Method for evaluating corrosion resistance and service life of hot end component of aero-engine

Abstract

The invention belongs to the technical field of corrosion tests, and relates to a corrosion resistance evaluation and service life evaluation method for a hot end component of an aero-engine. The invention designs a corrosion test method which simulates a working-stopping state alternating effect and is moderate in acceleration rate. Comprising the following steps: determining corrosion factors of a parking state and a working condition state; designing an accelerated corrosion test method with different corrosion action strengths; short-time accelerated corrosion tests with different corrosion strengths are carried out, and accelerated corrosion test parameter screening is completed; according to test parameters obtained through screening, a long-time accelerated corrosion test is completed, and corrosion damage law analysis, mechanical property attenuation analysis and service life evaluation after different times are carried out. According to the method, the corrosion resistance of the hot-end component in the marine atmospheric environment can be truly evaluated, the corrosion damage rule and the mechanical property attenuation evolution rule are efficiently obtained, and the service life of related materials serving in the marine atmospheric environment is accurately evaluated.

Description

Technical Field

[0001] The invention belongs to the technical field of corrosion testing and relates to a method for evaluating the corrosion resistance and life of a hot end component of an aero-engine. Background Art

[0002] As aircraft and helicopters move into marine environments, aircraft engines are exposed to the corrosive effects of the marine atmosphere. When operating in marine environments, aircraft engines alternate between parking and flight. In these two environments, the hot-end components of aircraft engines face different corrosive environmental factors. During the parking phase, they face corrosive effects from the high temperatures (relative to inland climates, the marine atmosphere (such as in Hainan) is relatively high), high humidity, and high salt fog. While in flight, the hot-end components of aircraft engines are subject to a variety of environmental factors, including high temperatures (approximately 700°C to 1300°C due to engine gas combustion), gas, salt fog, and thermal stress. In actual service, hot-end components are subject to alternating corrosive factors in these two environments. In the early stages, aircraft engines were mostly operated inland, and the corrosion experienced by hot-end components primarily came from the operational phase. Most testing methods, such as high-temperature oxidation and hot corrosion, only considered the corrosion factors during operational operation, ignoring the corrosion effects of the parking phase and the alternating cycle between the two. Therefore, they were unable to effectively and effectively assess the corrosion resistance of hot-end components in marine atmospheric service.

[0003] In the process of evaluating the corrosion resistance of aircraft engine hot end components, the rationality of the acceleration rate setting of the simulated service environment test method is crucial to effectively capture the corrosion damage pattern and accurately evaluate the life of the components. When the test acceleration rate is small, the test time for corrosion phenomena to appear is long, or the corrosion degree evolves slowly, resulting in high test costs and long test cycles. When the test acceleration rate is too fast, the evolution pattern of corrosion damage may not be captured, and the corrosion damage degree changes too quickly, making it impossible to accurately evaluate the life. At present, there is no relevant test procedure designed to obtain a reasonable acceleration rate, so there is a risk of difficulty in capturing the evolution pattern of corrosion damage of different materials and evaluating the corrosion life. Summary of the Invention

[0004] The present invention proposes an accelerated corrosion test method for hot-end components of aircraft engines serving in a marine atmospheric environment. The purpose is to obtain a corrosion test method that simulates the alternating state of parking and working and has a moderate acceleration rate, so as to truly assess the corrosion resistance of the hot-end parts of aircraft engines in a marine atmospheric environment, obtain the evolution law of corrosion damage and complete the corrosion life assessment.

[0005] The technical solution of the present invention is a method for evaluating the corrosion resistance of hot end components of an aircraft engine, comprising the following steps:

[0006] (1) Determination of corrosion factors:

[0007] The marine atmospheric environmental factors of the sea areas where aircraft engines are parked in service are collected to determine the main corrosion factors to which the engines are subject when parked. At the same time, combined with the sensitivity of different materials to various corrosion factors, salt spray and hot and humid environment test methods are selected as test spectrum blocks to simulate the parking state and reproduce the corrosion effects of the parking state.

[0008] When an aircraft engine is in operation, the hot end components in the flow path are affected by high temperature, gas, salt accumulation, and thermal stress. The test methods of gas hot corrosion or salt hot corrosion are selected as test spectrum blocks to simulate the working state and reproduce the main corrosion effects of the working state.

[0009] (2) Design of accelerated corrosion test method with different acceleration rates:

[0010] The test spectrum blocks simulating the parking state and the test spectrum blocks simulating the working state are performed alternately and cycled multiple times.

[0011] By changing the key test parameters of the wet heat test, salt spray test, gas hot corrosion test, and salt coating hot corrosion test, corrosion spectrum block parameters with different corrosion acceleration degrees are obtained; combining test spectrum blocks with small key test parameter values to obtain a test method with low corrosion intensity; combining test spectrum blocks with large key test parameter values to obtain a test method with high corrosion intensity;

[0012] (3) Determination of accelerated corrosion test parameters:

[0013] A typical material from a class of materials is selected, and a short-term corrosion test of 10 to 15 days is carried out using the test method of different corrosion intensities in step (2); the appearance and corrosion area after the test are observed, and the corrosion test parameters that cause slight corrosion of the material within 10 to 15 days are selected as the final test parameters; the final accelerated corrosion test method is screened and obtained; a 50 to 100-day corrosion test is carried out using the obtained accelerated corrosion test method, and 3 to 5 time points are set for sampling during the test to obtain different test pieces with corrosion degrees ranging from mild to severe, and the corrosion area, corrosion depth, corrosion weight gain or weight loss, and key mechanical properties are tested, and the evolution law of material corrosion damage and the degree of mechanical property attenuation are analyzed to complete the corrosion resistance evaluation of the hot end component.

[0014] Furthermore, the marine atmospheric environmental factors of the service sea area include temperature, humidity, annual rainfall, wind direction, and salt deposition.

[0015] Furthermore, in the damp heat test, the key test parameters that determine the intensity of corrosion are the test temperature and the test humidity. By setting 3 to 5 temperature (30°C to 60°C) and humidity (70% to 95%) test parameters from low to high, damp heat spectrum block parameters with different degrees of corrosion acceleration are obtained.

[0016] Furthermore, in the salt spray test, the key test parameter that determines the intensity of the corrosion effect is the concentration of the sodium chloride solution. By setting 3 to 5 sodium chloride solution concentration parameters (2wt% to 10wt%) from low to high, salt spray spectrum block parameters with different degrees of corrosion acceleration are obtained.

[0017] Furthermore, in the gas hot corrosion test, the key test parameters that determine the corrosion intensity are the oil-gas ratio and the artificial seawater concentration. By setting 3 to 5 oil-gas ratios (1 / 100 to 1 / 15 (volume ratio)) and artificial seawater concentrations (5×10 -6 ~50×10 -6 (Volume ratio)) to obtain the gas hot corrosion spectrum block parameters with different corrosion acceleration degrees.

[0018] Furthermore, in the salt coating hot corrosion test, the key test parameter that determines the corrosion intensity is the salt coating amount. By setting 3 to 5 salt coating amounts from low to high, gas hot corrosion spectrum block parameters with different corrosion acceleration degrees are obtained.

[0019] Life assessment method for hot end components of aircraft engines:

[0020] Corrosion failure criteria are formulated based on the characteristics of different hot end components. The failure criteria are formulated using quantitative indicators of corrosion depth and corrosion area.

[0021] Accelerated corrosion testing was used, and the test was stopped when the corrosion index reached the corrosion failure criterion. Samples were taken at 3 to 5 time points during the test to obtain test pieces with varying degrees of corrosion, ranging from mild to severe. The corrosion area, corrosion depth, and corrosion weight gain or weight loss were tested to determine the extent of corrosion damage.

[0022] Use dismantled parts after actual service to conduct corrosion damage testing and analysis in terms of corrosion area, corrosion depth, and corrosion product layer thickness to determine the extent of corrosion damage to the dismantled parts;

[0023] Compare the corrosion degree of the test piece and the disassembled part after the accelerated corrosion test to obtain the acceleration rate of the corrosion test;

[0024] When the corrosion level reaches the failure level, the hot end component is considered to have failed, and the service life assessment of the material in the marine atmospheric environment is calculated and completed based on the acceleration rate.

[0025] Furthermore, the acceleration rate is determined based on the test time and the service life of the disassembled parts.

[0026] Furthermore, the calculation method of the acceleration rate is: a=t1 / t2(1)

[0027] In the above formula, a is the acceleration rate, t1 is the service time of the dismantled parts, and t2 is the accelerated corrosion test time when the corrosion level of the test piece reaches a level similar to that of the dismantled parts.

[0028] Furthermore, the service life calculation formula in marine atmospheric environment is as follows:

[0029] T1=aT2 (2)

[0030] In the above formula, a is the acceleration rate, T1 is the service life of the material in the marine atmosphere environment, and T2 is the time of the accelerated corrosion test when the corrosion level reaches the failure level.

[0031] The characteristics and beneficial effects of the present invention are:

[0032] This patent addresses the inability of traditional hot corrosion testing methods to accurately assess the corrosion resistance of engine hot-end components under the alternating conditions of parking and flight during service in a marine atmosphere. A new corrosion testing method has been designed to address the inability of traditional hot corrosion testing methods to accurately assess the corrosion resistance of engine hot-end components under the alternating conditions of parking and flight during service in a marine atmosphere. Traditional corrosion testing methods for hot-end components primarily include high-temperature oxidation, salt-coated hot corrosion, gas-coated hot corrosion, and thermal shock, all of which are designed to address the corrosion factors encountered during engine operation. This patent utilizes a test method that alternates salt spray and damp heat tests with salt-coated hot corrosion and gas-coated hot corrosion tests to establish a corrosion testing method that simulates a realistic service environment of alternating parking and flight conditions, enabling accurate assessment of the corrosion resistance of aircraft engine hot-end components in a marine environment. Furthermore, to address the issue of unreasonable corrosion acceleration rates in evaluating the corrosion resistance of aircraft engine hot-end components, a representative material from a given material class is selected and short-term corrosion tests are conducted using testing methods with varying corrosion intensities and the same test spectrum. The test results are then compared to determine the accelerated corrosion test parameters. The resulting accelerated corrosion test method is then used to conduct long-term corrosion testing, effectively capturing the patterns of corrosion damage and accurately assessing component lifespan. The resulting method can be extended to similar materials.

[0033] The test method established in the above manner with alternating parking and working effects and optimized acceleration rate can truly evaluate the corrosion resistance of hot end components in the marine atmospheric environment, efficiently obtain the corrosion damage law, and accurately evaluate the service life of related materials in the marine atmospheric environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Flow chart of the accelerated corrosion test method simulating parking-operation alternation;

[0035] Figure 2Appearance morphology of DD6 after one cycle of accelerated corrosion test simulating parking-operation alternation. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described in detail below with reference to the embodiments:

[0037] The method and steps for simulating the parking-operating alternating corrosion test and rapid evaluation of aircraft engine hot end parts in a marine atmosphere environment are as follows:

[0038] (1) Determination of corrosion factors:

[0039] When parked, aircraft engines are primarily subject to corrosion from the marine atmosphere. Marine atmospheric environmental factors in the sea areas where aircraft engines are in service, such as temperature, humidity, annual rainfall, wind direction, and salt deposition, are collected and analyzed to determine the primary factors within the marine atmosphere. Since aircraft engine hot-end components are typically located within the nacelle, solar radiation is not considered. This analysis identifies the primary corrosion factors. Furthermore, considering the sensitivity of different materials to these factors, appropriate environmental testing methods are selected to replicate these factors, typically including salt spray and damp heat testing.

[0040] When an aircraft engine is in operation, the hot end components in the flow path are mainly affected by factors such as high temperature, gas, salt accumulation, and thermal stress. Usually, the test methods of gas thermal corrosion or salt coating thermal corrosion are selected to simulate the main corrosion factors in the working state.

[0041] (2) Design of accelerated corrosion test method with different acceleration rates:

[0042] By changing the key parameters of each test, test methods with different corrosion acceleration rates can be obtained.

[0043] For the damp heat test, the key test parameters that determine the intensity of corrosion are the test temperature and test humidity. By setting 3 to 5 temperature (30℃~60℃) and humidity (70%~95%) test parameters from low to high, the damp heat spectrum block parameters with different degrees of corrosion acceleration are obtained.

[0044] For the salt spray test, the key test parameter that determines the intensity of the corrosion effect is the concentration of the sodium chloride solution. By setting 3 to 5 sodium chloride solution concentration parameters from low to high (2wt% to 10wt%), salt spray spectrum block parameters with different degrees of corrosion acceleration are obtained.

[0045] For the gas hot corrosion test, the key test parameters that determine the corrosion intensity are the oil-gas ratio and the artificial seawater concentration. By setting 3 to 5 oil-gas ratios (1 / 100 to 1 / 15 (volume ratio)) and artificial seawater concentrations (5×10 -6 ~50×10 -6(Volume ratio)) to obtain the gas hot corrosion spectrum block parameters with different corrosion acceleration degrees.

[0046] For the salt coating hot corrosion test, the key test parameter that determines the corrosion intensity is the salt coating amount. By setting 3 to 5 salt coating amounts from low to high (2 g / m 2 ~50g / m 2 ) Obtain gas hot corrosion spectrum block parameters with different corrosion acceleration levels.

[0047] Alternate test blocks simulating parking conditions with test blocks simulating operating conditions, and repeat multiple cycles to achieve a corrosion test method that simulates alternating operation and parking. Combining test blocks with small values for key test parameters yields a low-corrosion intensity test method; combining test blocks with large values for key test parameters yields a high-corrosion intensity test method.

[0048] (3) Determination of accelerated corrosion test parameters:

[0049] Select a typical material from a class of materials and conduct a short-term corrosion test for 10 to 15 days using the above-mentioned test methods with different corrosion intensities. Observe the appearance and corrosion area after the test, and select the corrosion test parameters that cause slight corrosion of the material within 10 to 15 days as the final test parameters. If the test parameters set in the early stage do not cause slight corrosion of the material within 10 to 15 days, further increase or decrease the key test parameters until the final accelerated corrosion test parameters are obtained. The resulting accelerated corrosion test method can be extended to similar materials or coatings.

[0050] (4) Accelerated corrosion testing, corrosion performance evaluation and service life assessment:

[0051] The accelerated corrosion test method obtained in step (3) is used to conduct a corrosion test for 50 to 100 days. Samples are taken after different test times to obtain different test pieces with different degrees of corrosion of the hot end components ranging from mild to severe. The corrosion area, corrosion depth, corrosion weight gain or weight loss, and key mechanical properties are tested to complete the analysis of the evolution law of material corrosion damage and the degree of mechanical property attenuation.

[0052] If corrosion life assessment is required, corrosion damage testing and analysis of corrosion area, corrosion depth, and corrosion product layer thickness are performed on dismantled parts after actual service to determine the extent of corrosion damage.

[0053] Compare the corrosion levels of the test piece and the dismantled parts after different corrosion times to obtain the corrosion time when the corrosion level is close to that of the dismantled parts. Determine the acceleration rate based on the test time and the service life of the dismantled parts:

[0054] a=t1 / t2 (1)

[0055] In the above formula, a is the acceleration rate, t1 is the service time of the dismantled parts, and t2 is the accelerated corrosion test time to reach a corrosion level similar to that of the dismantled parts;

[0056] Corrosion failure criteria are formulated based on the characteristics of different hot-end components. The failure criteria are formulated using quantitative indicators such as corrosion depth and the degree of mechanical property degradation after corrosion. When the corrosion level reaches the failure level, the hot-end component is considered to have failed. Based on the acceleration rate, the service life assessment of the material in the marine atmosphere environment is calculated and completed. The calculation formula is as follows:

[0057] T1=aT2 (1)

[0058] In the above formula, a is the acceleration rate, T1 is the service life of the material in the marine atmosphere environment, and T2 is the time of the accelerated corrosion test when the corrosion level reaches the failure level.

[0059] Example 1,

[0060] The turbine blades of a certain aircraft engine are made of DD6 high-temperature alloy.

[0061] (1) Determination of corrosion factors:

[0062] In actual service, the stationary state is subject to corrosion in a marine atmosphere characterized by high humidity, high temperature, and high salt spray. Previous testing revealed that DD6 high-temperature alloy exhibits no corrosion during long-term wet heat testing. Therefore, the wet heat environment was not considered, and the primary focus was on the salt spray environment. Furthermore, the atmospheric environment surrounding the engine is also affected by the sulfur element in the engine exhaust, creating an acidic atmosphere. Therefore, the acidic salt spray test method was used to simulate the stationary state. During operation, turbine components are primarily subject to factors such as high temperature, gas, salt accumulation, and thermal stress. In the gas hot corrosion test, fuel oil and artificial seawater are simultaneously introduced into a high-temperature furnace using test equipment, creating a mixed atmosphere containing gas and salt. This mixed atmosphere is then introduced into the test chamber, subjecting the test components to the combined corrosive effects of high temperature, gas, and salt accumulation. The test procedure was set to alternate between air cooling and heating, subjecting the test components to the thermal stresses generated by the alternating heating and cooling cycles, recreating the various corrosion factors encountered during turbine blade operation. Therefore, the gas hot corrosion test method was selected to simulate operating conditions.

[0063] (2) Design of accelerated corrosion test method with different acceleration rates:

[0064] ① The parameters of the acid salt spray test method for one cycle are set as follows:

[0065] Key test parameter settings for different corrosion intensities in acid salt spray tests:

[0066] The concentrations of the salt solutions were 2.5% ± 1%, 5% ± 1%, 7.5% ± 1%, and 10% ± 1%, respectively.

[0067] Other test parameter settings in the acid salt spray test:

[0068] Use sulfuric acid or sodium hydroxide to adjust the pH value to 3.5±0.5, the test temperature is 35℃±2℃, 80cm 2 The average sedimentation rate of the horizontal area is 1.0mL / h to 3.0mL / h. The test procedure of alternating dry and wet is adopted, with 24 hours of spraying and 24 hours of drying alternating, and one cycle is 192 hours (4 cycles).

[0069] ② The parameters of the gas hot corrosion test method for one cycle are set as follows:

[0070] Key test parameter settings for different corrosion intensities in gas hot corrosion tests:

[0071] The concentration of artificial seawater (volume ratio) is 10×10 -6 , 20×10 -6 , 30×10 -6 , 40×10 -6 .

[0072] The oil-gas ratio (volume ratio) is 1 / 90, 1 / 45, 1 / 30, and 1 / 20.

[0073] Other test parameter settings in the gas hot corrosion test method:

[0074] Artificial seawater consisted of 27 g / L NaCl, 12.8 g / L MgCl₂, 1 g / L KCl, and 1 g / L CaCl₂, diluted with deionized water to varying concentrations at a flow rate of 0.2 L / h. No. 3 jet fuel (GB 6537-2018) was used, with varying fuel-to-gas ratios and a flow rate of 0.2 L / h. The test temperature was 950°C. A hot-cold alternating test procedure was employed, with 55 minutes of warming followed by 5 minutes of cooling, with each cycle lasting 50 hours (50 cycles).

[0075] ③ The acid salt spray test spectrum blocks and the gas hot corrosion test spectrum blocks were carried out alternately, and different test parameters were combined from low to high to obtain four test methods with different corrosion intensities. Each cycle included a 192-hour acid salt spray test and a 50-hour gas hot corrosion test.

[0076] (3) Accelerated corrosion test parameter screening:

[0077] Using DD6 alloy test pieces and rotating bending mechanical test bars, the above-mentioned test methods with different corrosion intensities were used to carry out a short-term corrosion test of one cycle (192h acid salt spray test + 50h gas hot corrosion test). After the test, the appearance of the test pieces was observed. Figure 1After one cycle of the corrosion test method with medium test parameters, the appearance of DD6 is as follows Figure 2 As shown in the figure, gray-green corrosion products appeared on the surface of DD6 alloy, but no obvious corrosion pits appeared on the surface, indicating that DD6 alloy was slightly corroded. Therefore, this test parameter was selected as the final accelerated corrosion test parameter.

[0078] (4) Accelerated corrosion testing and performance evaluation:

[0079] use Figure 1 Four cycles of accelerated corrosion testing were conducted using the method shown. Samples were taken after different test times to obtain DD6 specimens with varying degrees of corrosion. The corrosion appearance was observed, and the micromorphology and composition of the corrosion products were analyzed using SEM and EDS to determine the evolution of corrosion damage in the DD6 superalloy. Rotating bending fatigue life tests were conducted using a high-temperature fatigue testing machine at 950°C, a stress ratio of -1, and a stress level of 550 MPa to determine the degradation patterns of key mechanical properties at the median fatigue life.

Claims

1. A method for evaluating the corrosion resistance of hot end components of an aircraft engine, characterized in that: The steps are as follows: (1) Determination of corrosion factors: The marine atmospheric environmental factors of the sea areas where aircraft engines are parked in service were collected to determine the main corrosion factors to which the engines are subject when parked. Furthermore, considering the sensitivity of different materials to various corrosion factors, salt spray and damp heat environmental test methods were selected as test spectrum blocks to simulate the parking state and reproduce the corrosion effects of the parking state. When an aircraft engine is in operation, the hot end components in the flow path are affected by high temperature, gas, salt accumulation, and thermal stress. The test methods of gas hot corrosion or salt hot corrosion are selected as test spectrum blocks to simulate the working state and reproduce the main corrosion effects of the working state. (2) Design of accelerated corrosion test method with different acceleration rates: Alternate the test spectrum blocks simulating the parking state and the test spectrum blocks simulating the working state, and repeat multiple times; By changing the key test parameters of the wet heat test, salt spray test, gas hot corrosion test, and salt coating hot corrosion test, corrosion spectrum block parameters with different corrosion acceleration degrees are obtained; combining test spectrum blocks with small key test parameter values to obtain a test method with low corrosion intensity; combining test spectrum blocks with large key test parameter values to obtain a test method with high corrosion intensity; (3) Determination of accelerated corrosion test parameters: A typical material from a class of materials is selected, and a short-term corrosion test of 10 to 15 days is carried out using the test method of different corrosion intensities in step (2); the appearance and corrosion area after the test are observed, and the corrosion test parameters that cause slight corrosion of the material within 10 to 15 days are selected as the final test parameters; the final accelerated corrosion test method is screened and obtained; a 50 to 100-day corrosion test is carried out using the obtained accelerated corrosion test method, and 3 to 5 time points are set for sampling during the test to obtain different test pieces with corrosion degrees ranging from mild to severe, and the corrosion area, corrosion depth, corrosion weight gain or weight loss, and key mechanical properties are tested, and the evolution law of material corrosion damage and the degree of mechanical property attenuation are analyzed to complete the corrosion resistance evaluation of the hot end component.

2. The method for evaluating the corrosion resistance of hot end components of an aircraft engine according to claim 1, characterized in that: The marine atmospheric environmental factors of the service sea area include temperature, humidity, annual rainfall, wind direction, and salt deposition.

3. The method for evaluating the corrosion resistance of hot end components of an aircraft engine according to claim 1, wherein: In the damp heat test, the key test parameters that determine the intensity of corrosion are the test temperature and the test humidity. By setting 3 to 5 temperature (30°C to 60°C) and humidity (70% to 95%) test parameters from low to high, damp heat spectrum block parameters with different degrees of corrosion acceleration are obtained.

4. The method for evaluating the corrosion resistance of hot end components of an aircraft engine according to claim 1, wherein: In the salt spray test, the key test parameter that determines the intensity of the corrosion effect is the concentration of the sodium chloride solution. By setting 3 to 5 sodium chloride solution concentration parameters (2wt% to 10wt%) from low to high, salt spray spectrum block parameters with different degrees of corrosion acceleration are obtained.

5. The method for evaluating the corrosion resistance of hot end components of an aircraft engine according to claim 1, wherein: In the gas hot corrosion test, the key test parameters that determine the corrosion intensity are the oil-gas ratio and the artificial seawater concentration. By setting 3 to 5 oil-gas ratios (1 / 100 to 1 / 15 (volume ratio)) and artificial seawater concentrations (5×10 -6 ~50×10 -6 (volume ratio)) to obtain the gas hot corrosion spectrum block parameters with different corrosion acceleration degrees.

6. The method for evaluating the corrosion resistance of hot end components of an aircraft engine according to claim 1, wherein: In the salt coating hot corrosion test, the key test parameter that determines the corrosion intensity is the salt coating amount. By setting 3 to 5 salt coating amounts from low to high, gas hot corrosion spectrum block parameters with different corrosion acceleration degrees are obtained.

7. A method for evaluating the life of hot end components of an aircraft engine, characterized in that: Formulate corrosion failure criteria based on the characteristics of different hot end components. The failure criteria are formulated using quantitative indicators of corrosion depth and corrosion area. The test is conducted using an accelerated corrosion test method, and the test is stopped when the corrosion index reaches the corrosion failure criterion. Samples are taken at 3 to 5 time points during the test to obtain test pieces with different corrosion levels ranging from mild to severe. The corrosion area, corrosion depth, and corrosion weight gain or weight loss are tested to determine the extent of corrosion damage. Use dismantled parts after actual service to conduct corrosion damage testing and analysis in terms of corrosion area, corrosion depth, and corrosion product layer thickness to determine the extent of corrosion damage to the dismantled parts; Compare the corrosion degree of the test piece and the disassembled part after the accelerated corrosion test to obtain the acceleration rate of the corrosion test; When the corrosion level reaches the failure level, the hot end component is considered to have failed, and the service life assessment of the material in the marine atmospheric environment is calculated and completed based on the acceleration rate.

8. The method for evaluating the life of an aircraft engine hot end component according to claim 7, wherein: The acceleration rate is determined based on the test time and the service life of the disassembled parts.

9. The method for evaluating the life of an aircraft engine hot end component according to claim 7, wherein: Calculation method of acceleration rate: a=t1 / t2 (1) In the above formula, a is the acceleration rate, t1 is the service time of the dismantled parts, and t2 is the accelerated corrosion test time when the corrosion level of the test piece reaches a level similar to that of the dismantled parts.

10. The method for evaluating the life of an aircraft engine hot end component according to claim 7, wherein: The service life calculation formula in marine atmospheric environment is as follows: T1=aT2 (2) In the above formula, a is the acceleration rate, T1 is the service life of the material in the marine atmosphere environment, and T2 is the time of the accelerated corrosion test when the corrosion level reaches the failure level.

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