Method for testing ion release rate of corrosion product in high-temperature and high-pressure water

Abstract

The invention relates to the field of corrosion tests, in particular to a method for testing the ion release rate of a corrosion product in high-temperature and high-pressure water, which is used for accurately testing the metal ion release rate of a metal sample in the high-temperature and high-pressure water. The test method mainly comprises the following four steps: S1, sample processing and pretreatment; S2, high-temperature and high-pressure water corrosion test; S3, corrosion sample processing and analysis test; and S4, sample result evaluation and recording. The ion release rate of the corrosion product can be accurately tested. According to the method, the release rate of the corrosion product ions is tested by comprehensively using a water sample method and a demolding method, the deposition condition of the corrosion product ions on the wall of the autoclave is fully considered, and the ratio of the total surface area of intermediate sampling to the volume of the taken solution is kept consistent with the initial value through experimental design; therefore, the ion release rate of the corrosion product can be accurately measured, and the method has the characteristics of simplicity, convenience in operation and high practicability.

Description

Technical Field

[0001] The invention relates to the field of corrosion testing, in particular to a test method for the release rate of corrosion product ions in high-temperature and high-pressure water, which is used to more accurately test the release rate of metal ions of a metal sample in high-temperature and high-pressure water. Background Art

[0002] In high temperature and high pressure water (200-360℃, 4-20MPa) environment, the corrosion behavior of metal materials is crucial for many industrial applications, especially in thermal power and nuclear power. Testing the corrosion product ion release rate of structural materials can provide service durability data of materials in extreme environments, which is of great significance for predicting material life, optimizing design and selecting suitable materials.

[0003] For example, in the cooling system of a nuclear reactor, metal materials are exposed to extreme service conditions, which may lead to rapid release of corrosion product ions, thus affecting the safety and efficiency of the entire system. It is necessary to accurately measure the ion dissolution behavior. In addition, when studying the risk formation mechanism and important phenomena caused by reactor fouling, accurately obtaining the release rate of metal corrosion product ions is an important basis for studying the migration of corrosion products and the deposition behavior of core fouling.

[0004] However, due to the complexity of the corrosion behavior of metals in high-temperature and high-pressure water, it is difficult to directly measure the release of corrosion product ions, and there are many factors that need to be considered during the test process. It is urgent to propose a test process and experimental method for the release rate of corrosion product ions (mainly Fe, Cr and Ni ions, etc.) in high-temperature and high-pressure water to meet laboratory testing needs. Summary of the invention

[0005] The purpose of the present invention is to provide a test method for the release rate of corrosion product ions in high-temperature and high-pressure water. The test method is specially designed to meet the laboratory's needs for testing the release rate of corrosion product ions of metal materials in high-temperature and high-pressure water. The test method solves the problem of the high difficulty in directly measuring the amount of corrosion product ions released in the prior art, and can more accurately test the release rate of corrosion product ions.

[0006] The technical solution of the present invention is as follows:

[0007] A test method for the release rate of corrosion product ions in high-temperature and high-pressure water comprises the following steps: S1 sample processing and pretreatment, S2 high-temperature and high-pressure water corrosion test, S3 corrosion sample processing and analytical testing, S4 sample result evaluation and recording, and adopts a water sample method and a film stripping method to test the release rate of corrosion product ions.

[0008] The test method for the release rate of corrosion product ions in high temperature and high pressure water, S1 sample processing and pretreatment includes the following steps:

[0009] S1.1 Number of samples

[0010] When processing samples of metal materials to be tested, sufficient number of samples must be prepared to meet the requirements of release measurement and sampling analysis during the test and at the end of the test; the processing of samples must be carried out strictly in accordance with standard operating procedures to ensure the accuracy and repeatability of the test results;

[0011] S1.2 Sample size design

[0012] The sample types are divided into high exposure area samples and surface oxide film analysis samples. High exposure area samples are used as the main ion release source, and surface oxide film analysis samples are used to analyze the morphology and structure of the surface oxide film.

[0013] S1.3 Pure titanium sheet reference sample setup

[0014] In order to calculate the content of elements deposited on the inner wall of the autoclave during the test, a pure titanium sheet is required as a reference sample to evaluate the deposition of corrosion products on the inner wall of the autoclave, so as to calculate the overall release of corrosion product ions;

[0015] S1.4 Sample grinding and cleaning

[0016] The processed samples were surface-polished, degreased and cleaned with ethanol and acetone respectively;

[0017] S1.5 Specimen mass and size measurement

[0018] Use a high-precision analytical balance and vernier caliper to measure the mass and actual size of the sample, and record the mass and size information of each sample.

[0019] In the test method for the release rate of corrosion product ions in high-temperature and high-pressure water, in S1.2 sample size design, when designing the size of a single sample, the ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave after each sampling remains constant, that is, after the sampling loss of sample area, the solution in the autoclave is also taken out proportionally. The sampling loss sample area refers to the sample area reduced in the autoclave each time a sample is taken out, and the ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave is determined according to the test requirements.

[0020] The test method for the release rate of corrosion product ions in high temperature and high pressure water, S1.2 In the design of sample size, the exposure area of ​​the high exposure area sample is 1000~4000mm 2 The size of the surface oxide film analysis sample is 10mm×10mm×1.5mm, which is convenient for subsequent test characterization requirements.

[0021] The test method for the release rate of corrosion product ions in high temperature and high pressure water, S2 high temperature and high pressure water corrosion test, comprises the following steps:

[0022] S2.1 Kettle body material

[0023] When conducting corrosion tests, avoid using autoclaves containing materials that release ions of the elements to be tested;

[0024] S2.2 Autoclave cleaning and sample installation

[0025] After cleaning the autoclave with deionized water and then with anhydrous alcohol, place the sample on the sample rack in the autoclave;

[0026] S2.3 Environmental corrosion test

[0027] Use a glass rod to drain the prepared solution into the autoclave, cover the autoclave with a lid and seal it. Heat the autoclave to the target temperature of 200-360°C and pressurize it to 4-20MPa according to the test requirements. Continue the corrosion test until the set test time is reached.

[0028] S2.4 Solution volume proportional control

[0029] In order to ensure that the ratio of solution volume to sample exposure area does not change significantly, after each sampling, the volume of solution in the autoclave decreases in proportion to the increase in the number of samples taken.

[0030] The test method for the release rate of corrosion product ions in high-temperature and high-pressure water, S2.1, in the autoclave material, for the Fe, Cr and Ni release rate test scenarios, a pure titanium autoclave is used to carry out corrosion tests, effectively avoiding the interference of the autoclave material on the test results.

[0031] The test method for the release rate of corrosion product ions in high temperature and high pressure water, S3 corrosion sample processing and analysis test comprises the following steps:

[0032] S3.1 Sample drying

[0033] After each stage of the test, the sample was dried with a hair dryer and then placed in an oven at 70-90°C for 12 hours;

[0034] S3.2 Water sample method

[0035] Use a syringe to extract water samples. Repeated extraction and release are used to ensure that the water samples are evenly mixed. The volume of each water sample extraction is 80-160 mL. Add 3-5 mL of 4wt% hydrochloric acid to the water sample to avoid ion deposition on the surface of the sampling bottle. Send the water sample for analysis.

[0036] S3.3 Defilming method

[0037] Mass W of high exposure area specimen before test 0 , take out the high exposure area sample corresponding to the test time and weigh it to obtain the mass W after corrosion 1 ; Characterize the oxide film on the surface of the sample, use an energy spectrometer and X-ray photoelectron spectroscopy to analyze its composition and obtain its composition information; remove the oxide film on the surface of the sample by chemical methods and obtain the mass W after film removal 2 ;

[0038] S3.4 Pure Titanium Thin Sheet Reference Sample Processing

[0039] The oxide film on the surface of the pure titanium sheet after the test was pickled and the water sample was analyzed to obtain the element content corresponding to the unit area of ​​the pure titanium sheet, and then the element deposition amount on the inner wall of the entire autoclave was calculated.

[0040] The test method for the release rate of corrosion product ions in high temperature and high pressure water, the evaluation and recording of S4 sample results include the following steps:

[0041] S4.1 Evaluation of release rate using water sample method

[0042] The release amount of target ions in the solution per unit volume is directly obtained by water sample analysis, and then the release rate is calculated in combination with the total exposure area and corrosion time;

[0043] S4.2 Evaluation of release rate by demolding method

[0044] Calculate the area of ​​all samples in the autoclave to obtain the total exposure area S; analyze and test to obtain the proportion of metal A element X A , the mass proportion of element A in the oxide film is obtained by characterizing the sample using the surface oxide film analysis test A , the mass ratio of metal elements to oxide film is obtained by testing m ; Calculate the metal corrosion mass W C =W 0 -W 2 , calculate the oxide film mass W f =W 1 -W 2 ; Calculate the corrosion release mass W r =W c -Σf m ×W f ; Calculate the A element between 0 and t 1 The release rate R A,1 =(X A *ΣW c1 -Y A *ΣW r1 ) / (ΣS 1 *t 1 ), in t1 ~t 2 The release rate R A,2 =[(X A *ΣW c2 -Y A *ΣW r2 )-R A,1 *ΣS 2 *t 1 ] / [ΣS 2 *(t 2 -t 1 )]; where ΣW c1 Represents the total corrosion mass of all samples in the time period from 0 to t1, ΣW r1 Represents the total corrosion release mass of all samples in the time period from 0 to t1, ΣS 1 Represents the total exposure area from 0 to t1, ΣS 2 Represents the total exposure area during the time period t1 to t2;

[0045] S4.3 Summary of results

[0046] Record the corrosion product ion release rate of metal materials in water sample analysis and film stripping analysis, and indicate the corresponding working conditions.

[0047] The present invention is a test method capable of more accurately measuring the release rate of corrosion product ions of metal materials in high temperature and high pressure water. The design concept is:

[0048] First, the advantages and disadvantages of different measurement methods were taken into consideration, and the water sampling method and the film stripping method were used in combination. The two methods verified each other, minimized their respective measurement errors, and improved the accuracy of the test results.

[0049] Secondly, considering the influence of ion deposition, the deposition of corrosion product ions on the inner wall of the autoclave was fully considered in the experimental design. By setting a pure titanium sheet as a reference sample before the test, the amount of corrosion products deposited on the autoclave wall can be effectively evaluated and calculated, thereby accurately determining the overall ion release.

[0050] Furthermore, the concept of keeping the ratio of the solution volume of the intermediate sampling to the total exposed area of ​​the sample consistent was introduced in the experimental design process. By controlling the reduction of the solution volume in the kettle after sampling to correspond to the reduction of the exposed area of ​​the sample, the ratio of the sample surface area to the solution volume was ensured to be constant during the entire test, thereby ensuring that the measurement of the corrosion product ion release rate was not affected by the intermediate sampling link.

[0051] The advantages and beneficial effects of the present invention are:

[0052] 1. The present invention uses a water sample method and a film stripping method to test the release rate of corrosion product ions. The results of these two methods can verify each other and specifically compensate for their respective measurement errors, thereby effectively improving the test accuracy.

[0053] 2. The present invention fully considers the deposition of corrosion product ions on the autoclave wall and uses pure titanium sample slices as reference samples, further improving the accuracy of corrosion release test.

[0054] 3. The present invention takes into account the impact of multiple sampling on the total exposure area and total release amount of the sample during the test process. It is proposed that when designing the scheme, the ratio of the total surface area of ​​the intermediate sampling to the volume of the solution taken should be consistent with the initial one, so as to minimize the impact of the intermediate sampling on the subsequent corrosion release rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 The figure is a schematic diagram of the main steps of the present invention, wherein S1 is sample processing and pretreatment, S2 is high temperature and high pressure water corrosion test, S3 is corrosion sample processing and analysis test, and S4 is sample result evaluation and recording. DETAILED DESCRIPTION

[0056] like Figure 1 As shown, the present invention provides a test method for the release rate of corrosion product ions in high temperature and high pressure water, which mainly includes the following steps:

[0057] S1 Sample processing and pretreatment

[0058] S1.1 Number of samples

[0059] For the sample processing of the metal material to be tested, a sufficient number of samples should be prepared to meet the requirements of release measurement and sampling analysis during the test (including water sample analysis and film stripping method analysis) and sampling analysis at the end of the test; the processing of the samples should be carried out in strict accordance with the standard operating procedures to ensure the accuracy and repeatability of the test results. In this embodiment, the grade of the metal material to be tested is Inconel690TT, and the total number of samples is 44, including: 32 samples with high exposure area and 12 samples for surface oxide film analysis.

[0060] S1.2 Sample size design

[0061] The sample types are generally divided into high exposure area samples (larger in size, as the main ion release source, the size of this embodiment is a tube section with an outer diameter of 17.48mm, an inner diameter of 15.46mm, and a length of 11.56mm. The exposed surface area of ​​a single sample is about 1300mm 2) and surface oxide film analysis samples (used for surface oxide film morphology and structure analysis. The size of this embodiment is a circular arc sample with a cross section of one sixth of the above pipe section, 11.56 mm long, and the exposed area of ​​the sample is about 217 mm 2 ).

[0062] When designing the size of a single sample, it should be determined according to the number of samples and the volume of the autoclave in the high-temperature and high-pressure water corrosion test, so that the ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave after each sampling remains constant, that is, after a certain amount of sample area is lost in sampling, the solution in the autoclave should also be taken out proportionally. The sample area lost in sampling refers to the sample area reduced in the autoclave each time a sample is taken out. In this embodiment, the ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave is controlled at 30:1 to 34:1 (mm 2 / cm 3 ).

[0063] S1.3 Pure titanium sheet reference sample setup

[0064] In order to calculate the element content deposited on the inner wall of the autoclave (generally made of pure titanium) during the test, a number of pure titanium thin sheets need to be set in advance. The size of this embodiment is 10mm×20mm×1mm. These thin sheets will be used as reference samples to evaluate the deposition of corrosion products on the inner wall of the autoclave in order to calculate the overall release of corrosion product ions.

[0065] S1.4 Specimen polishing and cleaning

[0066] The processed samples were surface-polished (depending on the surface condition required by the test), and degreased and cleaned with ethanol and acetone respectively.

[0067] S1.5 Specimen mass and size measurement

[0068] Use a high-precision analytical balance and vernier caliper to measure the mass and actual size of the sample, and record the mass and size information of each sample.

[0069] S2 High temperature and high pressure water corrosion test

[0070] S2.1 Kettle body material

[0071] When conducting corrosion tests, avoid using autoclaves made of materials containing the elements whose ions are to be released. For example, for common Fe, Cr, and Ni release rate test scenarios, use autoclaves made of pure titanium for corrosion tests to effectively avoid interference of the autoclave material with the test results.

[0072] S2.2 Autoclave cleaning and sample installation

[0073] After cleaning the autoclave several times with deionized water and then with anhydrous alcohol, place the samples on the sample rack in the autoclave.

[0074] S2.3 Environmental corrosion test

[0075] Use a glass rod to drain and pour the prepared solution into the autoclave, cover the autoclave cover and seal it, adjust the water quality, close the valve after completion, heat the autoclave to the target temperature, and continue the corrosion test until the predetermined experimental test time is reached. In this embodiment, the meaning of water quality adjustment is to adjust the solution to dissolve hydrogen and deoxygenate, and the high-temperature and high-pressure aqueous solution after water quality adjustment contains 1100ppmB and 2.3ppmLi, the volume of the high-temperature and high-pressure aqueous solution is 1300mL, and it is heated to 325℃, and the pressure is the saturated vapor pressure of the solution.

[0076] S2.4 Solution volume proportional control

[0077] In order to ensure that the ratio of solution volume to specimen exposure area does not change significantly, after each sampling, the volume of solution in the autoclave should be reduced in proportion to the increase in the number of samples taken.

[0078] S3 corrosion sample processing and analysis test

[0079] S3.1 Sample drying

[0080] After each stage of the test, the sample was dried with a hair dryer and then placed in an oven at 80°C for 12 hours.

[0081] S3.2 Water sample method

[0082] The water sample was extracted using a syringe, and the extraction was repeated five times to ensure that the water sample was evenly mixed. In this embodiment, the volume of each water sample extraction was 150 mL, and 4 mL of 4 wt% hydrochloric acid was added to the water sample to avoid ion deposition on the surface of the sampling bottle, and the water sample was sent for analysis.

[0083] S3.3 Defilming method

[0084] Take out the high exposure area sample corresponding to the test time (the mass before the test W 0 ) to weigh and obtain the mass W after corrosion 1 ; Characterize the oxide film on the surface of the sample, analyze its composition using energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and other means to obtain its composition information; remove the oxide film on the surface of the sample by chemical methods to obtain the mass W after film removal 2 .

[0085] S3.4 Pure Titanium Thin Sheet Reference Sample Processing

[0086] The oxide film on the surface of the pure titanium sheet after the test was pickled (4wt% hydrochloric acid, 150mL) and the water sample was analyzed to obtain the element content per unit area of ​​the pure titanium sheet, and then calculate the element deposition amount on the inner wall of the entire autoclave.

[0087] S4 Test results evaluation and recording

[0088] S4.1 Evaluation of release rate using water sample method

[0089] The release amount of target ions in the solution per unit volume is obtained directly through water sample analysis (using methods such as inductively coupled plasma mass spectrometry), and then the release rate is calculated based on the total exposure area and corrosion time.

[0090] S4.2 Evaluation of release rate by demolding method

[0091] Calculate the area of ​​all samples in the autoclave to obtain the total exposure area S. The total exposure area S of the sample in this embodiment is 44205mm 2 ; Analyze and test to obtain the proportion of specific metal elements X A Taking Inconel690TT alloy as an example, its main components are Ni~59.2wt.%, Cr~29.8wt.%, Fe~10.2wt.% (the three main elements account for 99.2wt%, and the remaining Al, Ti, and Co are trace elements). Then for the Ni element, its X A =0.592; Using the surface oxide film analysis sample characterization test to obtain the mass proportion of specific elements in the oxide film Y A , that is, the proportion of the main elements that do not contain oxygen; the test results show that the mass proportion of metal elements in the oxide film is f m ; Calculate the metal corrosion mass W C =W 0 -W 2 , calculate the oxide film mass W f =W 1 -W 2 ; Calculate the corrosion release mass W r =W c -Σf m ×W f (the difference between the corrosion mass and the residual mass in the film); the calculation can obtain the A element in 0~t 1 The release rate R A,1 =(X A *ΣW c1 -Y A *ΣW r1 ) / (ΣS 1 *t 1 ), in t 1 ~t 2 The release rate R A,2=[(X A *ΣW c2 -Y A *ΣW r2 )-R A,1 *ΣS 2 *t 1 ] / [ΣS 2 *(t 2 -t 1 )]. Where ΣW c1 Represents the total corrosion mass of all samples in the time period from 0 to t1, ΣW r1 Represents the total corrosion release mass of all samples in the time period from 0 to t1, ΣS 1 Represents the total exposure area from 0 to t1, ΣS 2 Represents the total exposure area during the time period from t1 to t2.

[0092] S4.3 Summary of results

[0093] Record the corrosion product ion release rate of metal materials in water sample analysis and stripping method analysis, and indicate the corresponding working conditions (such as temperature, corrosion time, water chemistry, etc.).

[0094] The implementation results show that the present invention uses a comprehensive water sampling method and a film stripping method to test the release rate of corrosion product ions, fully considering the deposition of corrosion product ions on the wall of the autoclave, and through experimental design, the ratio of the total surface area of ​​the intermediate sampling to the volume of the solution taken is kept consistent with the initial value, thereby achieving a more accurate measurement of the release rate of corrosion product ions, which has the characteristics of simple method, easy operation and strong practicality.

Claims

1. A test method for the release rate of corrosion product ions in high temperature and high pressure water, characterized in that: The method comprises the following steps: S1 sample processing and pretreatment, S2 high temperature and high pressure water corrosion test, S3 corrosion sample processing and analytical test, S4 sample result evaluation and recording, and adopts water sample method and film stripping method to test the release rate of corrosion product ions.

2. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 1, characterized in that: S1 sample processing and pretreatment include the following steps: S1.1 Number of samples When processing samples of metal materials to be tested, sufficient number of samples must be prepared to meet the requirements of release measurement and sampling analysis during the test and at the end of the test; the processing of samples must be carried out strictly in accordance with standard operating procedures to ensure the accuracy and repeatability of the test results; S1.2 Sample size design The sample types are divided into high exposure area samples and surface oxide film analysis samples. High exposure area samples are used as the main ion release source, and surface oxide film analysis samples are used to analyze the morphology and structure of the surface oxide film. S1.3 Pure titanium sheet reference sample setup In order to calculate the content of elements deposited on the inner wall of the autoclave during the test, a pure titanium sheet is required as a reference sample to evaluate the deposition of corrosion products on the inner wall of the autoclave, so as to calculate the overall release of corrosion product ions; S1.4 Sample grinding and cleaning The processed samples were surface-polished, degreased and cleaned with ethanol and acetone respectively; S1.5 Specimen mass and size measurement Use a high-precision analytical balance and vernier caliper to measure the mass and actual size of the sample, and record the mass and size information of each sample.

3. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 2, characterized in that: S1.2 In the design of sample size, when designing the size of a single sample, the ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave after each sampling remains constant, that is, after the sample area is lost due to sampling, the solution in the autoclave is also taken out proportionally. The sample area lost due to sampling refers to the sample area that is reduced in the autoclave each time a sample is taken out. The ratio of the total exposed area of ​​the sample to the volume of the solution in the autoclave is determined according to the test requirements.

4. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 2, characterized in that: S1.2 In the design of specimen size, the exposure area of ​​high exposure area specimens is between 1000 and 4000 mm 2 The size of the surface oxide film analysis sample is 10mm×10mm×1.5mm, which is convenient for subsequent test characterization requirements.

5. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 1, characterized in that: The S2 high temperature and high pressure water corrosion test includes the following steps: S2.1 Kettle body material When conducting corrosion tests, avoid using autoclaves containing materials that release ions of the elements to be tested; S2.2 Autoclave cleaning and sample installation After cleaning the autoclave with deionized water and then with anhydrous alcohol, place the sample on the sample rack in the autoclave; S2.3 Environmental corrosion test Use a glass rod to drain the prepared solution into the autoclave, cover the autoclave with a lid and seal it. Heat the autoclave to the target temperature of 200-360°C and pressurize it to 4-20MPa according to the test requirements. Continue the corrosion test until the set test time is reached. S2.4 Solution volume proportional control In order to ensure that the ratio of solution volume to sample exposure area does not change significantly, after each sampling, the volume of solution in the autoclave decreases in proportion to the increase in the number of samples taken.

6. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 5, characterized in that: In the S2.1 autoclave material, for the Fe, Cr and Ni release rate test scenarios, a pure titanium autoclave was used for corrosion testing, effectively avoiding the interference of the autoclave material on the test results.

7. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 1, characterized in that: S3 corrosion sample processing and analysis test includes the following steps: S3.1 Sample drying After each stage of the test, the sample was dried with a hair dryer and then placed in an oven at 70-90°C for 12 hours; S3.2 Water sample method Use a syringe to extract water samples. Repeated extraction and release are used to ensure that the water samples are evenly mixed. The volume of each water sample extraction is 80-160 mL. Add 3-5 mL of 4wt% hydrochloric acid to the water sample to avoid ion deposition on the surface of the sampling bottle. Send the water sample for analysis. S3.3 Defilming method The mass of the high-exposure area sample before the test is W0, and the high-exposure area sample corresponding to the test time is taken out and weighed to obtain the mass after corrosion W1; the oxide film on the surface of the sample is characterized, and its composition is analyzed using an energy spectrometer and X-ray photoelectron spectroscopy to obtain its composition information; the oxide film on the surface of the sample is removed by chemical methods to obtain the mass after film removal W2; S3.4 Pure Titanium Thin Sheet Reference Sample Processing The oxide film on the surface of the pure titanium sheet after the test was pickled and the water sample was analyzed to obtain the element content corresponding to the unit area of ​​the pure titanium sheet, and then the element deposition amount on the inner wall of the entire autoclave was calculated.

8. The test method for the release rate of corrosion product ions in high temperature and high pressure water according to claim 1, characterized in that: S4 test result evaluation and recording includes the following steps: S4.1 Evaluation of release rate using water sample method The release amount of target ions in the solution per unit volume is directly obtained by water sample analysis, and then the release rate is calculated in combination with the total exposure area and corrosion time; S4.2 Evaluation of release rate by demolding method Calculate the area of ​​all specimens in the autoclave to obtain the total exposure area S; The analysis and test result shows the ratio of metal A element X A , the mass proportion of element A in the oxide film is obtained by characterizing the sample using the surface oxide film analysis test A , the mass ratio of metal elements to oxide film is obtained by testing m ; Calculate the metal corrosion mass W C =W0-W2, calculate the oxide film mass W f =W1-W2; calculate the corrosion release mass W r =W c -Σf m ×W f ; Calculate the release rate R of element A in the 0~t1 stage A,1 =(X A *ΣW c1 -Y A *ΣW r1 ) / (ΣS1*t1), the release rate R in the stage t1~t2 A,2 =[(X A *ΣW c2 -Y A *ΣW r2 )-R A,1 *ΣS2*t1] / [ΣS2*(t2-t1)]; where ΣW c1 Represents the total corrosion mass of all samples in the time period from 0 to t1, ΣW r1 represents the total corrosion release mass of all samples during the time period from 0 to t1, ΣS1 represents the total exposure area during the time period from 0 to t1, and ΣS2 represents the total exposure area during the time period from t1 to t2; S4.3 Summary of results Record the corrosion product ion release rate of metal materials in water sample analysis and film stripping analysis, and indicate the corresponding working conditions.

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