JP2003035608A - METAL TEMPERATURE AND MATERIAL CHARACTERISTIC ESTIMATION METHOD FOR PART MADE OF Ni BASE ALLOY - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate the residual life of a gas turbine. SOLUTION: The metal temperature of a high temperature part made of an Ni base alloy is estimated on the basis of a change in the structure of the Ni base alloy used in the high temperature part of a gas turbine, a jet engine or the like. This estimation method includes a process for calculating a base line for showing the relation of the size of a grain boundary carbide with a Larson-Miller parameter(LMP) from the heating temperature and heating time of a test piece on the basis of the relational expression of LMP: LMP=(273+T) (K+logt)/1,000, and a process for estimating the metal temperature from the size of the grain boundary carbide or transgranular carbide measured from the micro-structure of the cross section of each part of an actual machine by utilizing the base line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating metal temperature and material properties of high temperature parts such as gas turbines and jet engines, especially Ni-base alloy parts used for moving blades or stationary blades.

[0002]

2. Description of the Related Art As is well known, Ni-base alloys are used for high temperature parts such as moving blades and stationary blades of gas turbines. Since such rotor blades and stator blades are used for a long time while being stressed at high temperatures, they suffer creep damage during operation, causing a metallic structure, especially the γ'phase (Ni ₃ Al intermetallic compound).
Morphological changes such as coarsening occur. This morphological change means material deterioration, and factors such as the temperature (metal temperature) of the Ni-based alloy, stress, usage time, etc. are mentioned. Therefore,
In the gas turbine, the material composition, shape, etc. of the blade are determined in consideration of material deterioration so as to withstand long-term use.

However, even if such consideration is given, the gas turbine may be damaged before it reaches the end of its life due to a sudden rise in the metal temperature for some reason. Therefore, there is a demand for a technique for accurately detecting the deterioration state of a moving blade or a stationary blade and accurately predicting the remaining life. Conventionally, as one of the means, the metal temperature is determined by measuring the morphological change of the γ'phase by the cross-sectional microstructure of the moving blade or the stationary blade.

[0004]

However, the change in the γ'phase may be influenced by stress (centrifugal force), and it has been required to estimate the metal temperature and the material properties based on other parameters.

The present invention has been made in consideration of such circumstances. Therefore, based on the relational expression of LMP, the size of the grain boundary carbide or intragranular carbide and the LMP can be determined from the heating temperature and the heating time of the specimen.
After obtaining the baseline showing the relationship with the parameters,
Ni can accurately predict the remaining life of the gas turbine by estimating the metal temperature from the size of the grain boundary carbides or intragrain carbides measured from the cross-sectional microstructure of each part of the actual machine using the baseline. It is an object to provide a metal temperature estimation method for base alloy parts.

Further, according to the present invention, a baseline showing the relationship between material properties and LMP parameters is obtained from the heating temperature and heating time of the specimen based on the relational expression of LMP, and then from the cross-sectional microstructure of each part of the actual machine. Estimating the material properties from the measured size of grain boundary carbides or intragranular carbides by using the baseline to accurately predict the remaining service life of the gas turbine. The purpose is to provide the law.

[0007]

According to a first aspect of the present invention, the metal temperature of a Ni-based alloy high temperature component is estimated on the basis of the structural change of the Ni-based alloy used for a high temperature component such as a gas turbine or a jet engine. In the method, the following formula (3)
Based on the relational expression of the Larson-Miller parameter (LMP) shown in, the step of obtaining the baseline showing the relationship between the size of the grain boundary carbide or intragranular carbide and the LMP parameter from the heating temperature and heating time of the specimen, and each part of the actual machine Estimating the metal temperature from the size of the grain boundary carbides or intragrain carbides measured from the cross-sectional microstructure of Is the law.

LMP = (273 + T) (K + logt) / 1000 (3) However, in the formula (3), T represents a heating temperature (° C.) and t represents a heating time (h). K is a constant and represents an appropriate number of 15 to 20.

The second invention of the present application is a method for estimating the material properties of a Ni-based alloy high-temperature component based on the microstructural change of the Ni-based alloy used for a high-temperature component such as a gas turbine or a jet engine. Based on the Larson-Miller parameter (LMP) relational expression shown in 3), from the heating temperature and heating time of the specimen to obtain the baseline showing the relationship between the material properties and the LMP parameter, and from the cross-sectional microstructure of each part of the actual machine And a step of estimating the material properties from the measured size of the grain boundary carbides or the intragranular carbides by using the baseline, the method for estimating material properties of a Ni-based alloy part.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. In the present invention, the size of the intergranular carbide or intragranular carbide indicates the grain size, width or area of the intergranular carbide or intragranular carbide. Here, grain boundary carbide refers to the case where it is deposited on the surface of the Ni-based alloy by heating, and intra-grain carbide refers to the case where it is present in the Ni-based alloy without being deposited on the surface due to heating. Further, for example, in a Ni-based alloy such as IN738LC, grain boundary carbides (intra-grain carbides) exist as separated as shown in FIG. 5A, so the diameter R of the grain boundary carbides is to be measured. For example Tomill
Since a Ni-based alloy such as oy is connected in a bell shape as shown in FIG. 5 (B), the width W of the grain boundary carbide (intragrain carbide) is to be measured.

In the present invention, the material characteristic is Ni.
By indicating at least one of creep rupture strength, life, and tensile strength of a high-temperature component made of a base alloy and estimating these material properties together with the metal temperature, the remaining life of the component can be obtained more accurately.

[0012]

EXAMPLE A method for estimating the temperature of a Ni-based alloy part according to an example of the present invention will be described below. Note that the materials, numerical values, etc. of the respective members described in the following examples are merely examples, and do not specify the scope of rights of the present invention.

(Example 1) In this example 1, a Ni-based alloy as a specimen is a product name: IN7 manufactured by INCO Corporation.
38LC, that is, Ni-16Cr-8.5Co-1.7M
o-2.6W-1.8Ta-3.4Ti-3.44Al
The case of -0.12C-0.1Zr-0.01B was tested.

[1] Method of determining relationship between grain boundary carbide size and LMP parameter: LMP value (parameter:
P) is the Larson-Miller parameter (LMP) formula of the above formula (3), that is, LMP = (273 + T ° C.) (K + 1
ogt) / 1000 is used (however, the constant K is 15).
The constant K is not limited to 15, and may be any suitable numerical value from 15 to 20.

First, a specimen having the same composition as the Ni-based alloy is prepared, and the heating time t ₁ , t ₂ , t ₃ , ... T of the specimen is prepared.
The heating temperatures of the specimen corresponding to _n are T ₁ , T ₂ ,
T ₃ , ... T _n, and the sizes (for example, diameters) of the grain boundary carbides at that time are R ₁ , R ₂ , R ₃ , ... R _n (grain size of heating material carbide) and R ₀₁ , R ₀₂ , R, respectively. ₀₃ , ..., R _0n (grain size of initial material carbide). At the same time, the heating time t ₁ , t
₂ , t ₃ , ... T _n , heating temperatures T ₁ , T ₂ , T ₃ , ... T _n
Are respectively substituted into the above LMP equations to obtain LMP values (parameters P) P ₁ , P ₂ , P ₃ , ... P _n, and the ratio (H) of the carbide particle diameter of the heating material to the carbide material of the initial material and the parameter P ₁ ,
A baseline showing the relationship with P ₂ , P ₃ , ... P _n is obtained (see FIG. 1).

[2] Method of estimating metal temperature: Grain boundary carbide diameter measured from the cross-sectional microstructure of an actual machine (Ni-based alloy having the above composition) (ratio of carbide particle diameter of heated material to carbide particle diameter of initial material) From the above, the parameter P is obtained based on the baseline of FIG. 1 obtained in [1] above. Continuing, the above LMP
The metal temperature T of the actual machine is obtained by substituting the parameter P and the heating time t into the equation.

As described above, according to the first embodiment, the Ni
Using a specimen with the same composition as the base alloy part, find the baseline as shown in Fig. 1 from the relationship between the heating material carbide grain size, initial material carbide ratio (H) and parameter P, and use this baseline Then, since the heating temperature T is obtained from the ratio (H) of the heating material carbide particle size and the initial material carbide at the heating time t of the actual machine and the heating temperature t, the metal temperature of the actual machine in use can be accurately estimated, The remaining life of the actual machine can be estimated.

(Example 2) In Example 2, a Ni-based alloy as a test piece, manufactured by Mitsubishi Heavy Industries, Ltd., trade name: To
milley, that is, Ni-22Cr-8Co-9Mo-
The case of 3W-0.3Ti-1Al-0.07C was tested.

[1] How to determine the relation between the area of grain boundary carbide and the LMP parameter: LMP value (parameter: P)
Is the Larson-Miller parameter (LM
P) formula, that is, LMP = (273 + T ° C.) (K + log
t) / 1000 is used.

First, a specimen having the same composition as the Ni-based alloy
To prepare the heating time t₁, T_Two, T_Three, ... t
_nThe heating temperature of the specimen corresponding to₁, T_Two，
T_Three, ... T_nAnd the size of the grain boundary carbide at that time (example
S)₁, S_Two, S_Three,… S_nAnd same
Sometimes, the heating time t₁, T_Two, T_Three, ... t_n, Heating temperature
Degree T ₁, T_Two, T_Three, ... T_nEach into the above LMP formula
And LMP value (parameter P) P₁, P_Two, P_Three、…
P_nThe grain size of the grain boundary carbide S₁, S_Two, S_Three,… S
_nAnd parameter P₁, P_Two, P_Three,… P_nRelationship with
Determine the baseline shown (see Figure 2).

[2] Method of estimating metal temperature: Based on the base curve of FIG. 2 obtained in the above [1] from the area of grain boundary carbide measured from the cross-sectional microstructure of an actual machine (Ni-based alloy having the above composition) To obtain the parameter P. Continuing,
The metal temperature T of the actual machine is obtained by substituting the parameter P and the heating time t into the above LMP formula.

As described above, according to the second embodiment, Ni
Using a specimen having the same composition as the base alloy part, a base curve as shown in Fig. 2 was obtained from the relationship between the area of the grain boundary carbides and the parameter P, and the grain at the heating time t of the actual machine was calculated using this base curve. Since the heating temperature T is obtained from the field carbide area and the heating temperature t, the metal temperature of the actual machine in use can be accurately estimated, and the remaining life of the actual machine can be estimated.

(Embodiment 3) In the present embodiment 3, as a test piece, a Ni-based alloy manufactured by Special Metals, trade name: U520, that is, Ni-19Cr-12Co-.
6Mo-1W-3Ti-2Al-0.05C-0.00
The case of 5B was tested.

[1] Method of determining relationship between grain boundary carbide width and LMP parameter: LMP value (parameter: P)
Is the Larson-Miller parameter (LM
P) formula, that is, LMP = (273 + T ° C.) (15 + log
t) / 1000 is used.

First, a specimen having the same composition as that of the Ni-based alloy is prepared, and heating time t ₁ , t ₂ , t ₃ , ... T of the specimen is prepared.
The heating temperatures of the specimen corresponding to _n are T ₁ , T ₂ ,
T _3, ... and _{T n,} the grain boundary size of carbides (e.g., width) of each _W 1 _when, W _2, W 3, and ... _{W n.} At the same time, the heating time _{t 1, t 2, t 3} , ... t n, the heating temperature _{T 1, T 2, T 3} , ... T n are substituted respectively the LMP expression LMP value (parameter _{P) P} 1, P ₂ , P ₃ , ... P
_{Then, n} is obtained, and a baseline showing the relationship between the widths W ₁ , W ₂ , W ₃ , ... W _{n of} the grain boundary carbides and the parameters P ₁ , P ₂ , P ₃ , ... P _n is obtained (see FIG. 3).

[2] Method of estimating metal temperature: Based on the baseline of FIG. 3 obtained in the above [1] from the width of the grain boundary carbide measured from the cross-sectional microstructure of an actual machine (Ni-based alloy having the above composition) To obtain the parameter P. Next, the metal temperature T of the actual machine is obtained by substituting the parameter P and the heating time t into the above LMP formula.

As described above, according to the third embodiment, Ni
A base line as shown in FIG. 3 is obtained from the relationship between the width of the grain boundary carbides and the parameter P using a specimen having the same composition as the base alloy part, and the grain is used at the heating time t of the actual machine by using this baseline. Since the heating temperature T is obtained from the width of the field carbide and the heating temperature t, the metal temperature of the actual machine in use can be accurately estimated, and the remaining life of the actual machine can be estimated.

(Embodiment 4) In the present embodiment 4, as a test piece, a Ni-based alloy manufactured by Special Metals Co., Ltd., trade name: U520, that is, Ni-19Cr-12Co-.
6Mo-1W-3Ti-2Al-0.05C-0.00
The case of 5B was tested.

[1] Width of grain boundary carbide and LMP parameter
-How to obtain the relationship with:
As a result, as shown in FIG. ₁, W_Two，
W_Three, ... W_nAnd parameter P₁, P_Two, P_Three,… P_n
The baseline showing the relationship with is calculated. At the same time, grain boundary coal
Width W₁, W_Two, W_Three, ... W_nLife span L corresponding to
₁, L_Two, L_Three, ... L_nI want And FIG.
As shown in, the grain boundary carbide width W₁, W_Two, W_Three, ... W
_nAnd life L₁, L_Two, L_Three, ... L_nCharacteristic indicating the relationship with
Request a figure.

[2] Method of estimating life: Based on the characteristic diagram of FIG. 4 obtained in [1] above from the width of the grain boundary carbide measured from the cross-sectional microstructure of an actual machine (Ni-based alloy having the above composition) The width W of the grain boundary carbide is determined. As described above, according to the above-mentioned Example 4, the base line as shown in FIG. 3 is obtained from the relationship between the width W of the grain boundary carbide and the parameter P using the specimen having the same composition as the Ni-based alloy part , A characteristic diagram (FIG. 4) showing the relationship between the width W of the grain boundary carbide and the life L is obtained, and the life L is obtained from the width of the grain boundary carbide at the heating time t of the actual machine by using this characteristic diagram. It is possible to accurately estimate the life of the actual machine inside.

In the first to third embodiments, the case where the metal temperature of the actual machine is estimated is described, and the case where the life is obtained is described in the fourth embodiment. However, the life may be obtained together with the metal temperature. Further, in the above embodiment, the case where the width of the grain boundary carbide is obtained has been described, but the case where the diameter of the grain boundary carbide is obtained may be used. Further, instead of the width (or diameter) of the grain boundary carbide, the width (or diameter) of the intragrain carbide may be obtained.

[0032]

As described above in detail, according to the present invention, L
Based on the relational expression of MP, the baseline showing the relationship between the grain boundary carbide size and the LMP parameter was obtained from the heating temperature and heating time of the specimen, and then the grain boundary carbide measured from the cross-sectional microstructure of each part of the actual machine. It is possible to provide a metal temperature estimation method for a Ni-based alloy component that can accurately predict the remaining life of the gas turbine by estimating the metal temperature from the size of the above using the baseline.

Further, according to the present invention, based on the relational expression of LMP, from the heating temperature and the heating time of the specimen, the material characteristics and L
After obtaining the baseline showing the relationship with the MP parameter, by using the baseline to estimate the material properties from the grain boundary carbide size measured from the cross-sectional microstructure of each part of the actual machine, the gas turbine It is possible to provide a method for estimating material properties of a Ni-based alloy component that can accurately predict the remaining life.

[Brief description of drawings]

FIG. 1 is an M used in a Ni-based alloy part according to the present invention.
The characteristic view which shows the relationship between the heating material carbide particle diameter / initial material carbide particle diameter of GA1400, and the heating condition parameter by a LMP type | formula.

FIG. 2 shows the T used in the Ni-based alloy part according to the present invention.
The characteristic view which shows the relationship between the area of the carbide of omilloy and the heating condition parameter by a LMP formula.

FIG. 3 U used in a Ni-based alloy part according to the present invention
The characteristic view which shows the relationship between the width | variety of the grain boundary carbide | grain of 520, and the heating condition parameter by a LMP type | formula.

FIG. 4 U used in a Ni-based alloy part according to the present invention
The characteristic view which shows the relationship between the life of 520 and the width of a grain boundary carbide.

FIG. 5 is an explanatory view of the width or diameter of the grain boundary carbide in the sample having the same composition as the Ni-based alloy according to the present invention.

[Explanation of symbols]

1 ... Grain boundary carbide.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Taiji Koji             2-1-1 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. F term (reference) 2F056 TZ00                 3G002 EA06

Claims (5)

[Claims] 1. A method for estimating the metal temperature of a Ni-based alloy high temperature component based on a structural change of a Ni-based alloy used for a high temperature component such as a gas turbine and a jet engine, wherein a Larson represented by the following formula (1) is used. Mirror parameter (LM
P) Based on the relational expression of P), the process of obtaining the baseline showing the relationship between the grain size of intergranular carbide or intragranular carbide and the LMP parameter from the heating temperature and heating time of the specimen, and the measurement from the microstructure of the cross section of each part Estimating the metal temperature from the size of the formed intergranular carbides or intragranular carbides by using the baseline. LMP = (273 + T) (K + logt) / 1000 ... (1) However, in Formula (1), T shows heating temperature (degreeC) and t shows heating time (h). K is a constant and represents an appropriate number of 15 to 20. 2. The Ni-based alloy part according to claim 1, wherein the size of the grain boundary carbide or the intragranular carbide is the grain size, width or area of the grain boundary carbide or the intragrain carbide. Metal temperature estimation method. 3. A method for estimating material properties of a Ni-based alloy high temperature component based on a structural change of a Ni-based alloy used for a high temperature component such as a gas turbine and a jet engine, wherein a Larson represented by the following formula (2) is used. Mirror parameter (LM
P) a step of obtaining a baseline showing the relationship between material properties and LMP parameters from the heating temperature and heating time of the specimen based on the relational expression of P), and grain boundary carbides or grains measured from the cross-sectional microstructure of each part of the actual machine And a step of estimating material properties from the size of internal carbides using the baseline, a method for estimating material properties of a Ni-based alloy part. LMP = (273 + T) (K + logt) / 1000 ... (2) However, in Formula (2), T shows heating temperature (degreeC) and t shows heating time (h). K is a constant and represents an appropriate number of 15 to 20. 4. The Ni-based alloy component according to claim 3, wherein the size of the intergranular carbide or the intragranular carbide is the grain size, width or area of the intergranular carbide or the intragranular carbide. Material property estimation method. 5. The method for estimating material properties of Ni-based alloy parts according to claim 3, wherein the material properties are any of creep rupture strength, life and tensile strength of high-temperature Ni-based alloy parts. .