A method for predicting creep life of single crystal alloys considering the effect of overheating

Abstract

The present application relates to a method for predicting the creep life of a single crystal alloy taking into account the influence of overheating, obtaining material parameters of a sample at different overheating temperatures; observing the sample once after overheating by scanning electron microscopy; c 'Phase volume fraction and secondary c 'Phase volume fraction and radius; based on a c The volume fraction of the phase is used to calculate the matrix channel width, and the Orowan stress is calculated based on the matrix channel width and material parameters; c 'Interaction between phases and dislocations, secondary c The volume fraction and radius of the phase, shear mechanism, and Orowan mechanism are used to obtain the critical shear stress of different mechanisms. The total value of the critical shear stress obtained by weighted summation of the mean values ​​of each critical shear stress is converted into the precipitation strengthening value. The minimum creep rate is calculated based on the Orowan stress, precipitation strengthening value and the classical high-temperature alloy plastic constitutive equation, and then the creep life prediction model is constructed based on the Monkman-Grant relationship.

Description

Technical Field

[0001] The present application relates to the technical field of creep life prediction of nickel-based single crystal high-temperature alloys, and in particular to a single crystal alloy creep life prediction method taking into account the influence of overheating. Background Art

[0002] Aircraft engines are subjected to extreme high temperature and high pressure environments during their service. In some special cases, an engine may experience a single engine inoperative (OEI, One Engine Inoperative), that is, due to the failure of one engine, the remaining engines are required to provide short-term high power output to ensure flight safety. At this time, the operating temperature of key engine components rises sharply, resulting in overheating. This overheating process will cause changes in the microstructure and mechanical properties of the material, which will directly affect the structural strength of the hot end components of the engine.

[0003] At present, nickel-based single crystal superalloys have been widely used in key hot end components of aircraft engines, such as turbine blades, due to their excellent high-temperature mechanical properties and oxidation resistance. The effect of overheating on the microstructure of nickel-based superalloys can be summarized as follows: the initial strengthening phase partially merges and grows, dissolves locally, the collective channel width widens, and there are a large number of secondary c 'phase is generated, in which the width of the matrix channel allows dislocations to move more freely in subsequent creep tests after overheating, thereby accelerating creep failure. However, to date, there is still a lack of prediction methods for the creep life of nickel-based single crystal high-temperature alloys under overheating, and there is no suitable theory to parameterize the above-mentioned microstructural evolution effects to link the macroscopic mechanical properties of the alloy. Therefore, establishing a method that can predict the creep life of high-temperature alloys under OEI overheating conditions is of great significance for ensuring the safety of aircraft engines under extreme conditions. Summary of the invention

[0004] Based on this, it is necessary to provide a single crystal alloy creep life prediction method considering the influence of overheating, which includes:

[0005] S1: obtaining material parameters of a sample at different overheating temperatures, wherein the sample is a nickel-based single crystal high-temperature alloy; the material parameters of the sample at different overheating temperatures include: shear modulus, Burgers vector, antiphase domain boundary energy, and Poisson's ratio;

[0006] S2: Scanning electron microscopy was used to observe the sample after overheating. c 'Phase volume fraction and secondary c 'Volume fraction and radius of the phase;

[0007] S3: Once-based c'The volume fraction of the phase is used to calculate the matrix channel width, and the Orowan stress is calculated based on the matrix channel width and the material parameters;

[0008] The calculation formula of Orowan stress is:

[0009] ;

[0010] in, represents Orowan stress; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; W represents the width of the matrix channel;

[0011] S4: Based on the second c 'Interaction between phases and dislocations, secondary c 'The volume fraction and radius of the phase, shear mechanism, Orowan mechanism, the critical shear stress of different mechanisms are obtained, and the sum of the critical shear stresses obtained by weighted summation of the mean values ​​of each critical shear stress is converted into the precipitation strengthening value;

[0012] S5: Based on the Orowan stress, precipitation hardening value and the classic high-temperature alloy plastic constitutive equation, the minimum creep rate is calculated, and then based on the Monkman-Grant relationship, a creep life prediction model is constructed.

[0013] Preferably, the one-time c 'The volume fraction of the phase is used to calculate the matrix channel width including:

[0014] A three-dimensional unit cell model is used to describe c 'The geometric characteristics of the phase, and the geometric shape of the three-dimensional unit cell model is a cube, based on a c The volume fraction of the phase and the side length of the three-dimensional unit cell model are used to calculate the matrix channel width. The calculation formula is:

[0015] ;

[0016] in, W represents the width of the matrix channel; Represents the side length of the three-dimensional unit cell model; Indicates once c 'The volume fraction of the phase.

[0017] Preferably, the process of obtaining the sum of critical shear stresses comprises:

[0018] The secondary c The interaction between phases and dislocations is divided into:

[0019] When the second time c'When the radius of the phase is greater than or equal to the first critical radius value, based on the quadratic c 'Volume fraction and radius of the phase, Orowan mechanism, calculate the first critical shear stress of Orowan mechanism;

[0020] otherwise,

[0021] When the second time c When the radius of the phase is less than the second critical radius, based on the quadratic c 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the second critical shear stress of the weak coupling in the shear mechanism;

[0022] When the second time c 'When the radius of the phase is greater than or equal to the second critical radius value, based on the quadratic c 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the third critical shear stress of the weak coupling in the shear mechanism;

[0023] Calculating average values ​​of the first critical shear stress, the second critical shear stress, and the third critical shear stress, respectively, to obtain a first critical shear stress mean value, a second critical shear stress mean value, and a third critical shear stress mean value;

[0024] The first critical shear stress mean value, the second critical shear stress mean value, and the third critical shear stress mean value are weightedly summed to obtain the critical shear stress sum value.

[0025] Preferably, the calculation formula of the first critical shear stress is:

[0026] ;

[0027] ;

[0028] The calculation formula of the second critical shear stress is:

[0029] ;

[0030] ;

[0031] The calculation formula of the third critical shear stress is:

[0032] ;

[0033] in, represents the first critical shear stress; represents the second critical shear stress; represents the third critical shear stress; b represents the Burgers vector; represents Poisson's ratio; Represents two quadratic c 'The spacing between phase surfaces; R Represents secondary c 'The radius of the phase; f Represents secondary c 'Volume fraction of phase; represents the antiphase domain boundary energy; T represents the line tension of the dislocation; G It represents the shear modulus of the sample at different overheating temperatures.

[0034] Preferably, the calculation formula for the sum of critical shear stress is:

[0035] ;

[0036] ;

[0037] ;

[0038] ;

[0039] ;

[0040] ;

[0041] ;

[0042] in, represents the sum of critical shear stress; represents the mean value of the first critical shear stress; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress; represents the first occurrence probability; represents the second probability of occurrence; represents the third probability of occurrence; R Represents secondary c 'The radius of the phase; represents the second critical radius value; represents the first critical radius value; t Indicates that the radius is less than the second critical radius value of the quadratic c 'Number of phases; Indicates i The radius is less than the second critical radius of the quadratic c 'The second critical shear stress of the phase; q Indicates that the radius is greater than or equal to the second critical radius value and less than the first critical radius value. c 'Number of phases; Indicates jA quadratic with a radius greater than or equal to the second critical radius and less than the first critical radius c 'The third critical shear stress of the phase; e Indicates that the radius is greater than or equal to the first critical radius value. c 'Number of phases; Indicates k A quadratic with a radius greater than or equal to the first critical radius c 'The first critical shear stress of the phase.

[0043] Preferably, the second critical shear stress mean and the third critical shear stress mean are weightedly combined to obtain the shear critical shear stress mean, and the calculation formula is:

[0044] ;

[0045] ;

[0046] in, represents the mean value of critical shear stress; represents the first weight; represents the second weight; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress;

[0047] Based on the average value of the second critical shear stress, the average value of the shear critical shear stress and the sum of the critical shear stresses, the precipitation strengthening value is calculated. The calculation formula of the precipitation strengthening value is:

[0048] ;

[0049] in, Indicates precipitation strengthening value; Represents the total value of critical shear stress.

[0050] Preferably, the calculation formula for the minimum creep rate is:

[0051] ;

[0052] ;

[0053] in, represents the minimum creep rate; D represents the lattice diffusion coefficient; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; prepresents the grain size index; n represents the stress index; Indicates the application of stress; Indicates internal stress; Z is the ratio of stress threshold to Orowan stress; represents Orowan stress; Indicates precipitation strengthening value; A is a constant.

[0054] Preferably, the Monkman-Grant relationship is expressed as:

[0055] ;

[0056] The creep life prediction model is obtained by transforming the Monkman-Grant relationship, and the expression is:

[0057] ;

[0058] ;

[0059] in, represents the creep life prediction model; represents the minimum creep rate; represents the Monkman-Grant constant; Represents a constant algebraic expression; n represents the stress index; Indicates the application of stress; G It represents the shear modulus of the sample at different overheating temperatures; Z is the ratio of stress threshold to Orowan stress; b represents the Burgers vector; W represents the width of the matrix channel; Indicates precipitation strengthening value; A represents the creep coefficient; D represents the lattice diffusion coefficient; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; p Represents the grain size index.

[0060] Beneficial effects: This method correctly captures the key microstructural characteristics and physical properties of nickel-based single crystal high-temperature alloys, and constructs a creep life prediction model for nickel-based single crystal high-temperature alloys that takes into account the influence of overheating based on classical theories such as Orowan mechanism, shear mechanism, classical probability-dependent precipitation strengthening theory, classical high-temperature alloy plasticity constitutive equation, and Monkman-Grant relationship. This model can quickly predict the creep life of nickel-based single crystal high-temperature alloys after overheating, providing theoretical guidance for the design and composition optimization of single crystal high-temperature alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0062] Figure 1 This is a flow chart of a single crystal alloy creep life prediction method taking into account the effect of overheating in an embodiment of the present application.

[0063] Figure 2 Schematic diagram of OEI processing in an embodiment of the present application.

[0064] Figure 3 Schematic diagram of distinguishing the first critical shear stress, the second critical shear stress and the third critical shear stress in the embodiment of the present application.

[0065] Figure 4 This is a schematic diagram of the creep life prediction results in the embodiments of the present application. DETAILED DESCRIPTION

[0066] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0068] like Figure 1 As shown, this embodiment provides a single crystal alloy creep life prediction method considering the influence of overheating, the method comprising:

[0069] S1: Obtain material parameters of a sample at different overheating temperatures, wherein the sample is a nickel-based single crystal high temperature alloy. In this embodiment, the material parameters of the sample at different overheating temperatures include: shear modulus, Burgers vector, antiphase domain boundary energy, and Poisson's ratio.

[0070] S2: Scanning electron microscopy was used to observe the sample after overheating. c 'Phase volume fraction and secondary c In this embodiment, the sample is electrolytically polished using 150 ml H3PO4 + 15 g CrO3 + 10 ml H2SO4 + 10 ml H2O before observation.

[0071] S3: Once-based c The volume fraction of the 'phase is used to calculate the matrix channel width, and the Orowan stress is calculated based on the matrix channel width and the material parameters.

[0072] Specifically, the c 'The volume fraction of the phase is used to calculate the matrix channel width including:

[0073] A three-dimensional unit cell model is used to describe c 'The geometric characteristics of the phase, and the geometric shape of the three-dimensional unit cell model is a cube, based on a c The volume fraction of the phase and the side length of the three-dimensional unit cell model are used to calculate the matrix channel width. The calculation formula is:

[0074] ;

[0075] in, W represents the width of the matrix channel; Represents the side length of the three-dimensional unit cell model; Indicates once c 'The volume fraction of the phase.

[0076] Furthermore, the calculation formula of Orowan stress is:

[0077] ;

[0078] in, represents Orowan stress; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; W Indicates the width of the matrix channel.

[0079] S4: Based on the second c 'Interaction between phases and dislocations, secondary c The volume fraction and radius of the phase, shear mechanism, and Orowan mechanism are used to obtain the critical shear stress of different mechanisms. The total value of the critical shear stress obtained by weighted summation of the mean values ​​of each critical shear stress is converted into the precipitation strengthening value.

[0080] Specifically, the process of obtaining the sum of critical shear stresses includes:

[0081] like Figure 3 As shown, the secondary c The interaction between phases and dislocations is divided into:

[0082] When the second time c 'When the radius of the phase is greater than or equal to the first critical radius value, based on the quadratic c 'Volume fraction and radius of the phase, Orowan mechanism, calculate the first critical shear stress of Orowan mechanism;

[0083] The calculation formula of the first critical shear stress is:

[0084] ;

[0085] ;

[0086] otherwise,

[0087] When the second time c When the radius of the phase is less than the second critical radius, based on the quadratic c 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the second critical shear stress of the weak coupling in the shear mechanism;

[0088] The calculation formula for the second critical radius is:

[0089] ;

[0090] The calculation formula of the second critical shear stress is:

[0091] ;

[0092] ;

[0093] When the second time c 'When the radius of the phase is greater than or equal to the second critical radius value, based on the quadratic c 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the third critical shear stress of the weak coupling in the shear mechanism;

[0094] The calculation formula of the third critical shear stress is:

[0095] ;

[0096] In the above three calculation formulas for critical shear stress, represents the first critical shear stress; represents the second critical shear stress; represents the third critical shear stress; b represents the Burgers vector; represents Poisson's ratio; Represents two quadratic c 'The spacing between phase surfaces; R Represents secondary c 'The radius of the phase; f Represents secondary c 'Volume fraction of phase; Indicates the second critical radius value; represents the antiphase domain boundary energy; T represents the line tension of the dislocation; G It represents the shear modulus of the sample at different overheating temperatures.

[0097] Calculating average values ​​of the first critical shear stress, the second critical shear stress, and the third critical shear stress, respectively, to obtain a first critical shear stress mean value, a second critical shear stress mean value, and a third critical shear stress mean value;

[0098] Performing weighted summation on the first critical shear stress mean, the second critical shear stress mean, and the third critical shear stress mean to obtain the critical shear stress sum value;

[0099] The calculation formula for the sum of critical shear stress is:

[0100] ;

[0101] ;

[0102] ;

[0103] ;

[0104] ;

[0105] ;

[0106] ;

[0107] in, represents the sum of critical shear stress; represents the mean value of the first critical shear stress; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress; represents the first occurrence probability; represents the second probability of occurrence; represents the third probability of occurrence; R Represents secondary c 'The radius of the phase; Indicates the second critical radius value; represents the first critical radius value; t Indicates that the radius is less than the second critical radius value of the quadratic c 'Number of phases; Indicates i The radius is less than the second critical radius of the quadratic c 'The second critical shear stress of the phase; q Indicates that the radius is greater than or equal to the second critical radius value and less than the first critical radius value. c 'Number of phases; Indicates j A quadratic with a radius greater than or equal to the second critical radius and less than the first critical radius c 'The third critical shear stress of the phase; e Indicates that the radius is greater than or equal to the first critical radius value. c 'Number of phases; Indicates k A quadratic with a radius greater than or equal to the first critical radius c 'The first critical shear stress of the phase.

[0108] Furthermore, the second critical shear stress mean and the third critical shear stress mean are weighted combined to obtain the shear critical shear stress mean, which is calculated as follows:

[0109] ;

[0110] ;

[0111] in, represents the mean value of critical shear stress; represents the first weight; represents the second weight; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress;

[0112] Based on the average value of the second critical shear stress, the average value of the shear critical shear stress and the sum of the critical shear stresses, the precipitation strengthening value is calculated. The calculation formula of the precipitation strengthening value is:

[0113] ;

[0114] in, Indicates precipitation strengthening value; Represents the total value of critical shear stress.

[0115] S5: Based on the Orowan stress, precipitation hardening value and the classic high-temperature alloy plastic constitutive equation, the minimum creep rate is calculated, and then based on the Monkman-Grant relationship, a creep life prediction model is constructed.

[0116] Specifically, the calculation formula for the minimum creep rate is:

[0117] ;

[0118] ;

[0119] in, represents the minimum creep rate; D represents the lattice diffusion coefficient; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; p represents the grain size index; n represents the stress index; Indicates the application of stress; Indicates internal stress; Z is the ratio of stress threshold to Orowan stress; represents Orowan stress; Indicates precipitation strengthening value; A is a constant with dimension 1.

[0120] Furthermore, the Monkman-Grant relationship is expressed as:

[0121] ;

[0122] The creep life prediction model is obtained by transforming the Monkman-Grant relationship, and the expression is:

[0123] ;

[0124] ;

[0125] in, represents the creep life prediction model; represents the minimum creep rate; represents the Monkman-Grant constant; Represents a constant algebraic expression; n represents the stress index; Indicates the application of stress; G It represents the shear modulus of the sample at different overheating temperatures; Z is the ratio of stress threshold to Orowan stress; b represents the Burgers vector; W represents the width of the matrix channel; Indicates precipitation strengthening value; A represents the creep coefficient; D represents the lattice diffusion coefficient; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; p Represents the grain size index.

[0126] In this embodiment, the prediction process includes:

[0127] Obtain the material parameters of nickel-based single crystal high-temperature alloy at the overheat temperature to be measured, once c 'Phase volume fraction and secondary c 'Volume fraction and radius of the phase;

[0128] Based on the superheat temperature to be measured c 'The volume fraction of the phase, and the matrix channel width at the superheat temperature to be measured is calculated by the matrix channel width calculation formula;

[0129] Based on the secondary c 'The volume fraction and radius of the phase, and calculate the precipitation strengthening value at the superheated temperature to be tested through the precipitation strengthening value calculation formula;

[0130] Finally, the material parameters, matrix channel width and precipitation strengthening value at the overheat temperature to be tested are substituted into the creep life prediction model, combined with other parameters set / calculated in the model (such as creep coefficient A , stress index n etc.), and predict the creep life of nickel-based single crystal high-temperature alloy at the overheat temperature to be tested.

[0131] In this embodiment, a nickel-based single crystal high temperature alloy DD6 is used for creep life prediction test. The chemical composition of the DD6 alloy is shown in Table 1, and the material parameters are shown in Table 2;

[0132] Table 1 is the chemical composition table of DD6 alloy;

[0133] ;

[0134] The DD6 alloy was Figure 2The OEI treatment shown in the figure includes: under normal working conditions, the load on the failed section of a certain type of aircraft engine turbine blade is 1000℃ and 230MPa respectively; in the OEI stage, the temperature rises rapidly from the base temperature 1000℃ to T at a rate of 60℃ / s. OEI The temperature was 1100℃, 1150℃, 1160℃ for 30s, and then cooled to room temperature. s OEI level to evaluate the influence of mechanical load during the overheating process.

[0135] Table 2 is the material parameter table of DD6 alloy;

[0136] ;

[0137] The creep life of DD6 alloy after different overheat treatment conditions is shown in Table 3;

[0138] Table 3 is the results of the short-time overheating test of DD6 alloy;

[0139] ;

[0140] As shown in Table 3, all overheating treatments reduce the creep life of DD6 alloy. Compared with the sample that has not undergone heat treatment, the creep life under the 1160℃ / 230MPa test condition is shortened by 34.07%. In addition, the creep life test results obtained from overheating treatments at different times under 1150℃ / 230MPa conditions show that when the overheating treatment duration is 30s, the reduction degree of the creep life of DD6 alloy at different action times is close to the average value of the reduction at each time; and the average creep life reduction obtained from the 7 different action time treatments is 8.2%.

[0141] Based on the material parameters of DD6 alloy shown in Table 2, the precipitation strengthening value calculation formula is used to calculate the secondary c 'The precipitation strengthening value produced by the phase, the calculation results are shown in Table 4;

[0142] Table 4 shows the secondary c 'Precipitation strengthening value table of phases;

[0143] ;

[0144] The data shown in Table 2 and Table 4, as well as the parameters C t = 5.82 × 10 −14 , Z = 0.91737, n= 7.0354, the creep coefficient is 0.9, and the creep life prediction model is substituted. The creep life prediction results are as follows: Figure 4 As shown by Figure 4 The analysis shows that under all overheat treatment conditions, the predicted creep life is consistent with the experimental life, and the error is within 1.2 times, which shows that the proposed physics-based creep life prediction model correctly captures the microstructural damage value caused by overheat treatment.

[0145] The single crystal alloy creep life prediction method considering the effect of overheating provided in this embodiment correctly captures the key microstructural characteristics and physical properties of the nickel-based single crystal high-temperature alloy, and based on classical theories such as the Orowan mechanism, shear mechanism, classical probability-dependent precipitation strengthening theory, classical high-temperature alloy plasticity constitutive equation and Monkman-Grant relationship, a creep life prediction model of the nickel-based single crystal high-temperature alloy considering the effect of overheating is constructed. Through this model, the creep life of the nickel-based single crystal high-temperature alloy after overheating can be quickly predicted, which provides theoretical guidance for the design and composition optimization of single crystal high-temperature alloys.

[0146] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for predicting the creep life of a single crystal alloy taking into account the influence of overheating, characterized in that: include: S1: Obtaining material parameters of a sample at different overheating temperatures, wherein the sample is a nickel-based single crystal high-temperature alloy; The material parameters of the samples at different overheating temperatures include: shear modulus, Burgers vector, antiphase domain boundary energy, and Poisson's ratio; S2: Scanning electron microscopy was used to observe the sample after overheating. γ 'Phase volume fraction and secondary γ 'Volume fraction and radius of the phase; S3: Once-based γ 'The volume fraction of the phase is used to calculate the matrix channel width, and the Orowan stress is calculated based on the matrix channel width and the material parameters; The calculation formula of Orowan stress is: ； in, represents Orowan stress; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; W represents the width of the matrix channel; S4: Based on the second γ 'Interaction between phases and dislocations, secondary γ 'The volume fraction and radius of the phase, shear mechanism, Orowan mechanism, the critical shear stress of different mechanisms are obtained, and the sum of the critical shear stresses obtained by weighted summation of the mean values ​​of each critical shear stress is converted into the precipitation strengthening value; S5: Based on the Orowan stress, precipitation hardening value and the classic high-temperature alloy plastic constitutive equation, the minimum creep rate is calculated, and then based on the Monkman-Grant relationship, a creep life prediction model is constructed.

2. The single crystal alloy creep life prediction method considering overheating effect according to claim 1 is characterized in that: Based on a γ 'The volume fraction of the phase is used to calculate the matrix channel width including: A three-dimensional unit cell model is used to describe γ 'The geometric characteristics of the phase, and the geometric shape of the three-dimensional unit cell model is a cube, based on a γ The volume fraction of the phase and the side length of the three-dimensional unit cell model are used to calculate the matrix channel width. The calculation formula is: ； in, W represents the width of the matrix channel; Represents the side length of the three-dimensional unit cell model; Indicates once γ 'The volume fraction of the phase.

3. The single crystal alloy creep life prediction method considering overheating effect according to claim 1, characterized in that: The process of obtaining the sum of critical shear stresses includes: The secondary γ The interaction between phases and dislocations is divided into: When the second time γ 'When the radius of the phase is greater than or equal to the first critical radius value, based on the quadratic γ 'Volume fraction and radius of the phase, Orowan mechanism, calculate the first critical shear stress of Orowan mechanism; otherwise, When the second time γ When the radius of the phase is less than the second critical radius, based on the quadratic γ 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the second critical shear stress of the weak coupling in the shear mechanism; When the second time γ 'When the radius of the phase is greater than or equal to the second critical radius value, based on the quadratic γ 'The volume fraction and radius of the phase, the shear mechanism, and the calculation of the third critical shear stress of the weak coupling in the shear mechanism; Calculating average values ​​of the first critical shear stress, the second critical shear stress, and the third critical shear stress, respectively, to obtain a first critical shear stress mean value, a second critical shear stress mean value, and a third critical shear stress mean value; The first critical shear stress mean value, the second critical shear stress mean value, and the third critical shear stress mean value are weightedly summed to obtain the critical shear stress sum value.

4. The single crystal alloy creep life prediction method considering overheating effect according to claim 3 is characterized in that: The calculation formula of the first critical shear stress is: ； ； The calculation formula of the second critical shear stress is: ； ； The calculation formula of the third critical shear stress is: ； in, represents the first critical shear stress; represents the second critical shear stress; represents the third critical shear stress; b represents the Burgers vector; represents Poisson's ratio; Represents two quadratic γ 'The spacing between phase surfaces; R Represents secondary γ 'The radius of the phase; f Represents secondary γ 'Volume fraction of phase; represents the antiphase domain boundary energy; T represents the line tension of the dislocation; G It represents the shear modulus of the sample at different overheating temperatures.

5. The single crystal alloy creep life prediction method considering overheating effect according to claim 4, characterized in that: The calculation formula for the sum of critical shear stress is: ； ； ； ； ； ； ； in, represents the sum of critical shear stress; represents the mean value of the first critical shear stress; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress; represents the first occurrence probability; represents the second probability of occurrence; represents the third probability of occurrence; R Represents secondary γ 'The radius of the phase; Indicates the second critical radius value; represents the first critical radius value; t Indicates that the radius is less than the second critical radius value of the quadratic γ 'Number of phases; Indicates i The radius is less than the second critical radius of the quadratic γ 'The second critical shear stress of the phase; q Indicates that the radius is greater than or equal to the second critical radius value and less than the first critical radius value. γ 'Number of phases; Indicates j A quadratic with a radius greater than or equal to the second critical radius and less than the first critical radius γ 'The third critical shear stress of the phase; e Indicates that the radius is greater than or equal to the first critical radius value. γ 'Number of phases; Indicates k A quadratic with a radius greater than or equal to the first critical radius γ 'The first critical shear stress of the phase.

6. The single crystal alloy creep life prediction method considering overheating effect according to claim 5, characterized in that: The mean value of the shear critical shear stress is obtained by weighted combination of the mean value of the second critical shear stress and the mean value of the third critical shear stress. The calculation formula is: ； ； in, represents the mean value of critical shear stress; represents the first weight; represents the second weight; represents the mean value of the second critical shear stress; represents the mean value of the third critical shear stress; Based on the average value of the second critical shear stress, the average value of the shear critical shear stress and the sum of the critical shear stresses, the precipitation strengthening value is calculated. The calculation formula of the precipitation strengthening value is: ； in, Indicates precipitation strengthening value; Represents the total value of critical shear stress.

7. The single crystal alloy creep life prediction method considering overheating effect according to claim 6, characterized in that: The calculation formula for the minimum creep rate is: ； ； in, represents the minimum creep rate; D represents the lattice diffusion coefficient; G It represents the shear modulus of the sample at different overheating temperatures; b represents the Burgers vector; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; p represents the grain size index; n represents the stress index; Indicates the application of stress; Indicates internal stress; Z is the ratio of stress threshold to Orowan stress; represents Orowan stress; Indicates precipitation strengthening value; A is a constant.

8. The single crystal alloy creep life prediction method considering overheating effect according to claim 7, characterized in that: The Monkman-Grant relationship is expressed as: ； The creep life prediction model is obtained by transforming the Monkman-Grant relationship, and the expression is: ； ； in, represents the creep life prediction model; represents the minimum creep rate; represents the Monkman-Grant constant; Represents a constant algebraic expression; n represents the stress index; Indicates the application of stress; G It represents the shear modulus of the sample at different overheating temperatures; Z is the ratio of stress threshold to Orowan stress; b represents the Burgers vector; W represents the width of the matrix channel; Indicates precipitation strengthening value; A represents the creep coefficient; D represents the lattice diffusion coefficient; represents the Boltzmann constant; T represents the line tension of the dislocation; d Indicates grain size; p Represents the grain size index.

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