Determination of environmental damage coefficient and fatigue life design method in high temperature lead bismuth environment

Abstract

This invention relates to a method for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth environments. The method includes: conducting fatigue tests on components in room temperature air environments and different lead-bismuth environments to obtain fatigue test data under different environments; establishing a room temperature air environment life prediction model based on the fatigue test data; determining the lead-bismuth environmental damage coefficient based on the fatigue test data under different lead-bismuth environments; inputting the lead-bismuth environmental damage coefficient into the air environment life prediction model to establish a life prediction model considering the influence of the lead-bismuth environment; determining a fatigue curve considering the influence of the lead-bismuth environment based on the life prediction model considering the influence of the lead-bismuth environment; the fatigue curve considering the influence of the lead-bismuth environment is used to assess the environmental damage of the component under lead-bismuth environments. This invention enables accurate assessment of the environmental damage of components under lead-bismuth environments.

Description

Technical Field

[0001] This invention relates to the field of fatigue design, and in particular to a method for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth conditions. Background Technology

[0002] Nuclear energy is widely considered a clean, safe, and efficient energy source with the potential to replace oil and gas, and it occupies an important position in the current global energy structure. Due to the low resource utilization, radioactive waste accumulation, and nuclear safety issues of existing third-generation nuclear reactors, fourth-generation reactors, following the "thermal reactor-fast reactor-fusion reactor" technology route, will become the main trend in future nuclear energy development. Among fourth-generation nuclear reactors, the lead-bismuth fast-cooled reactor has received widespread attention both domestically and internationally due to its excellent safety and neutron economy.

[0003] However, due to the wettability and corrosiveness of lead and bismuth, as well as the inherent structural composition of the metal, prolonged contact with a lead-bismuth environment can lead to material degradation phenomena such as liquid metal corrosion and liquid metal embrittlement, which severely restricts the development of lead-bismuth reactors. Existing high-temperature fatigue design curves are obtained from fatigue tests in high-temperature air environments, failing to consider the impact of complex environments such as lead and bismuth on the fatigue life of components. Therefore, establishing a fatigue design method for components in lead-bismuth environments is urgently needed. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment, so as to achieve accurate assessment of the environmental damage of components in a lead-bismuth environment.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] Methods for determining environmental damage coefficients and designing fatigue life in high-temperature lead-bismuth environments include:

[0007] Fatigue tests were conducted on the components in room temperature air environment and in different lead-bismuth environments to obtain fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments.

[0008] A life prediction model for room temperature air environment was established based on the fatigue test data under the aforementioned room temperature air environment.

[0009] Based on fatigue test data under different lead-bismuth environments, the lead-bismuth environmental damage coefficient is determined; the lead-bismuth environmental damage coefficient includes the lead-bismuth environmental damage coefficient at different temperatures and the lead-bismuth environmental damage coefficient at different strain rates under a given temperature.

[0010] The lead-bismuth environmental damage coefficient is incorporated into the air environment lifetime prediction model to establish a lifetime prediction model that considers the environmental impact of lead-bismuth.

[0011] The fatigue curve considering the environmental impact of lead and bismuth is determined based on the life prediction model that takes into account the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to assess the environmental damage of the component in a lead and bismuth environment.

[0012] Optionally, the strain amplitude range of the fatigue test in the room temperature air environment is 0.2% to 2%;

[0013] The fatigue tests conducted under different lead-bismuth environments included high-oxygen and low-oxygen ranges, with test temperatures ranging from 150℃ to 450℃ and test strain rates ranging from 5×10⁻⁶. -6 / s to 5×10 -3 / s.

[0014] Optionally, the functional relationship between strain and lifespan in the room temperature air environment lifespan prediction model is as follows:

[0015]

[0016] Where, ε t The total strain range is represented by 'a', where 'a' is the equation coefficient; N is the total strain range. f denoted as fatigue life; b is the first material constant; c is the second material constant.

[0017] Optionally, determining the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments specifically includes:

[0018] Set the temperature extrapolation factor and the strain rate extrapolation factor;

[0019] 350℃ was used as the calibration temperature for the lead-bismuth environment. The fatigue life under room temperature air environment, the fatigue life under the calibration temperature for the lead-bismuth environment, the fatigue life under different temperatures for the lead-bismuth environment, and the damage coefficient of the lead-bismuth environment under the calibration temperature were obtained.

[0020] The first ratio of the fatigue life under the same strain amplitude in the room temperature air environment to the fatigue life under different oxygen concentrations in the lead-bismuth environment is determined based on the fatigue life under the room temperature air environment and the fatigue life under the lead-bismuth environment at the calibration temperature.

[0021] The first ratio is used to calculate the high oxygen concentration and low oxygen concentration respectively, and the power-law relationship between the first ratio and the strain amplitude is determined.

[0022] A second ratio of the fatigue life of lead-bismuth environments at different temperatures under the same strain amplitude is determined based on the fatigue life of lead-bismuth environments at the calibration temperature and the fatigue life of lead-bismuth environments at different temperatures.

[0023] The environmental damage coefficient of lead and bismuth at the specified temperature is calculated and determined based on the environmental damage coefficient of lead and bismuth at the specified temperature and the second ratio.

[0024] The environmental damage coefficients of lead and bismuth at different temperatures are determined based on the environmental damage coefficients of lead and bismuth at the specified temperature and the power-law relationship.

[0025] Optionally, determining the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments specifically includes:

[0026] The fatigue life of lead-bismuth in a calibrated strain rate, the damage coefficient of lead-bismuth in a calibrated strain rate, and the fatigue life of lead-bismuth in a calibrated strain rate at different strain rates were obtained.

[0027] Determine the third ratio of the fatigue life of lead-bismuth in the calibrated strain rate to the fatigue life of lead-bismuth in the different strain rates.

[0028] The lead-bismuth environmental damage coefficient at the strain rate is calculated and determined based on the third ratio and the lead-bismuth environmental damage coefficient at the calibrated strain rate.

[0029] The environmental damage coefficients of lead and bismuth at different strain rates at a given temperature are calculated based on the environmental damage coefficients of lead and bismuth at the given strain rate.

[0030] Optionally, the lifetime prediction model considering the environmental impact of lead and bismuth is as follows:

[0031]

[0032] in, The environmental fatigue life of lead-bismuth under any given condition; Fatigue life at room temperature air; F LBE The environmental damage coefficient for lead and bismuth.

[0033] A system for determining environmental damage coefficients and designing fatigue life in high-temperature lead-bismuth environments includes:

[0034] The fatigue test data acquisition module is used to conduct fatigue tests on components in room temperature air environment and different lead-bismuth environments, and to acquire fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments.

[0035] The module for establishing a life prediction model for room temperature air environment is used to establish a life prediction model for room temperature air environment based on fatigue test data under the room temperature air environment.

[0036] The lead-bismuth environmental damage coefficient determination module is used to determine the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments; the lead-bismuth environmental damage coefficient includes the lead-bismuth environmental damage coefficient at different temperatures and the lead-bismuth environmental damage coefficient at different strain rates at a given temperature.

[0037] The lifetime prediction model establishment module considering the environmental impact of lead and bismuth is used to input the lead and bismuth environmental damage coefficient into the air environment lifetime prediction model to establish a lifetime prediction model considering the environmental impact of lead and bismuth.

[0038] The fatigue curve determination module is used to determine the fatigue curve considering the environmental impact of lead and bismuth based on the life prediction model considering the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to assess the environmental damage of the component in a lead and bismuth environment.

[0039] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention provides a method for determining the environmental damage coefficient and fatigue life design in a high-temperature lead-bismuth environment. By combining the lead-bismuth environmental damage coefficient and the room temperature air environment life prediction model, a life prediction model considering the influence of the lead-bismuth environment is constructed, and a fatigue curve considering the influence of the lead-bismuth environment is obtained to achieve accurate assessment of the environmental damage of components in a lead-bismuth environment. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 Flowchart of the fatigue life prediction method for components in a lead-bismuth environment provided by the present invention.

[0042] Figure 2 A schematic diagram of the fitted room temperature air environment lifetime prediction model provided by the present invention;

[0043] Figure 3 The oxygen concentration lead-bismuth environmental damage coefficient F provided by this invention LBE (O * ) Schematic diagram;

[0044] Figure 4 The extrapolation factor F for lead-bismuth environments at different temperatures provided by this invention LBE (T * ) Schematic diagram;

[0045] Figure 5 A schematic diagram of strain rate extrapolation factor for lead-bismuth environment under low oxygen conditions provided by the present invention.

[0046] Figure 6 A schematic diagram of strain rate extrapolation factor for lead-bismuth environment under high oxygen environment provided by the present invention.

[0047] Figure 7This is a schematic diagram of the predicted lifetime results provided by the present invention;

[0048] Figure 8 High-temperature fatigue design curves for lead-bismuth environments provided in embodiments of the present invention;

[0049] Figure 9 This is a schematic diagram of the fatigue design curve of T91 steel under low oxygen lead-bismuth (LOC-LBE) environment at 350℃, provided by the present invention.

[0050] Figure 10 This is a schematic diagram of the fatigue design curve of T91 steel under high oxygen lead-bismuth (HOC-LBE) environment at 350℃, provided by the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The purpose of this invention is to provide a method for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth environment, which can achieve accurate assessment of the environmental damage of components under lead-bismuth environment.

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] Example 1

[0055] Figure 1 The flowchart of the fatigue life prediction method for components in a lead-bismuth environment provided by the present invention is as follows: Figure 1 As shown, the method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment includes:

[0056] Step 101: Conduct fatigue tests on the components in room temperature air environment and different lead-bismuth environments to obtain fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments.

[0057] In practical applications, the strain amplitude range of the fatigue test in the room temperature air environment is 0.2% to 2%;

[0058] The fatigue tests conducted under different lead-bismuth environments included high-oxygen and low-oxygen ranges, with test temperatures ranging from 150℃ to 450℃ and test strain rates ranging from 5×10⁻⁶. -6 / s to 5×10 -3 / s.

[0059] Step 102: Establish a life prediction model for room temperature air environment based on the fatigue test data under the room temperature air environment.

[0060] In practical applications, Figure 2 This is a schematic diagram of the fitted room temperature air environment lifetime prediction model provided by the present invention, as shown below. Figure 2 As shown, the functional relationship between strain and lifespan in the room temperature air environment lifespan prediction model is as follows:

[0061]

[0062] Where, ε t The total strain range is represented by 'a', where 'a' is the equation coefficient; N is the total strain range. f denoted as fatigue life; b is the first material constant; c is the second material constant.

[0063] Step 103: Determine the lead-bismuth environmental damage coefficient based on the fatigue test data under different lead-bismuth environments; the lead-bismuth environmental damage coefficient includes the lead-bismuth environmental damage coefficient at different temperatures and the lead-bismuth environmental damage coefficient at different strain rates under different temperatures.

[0064] In practical applications, the environmental damage coefficient F of lead-bismuth LBE The function expression is represented as:

[0065]

[0066] Where, N AIR For the fatigue life of the test component in a room temperature air environment, N LBE The fatigue life of the sample component under the strain amplitude corresponding to the fatigue life in the air environment is the fatigue life of the lead-bismuth environment.

[0067] Environmental damage coefficient F of lead-bismuth under different temperatures and strain rates LBE The solution can be obtained through extrapolation, by setting F. LBE (T * ) is the temperature extrapolation factor, F LBE (R * ) is the strain rate extrapolation factor.

[0068] Environmental damage coefficients of lead and bismuth at different temperatures:

[0069] Step 103 specifically includes: setting a temperature extrapolation factor and a strain rate extrapolation factor; using 350℃ as the calibration temperature of the lead-bismuth environment, obtaining the fatigue life under room temperature air conditions, the fatigue life of the lead-bismuth environment at the calibration temperature, the fatigue life of the lead-bismuth environment at different temperatures, and the damage coefficient of the lead-bismuth environment at the calibration temperature; determining a first ratio (the first ratio being the environmental damage coefficient) between the fatigue life under room temperature air conditions and the fatigue life of the lead-bismuth environment at the calibration temperature under the same strain amplitude and the fatigue life of the lead-bismuth environment at different oxygen concentrations; using the first ratio... The values ​​are calculated for high oxygen concentration and low oxygen concentration respectively to determine the power-law relationship between the first ratio and the strain amplitude; a second ratio (the second ratio is a temperature extrapolation factor) is determined based on the fatigue life of the lead-bismuth environment at the calibration temperature and the fatigue life of the lead-bismuth environment at different temperatures under the same strain amplitude; the damage coefficient of the lead-bismuth environment at the determined temperature is calculated based on the damage coefficient of the lead-bismuth environment at the calibration temperature and the second ratio; the damage coefficient of the lead-bismuth environment at different temperatures is determined based on the damage coefficient of the lead-bismuth environment at the determined temperature and the power-law relationship.

[0070] Figure 3 The oxygen concentration lead-bismuth environmental damage coefficient F provided by this invention LBE (O * ) Schematic diagram, such as Figure 3 As shown, the environmental damage coefficient F of lead-bismuth at oxygen concentration LBE (O * The first ratio of the fatigue life in an air environment under the same strain amplitude to the fatigue life in a lead-bismuth environment under different oxygen concentrations is expressed as follows:

[0071]

[0072] The temperature calibration was performed in a lead-bismuth environment at 350℃. The fatigue life under room temperature air conditions. The fatigue life of lead-bismuth environment at 350℃.

[0073] F LBE (O * The high oxygen concentration and low oxygen concentration need to be calculated separately. LBE (O * There is a time-related effect, F LBE (O * The strain amplitude gradually decreases as the strain amplitude increases, requiring power-law fitting to obtain F. LBE (O * The expression for the power-law relationship between the strain amplitude and the strain amplitude is as follows:

[0074]

[0075] Where A and B are material fitting parameters, ε t This represents the total strain range.

[0076] Figure 4 The extrapolation factor F for lead-bismuth environments at different temperatures provided by this invention LBE (T * ) Schematic diagram, such as Figure 4 As shown, the extrapolation factor F of the lead-bismuth environment at different temperatures LBE (T * The second ratio of fatigue life in lead-bismuth environments at different temperatures under the same strain amplitude is defined as follows: (The calibration temperature is 350℃).

[0077]

[0078] in, The fatigue life in a lead-bismuth environment at 350℃. For lead-bismuth environmental fatigue data at other temperatures.

[0079] At different temperatures Through F LBE (T * Extrapolation is performed, and the extrapolation formula is as follows:

[0080]

[0081] in, To determine the environmental damage coefficient at temperature, The environmental damage coefficient, as specified in Equation 6, can be extrapolated to different temperatures. The value was fitted using Equation 4 to obtain the environmental damage coefficient at different temperatures. expression.

[0082] First, determine the environmental damage coefficient at different temperatures, and then calculate the environmental damage coefficient at different strain rates at the determined temperature.

[0083] For the environmental damage coefficient of lead-bismuth at different strain rates at a given temperature:

[0084] In practical applications, step 103 specifically includes: obtaining the lead-bismuth environmental fatigue life at a calibrated strain rate, the lead-bismuth environmental damage coefficient at a calibrated strain rate, and the lead-bismuth environmental fatigue life at different strain rates; determining a third ratio between the lead-bismuth environmental fatigue life at the calibrated strain rate and the lead-bismuth environmental fatigue life at different strain rates; calculating and determining the lead-bismuth environmental damage coefficient at a given strain rate based on the third ratio and the lead-bismuth environmental damage coefficient at the calibrated strain rate; and calculating and determining the lead-bismuth environmental damage coefficient at different strain rates at a given temperature based on the determined lead-bismuth environmental damage coefficient at the given strain rate.

[0085] Figure 5 This is a schematic diagram of the strain rate extrapolation factor for lead-bismuth environment under low oxygen conditions provided by the present invention. Figure 6 This is a schematic diagram of the strain rate extrapolation factor for lead-bismuth under high oxygen conditions provided by the present invention, showing the strain rate extrapolation factor F for lead-bismuth under low or high oxygen conditions. LBE (R * The third ratio of fatigue life in lead-bismuth environments at different strain rates under the same strain amplitude is defined as the ratio of the calibrated strain rate R to the fatigue life in lead-bismuth environments at different strain rates. -3 The expression is as follows:

[0086]

[0087] in, 4.5×10 -3 Fatigue life in lead-bismuth environment under strain rate The fatigue life of lead-bismuth in an environment under other strain rates.

[0088] Different strain rates Through F LBE (R * Extrapolation is performed, and the extrapolation formula is as follows:

[0089]

[0090] in, To determine the environmental damage coefficient at strain rate, F LBE (R * The environmental damage coefficient is calibrated, and it can be extrapolated at different strain rates using Equation 8. The value of F is obtained by fitting the calculated value using Equation 4, and the environmental damage coefficient F under different strain rates is obtained. LBE expression.

[0091] The environmental damage coefficients of lead-bismuth at different temperatures and at different strain rates at a given temperature are both expressed as:

[0092] Step 104: Incorporate the lead-bismuth environmental damage coefficient into the air environment lifetime prediction model to establish a lifetime prediction model that considers the environmental impact of lead-bismuth.

[0093] In practical applications, the lifetime prediction model considering the environmental impact of lead and bismuth is as follows:

[0094]

[0095] in, The environmental fatigue life of lead-bismuth under any given condition; Fatigue life at room temperature air; F LBE The environmental damage coefficient for lead and bismuth.

[0096] Step 105: Determine the fatigue curve considering the environmental impact of lead and bismuth based on the life prediction model considering the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to evaluate the environmental damage of the component in the lead and bismuth environment, so as to achieve reliable fatigue design analysis.

[0097] In practical applications, Figure 7 This is a schematic diagram of the predicted lifetime results provided by the present invention. Figure 8 The high-temperature fatigue design curves for lead-bismuth environments provided in the embodiments of the present invention are as follows: Figures 7-8 As shown, the lifetime prediction model considering the environmental impact of lead and bismuth is defined according to ASME Section III, with the model's lifetime N... f Divide by 20, multiply stress / strain by 2 and take the envelope to obtain the high-temperature fatigue design curve considering the influence of lead-bismuth environment.

[0098] The safety of fatigue design of T91 steel in a lead-bismuth environment at 350℃ was verified by using the high-temperature fatigue design curve provided by this invention, and compared with the T91 fatigue design curve provided by ASME Volume III.

[0099] Figure 9 The schematic diagram of the fatigue design curve of T91 steel in a low-oxygen lead-bismuth (LOC-LBE) environment at 350℃ provided by this invention shows that when the number of cycles is below 1000, the T91 fatigue design curve provided by ASME Volume III has insufficient safety margin when evaluating fatigue data in a low-oxygen lead-bismuth environment. However, when the number of cycles is above 1000, due to the excellent fatigue resistance of the selected T91 steel, the ASME fatigue design curve has an overly conservative safety margin. The fatigue design curve that considers the influence of the lead-bismuth environment and is established using the environmental damage factor can solve the above two problems at the same time, has higher accuracy, and is beneficial to the lightweight and safety of the design.

[0100] Figure 10 This is a schematic diagram of the fatigue design curve of T91 steel under high oxygen lead-bismuth (HOC-LBE) environment at 350℃ provided by the present invention. The fatigue design curve provided by ASME has similar problems to those of low oxygen lead-bismuth in the evaluation of data under high oxygen lead-bismuth environment. The design curve acquisition method provided by the present invention can also achieve the goals of fatigue design safety and lightweighting under high oxygen environment, demonstrating good applicability.

[0101] Example 2

[0102] In order to implement the method corresponding to Embodiment 1 above and achieve the corresponding functions and technical effects, the following provides a system for determining the environmental damage coefficient and designing fatigue life under high temperature lead-bismuth environment.

[0103] A system for determining environmental damage coefficients and designing fatigue life in high-temperature lead-bismuth environments includes:

[0104] The fatigue test data acquisition module is used to conduct fatigue tests on components in room temperature air environment and different lead-bismuth environments, and to acquire fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments.

[0105] The module for establishing a life prediction model for room temperature air environment is used to establish a life prediction model for room temperature air environment based on fatigue test data under the room temperature air environment.

[0106] In practical applications, the strain amplitude range of the fatigue test under room temperature air environment is 0.2% to 2%; the oxygen concentration range of the fatigue test under different lead-bismuth environments is divided into high oxygen and low oxygen, the test temperature range is 150℃ to 450℃, and the test strain rate range is 5×10⁻⁶. -6 / s to 5×10 -3 / s.

[0107] The lead-bismuth environmental damage coefficient determination module is used to determine the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments; the lead-bismuth environmental damage coefficient includes the lead-bismuth environmental damage coefficient at different temperatures and the lead-bismuth environmental damage coefficient at different strain rates under a determined temperature.

[0108] The lifetime prediction model establishment module considering the environmental impact of lead and bismuth is used to input the environmental damage coefficient of lead and bismuth into the air environment lifetime prediction model to establish a lifetime prediction model considering the environmental impact of lead and bismuth.

[0109] The fatigue curve determination module is used to determine the fatigue curve considering the environmental impact of lead and bismuth based on the life prediction model considering the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to evaluate the environmental damage of the component in a lead and bismuth environment, and to achieve reliable fatigue design analysis.

[0110] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0111] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment, characterized in that, include: Fatigue tests were conducted on the components in room temperature air environment and in different lead-bismuth environments to obtain fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments. A life prediction model for room temperature air environment was established based on the fatigue test data under the aforementioned room temperature air environment. Based on fatigue test data under different lead-bismuth environments, the lead-bismuth environmental damage coefficient is determined, specifically including: Set the temperature extrapolation factor and the strain rate extrapolation factor; 350℃ was used as the calibration temperature for the lead-bismuth environment. The fatigue life under room temperature air environment, the fatigue life under the calibration temperature for the lead-bismuth environment, the fatigue life under different temperatures for the lead-bismuth environment, and the damage coefficient of the lead-bismuth environment under the calibration temperature were obtained. The first ratio of the fatigue life under the same strain amplitude in the room temperature air environment to the fatigue life under different oxygen concentrations in the lead-bismuth environment is determined based on the fatigue life under the room temperature air environment and the fatigue life under the lead-bismuth environment at the calibration temperature. The first ratio is used to calculate the high oxygen concentration and low oxygen concentration respectively, and the power-law relationship between the first ratio and the strain amplitude is determined. A second ratio of the fatigue life of lead-bismuth environments at different temperatures under the same strain amplitude is determined based on the fatigue life of lead-bismuth environments at the calibration temperature and the fatigue life of lead-bismuth environments at different temperatures. The environmental damage coefficient of lead and bismuth at the specified temperature is calculated and determined based on the environmental damage coefficient of lead and bismuth at the specified temperature and the second ratio. The lead-bismuth environmental damage coefficients at different temperatures are determined based on the lead-bismuth environmental damage coefficients at the determined temperature and the power-law relationship; the lead-bismuth environmental damage coefficients include lead-bismuth environmental damage coefficients at different temperatures and lead-bismuth environmental damage coefficients at different strain rates at the determined temperature. The lead-bismuth environmental damage coefficient is incorporated into the air environment lifetime prediction model to establish a lifetime prediction model that considers the environmental impact of lead-bismuth; the lifetime prediction model considering the environmental impact of lead-bismuth is as follows: ； in, The environmental fatigue life of lead-bismuth under any given condition; Fatigue life at room temperature air; F LBE The environmental damage coefficient for lead and bismuth; The fatigue curve considering the environmental impact of lead and bismuth is determined based on the life prediction model that takes into account the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to assess the environmental damage of the component in a lead and bismuth environment.

2. The method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment according to claim 1, characterized in that, The strain amplitude range of the fatigue test in the room temperature air environment is 0.2% to 2%; The fatigue tests conducted under different lead-bismuth environments included oxygen concentration ranges of high and low oxygen, a test temperature range of 150℃ to 450℃, and a test strain rate range of [missing information]. / s to / s.

3. The method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment according to claim 1, characterized in that, The functional relationship between strain and lifespan in the room temperature air environment lifespan prediction model is as follows: ； in, This refers to the total strain range; a These are the equation coefficients; For fatigue life; b It is the first material constant; c is the second material constant.

4. The method for determining the environmental damage coefficient and designing fatigue life in a high-temperature lead-bismuth environment according to claim 1, characterized in that, The determination of the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments specifically includes: The fatigue life of lead-bismuth in a calibrated strain rate, the damage coefficient of lead-bismuth in a calibrated strain rate, and the fatigue life of lead-bismuth in a calibrated strain rate at different strain rates were obtained. Determine the third ratio of the fatigue life of lead-bismuth in the calibrated strain rate to the fatigue life of lead-bismuth in the different strain rates. The lead-bismuth environmental damage coefficient at the strain rate is calculated and determined based on the third ratio and the lead-bismuth environmental damage coefficient at the calibrated strain rate. The environmental damage coefficients of lead and bismuth at different strain rates at a given temperature are calculated based on the environmental damage coefficients of lead and bismuth at the given strain rate.

5. A system for determining environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth conditions, characterized in that, The system for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth conditions executes the method for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth conditions according to any one of claims 1-4. The system for determining the environmental damage coefficient and designing fatigue life under high-temperature lead-bismuth conditions includes: The fatigue test data acquisition module is used to conduct fatigue tests on components in room temperature air environment and different lead-bismuth environments, and to acquire fatigue test data in room temperature air environment and fatigue test data in different lead-bismuth environments. The module for establishing a life prediction model for room temperature air environment is used to establish a life prediction model for room temperature air environment based on fatigue test data under the room temperature air environment. The lead-bismuth environmental damage coefficient determination module is used to determine the lead-bismuth environmental damage coefficient based on fatigue test data under different lead-bismuth environments; the lead-bismuth environmental damage coefficient includes the lead-bismuth environmental damage coefficient at different temperatures and the lead-bismuth environmental damage coefficient at different strain rates at a given temperature. The lifetime prediction model establishment module considering the environmental impact of lead and bismuth is used to input the lead and bismuth environmental damage coefficient into the air environment lifetime prediction model to establish a lifetime prediction model considering the environmental impact of lead and bismuth. The fatigue curve determination module is used to determine the fatigue curve considering the environmental impact of lead and bismuth based on the life prediction model considering the environmental impact of lead and bismuth; the fatigue curve considering the environmental impact of lead and bismuth is used to assess the environmental damage of the component in a lead and bismuth environment.

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