The heat-resistant material refers to a material having the same composition as the heat-resistant member to be inspected or a similar composition. The shape of the heat-resistant material may not be the same shape as the heat-resistant member to be inspected. That is, the heat resistant material is a standard sample. In one embodiment, the heat-resistant material and the heat-resistant member to be inspected are, for example, high-strength austenitic steel.

Here, the reason for calculating the average particle diameter of the precipitate having the first particle diameter or more when calculating the average particle diameter of the precipitate in the structure of the heat-resistant material will be described.
The relationship calculated in the relationship acquisition step S10, that is, the master curve, is data that is referred to when determining a parameter related to the use temperature of the heat-resistant member to be inspected in the use temperature parameter acquisition step S30 described later. Although detailed description will be given later, in the use temperature parameter acquisition step S30, temperature and time parameters corresponding to the average particle size of the precipitate in the structure of the heat-resistant member to be inspected obtained in the average particle size acquisition step S20 are set. The temperature is read from the master curve calculated in the relationship acquisition step S10, and the operating temperature of the heat-resistant member to be inspected is estimated based on the read temperature / time parameter.
Therefore, if the change rate of the average particle size relative to the temperature / time parameter value in the master curve is small, the reading accuracy when reading the temperature / time parameter value corresponding to the average particle size from the master curve is low, and the inspection target There is a possibility that the estimation accuracy of the use temperature of the heat-resistant member may be lowered.

  Generally, heat-resistant materials and heat-resistant materials to be inspected have both precipitates that become coarser over time and precipitates that become smaller and disappear at a certain time when placed in a high-temperature environment. There is. Therefore, there is a period in which no clear change is observed in the average particle size of the precipitate over time. Therefore, when calculating the average particle size of the precipitates, including the precipitates that disappear by micronization, and obtaining the master curve described above, the change in the average particle size is within the range of the temperature and time parameters corresponding to the period. Since the rate becomes small, when this master curve is used, there is a possibility that the estimation accuracy of the use temperature of the heat-resistant member to be inspected is lowered as described above.

  Therefore, in some embodiments, when calculating the average particle size of the precipitates in the structure of the heat-resistant material, in order to suppress the influence of the precipitates that become finer and disappear as described above, precipitation of the first particle size or more is performed. The average particle size of the product is calculated. In one embodiment described below, the first particle size is n micrometers. Here, the value of n is determined as appropriate in consideration of the composition of the heat-resistant material, the type of precipitate, and a standard error in regression analysis at the time of calculating the master curve as will be described later.

  Thus, in the relationship acquisition step S10 of one embodiment, there is a relationship between the average particle size of precipitates having a first particle size or larger among the precipitates in the structure of the heat-resistant material and the parameters regarding the use temperature and use time of the heat-resistant material. To be acquired. Therefore, it is possible to eliminate the influence of precipitates having a particle size less than the first particle size in the acquired relationship, that is, the master curve. As a result, in the acquired master curve, the influence of newly generated precipitates and the influence of precipitates that disappear over time can be suppressed, so the acquired master curve is suitable for estimating the operating temperature. Become.

In the relationship acquisition step S10, first, a standard sample is prepared in a standard sample preparation step S101. In the standard sample preparation step S101, a plurality of standard samples having different temperatures and heating times are prepared.
Such a plurality of standard samples can be obtained, for example, by preparing a plurality of untreated samples and subjecting these samples to heat treatment (aging treatment) at different temperatures. Such a plurality of standard samples can also be obtained by conducting a creep strength test on a plurality of untreated samples and stopping the creep strength test at different times for each sample.

  In the tissue observation step S103, a plurality of standard samples prepared in the standard sample preparation step S101 are observed. For tissue observation, for example, a scanning electron microscope is used, but an optical microscope may be used.

  In the precipitate identification step S105, the precipitate of the standard sample subjected to the structure observation in the structure observation step S103 is identified. If a scanning electron microscope is used for the structure observation in the structure observation step S103, the precipitate can be identified by the scanning electron microscope.

FIG. 5 is an example of an image obtained by observing the surface of a standard sample of austenitic stainless steel with a scanning electron microscope. In the example shown in FIG. 5, for example, Z phase, σ phase, M ₂₃ C ₆ , and Cu are recognized as precipitates.

In the TTP diagram creation step S107, a TTP (Time-Temperature-Precipitation) diagram is created, and in the particle size distribution acquisition step S109, the particle size distribution of the type of precipitate that is the target of creation of the master curve is obtained.
In the TTP diagram creation step S107, a TTP diagram is created based on the result of the structure observation in the structure observation step S103 and the identification result of the precipitate in the precipitate identification step S105.

FIG. 6 shows an example of a TTP diagram of austenitic stainless steel. A region α in FIG. 6 is a region where there is no type of precipitate for which a master curve is to be created. The region β is a region where one type of precipitate (first type precipitate) is present among the types of precipitates for which the master curve is to be created. The region γ is a region where two types of precipitates (first-type precipitates and second-type precipitates) exist among the types of precipitates for which a master curve is to be created.
For example, in the case of an austenitic stainless steel whose structural image is shown in FIG. 5, as will be described later, the Z phase is a first type precipitate and the σ phase is a second type precipitate. In the image of FIG. 5, the Z phase, ie, the first type precipitate, and the σ phase, ie, the second type precipitate, are recognized, so that the image in FIG. 5 was subjected to the heat treatment corresponding to the region γ in FIG. It corresponds to an image of a standard sample.

In the particle size distribution acquisition step S109, the particle size distribution of the type of precipitates for which a master curve is to be created is acquired. Specifically, for example, from the observation image as shown in FIG. 5, an image of the type of precipitate that is a target for creating the master curve is extracted by known image processing based on the gradation of the image. That is, since the gradation of the precipitate image in the observation image varies depending on the type of the precipitate, it is easy to extract the type of precipitate for which the master curve is to be created by a known image processing technique.
And each particle size of the extracted image is measured by a well-known image process, and a particle size distribution is calculated | required for every kind of deposit based on the measured particle size, respectively.

  In the master curve acquisition step S110, a master curve is acquired based on the particle size distribution information acquired in the particle size distribution acquisition step S109.

  FIG. 7 is a flowchart illustrating an example of a procedure in the master curve acquisition step S110 illustrated in FIG. In some embodiments, in step S111, a master curve is obtained for the precipitate in the region β in the TTP diagram created in the TTP diagram creating step S107 in FIG. 3, that is, the first type precipitate. A detailed procedure for acquiring the master curve will be described later with reference to FIG.

  Next, in step S113, it is determined whether or not the region γ exists in the TTP diagram created in the TTP diagram creation step S107 of FIG.

  If the region γ does not exist, there is no other master curve to be acquired, and the master curve acquisition process is terminated.

  When the region γ exists, in step S115, based on the result of the structure observation in the structure observation step S103 of FIG. 3 and the identification result of the precipitate in the precipitate identification step S105, the first type precipitation in the region γ. The coarsening speed S1 of the product and the coarsening speed S2 of the second type precipitate are confirmed.

  When the coarsening rate is reduced, the change rate of the average particle diameter with respect to the temperature / time parameter value is reduced in the calculated master curve. When the rate of change is small, as described above, the reading accuracy when reading the temperature / time parameter corresponding to the average particle diameter from the master curve is lowered, and the estimation accuracy of the use temperature of the heat-resistant member to be inspected may be lowered. There is.

Therefore, the master curve to be acquired is determined according to the magnitude of the coarsening speed as follows.
For example, the coarsening rate S1 is large, and the use temperature of the heat-resistant member to be inspected can be accurately estimated from the master curve related to the first type precipitate, but the coarsening rate S2 is small and the master curve related to the second type precipitate. If it is considered that the use temperature of the heat-resistant member to be inspected cannot be accurately estimated (S1 >> S2), the process proceeds to step S121. In step S121, a first master curve for the first type precipitate in the region γ in the TTP diagram is acquired.

  Although the coarsening rate S1 is large and the operating temperature of the heat-resistant member to be inspected can be accurately estimated from the master curve related to the first type precipitate, the coarsening rate S2 is small and the master curve related to the second type precipitate. If it is considered that the operating temperature of the heat-resistant member to be inspected cannot be accurately estimated (S1 >> S2), there is no other type of precipitate for which a master curve is to be acquired in the region γ. finish.

  Further, for example, the coarsening rate S2 is large, and the use temperature of the heat-resistant member to be inspected can be accurately estimated from the master curve related to the second type precipitate, but the coarsening rate S1 is small and the master related to the first type precipitate. When it is considered that the use temperature of the heat-resistant member to be inspected cannot be accurately estimated from the curve (S1 << S2), the process proceeds to step S123. In step S123, a second master curve for the second type precipitate in the region γ in the TTP diagram is acquired.

  The coarsening rate S2 is large, and the operating temperature of the heat-resistant member to be inspected can be accurately estimated from the master curve related to the second type precipitate, but the coarsening rate S1 is small and the master curve related to the first type precipitate. If it is considered that the operating temperature of the heat-resistant member to be inspected cannot be accurately estimated (S1 << S2), there is no other type of precipitate for which a master curve is to be acquired in the region γ. finish.

  Further, for example, both the coarsening speeds S1 and S2 are large, and it is considered that the use temperature of the heat-resistant member to be inspected can be accurately estimated from the master curve related to the first type precipitate and the master curve related to the second type precipitate. If so, the process proceeds to step S125. In step S125, a first master curve for the first type precipitate in the region γ in the TTP diagram is acquired, a second master curve for the second type precipitate in the region γ in the TTP diagram is acquired, and the master The curve acquisition process ends.

  FIG. 8 is a flowchart illustrating an example of a detailed procedure for acquiring a master curve. The procedure shown in the flowchart of FIG. 8 is a specific procedure in step S111, step S121, step S123, and step S125 of FIG.

In some embodiments, in step S151, with respect to the type of precipitate for which a master curve is to be created, based on the particle size distribution information acquired in the particle size distribution acquisition step S109 in FIG. Extract the precipitate.
When step S151 is performed as part of the process in step S111 of FIG. 7, the precipitates in the region β, that is, the first-type precipitates of each of the standard samples that belong to the region β in the TTP diagram. Among them, a precipitate having a first particle size or larger is extracted.
Similarly, when step S151 is performed as a part of the process in step S121 of FIG. 7, the first of the first type precipitates in the region γ for each standard sample that belongs to the region γ in the TTP diagram. Extract precipitates larger than the particle size.
Moreover, when implementing step S151 as a part of process in step S123 of FIG. 7, about each standard sample which will belong to the area | region (gamma) in a TTP diagram, it is 1st grain among the 2nd seed precipitates of the area | region (gamma). Extract precipitates larger than the diameter.
When step S151 is performed as part of the process in step S125 of FIG. 7, for each standard sample that will belong to region γ in the TTP diagram, the first particle size or more of the first type precipitates in region γ And the precipitate having the first particle size or larger is extracted from the second type precipitate in the region γ.

In step S153, the average particle size of the precipitates of the first particle size or more extracted in step S151 is calculated, and the calculated average particle size is organized by temperature / time parameters.
That is, a plurality of data represented by the average particle diameter and the temperature / time parameter λ is generated by associating the calculated average particle diameter with the temperature / time parameter λ of the standard sample.

In step S155, based on the plurality of data generated in step S153, a graph with the temperature and time parameters λ on the horizontal axis and the average particle size on the vertical axis is created, and regression analysis is performed to obtain a regression curve. Standard error is calculated.
In addition, when implementing step S155 as a part of process in step S125 of FIG. 7, based on the several data which concern on 1st seed precipitate among several data produced | generated by step S153, temperature is shown on a horizontal axis.・ Take a time parameter λ, create a graph with the average particle size on the vertical axis, and perform regression analysis to calculate the regression curve and standard error. Similarly, among the plurality of data generated in step S153, the horizontal axis represents the temperature / time parameter λ and the vertical axis represents the average particle diameter based on the plurality of data related to the second type precipitate. And perform regression analysis to calculate the regression curve and standard error.

In step S157, it is determined whether or not the standard error calculated in step S155 is within a predetermined allowable range.
If an affirmative determination is made in step S157, the regression curve calculated in step S155 is adopted as a master curve in step S159.
In addition, when implementing step S159 as a part of process in FIG.7 S125, the regression curve which concerns on 1st type precipitation is employ | adopted as a 1st master curve among the regression curves calculated by step S155, and 2nd The regression curve related to the seed deposit is adopted as the second master curve.

  If a negative determination is made in step S157, the first particle size is changed in step S161. Then, it returns to step S151 and performs the process mentioned above again.

  Thus, in one embodiment, it is used to obtain the relationship between the average particle size of precipitates having a first particle size or larger among the precipitates in the structure of the heat-resistant material and the parameters regarding the use temperature and use time of the heat-resistant material. If the standard error between the obtained average particle size and temperature / time parameter λ and the acquired relationship is outside the allowable range, the first particle size is changed and the relationship is reacquired. As a result, the standard error between the average particle diameter and temperature / time parameter λ used to reacquire the above relationship and the above reacquired relationship can be reduced, and consequently the operating temperature of the heat-resistant member to be inspected. The estimation accuracy of can be further improved.

(Average particle size acquisition step S20)
Hereinafter, the average particle diameter acquisition step S20 will be described. FIG. 9 is a flowchart showing an example of a schematic procedure of the average particle diameter acquisition step S20.
In some embodiments, a heat-resistant member to be inspected is acquired in the inspection target acquisition step S201. For example, if the heat-resistant member to be inspected is a steel pipe constituting the superheater 18 or the reheater 22 of the boiler 10, the heat-resistant object to be inspected can be removed by excising a part of the steel pipe when the boiler 10 is stopped periodically. Get a member. If it is difficult to obtain the heat-resistant member to be inspected, a replica of the surface of the heat-resistant member to be inspected is obtained by, for example, the replica method. In the following description, the case where the heat-resistant member to be inspected can be obtained will be mainly described.

  In the tissue observation process S203, the structure of the heat-resistant member to be inspected acquired in the inspection object acquisition process S201 is observed. For tissue observation, for example, a scanning electron microscope is used, but an optical microscope may be used.

  In the precipitate identification step S205, the precipitate of the heat-resistant member to be inspected that has undergone the structure observation in the structure observation step S203 is identified. If a scanning electron microscope is used for the structure observation in the structure observation step S203, the precipitate can be identified by the scanning electron microscope.

An area determination step S207 and a particle size distribution acquisition step S209 are performed.
In the region determination step S207, with reference to the TTP diagram created in the TTP diagram creation step S107 of FIG. 3, from the identification result of the precipitate in the precipitate identification step S205, the structure observation in the structure observation step S203 is performed. It is determined which region of the TTP diagram the tissue of the target heat-resistant member is.

  In the particle size distribution acquisition step S209, among the precipitates of the heat-resistant member to be inspected subjected to the structure observation in the structure observation step S203, the same type of precipitate as the target of creation of the master curve in the relationship acquisition step S10 of FIG. Obtain the particle size distribution of the types of precipitates. For obtaining the particle size distribution, for example, the same method as the particle size distribution obtaining step S109 of FIG. 3 can be used.

  In the average particle size calculation step S211, based on the information on the particle size distribution acquired in the particle size distribution acquisition step S209, a precipitate having a particle size equal to or larger than the second particle size corresponding to the first particle size is obtained for each type of precipitate. Each is extracted and the average particle size is calculated. In addition, let the 2nd particle size in one Embodiment be a particle size equal to the 1st particle size about the precipitate which concerns on the master curve acquired by relationship acquisition process S10. That is, in one embodiment, for example, if the first particle size of the first type precipitate related to the master curve for the region β acquired in the relationship acquisition step S10 is n micrometers, the heat resistant member to be inspected is related. The second particle size of the first type precipitate in the region β is also set to n micrometers.

Thus, in average particle diameter acquisition process S20 of one embodiment, the average grain of the precipitate more than the 2nd particle size which is the particle size corresponding to the 1st particle size among the precipitates in the structure of the heat-resistant member to be examined. The diameter is determined by measurement. Therefore, the influence of precipitates smaller than the second particle size, which is the particle size corresponding to the first particle size, is excluded from the average particle size of the precipitates in the structure of the heat-resistant member to be inspected obtained in the average particle size acquisition step S20. it can.
In one embodiment, the first particle size and the second particle size are both n micrometers. As a result, the selection criteria for determining whether or not the precipitates are to be calculated for the average particle diameter can be made uniform between the heat-resistant material and the heat-resistant member to be inspected, so that the estimation is based on the state of the structure of the surface of the heat-resistant member to be inspected. The estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

(Use temperature parameter acquisition step S30)
Hereinafter, the use temperature parameter acquisition step S30 will be described. FIG. 10 is a flowchart illustrating an example of the procedure of the use temperature parameter acquisition step S30.

In some embodiments, in step S301, the process to be performed next is determined based on the determination result in the region determination step S207 of FIG. 9, that is, which region the tissue of the heat-resistant member to be inspected is.
For example, when it is determined in the region determination step S207 of FIG. 9 that the structure of the heat-resistant member to be inspected is the region α, the use temperature is estimated based on the master curve for the structure of the heat-resistant member to be inspected. For this reason, the necessary deposits are not present. In this case, after performing the determination process in step S301, the use temperature parameter acquisition step S30 is terminated.

  For example, when it is determined in the region determination step S207 of FIG. 9 that the tissue of the heat-resistant member to be inspected is the region β, the process proceeds to step S303. In step S303, from the master curve related to the first type precipitate for the region β obtained in step S111 of FIG. 7, the first type precipitate of the second particle size or more calculated in the average particle size calculation step S211 of FIG. A temperature / time parameter λ corresponding to the average particle diameter is obtained. Then, by substituting the acquired temperature / time parameter λ and the use time of the heat-resistant member to be inspected into the above-described equation (1), an estimated value of the use temperature of the heat-resistant member to be inspected is obtained.

For example, when it is determined in the region determination step S207 of FIG. 9 that the structure of the heat-resistant member to be inspected is the structure of the region γ, the process proceeds to step S305, and the use temperature of the heat-resistant member to be inspected is as follows. Get an estimate of.
For example, when only the average particle size of the first type precipitate in the region γ is obtained in the average particle size calculation step S211 in FIG. 9, in step S305, it is obtained in either step S121 or step S125 in FIG. The temperature / time parameter λ corresponding to the average particle size of the first type precipitate calculated in the average particle size calculation step S211 of FIG. 9 is acquired from the first master curve of the first type precipitate in the region γ. Then, by substituting the acquired temperature / time parameter λ and the use time of the heat-resistant member to be inspected into the above-described equation (1), an estimated value of the use temperature of the heat-resistant member to be inspected is obtained.

  Further, for example, when only the average particle size of the second type precipitate in the region γ is obtained in the average particle size calculation step S211 in FIG. 9, in step S305, in either step S123 or step S125 in FIG. The temperature / time parameter λ corresponding to the average particle size of the second type precipitate calculated in the average particle size calculation step S211 of FIG. 9 is acquired from the second master curve of the second type precipitate in the obtained region γ. . Then, by substituting the acquired temperature / time parameter λ and the use time of the heat-resistant member to be inspected into the above-described equation (1), an estimated value of the use temperature of the heat-resistant member to be inspected is obtained.

For example, when both the average particle size of the first type precipitate and the average particle size of the second type precipitate in the region γ are obtained in the average particle size calculation step S211 of FIG. Temperature / time corresponding to the average particle size of the first type precipitate calculated in the average particle size calculation step S211 of FIG. 9 from the first master curve of the first type precipitate in the region γ obtained in step S125 of FIG. The first parameter λ1, which is the parameter λ, is acquired. Then, the first estimated value of the use temperature of the heat-resistant member to be inspected is obtained by substituting the acquired first parameter λ1 and the use time of the heat-resistant member to be inspected into the above-described equation (1).
Similarly, in step S305, the average of the second type precipitates calculated in the average particle size calculation step S211 in FIG. 9 from the second master curve of the second type precipitates in the region γ obtained in step S125 in FIG. A second parameter λ2 that is a temperature / time parameter λ corresponding to the particle diameter is acquired. Then, the second estimated value of the use temperature of the heat-resistant member to be inspected is obtained by substituting the acquired second parameter λ2 and the use time of the heat-resistant member to be inspected into the above-described equation (1).

  In one embodiment, when the first estimated value and the second estimated value of the use temperature of the heat-resistant member to be inspected are obtained in this way, for example, the estimated accuracy among the first estimated value and the second estimated value. The estimated value that is considered to be high is used as the estimated value of the operating temperature of the heat-resistant member to be inspected. When the first estimated value and the second estimated value of the use temperature of the heat-resistant member to be inspected are obtained in this way, for example, the average value of the first estimated value and the second estimated value is calculated as the heat-resistant value of the inspected object. You may employ | adopt as an estimated value of the use temperature of a member.

The first parameter λ1 and the second parameter λ2 obtained as described above are compared, and if there is no significant difference between the values of the first parameter λ1 and the second parameter λ2, the first parameter λ1 and the second parameter λ2 Therefore, it is possible to determine that the reliability of the value is high, so that the estimation accuracy of the use temperature of the heat-resistant member to be inspected is increased.
Thus, according to some embodiments, for the first type precipitate and the second type precipitate of different types, the first master curve that is the first relationship of the first type precipitate and the second type Since the parameters related to the use temperature of the heat-resistant member to be inspected can be obtained based on the second master curve that is the second relationship with respect to the precipitate, as described above, the use temperature of the heat-resistant member to be inspected is estimated. The accuracy can be further improved.

  Thus, in the use temperature parameter acquisition step S30 of some embodiments, the heat resistance of the inspection target is based on the relationship acquired in the relationship acquisition step S10 and the average particle size obtained in the average particle size acquisition step S20. Determine the parameters for the operating temperature of the member. Thereby, since the parameter regarding the operating temperature of the heat-resistant member to be inspected can be obtained in a state in which the influence of the precipitate having a particle size less than the predetermined particle size is excluded, the estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.

  As described above, in some embodiments, even if the frequency of occurrence of new precipitates increases at a short time after the start of use in high-strength austenitic steel, precipitation of a predetermined grain size or more among the precipitates. Since the use temperature of the heat-resistant member can be estimated based on the average particle diameter of the object, the estimation accuracy of the use temperature can be improved.

Hereinafter, other embodiments will be described. In some embodiments described above, in step S125 in the master curve acquisition step S110 shown in FIG. 7, the first master curve for the first seed precipitate and the second master curve for the second seed precipitate are acquired. . That is, the first type precipitate and the second type precipitate were distinguished, and a master curve was obtained for each precipitate.
In another embodiment, the third master curve is acquired without distinguishing between the first type precipitate and the second type precipitate as follows.

  That is, in another embodiment, in step S155 of FIG. 8, whether the plurality of data generated in the plurality of data generated in step S153 is the data related to the first type precipitate or the second type precipitate. Without distinguishing whether it is data, regression analysis is performed and a regression curve and a standard error are calculated.

In step S157, it is determined whether or not the standard error calculated in step S155 is within a predetermined allowable range.
If an affirmative determination is made in step S157, the regression curve calculated in step S155 is adopted as the third master curve in step S159.

If a negative determination is made in step S157, the first particle size is changed in step S161. Then, it returns to step S151 and performs the process mentioned above again.
By doing in this way, in relation acquisition process S10, it is the 1st grain among the 1st seed precipitate and the 2nd seed precipitate, without distinguishing whether it is the 1st seed precipitate or the 2nd precipitate. A third master curve that is a third relationship between the average particle diameter of the precipitates having a diameter equal to or larger than the parameters relating to the use temperature and use time of the heat-resistant material can be obtained.

  Thereby, even if it is not distinguished whether it is a 1st type precipitate or a 2nd precipitate, in the use temperature parameter acquisition process S30, the parameter regarding the use temperature of the heat-resistant member to be examined can be obtained. The operating temperature of the heat-resistant member to be inspected can be easily estimated.

  That is, for example, even if the first precipitate and the second precipitate cannot be accurately distinguished in the structure of the heat-resistant member to be inspected, if it is determined whether it is the first precipitate or the second precipitate, In the average particle size acquisition step S20, the average particle size of precipitates of the second particle size or larger can be obtained by measurement for the first precipitate and the second precipitate in the structure of the heat-resistant member to be inspected. And in use temperature parameter acquisition process S30, based on said 3rd master curve acquired in relation acquisition process S10, and said average particle diameter calculated | required in average particle diameter acquisition process S20, use of the heat-resistant member to be examined Parameters related to temperature can be determined.

  By doing in this way, since it becomes possible to obtain a parameter relating to the use temperature of the heat-resistant member to be inspected without distinguishing whether it is the first type precipitate or the second precipitate, the inspection object The operating temperature of the heat-resistant member can be easily estimated.

  Hereinafter, other embodiments will be described. In some embodiments described above, the first particle size and the second particle size were both n micrometers and were the same particle size. In another embodiment described below, the first particle size is the particle size of the n-th precipitate in order from the largest-sized precipitate among the precipitates in the structure of the heat-resistant material, and the second particle size is It is a particle size of the n-th precipitate in order from the largest diameter precipitate among the precipitates in the structure of the heat-resistant member to be inspected.

As a result, the first particle size and the second particle size can be made closer to each other, and therefore the selection criteria for whether or not the precipitates are to be calculated for the average particle size are aligned between the heat-resistant material and the heat-resistant member to be inspected. It is done. Therefore, it is possible to improve the estimation accuracy of the operating temperature of the heat-resistant member to be inspected, which is estimated based on the state of the structure of the surface of the heat-resistant member to be inspected.
In addition, if the size of the area where the precipitate is investigated in order to calculate the average particle size is approximately the same for the heat-resistant material and the heat-resistant member to be inspected, the precipitate used for calculating the average particle size is selected. In order to do this, it is only necessary to select n precipitates in order from the precipitate with the largest diameter, so that the precipitate used for calculating the average particle diameter can be easily selected. Therefore, it is possible to improve the working efficiency when investigating the precipitate in order to calculate the average particle diameter.

  Hereinafter, other embodiments will be described. In some embodiments described above, the first particle size and the second particle size were both n micrometers and were the same particle size. In other embodiments described below, the first particle size is the particle size of the smallest precipitate in the precipitates included in the top n% number of particles having the largest particle size among the precipitates in the structure of the heat-resistant material, The second particle size is the particle size of the smallest precipitate among the precipitates included in the upper n% of the large particles among the precipitates in the structure of the heat-resistant member to be inspected.

As a result, the selection criteria for determining whether or not the precipitates are to be calculated for the average particle size can be aligned between the heat-resistant material and the heat-resistant member to be inspected. The estimation accuracy of the operating temperature of the heat-resistant member to be inspected can be improved.
In addition, by selecting the selection criteria for the precipitate to be calculated as the average particle size as the particle size of the smallest precipitate among the precipitates included in the number of the top n% having the largest particle size, The selection criteria for the precipitates can be defined as a percentage of the total precipitates.

Hereinafter, other embodiments will be described. In some embodiments described above, in the inspection target acquisition step S201 in the average particle size acquisition step S20, a heat resistant member to be inspected or a replica of the surface of the heat resistant member to be inspected is acquired.
However, since extubation work and replica collection work require time, it is difficult to perform extubation and replica collection at many locations during a pause such as periodic inspection of the boiler 10.
Therefore, in another embodiment described below, the operating temperature of the heat-resistant member to be inspected is simply estimated prior to the average particle diameter acquisition step S20 in order to narrow down the places where the tube extraction work and the replica collection work are performed. It is said. Specifically, prior to the average particle diameter acquisition step S20, the hardness of the heat-resistant member to be inspected is measured, and the use temperature of the heat-resistant member to be inspected is estimated from the measured hardness. The location where extubation and replica collection are performed is narrowed down. That is, in another embodiment described below, the hardness and the use time of the heat-resistant member to be inspected are utilized by changing the hardness of the heat-resistant member to be inspected depending on the use temperature and the use time (aging time). From this, the operating temperature is estimated. Details will be described below.

FIG. 11 is a flowchart showing a schematic procedure of a heat-resistant member inspection method according to another embodiment.
The inspection method for a heat-resistant member according to another embodiment includes a use temperature estimation step S1 based on hardness and a use temperature estimation step S3 based on precipitates. Here, the use temperature estimation step S3 based on the precipitate includes a relationship acquisition step S10, an average particle size acquisition step S20, and a use temperature parameter acquisition step S30 according to some of the embodiments described above.
That is, in the inspection method for a heat-resistant member according to another embodiment, as described in detail later, based on the use temperature of the heat-resistant member to be inspected estimated in the use temperature estimation step S1 based on hardness, in step S2 Judging whether or not the temperature load is high and estimating the use temperature by the heat-resistant member inspection method according to some embodiments described above for the heat-resistant member to be inspected determined to have a high temperature load Yes. For the heat-resistant member to be inspected, which is determined to have a high temperature load in step S2, the use temperature is not estimated by the heat-resistant member inspection method according to some embodiments described above.

(Working temperature estimation step S1 based on hardness)
FIG. 12 is a flowchart showing the processing in the service temperature estimation step S1 based on hardness. The use temperature estimation step S1 based on hardness includes a correlation acquisition step S1010, a hardness measurement step S1020, and a use temperature estimation step S1030.

(Correlation acquisition step S1010)
FIG. 13 is a flowchart showing the processing in the correlation acquisition step S1010.
In the correlation acquisition step S1010, the correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material is acquired by steps S1101 to S1107 described below.

In the correlation acquisition step S1010, first, a sample for acquiring the correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material is prepared in the sample preparation step S1101. In the sample preparation step S1101, a plurality of samples having different temperatures and heating times are prepared.
As such a plurality of samples, for example, a plurality of untreated samples having the same composition as the heat-resistant member to be inspected or a similar composition are prepared, and these samples are subjected to heat treatment (aging) at different temperatures and different times. It is obtained by applying the treatment.

  Next, in the sample hardness measurement step S1103, the hardness of the plurality of samples prepared in the sample preparation step S1101 is measured. For the hardness measurement, various measuring devices such as a Vickers hardness tester and an ultrasonic hardness tester can be used.

  Next, in the master data acquisition step S1105, from the measurement results of the hardness of the plurality of samples measured in the sample hardness measurement step S1103, the hardness of the heat-resistant material, the use temperature of the heat-resistant material (heating temperature), and the use time of the heat-resistant material (heating time) Master data, which is information about aging time). FIG. 14 shows an example of the master data acquired in the master data acquisition step S1105. In the master data shown in FIG. 14, a graph with the hardness of the heat-resistant material on the vertical axis and the aging time on the horizontal axis is shown for each heating temperature.

  Next, in the master curve acquisition step S1107, the heat-resistant material extracted from the master data acquired in the master data acquisition step S1105 by the usage time of the heat-resistant member to be inspected, that is, for example, the operation time of the boiler 10 at the time of the current periodic inspection A master curve indicating the relationship between the hardness of the steel and the use temperature of the heat-resistant material is obtained. FIG. 15 is a diagram showing an example of a master curve showing the relationship between the hardness of the heat-resistant material and the use temperature of the heat-resistant material, and FIG. 15 (a) shows, for example, the heat-resistant material extracted at the use time of 10,000 hours. FIG. 15B is an example of a master curve showing the relationship between the hardness and the use temperature of the heat-resistant material. FIG. 15B shows the relationship between the hardness of the heat-resistant material extracted at the use time of, for example, 80,000 hours and the use temperature of the heat-resistant material. It is an example of the master curve which shows.

For example, when the operation time of the boiler 10 at the time of this regular inspection is 10,000 hours, the hardness of the heat-resistant material and the heat-resistant material when the aging time is 10,000 hours from the master data shown in FIG. Read the temperature and use. Then, for example, as shown in FIG. 15A, a master curve MA is created with the operating temperature on the horizontal axis and the hardness on the vertical axis.
Further, for example, when the operation time of the boiler 10 at the time of this periodic inspection is 80,000 hours, from the master data shown in FIG. 14, the hardness of the heat-resistant material when the aging time is 80,000 hours and Read the operating temperature of the heat-resistant material. Then, for example, as shown in FIG. 15B, a master curve MB is created with the operating temperature on the horizontal axis and the hardness on the vertical axis.

  Thus, in correlation acquisition process S1010, the correlation with the hardness of a heat-resistant material and the use temperature of a heat-resistant material is acquirable from the several sample from which heating temperature and heating time differ.

The correlation between the hardness of the heat-resistant material acquired in the correlation acquisition step S1010 and the use temperature of the heat-resistant material is determined based on the information (master data) on the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use time of the heat-resistant material. It is the relationship (master curve) between the hardness of the heat-resistant material extracted by the use time of the heat-resistant member and the use temperature of the heat-resistant material.
Thereby, the operating temperature of the heat-resistant member to be inspected can be immediately estimated from the hardness of the heat-resistant member to be inspected obtained by measurement and the above correlation.

(Hardness measurement step S1020)
FIG. 16 is a flowchart illustrating an example of a schematic procedure of the hardness measurement step S1020.
In the hardness measurement position determination step S1201, the measurement position of the hardness in the heat-resistant member to be inspected is determined. For example, if the heat-resistant member to be inspected is a steel pipe that constitutes the superheater 18 or the reheater 22 of the boiler 10, the thermal resistance depends on the period during which the superheater 18 or the reheater 22 is used or the operating conditions. A region where a large load is estimated to be relatively large may be specified, and a plurality of points spaced at predetermined intervals along the axial direction of the steel pipe may be determined as hardness measurement positions with respect to the steel pipe in the region. .

  Next, in the measurement step S1203, the hardness at the measurement position determined in the hardness measurement position determination step S1201 is measured. For the measurement of hardness, various portable measuring devices such as an ultrasonic hardness meter can be used.

(Usage temperature estimation step S1030)
In the use temperature estimation step S1030, the hardness of the heat resistant member to be inspected obtained in the hardness measurement step S1020 is input to the correlation (master curve) between the hardness of the heat resistant material obtained in the correlation obtaining step S1010 and the use temperature of the heat resistant material. Thus, the operating temperature of the heat-resistant member to be inspected is estimated.

  For example, when the operation time of the boiler 10 at the time of the current periodic inspection is 10,000 hours and the hardness value at a certain measurement position is, for example, h1, the hardness value is as shown in FIG. It can be read from the master curve MA that the temperature value at which the h becomes h1 is T1.

Further, for example, when the operation time of the boiler 10 at the time of the current periodic inspection is 80,000 hours and the hardness value at a certain measurement position is, for example, h2, as shown in FIG. It can be read from the master curve MB that the temperature value at which the value of h2 becomes h2 is T2 or T3.
In this case, there are two candidate values for the temperature at which the hardness value becomes h2. For example, the operation status of the boiler 10, the estimated value of the temperature at other nearby hardness measurement points, and the like are considered. Then, it may be determined which value is appropriate.
In this way, the operating temperature is estimated for all of the plurality of hardness measurement positions.

  After the use temperature is estimated from the hardness of the heat-resistant member to be inspected as described above, it is determined in step S2 of FIG. 11 whether the temperature load of the heat-resistant member to be inspected is high. Specifically, for example, based on the stress of the heat-resistant member to be inspected calculated from the steam pressure that is the operating condition of the boiler 10, the operating temperature estimated from the hardness of the heat-resistant member to be inspected, and the operating time of the boiler 10 Thus, the remaining life of the heat-resistant member to be inspected is simply evaluated. If the remaining life of the heat-resistant member to be inspected simply evaluated is equal to or less than the threshold value, it is determined that the temperature load of the heat-resistant member to be inspected is high, and the remaining life of the heat-resistant member to be inspected is simply evaluated. If it exceeds the threshold value, it is determined that the temperature load of the heat-resistant member to be inspected is not high.

Here, the threshold value will be described. Let ta [time] be the period from the time of the current periodic inspection to the next periodic inspection (next periodic inspection), for example. If the remaining life of the heat-resistant member to be inspected simply evaluated as described above is less than the above [ta] [time], in the case of not carrying out countermeasures such as repair on the heat-resistant member to be inspected in this periodic inspection, The heat-resistant member to be inspected may be creep ruptured before the next periodic inspection.
However, even if the remaining life of the heat-resistant member to be inspected simply evaluated exceeds the above ta [time], the heat-resistant member to be inspected is subjected to the next periodic inspection in consideration of the accuracy of simple remaining life evaluation. There is a risk of creep rupture at a point before this point.

Therefore, when the accuracy of the remaining life of the heat-resistant member to be inspected simply evaluated is, for example, a so-called half accuracy, the remaining life of the heat-resistant member to be inspected simply evaluated is ta [hour]. If it exceeds 2 times with a certain degree of clearance, it can be determined that the heat-resistant member to be inspected does not creep rupture until the next periodic inspection.
Therefore, the threshold c is, for example, a coefficient c (c) that is a value of 1 or more for giving a margin to a value (2 · ta) that is twice the ta [time] that is the period until the next periodic inspection. It is set to a value (2 · c · ta) multiplied by> 1).

That is, in step S2, it is determined whether or not the remaining life of the heat-resistant member to be inspected simply evaluated is equal to or less than the threshold (2 · c · ta) set as described above.
In step S2, when it is determined that the remaining life of the heat-resistant member to be inspected simply evaluated exceeds the threshold (2 · c · ta), the temperature load of the heat-resistant member to be inspected is not high, It is determined that the heat-resistant member to be inspected does not creep rupture until at least the next periodic inspection, and each process in the use temperature estimation step S3 based on the precipitate is not performed on the heat-resistant member to be inspected.
However, in step S2, if it is determined that the remaining life of the heat-resistant member to be inspected simply evaluated is equal to or less than the threshold (2 · c · ta), the temperature load of the heat-resistant member to be inspected is high, It is determined that the heat-resistant member to be inspected may be creep ruptured by the next periodic inspection, and each process in the use temperature estimation step S3 based on the precipitate is performed.

  As described above, the use temperature estimation step S3 based on the precipitate includes the relationship acquisition step S10, the average particle size acquisition step S20, and the use temperature parameter acquisition step S30 according to some of the embodiments described above. It is a process. Therefore, the detailed description about use temperature estimation process S3 based on a precipitate is abbreviate | omitted.

  Thus, in the heat-resistant member inspection method according to another embodiment, prior to the average particle diameter acquisition step S20, the hardness measurement step S1020 for measuring the hardness of the heat-resistant member to be inspected, the hardness of the heat-resistant material, and the heat-resistant material And a use temperature estimation step S1030 for estimating the use temperature of the heat-resistant member to be inspected by inputting the hardness of the heat-resistant member to be inspected obtained in the hardness measurement step S1020 to the correlation with the use temperature. Then, whether or not the average particle diameter acquisition step S20 is necessary is determined based on the use temperature of the heat-resistant member to be inspected estimated in the use temperature estimation step S1030.

As a result, the operating temperature of the heat-resistant member to be inspected is estimated by a simple method of measuring the hardness of the heat-resistant member to be inspected, and it is determined that more detailed estimation of the operating temperature is necessary based on the estimated operating temperature. In this case, the average particle size acquisition step S20 can be performed. Accordingly, it is possible to reduce the time for estimating the use temperature of the heat-resistant member to be inspected and improve the estimation accuracy of the use temperature of the heat-resistant member to be inspected.
Moreover, in the inspection method of the heat-resistant member which concerns on other embodiment, it extracts with the operation time of the boiler 10 from the master data which are the information about the hardness of the some sample prepared by sample preparation process S1101, heating temperature, and aging time. Since the obtained master curve is acquired, it is not necessary to verify the validity of the temperature acceleration when acquiring the master curve.

(Other embodiments related to the master curve)
Hereinafter, other embodiments relating to the master curve will be described. In the other embodiments described above, the master curve acquired in the master curve acquisition step S1107 of the correlation acquisition step S1010 shown in FIG. 13 is information on the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use time of the heat-resistant material. It was a relationship (master curve) between the hardness of the heat-resistant material extracted from the (master data) by the usage time of the heat-resistant member to be inspected and the use temperature of the heat-resistant material. On the other hand, in other embodiments related to the master curve described below, the master curve is obtained from information (master data) on the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use time of the heat-resistant material. The relationship between the hardness of the steel and the parameters relating to the use temperature and use time of the heat-resistant material is obtained.

In another embodiment regarding the master curve, in the master curve acquisition step S1107 of the correlation acquisition step S1010 shown in FIG. 13, from the master data acquired in the master data acquisition step S1105, the hardness of the heat resistant material, the use temperature and use of the heat resistant material Obtain a master curve that shows the relationship with parameters related to time.
FIG. 17 is a diagram showing an example of a master curve showing the relationship between the hardness of the heat-resistant material and the parameters related to the use temperature and the use time of the heat-resistant material. It is the graph of the master curve MC which took the temperature and time parameter (lambda) a which is a parameter regarding time on the horizontal axis. Here, the temperature / time parameter λa is a Larson mirror parameter expressed by, for example, the above-described equation (1).
That is, the correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material acquired in the correlation acquisition step S1010 is a correlation for obtaining the temperature / time parameter λa from the hardness of the heat-resistant material. Then, based on the obtained value of the temperature / time parameter λa and the usage time, the usage temperature can be obtained from the above-described equation (1).

  For example, when the hardness value at a certain measurement position is h4, for example, as shown in FIG. 17, reading from the master curve MC that the value of the temperature / time parameter λa at which the hardness value is h4 is λ4. Can do. The use temperature at a certain measurement position can be obtained from the value (λ4) of the temperature / time parameter λa thus obtained and the operation time of the boiler 10 at the time of the current periodic inspection, for example.

Thus, in another embodiment relating to the master curve, the correlation between the hardness of the heat-resistant material acquired in the correlation acquisition step S1010 and the use temperature of the heat-resistant material is the same as the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the use of the heat-resistant material. This is the relationship between the hardness of the heat-resistant material obtained from information about time (master data) and the temperature / time parameter λa related to the use temperature and use time of the heat-resistant material.
Since the temperature / time parameter λa relating to the use temperature and use time of the heat-resistant material is used, the use time of the heat-resistant member to be inspected is longer than the longest heating time in the sample prepared for obtaining the above correlation. However, the operating temperature of the heat-resistant member to be inspected can be estimated.

The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.
For example, in some of the above-described embodiments, a sample for performing tissue observation is obtained by excising a part of a device in which the heat-resistant member to be inspected is used. However, for example, as described above, a replica of the surface of the heat-resistant member to be inspected may be obtained by the replica method. In this case, since the shape of the precipitate on the surface of the heat-resistant member to be inspected is transferred to the acquired replica, the shape can be observed. Further, depending on the replica acquisition method, the precipitate may drop off the structure and adhere to the acquired replica. In this case, for example, by using a scanning electron microscope, the precipitate attached to the replica is removed. Can be identified directly.
However, when the precipitate itself does not adhere to the acquired replica, the precipitate may not be identified from the acquired replica. That is, depending on the type of precipitate, the precipitate may not be identified only by the shape of the precipitate transferred to the acquired replica.

  Even in such a case, if it can be determined from the appearance characteristics such as the shape and particle size whether the precipitate is at least one of the first type precipitate and the second type precipitate described above. For example, the use temperature of the heat-resistant member can be estimated by using the above-described third master curve.

  Further, in the above-described embodiments, the case where two types of precipitates of the first type precipitate and the second type precipitate can exist as the precipitate related to the estimation of the use temperature has been described as an example. It is sufficient that at least one or more kinds of precipitates related to temperature estimation exist, and three or more kinds may exist.

  In addition, for example, the heat-resistant member to be inspected may be used in a portion other than the superheater 18 and the reheater 22 of the boiler 10. Further, the heat-resistant member to be inspected may be used for high-temperature equipment other than the boiler 10. Furthermore, the steel type of the heat-resistant member to be inspected is not limited to high-strength austenitic steel.

In some embodiments described above, the relationship acquisition step S10 shown in FIG. 3 includes the average particle size of precipitates having a first particle size or more among the precipitates in the structure of the heat-resistant material, the use temperature of the heat-resistant material, and If the relationship with the parameter relating to the use time has already been acquired, it is not necessary to carry out again when estimating the use temperature of the heat-resistant member to be inspected thereafter.
Similarly, in some embodiments described above, the correlation acquisition step S1010 shown in FIG. 13 uses the heat-resistant member to be inspected thereafter if the master curve shown in FIG. 15 or FIG. 17 has already been acquired. There is no need to perform it again when estimating the temperature.

10 boiler 18 superheater 22 reheater

Claims (14)

A relationship acquisition step of acquiring a relationship between an average particle size of precipitates having a first particle size or more among precipitates in the structure of the heat-resistant material and parameters regarding the use temperature and use time of the heat-resistant material;
An average particle size obtaining step for obtaining an average particle size of a precipitate having a particle size equal to or larger than the second particle size among the precipitates in the structure of the heat-resistant member to be inspected by measurement;
Based on the relationship obtained in the relationship obtaining step and the average particle size obtained in the average particle size obtaining step, a use temperature parameter obtaining step for obtaining a parameter relating to the use temperature of the heat-resistant member to be inspected,
The inspection method of a heat-resistant member provided with. The first particle size is n micrometers;
The heat resistance member inspection method according to claim 1, wherein the second particle size is the n micrometers. The first particle size is a particle size of an nth precipitate in order from a precipitate having a maximum diameter among precipitates in the structure of the heat-resistant material,
The said 2nd particle size is a test | inspection of the heat resistant member of Claim 1 which is a particle size of the said nth precipitate in an order from the largest diameter precipitate among the precipitates in the structure | tissue of the said heat resistant member to be examined. Method. The first particle size is the particle size of the smallest precipitate in the precipitates included in the top n% of the particles having the largest particle size among the precipitates in the structure of the heat-resistant material,
The said 2nd particle size is a particle size of the smallest precipitate in the precipitate contained in the number of said upper n% with a large particle size among the precipitates in the structure | tissue of the said heat-resistant member to be examined. Inspection method of heat-resistant member as described. The precipitate in the structure of the heat-resistant material includes at least a first type precipitate and a second type precipitate different in type,
The relationship acquisition step includes a first relationship between an average particle size of precipitates of the first particle size or more among the first type precipitates and parameters relating to a use temperature and a use time of the heat-resistant material, and the second type. In any one of Claims 1 thru | or 4 which acquire the 2nd relationship between the average particle diameter of the precipitate more than the said 1st particle size among the precipitates, and the parameter regarding the use temperature and use time of the said heat-resistant material. Inspection method of heat-resistant member as described. The precipitate in the structure of the heat-resistant material includes at least a first type precipitate and a second type precipitate different in type,
In the relationship acquisition step, a third of the average particle diameter of the first particle size and the second particle size precipitate and the parameters relating to the use temperature and use time of the heat-resistant material. The heat-resistant member inspection method according to claim 1, wherein the relationship is acquired.   In the relationship acquisition step, when a standard error between the average particle size and the parameter used for acquiring the relationship and the acquired relationship is outside an allowable range, the first particle size is changed and the relationship is obtained. The method for inspecting a heat-resistant member according to claim 1, wherein the relationship is reacquired.   The method for inspecting a heat-resistant member according to any one of claims 1 to 7, wherein the heat-resistant material and the heat-resistant member to be inspected are made of high-strength austenitic steel. Of the precipitates in the structure of the heat-resistant member to be inspected, the average particle size obtained by measuring the average particle size of the precipitates having a particle size equal to or larger than the second particle size corresponding to the first particle size of the precipitate in the structure of the heat-resistant material Diameter acquisition process;
Of the precipitates in the structure of the heat-resistant material, the relationship between the average particle size of the precipitates of the first particle size or more and the parameters related to the use temperature and the use time of the heat-resistant material, and the average particle size obtaining step Based on the average particle diameter, a use temperature parameter obtaining step for obtaining a parameter related to the use temperature of the heat-resistant member to be inspected,
The inspection method of a heat-resistant member provided with. From a plurality of standard samples having different heating temperatures and heating times, among the precipitates in the structure of the heat-resistant material, the average particle size of the precipitates having the first particle size or more and the parameters relating to the use temperature and use time of the heat-resistant material The inspection method of the heat-resistant member according to claim 9, further comprising a relationship acquisition step of acquiring a relationship. Prior to the average particle diameter acquisition step, a hardness measurement step for measuring the hardness of the heat-resistant member to be inspected,
The operating temperature of the heat-resistant member to be inspected is estimated by inputting the hardness of the heat-resistant member to be inspected obtained in the hardness measurement step into the correlation between the hardness of the heat-resistant material and the operating temperature of the heat-resistant material. A service temperature estimation step,
The said average particle diameter acquisition process determines whether the necessity for implementation is determined based on the use temperature of the said heat-resistant member of the test object estimated in the said use temperature estimation process. Inspection method for heat-resistant materials. The inspection method for a heat-resistant member according to claim 11, further comprising obtaining a correlation between the hardness of the heat-resistant material and the use temperature of the heat-resistant material from a plurality of samples having different heating temperatures and heating times.   The correlation is the hardness of the heat-resistant material extracted from the information about the hardness of the heat-resistant material, the temperature of use of the heat-resistant material, and the time of use of the heat-resistant material. The inspection method of the heat-resistant member according to claim 11 or 12, which is a relationship with a use temperature.   The correlation includes the hardness of the heat-resistant material, the use temperature of the heat-resistant material, and the parameters relating to the use temperature and use time of the heat-resistant material obtained from information about the use time of the heat-resistant material. The heat-resistant member inspection method according to claim 11 or 12, which is related.