Method for evaluating creep life of aero-engine turbine blade

Abstract

The application discloses an aero-engine turbine blade creep life evaluation method, comprising the following steps: performing a creep test on a round bar test piece under different preset temperatures and preset stresses to obtain creep life data; performing polynomial fitting based on the creep test conditions and the creep life data of the round bar test piece to obtain creep parameters, and then establishing a creep life model; based on the creep life model, and combined with a creep damage accumulation formula, a creep damage accumulation life model is established; performing a creep test on a turbine blade airfoil simulation piece continuously under different cycle conditions to obtain accumulated creep life data; using the creep damage accumulation life model to calculate the accumulated creep life of the turbine blade airfoil simulation piece continuously under different cycle conditions; and comparing the accumulated creep life obtained through the creep test with the calculated accumulated creep life to verify the accuracy of the model. The application can predict and evaluate the accumulated creep life of the turbine blade.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine turbine blade performance testing technology, specifically relating to a method for evaluating the creep life of aero-engine turbine blades. Background Technology

[0002] Aero engines, hailed as the crown jewel of industry, have long been a crucial indicator of a nation's comprehensive national strength, military power, and international technological prowess. A highly complex and precise thermodynamic machine, an aero engine serves as the heart of the space shuttle, not only providing power for flight but also acting as a vital driving force for the development of the aviation industry.

[0003] Turbine blades, as core hot-end components of aero-engines, largely determine the engine's performance, and their service condition also determines its reliability and safety. Nickel-based single-crystal superalloys are widely used in the manufacture of turbine blades and other hot-end components of aero-engines due to their excellent high-temperature mechanical properties, oxidation and corrosion resistance, creep and fatigue resistance. Because turbine blades operate in extremely complex environments, enduring complex stresses at high temperatures for extended periods, creep failure has become one of the main modes of turbine blade damage. Furthermore, the complex and variable service environment of turbine blades, often requiring continuous operation under different conditions, further complicates the prediction of their creep life.

[0004] Chinese patent application CN113125275A discloses a method for determining creep model parameters and predicting creep life of nickel-based single-crystal superalloys. The method includes the following steps: providing a target test piece; conducting multiple creep tests on the target test piece at a preset temperature to obtain test data; determining a creep curve based on the test data; determining the creep rate of the steady-state creep stage under different stress conditions based on the creep curve; and determining the creep model parameters at the preset temperature through fitting based on the creep rate and crystal plasticity theory. The creep life prediction method includes the following steps: determining a creep constitutive model; and determining the creep life based on the creep parameters and the creep constitutive model. This technical solution can predict the creep life under different stress conditions at a certain temperature, but it only considers the change in stress, not the simultaneous change in temperature and stress, and it has not been verified using turbine blade profile simulation components. Therefore, the accuracy and reliability of the constructed creep life model are uncertain.

[0005] Chinese patent application CN116127750A discloses a method and apparatus for predicting the high-temperature creep performance of metal components. The method includes the following steps: collecting creep test data obtained from creep tests on a target material; fitting the creep test data to obtain a creep model of the target material, wherein the creep model reflects the relationship between creep strain and time under arbitrary temperature and stress; using the creep model to calculate creep stress-life data sets of the target material at different creep strains, wherein the creep stress-life data sets include creep stress, temperature, and creep fracture life of the target material at creep strains; fitting the creep stress-life data sets of the target material at different creep strains to obtain creep stress-life curves of the target material at different creep strains; and predicting the high-temperature creep performance of the target material based on the creep stress-life curves at different creep strains. This technical solution can predict the creep properties of the target material under specific temperature and stress, but it cannot assess the cumulative creep damage life of the component throughout the entire continuous service process. Moreover, it has not been verified by turbine blade airfoil simulation, so the accuracy and reliability of the constructed creep life model are uncertain. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for evaluating the creep life of aero-engine turbine blades, comprising the following steps in sequence:

[0007] Step 1: Conduct creep tests on the round bar specimen under different preset temperature and preset stress conditions to obtain the creep life data of the round bar specimen under the corresponding creep test conditions;

[0008] Step 2: Based on the creep test conditions of the round bar specimen and the obtained creep life data, analyze and perform polynomial fitting to obtain the specific values ​​of the creep parameters, and then establish a creep life model related to temperature and stress.

[0009] Step 3: Based on the creep life model and combined with the creep damage accumulation formula, establish a creep damage accumulation life model related to temperature, stress, service time and cycle number;

[0010] Step 4: Conduct creep tests on the turbine blade airfoil simulation component continuously under different preset temperature, preset stress and preset service time conditions to obtain the cumulative creep life data of the turbine blade airfoil simulation component under different cyclic conditions.

[0011] Step 5: Calculate the number of cycles when the cumulative creep damage of the turbine blade airfoil simulation part reaches 1 under different cyclic conditions using the creep damage cumulative life model. Calculate the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions by the number of cycles.

[0012] Step 6: Compare the cumulative creep life obtained from the creep test of the turbine blade profile simulation with the cumulative creep life calculated using the creep damage cumulative life model to verify the accuracy of the creep damage cumulative life model.

[0013] This invention establishes a creep life model based on material-level creep test data, and further establishes a creep damage cumulative life model by combining the creep damage accumulation formula. The established creep damage cumulative life model is then validated using creep test data from turbine blade airfoil simulation components. The creep damage cumulative life model can be used to calculate the cumulative creep damage of turbine blades under different cyclic operating conditions during continuous service, and to predict and evaluate the cumulative creep life of turbine blades.

[0014] Preferably, in step one, the cylindrical test specimen is made of second-generation nickel-based single-crystal high-temperature alloy DD6; at least four different creep test conditions are selected, and at least three sets of valid creep life data are obtained under each creep test condition.

[0015] In this invention, the cylindrical test specimen is subjected to a creep test after heat treatment. The heat treatment process is as follows: the cylindrical test specimen is placed in a heat treatment furnace, heated to 1315°C, held for 6 hours, and then air-cooled after the heat treatment is completed; after the air cooling is completed, the temperature is raised to 1130°C, held for 4 hours, and then air-cooled after the heat treatment is completed; after the air cooling is completed, the temperature is raised to 870°C, held for 32 hours, and then air-cooled after the heat treatment is completed.

[0016] Preferably, in any of the above schemes, in step two, the creep life model satisfies the following relationship: ,

[0017] In the formula, — Creep life, h;

[0018] —Temperature, K;

[0019] —Stress, MPa;

[0020] —Constant 2.71828, dimensionless;

[0021] —First creep parameter, dimensionless;

[0022] —Second creep parameter, dimensionless;

[0023] —The third creep parameter, dimensionless.

[0024] In any of the above schemes, the preferred option is that, in step two, the relation is... Taking the natural logarithm of both sides, we get... The creep test conditions for the round bar specimen , and creep life data Input into Origin software and create a result based on Using the z-axis, with Using the x-axis as the x-axis, The data in the 3D scatter plot along the y-axis is fitted with a nonlinear surface using the polynomial z = Ax + By + C to obtain the first creep parameter. Second creep parameter and the third creep parameter The first creep parameter obtained by fitting Second creep parameter and the third creep parameter Substitute the relation In this way, a creep life model related to temperature and stress can be established. In the polynomial z = Ax + By + C, C = .

[0025] In any of the above schemes, preferably, in step three, the creep damage accumulation formula is: D = ∑ k = 1 n [ w k ( T , σ ) × Δ t k ] ,

[0026] In the formula, —Cumulative creep damage, dimensionless;

[0027] —Damage rate under the k-th cycle condition, dimensionless;

[0028] —Service time under the k-th cycle condition, in hours;

[0029] —The number of cycles for different cyclic operating conditions, k=1-n;

[0030] —Temperature, K;

[0031] —Stress, MPa.

[0032] In any of the above schemes, the preferred option is that, in step three, let ,Will Substitute into the creep damage accumulation formula D = ∑ k = 1 n [ w k ( T , σ ) × Δ t k ] In this way, a creep damage cumulative life model related to temperature, stress, service time, and cycle number can be established, providing a basis for... ,

[0033] In the formula, —Cumulative creep damage, dimensionless;

[0034] — Creep life under the k-th cycle condition, h;

[0035] —Service time under the k-th cycle condition, in hours;

[0036] —The number of cycles for different cyclic operating conditions, k=1-n;

[0037] —Temperature, K;

[0038] —Stress, MPa.

[0039] In any of the above schemes, it is preferred that, in step four, the turbine blade profile simulation component is made of second-generation nickel-based single-crystal high-temperature alloy DD6, and the shape of the gauge section of the turbine blade profile simulation component simulates the real shape of the turbine blade.

[0040] In this invention, the turbine blade profile simulator replicates the actual shape of a turbine blade to a certain extent. Compared with traditional conventional test specimens, its test data is more accurate and closer to the actual service condition of turbine blades. Furthermore, the turbine blade profile simulator undergoes creep testing after heat treatment. The heat treatment process is as follows: the turbine blade profile simulator is placed in a heat treatment furnace, heated to 1315℃, held for 6 hours, and then air-cooled; after air cooling, it is heated to 1130℃, held for 4 hours, and then air-cooled; after air cooling, it is heated to 870℃, held for 32 hours, and then air-cooled.

[0041] In any of the above schemes, step five is preferably based on a creep damage cumulative life model related to temperature, stress, service time, and cycle number. When D≥1, that is, when the cumulative creep damage reaches 1, the cycle terminates and the number of cycles is obtained. Then, the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions is calculated by the number of cycles.

[0042] In any of the above schemes, it is preferred that the specific conditions of the different cyclic operating conditions in step five are the same as the specific conditions of the different cyclic operating conditions in step four.

[0043] In this invention, the cumulative creep life of a turbine blade profile simulator under different cyclic conditions is calculated using a creep damage cumulative life model. The specific conditions of these different cyclic conditions are the same as the specific conditions of the different cyclic conditions involved in the creep test of the turbine blade profile simulator.

[0044] The method for assessing the creep life of aero-engine turbine blades of this invention can calculate the cumulative creep damage of turbine blades under different operating conditions during continuous service, and use this to predict and assess the cumulative creep life of turbine blades. The cumulative creep damage life model of this invention has been effectively verified using turbine blade airfoil simulation components, exhibiting high accuracy. It provides technical support for assessing the service life of turbine blades, ensuring the stability and safety of turbine blades during service while avoiding economic losses due to overly conservative life calculations. Using the cumulative creep damage life model of this invention, the cumulative creep damage of turbine blades can be quantitatively monitored, which is beneficial for the health management of aero-engines, provides technical support for aero-engine maintenance and turbine blade replacement, and provides a theoretical basis for the research of nickel-based single-crystal superalloy turbine blades. Attached Figure Description

[0045] Figure 1 A flowchart of a preferred embodiment of the method for evaluating the creep life of aero-engine turbine blades according to the present invention;

[0046] Figure 2 for Figure 1 A schematic diagram of the structure of the cylindrical test specimen in the embodiment shown;

[0047] Figure 3 for Figure 1 The schematic diagram of the turbine blade airfoil simulation component in the embodiment shown is as follows;

[0048] Figure 4 for Figure 1 Polynomial fitting diagram of the circular bar-shaped test specimen in the illustrated embodiment;

[0049] Figure 5 for Figure 1 The error dispersion diagram of the actual creep life value obtained from the creep test of the cylindrical test specimen in the embodiment shown in the figure and the predicted creep life value calculated by the creep life model is shown in the figure.

[0050] Figure 6 for Figure 1 The creep curves of the engine takeoff and emergency state simulation tests in the illustrated embodiment are shown.

[0051] The markings in the diagram are as follows: 1 - Gauge length section, 2 - Takeoff status, 3 - Emergency status. Detailed Implementation

[0052] To further understand the invention, the following detailed description of the invention will be provided in conjunction with specific embodiments.

[0053] like Figure 1 As shown, a preferred embodiment of the method for evaluating the creep life of aero-engine turbine blades according to the present invention includes the following steps in sequence:

[0054] Step 1: Conduct creep tests on the round bar specimen under different preset temperature and preset stress conditions to obtain the creep life data of the round bar specimen under the corresponding creep test conditions;

[0055] Step 2: Based on the creep test conditions of the round bar specimen and the obtained creep life data, analyze and perform polynomial fitting to obtain the specific values ​​of the creep parameters, and then establish a creep life model related to temperature and stress.

[0056] Step 3: Based on the creep life model and combined with the creep damage accumulation formula, establish a creep damage accumulation life model related to temperature, stress, service time and cycle number;

[0057] Step 4: Conduct creep tests on the turbine blade airfoil simulation component continuously under different preset temperature, preset stress and preset service time conditions to obtain the cumulative creep life data of the turbine blade airfoil simulation component under different cyclic conditions.

[0058] Step 5: Calculate the number of cycles when the cumulative creep damage of the turbine blade airfoil simulation part reaches 1 under different cyclic conditions using the creep damage cumulative life model. Calculate the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions by the number of cycles.

[0059] Step 6: Compare the cumulative creep life obtained from the creep test of the turbine blade profile simulation with the cumulative creep life calculated using the creep damage cumulative life model to verify the accuracy of the creep damage cumulative life model.

[0060] This embodiment establishes a creep life model based on material-level creep test data, and further establishes a creep damage cumulative life model by combining the creep damage accumulation formula. The established creep damage cumulative life model is then validated using creep test data from a turbine blade airfoil simulation component. The creep damage cumulative life model can be used to calculate the cumulative creep damage of turbine blades under different cyclic operating conditions during continuous service, and to predict and evaluate the cumulative creep life of turbine blades.

[0061] In step one, the cylindrical test specimen is made of second-generation nickel-based single-crystal superalloy DD6, and its chemical composition is shown in Table 1. Four different creep test conditions are selected, and three sets of valid creep life data are obtained under each creep test condition. The creep test conditions and creep life data are shown in Table 2. The structure of the cylindrical test specimen is shown below. Figure 2 As shown.

[0062] Table 1 Chemical composition of DD6, a second-generation nickel-based single-crystal superalloy

[0063] Percentage by weight (wt%) 3.8 8.5 7.0 5.2 6.0 1.6 1.5 margin

[0064] Table 2 Creep test conditions and creep life data for round bar specimens

[0065] 1 900 445.5 338.1 2 900 445.5 338.4 3 900 445.5 296.0 4 1000 216 203.5 5 1000 216 193.0 6 1000 216 272.5 7 1000 283.5 84.2 8 1000 283.5 60.0 9 1000 283.5 75.9 10 1050 210 63.0 11 1050 210 64.0 12 1050 210 60.5

[0066] In this embodiment, the cylindrical test specimen is subjected to creep test after heat treatment. The heat treatment process is as follows: the cylindrical test specimen is placed in a heat treatment furnace, heated to 1315°C, held for 6 hours, and then air-cooled after the holding period; after the air-cooling period, the temperature is raised to 1130°C, held for 4 hours, and then air-cooled after the holding period; after the air-cooling period, the temperature is raised to 870°C, held for 32 hours, and then air-cooled after the holding period.

[0067] In step two, the creep life model satisfies the following relationship: In the formula:

[0068] — Creep life, h;

[0069] —Temperature, K;

[0070] —Stress, MPa;

[0071] —Constant 2.71828, dimensionless;

[0072] —First creep parameter, dimensionless;

[0073] —Second creep parameter, dimensionless;

[0074] —The third creep parameter, dimensionless.

[0075] For relational expressions Taking the natural logarithm of both sides, we get... The creep test conditions for the round bar specimen , and creep life data Input into Origin software and create a result based on... Using the z-axis, with Using the x-axis as the x-axis, A 3D scatter plot along the y-axis.

[0076] The first creep parameter is obtained by performing nonlinear surface fitting on the data in the three-dimensional scatter plot using the polynomial z=Ax+By+C. Second creep parameter and the third creep parameter The polynomial fitting curve of the cylindrical test specimen is as follows: Figure 4 As shown. In the polynomial z = Ax + By + C, C = .

[0077] The first creep parameter obtained by fitting Second creep parameter and the third creep parameter Substitute the relation In this way, a creep life model related to temperature and stress can be established, specifically as follows: .

[0078] By substituting the preset temperature and preset stress of the cylindrical bar specimen in the creep test into the creep life model, the predicted creep life value of the cylindrical bar specimen is calculated. Combined with the actual creep life value obtained from the creep test, an error dispersion band diagram between the actual creep life value and the predicted creep life value is generated using Origin software. Figure 5 As shown. By Figure 5 It can be seen that both the actual creep life and the predicted creep life are within the two-fold error dispersion band, which indicates that the creep life model has high accuracy.

[0079] In step three, the creep damage accumulation formula is: D = ∑ k = 1 n [ w k ( T , σ ) × Δ t k ] In the formula:

[0080] —Cumulative creep damage, dimensionless;

[0081] —Damage rate under the k-th cycle condition, dimensionless;

[0082] —Service time under the k-th cycle condition, in hours;

[0083] —The number of cycles for different cyclic operating conditions, k=1-n;

[0084] —Temperature, K;

[0085] —Stress, MPa.

[0086] make ,Will Substitute into the creep damage accumulation formula D = ∑ k = 1 n [ w k ( T , σ ) × Δ t k ] In this way, a creep damage cumulative life model related to temperature, stress, service time, and cycle number can be established, providing a basis for... In the formula:

[0087] —Cumulative creep damage, dimensionless;

[0088] — Creep life under the k-th cycle condition, h;

[0089] —Service time under the k-th cycle condition, in hours;

[0090] —The number of cycles for different cyclic operating conditions, k=1-n;

[0091] —Temperature, K;

[0092] —Stress, MPa.

[0093] In step four, the turbine blade profile simulation component is made of second-generation nickel-based single-crystal high-temperature alloy DD6, and its chemical composition is shown in Table 1; the structure of the turbine blade profile simulation component is as follows. Figure 3 As shown, the shape of its gauge length section 1 simulates the actual shape of a turbine blade.

[0094] In this embodiment, the turbine blade profile simulator replicates the actual shape of the turbine blade to a certain extent. Compared with traditional conventional test specimens, its test data is more accurate and closer to the actual service condition of the turbine blade. Furthermore, the turbine blade profile simulator undergoes creep testing after heat treatment. The heat treatment process is as follows: the turbine blade profile simulator is placed in a heat treatment furnace, heated to 1315℃, held for 6 hours, and then air-cooled; after air cooling, it is heated to 1130℃, held for 4 hours, and then air-cooled; after air cooling, it is heated to 870℃, held for 32 hours, and then air-cooled.

[0095] In step five, a creep damage cumulative life model related to temperature, stress, service time, and cycle number is used. When D≥1, that is, when the cumulative creep damage reaches 1, the cycle terminates and the number of cycles is obtained. Then, the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions is calculated by the number of cycles.

[0096] In this embodiment, the cumulative creep life of the turbine blade airfoil simulation component under different cyclic conditions is calculated using the creep damage cumulative life model. The specific conditions of these different cyclic conditions are the same as the specific conditions of the different cyclic conditions involved in the creep test of the turbine blade airfoil simulation component.

[0097] This embodiment simulates engine takeoff and emergency conditions, and the obtained creep curves are as follows: Figure 6 As shown, the temperature of takeoff state 2 is 970℃, the stress is 230MPa, and the service time is 100h. The temperature of emergency state 3 is 1010℃, the stress is 250MPa, and the service time is 90 seconds. The two states are alternately cycled until the sample breaks. The actual cumulative creep life obtained by this creep test is 270.7h.

[0098] Service conditions under takeoff state 2: temperature 970℃, stress 230MPa. The creep life calculated using the creep life model is 280.1h under this condition. Service conditions under emergency state 3: temperature 1010℃, stress 250MPa. The creep life calculated using the creep life model is 94.2h under this condition. The creep life values ​​and service times under both conditions are then substituted into the creep damage cumulative life model. The number of cycles obtained was 2.799, and the predicted cumulative creep life was calculated to be 279.9 hours. A comparison was made between the actual cumulative creep life obtained from the creep test and the predicted creep life calculated using the creep damage cumulative life model. The difference between the two was small, indicating that the creep damage cumulative life model has high accuracy.

[0099] The creep life assessment method for aero-engine turbine blades in this embodiment can calculate the cumulative creep damage of turbine blades under different operating conditions during continuous service, and use this to predict and assess the cumulative creep life of turbine blades. The creep damage cumulative life model in this embodiment has been effectively verified using turbine blade airfoil simulation components, exhibiting high accuracy. It provides technical support for assessing the service life of turbine blades, ensuring the stability and safety of turbine blades during service while avoiding economic losses due to overly conservative life calculations. Using the creep damage cumulative life model in this embodiment, the cumulative creep damage of turbine blades can be quantitatively monitored, which is beneficial for the health management of aero-engines, provides technical support for aero-engine maintenance and turbine blade replacement, and provides a theoretical basis for the research of nickel-based single-crystal superalloy turbine blades.

[0100] Special Note: The technical solution of this invention involves numerous parameters, and the synergistic effects between these parameters must be comprehensively considered to achieve the beneficial effects and significant progress of this invention. Furthermore, the value ranges of each parameter in the technical solution were obtained through extensive experimentation. For each parameter and the combinations thereof, the inventors have recorded a large amount of experimental data; however, due to space limitations, the specific experimental data is not disclosed here.

[0101] Those skilled in the art will readily understand that the method for evaluating the creep life of aero-engine turbine blades according to the present invention includes any combination of the inventive description and specific embodiments described in the above specification and the various parts shown in the accompanying drawings. Due to space limitations and for the sake of brevity, not all of these combinations have been described in detail. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the creep life of aero-engine turbine blades, comprising the following steps in sequence: Step 1: Conduct creep tests on the round bar specimen under different preset temperature and preset stress conditions to obtain the creep life data of the round bar specimen under the corresponding creep test conditions; Step 2: Based on the creep test conditions of the round bar specimen and the obtained creep life data, analyze and perform polynomial fitting to obtain the specific values ​​of the creep parameters, and then establish a creep life model related to temperature and stress. Step 3: Based on the creep life model and combined with the creep damage accumulation formula, establish a creep damage accumulation life model related to temperature, stress, service time and cycle number; Step 4: Conduct creep tests on the turbine blade airfoil simulation component continuously under different preset temperature, preset stress and preset service time conditions to obtain the cumulative creep life data of the turbine blade airfoil simulation component under different cyclic conditions. Step 5: Calculate the number of cycles when the cumulative creep damage of the turbine blade airfoil simulation part reaches 1 under different cyclic conditions using the creep damage cumulative life model. Calculate the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions by the number of cycles. Step 6: Compare the cumulative creep life obtained from the creep test of the turbine blade profile simulation with the cumulative creep life calculated using the creep damage cumulative life model to verify the accuracy of the creep damage cumulative life model.

2. The method for evaluating the creep life of aero-engine turbine blades according to claim 1, characterized in that: In step one, the cylindrical test specimen is made of second-generation nickel-based single-crystal high-temperature alloy DD6; at least four different creep test conditions are selected, and at least three sets of valid creep life data are obtained under each creep test condition.

3. The method for evaluating the creep life of aero-engine turbine blades according to claim 2, characterized in that: In step two, the creep life model satisfies the following relationship: , In the formula, — Creep life, h; —Temperature, K; —Stress, MPa; —Constant 2.71828, dimensionless; —First creep parameter, dimensionless; —Second creep parameter, dimensionless; —The third creep parameter, dimensionless.

4. The method for evaluating the creep life of aero-engine turbine blades according to claim 3, characterized in that: In step two, the relational expression Taking the natural logarithm of both sides, we get... The creep test conditions for the round bar specimen , and creep life data Input into Origin software and create a result based on... Using the z-axis, with Using the x-axis as the x-axis, The data in the 3D scatter plot along the y-axis is used to obtain the first creep parameter by performing nonlinear surface fitting on the data in the 3D scatter plot using the polynomial z=Ax+By+C. Second creep parameter and the third creep parameter ; The first creep parameter obtained by fitting Second creep parameter and the third creep parameter Substitute the relation In this way, a creep life model related to temperature and stress can be established.

5. The method for evaluating the creep life of aero-engine turbine blades according to claim 4, characterized in that: In step three, the creep damage accumulation formula is: , In the formula, —Cumulative creep damage, dimensionless; —Damage rate under the k-th cycle condition, dimensionless; —Service time under the k-th cycle condition, in hours; —The number of cycles for different cyclic operating conditions, k=1-n; —Temperature, K; —Stress, MPa.

6. The method for evaluating the creep life of aero-engine turbine blades according to claim 5, characterized in that: In step three, let ,Will Substitute into the creep damage accumulation formula In this way, a creep damage cumulative life model related to temperature, stress, service time, and cycle number can be established, providing a basis for... , In the formula, —Cumulative creep damage, dimensionless; — Creep life under the k-th cycle condition, h; —Service time under the k-th cycle condition, in hours; —The number of cycles for different cyclic operating conditions, k=1-n; —Temperature, K; —Stress, MPa.

7. The method for evaluating the creep life of aero-engine turbine blades according to claim 6, characterized in that: In step four, the turbine blade profile simulation component is made of second-generation nickel-based single-crystal high-temperature alloy DD6, and the shape of the gauge section of the turbine blade profile simulation component simulates the real shape of the turbine blade.

8. The method for evaluating the creep life of aero-engine turbine blades according to claim 7, characterized in that: In step five, a creep damage cumulative life model related to temperature, stress, service time, and cycle number is used. When D≥1, that is, when the cumulative creep damage reaches 1, the cycle terminates and the number of cycles is obtained. Then, the cumulative creep life of the turbine blade airfoil simulation part under different cyclic conditions is calculated by the number of cycles.

9. The method for evaluating the creep life of aero-engine turbine blades according to claim 8, characterized in that: The specific conditions for the different cyclic operating conditions in step five are the same as those for the different cyclic operating conditions in step four.

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