Corrosion Risk Assessment Method

Abstract

The present application discloses a corrosion risk assessment method, belonging to the technical field of industrial pipeline corrosion tests, which is used to guide users to adjust the actual operating parameters of the object to be evaluated and reduce the corrosion risk. The main technical solution of the present application is as follows: The corrosion risk assessment method first starts from normal temperature and pressure, and according to a preset gradient, based on the design parameters of the object to be evaluated, gradually increases the temperature, pressure and flow rate of the test medium in the reaction kettle to carry out multiple groups of simulation tests; then collects the reference corrosion parameters of the specimens on each layer of the test rack in the simulation tests and selects characteristic parameters; then replaces the specimens, and sets the reaction kettle conditions to carry out comparative tests with reference to the actual operating parameters of the object to be evaluated; then collects the actual corrosion rates of the specimens in gaseous, liquid, and gas-liquid two-phase test media in the comparative tests as actual corrosion parameters; finally, according to the phase state classification, compares the actual corrosion parameters with the characteristic parameters, and adjusts the actual operating parameters of the object to be evaluated according to the comparison results.

Description

Technical Field

[0001] This application belongs to the technical field of industrial pipeline corrosion tests, and specifically relates to a corrosion risk assessment method. Background Art

[0002] In various industrial production processes and infrastructure construction, the corrosion problem of equipment and materials has always been a key factor affecting the stability, safety, and economy of the system. From oil and gas extraction and transportation pipelines, to reaction vessels and transmission pipelines in chemical production, to offshore engineering facilities that are constantly eroded by seawater, metal structures are constantly facing corrosion risks.

[0003] Among the many factors affecting corrosion, the actual operating parameters of the object to be evaluated play a key role. However, there are many dilemmas in determining and adjusting operating parameters at present. Specifically, when setting operating parameters, many enterprises mainly rely on past experience or simple engineering estimates, lacking scientific and accurate method guidance, resulting in the fact that the actual operating parameters often cannot effectively control the corrosion risk while ensuring production efficiency. Summary of the Invention

[0004] In view of this, this application provides a corrosion risk assessment method, and the main purpose is to guide users to adjust the actual operating parameters of the object to be evaluated and reduce the corrosion risk.

[0005] To achieve the above purpose, this application mainly provides the following technical solutions:

[0006] This application provides a corrosion risk assessment method, which is applied to a corrosion test system. The corrosion test system includes a reaction kettle, a stirrer, and a test rack. The rotatable part of the stirrer and the test rack are both arranged in the reaction kettle. The test rack is used to fix the test pieces. The test rack is provided with three layers in the vertical direction. The reaction kettle is used to inject the test medium, and the liquid level of the test medium is controlled at the middle layer position of the test rack; the corrosion risk assessment method includes:

[0007] Starting from normal temperature and pressure, according to a preset gradient, in accordance with the design parameters of the object to be evaluated, gradually increase the temperature, pressure in the reaction kettle, and the flow rate of the test medium in the reaction kettle, and conduct multiple groups of simulation tests;

[0008] Respectively collect the reference corrosion parameters corresponding to the test pieces in each layer of the test rack in multiple groups of the simulation tests, and select the characteristic parameters from multiple groups of the reference corrosion parameters;

[0009] Replace the test pieces in each layer of the test rack, and set the temperature, pressure in the reaction kettle, and the flow rate of the test medium in the reaction kettle with reference to the actual operating parameters of the object to be evaluated, and conduct comparative tests;

[0010] Collect the actual corrosion parameters corresponding to the specimens on each layer of the test rack in the comparative test. The actual corrosion parameters include the actual corrosion rate of the specimens in the gaseous test medium, the actual corrosion rate in the liquid test medium, and the actual corrosion rate in the gas-liquid two-phase test medium.

[0011] Classify and compare the actual corrosion parameters with the characteristic parameters according to the phase state, and adjust the actual operating parameters of the object to be evaluated based on the comparison results.

[0012] Optionally, the steps of separately collecting the reference corrosion parameters corresponding to the specimens on each layer of the test rack in multiple groups of the simulation tests and selecting the characteristic parameters from multiple groups of the reference corrosion parameters include:

[0013] Before conducting multiple groups of the simulation tests, for each group of the simulation tests, weigh each of the specimens on each layer of the test rack in sequence, and record the initial weight of each of the specimens on each layer of the test rack in each group of the simulation tests.

[0014] After multiple groups of the simulation tests are completed, for each group of the simulation tests, weigh each of the specimens on each layer of the test rack in sequence again, and record the final weight of each of the specimens on each layer of the test rack in each group of the simulation tests.

[0015] Calculate the corrosion rate of each of the specimens on each layer of the test rack in each group of the simulation tests based on the weight loss method to obtain multiple groups of the reference corrosion parameters.

[0016] Screen and determine the reference corrosion parameter with the largest value among multiple groups of the reference corrosion parameters, and use it as the characteristic parameter.

[0017] Optionally, the corrosion test system further includes galvanic corrosion sensors. At least three galvanic corrosion sensors are provided, and at least three galvanic corrosion sensors are arranged in one-to-one correspondence with three layers of the test rack; the corrosion risk assessment method further includes:

[0018] During the continuous progress of each group of the simulation tests, obtain the real-time corrosion current data output by the galvanic corrosion sensors corresponding to each layer of the test rack in real time.

[0019] Calculate the corrosion rate of the galvanic corrosion sensors corresponding to each layer of the test rack based on the real-time corrosion current data.

[0020] Optionally, the calculating the corrosion rate of the galvanic corrosion sensors corresponding to each layer of the test rack based on the real-time corrosion current data includes:

[0021] Draw a curve graph of the mass loss of the material corrosion, with the reaction time as the independent variable and the total mass loss of the material at different reaction times as the dependent variable, and visually display the change of the total mass loss of the material with the reaction time;

[0022] Based on the curve graph of the mass loss of the material corrosion, calculate the corrosion rate of the galvanic corrosion sensor corresponding to each layer of the test rack.

[0023] Optionally, after calculating the corrosion rate of the galvanic corrosion sensor corresponding to each layer of the test rack based on the real-time corrosion current data, the corrosion risk assessment method further includes:

[0024] For multiple groups of the simulation tests, respectively sort out the corrosion rate data of the specimens on each layer of the test rack in each group of the simulation tests, and the corresponding corrosion rate data of the galvanic corrosion sensors on each layer;

[0025] Using a data analysis method, based on the sorted corrosion rate data of multiple groups of the specimens and the corrosion rate data of multiple groups of the galvanic corrosion sensors, determine the conversion relationship between the corrosion rate of the galvanic corrosion sensor and the corrosion rate of the specimens.

[0026] Optionally, the comparing the actual corrosion parameters with the characteristic parameters according to the phase state, and adjusting the actual operating parameters of the object to be evaluated based on the comparison result includes:

[0027] When the absolute value difference between the actual corrosion parameter and the characteristic parameter is within a preset interval, during the actual operation, reduce the temperature and / or pressure inside the object to be evaluated and / or the flow rate of the test medium.

[0028] Optionally, multiple specimens are fixed on each layer of the test rack, so that the corrosion test system can verify the relationship between the flow rate of the test medium in different phase states and the corrosion rate of the specimens.

[0029] Optionally, the corrosion test system further includes a pressure sensor, a temperature sensor and a flow rate sensor. The pressure sensor is arranged on the top cover of the reaction kettle, the temperature sensor is arranged on the bottom wall of the reaction kettle, and three flow rate sensors are arranged. The three flow rate sensors are all arranged on the outer wall of the reaction kettle and are arranged in one-to-one correspondence with the three layers of the test rack.

[0030] Optionally, the corrosion test system further includes a booster pump and a heater. The booster pump is connected to the inner cavity of the reactor and is used to adjust the pressure inside the reactor. The heater is disposed on the outer wall of the reactor and is used to adjust the temperature inside the reactor.

[0031] Optionally, a ceramic gasket is provided at the connection between the test piece and the test rack, and the ceramic gasket is used to isolate the test piece from the test rack.

[0032] By means of the above technical solution, the present application has at least the following beneficial effects:

[0033] In the corrosion risk assessment method provided in the embodiments of the present application, by arranging the test rack in three layers in the vertical direction and controlling the liquid level of the test medium at the middle layer, the corrosion conditions of the test pieces at different height positions in different gas-liquid phases and at the gas-liquid interface can be simulated, and the different corrosion environments that may exist in the metal structure in actual applications can be more comprehensively reflected. In multiple groups of simulation tests, starting from normal temperature and pressure, according to the preset gradient, the temperature, pressure and flow rate of the test medium in the reactor are gradually increased according to the design parameters, and the corresponding reference corrosion parameters are collected, so as to systematically study the influence law of different operating parameters on the corrosion rate and provide a scientific basis for determining the optimal operating parameters. By selecting the characteristic parameters from multiple groups of reference corrosion parameters, the combination of operating parameters such as the temperature, pressure and flow rate of the test medium in the reactor that causes the most serious corrosion can be determined. By referring to the actual operating parameters of the object to be evaluated and setting the temperature, pressure and flow rate of the test medium in the reactor, the real working environment of the object to be evaluated can be highly restored, so that the comparison test results in the corrosion test system can truly reflect the corrosion conditions of the metal structure in the object to be evaluated under actual working conditions, and the accuracy and reliability of the test results are improved. By collecting the actual corrosion parameters of the test pieces in the gaseous, liquid and gas-liquid two-phase test media during the test, a rich and detailed data basis is provided for subsequent corrosion risk assessment, and the corrosion characteristics of the metal structure in different medium phases can be comprehensively displayed, which helps to deeply understand the corrosion mechanism. By comparing the actual corrosion parameters with the characteristic parameters according to the phase state classification, the change trend and difference of the corrosion rate under different operating parameter conditions can be clearly analyzed, and based on this comparison result, the actual operating parameters of the object to be evaluated can be adjusted, which has strong pertinence and scientificity. By optimizing the actual operating parameters, the corrosion risk of the metal structure in the object to be evaluated can be effectively reduced, the service life of the object to be evaluated can be extended, the maintenance and replacement costs of the object to be evaluated can be reduced, and the safety and stability of production can be improved, thus bringing significant economic and social benefits to the enterprise. Description of the Drawings

[0034] Figure 1Flow chart of the corrosion risk assessment method for an alternative embodiment of the present application;

[0035] Figure 2 Structural schematic diagram of the corrosion test system for an alternative embodiment of the present application;

[0036] Figure 3 Structural schematic diagram of the test rack for an alternative embodiment of the present application;

[0037] Figure 4 Structural schematic diagram of the connection between the test piece and the test rack for an alternative embodiment of the present application.

[0038] The reference signs are shown as:

[0039] 1, reaction kettle; 2, stirrer; 3, test rack; 4, test piece; 5, galvanic corrosion sensor; 6, pressure sensor; 7, temperature sensor; 8, flow rate sensor; 9, heater; 10, ceramic gasket; 11, signal amplifier; 12, data acquisition instrument; 13, computer. Detailed implementation manners

[0040] The present application will be described in detail below with reference to the drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0041] See Figure 1 As shown, in this embodiment, a corrosion risk assessment method is provided, including:

[0042] Step S101: Starting from normal temperature and pressure, according to a preset gradient and in accordance with the design parameters of the object to be evaluated, gradually increase the temperature, pressure in the reaction kettle 1, and the flow rate of the test medium in the reaction kettle 1, and conduct multiple groups of simulation tests.

[0043] The corrosion risk assessment method provided by the embodiments of the present application can be used in fields such as industrial pipeline corrosion tests, and specifically can be used in oil and gas pipeline corrosion tests. It can be understood that in the oil and gas pipeline corrosion test, the object to be evaluated is the actual oil and gas pipeline, and the metal structure is the pipeline component in the oil and gas pipeline.

[0044] Here, the corrosion risk assessment method is applied to the corrosion test system, and the corrosion situation of the pipeline components in the oil and gas pipeline is simulated through the corrosion test system. See Figure 2 And Figure 3As shown in the figure, the corrosion test system includes a reaction kettle 1, a stirrer 2 and a test rack 3. The reaction kettle 1 serves as the container for the entire corrosion test, which is used to hold various substances required for the test to create an environment similar to the actual working conditions. Here, the test medium is injected into the reaction kettle 1, and by adjusting conditions such as temperature and pressure of the reaction kettle 1, the environment in which the object to be evaluated is located during actual operation is simulated. For example, when simulating the corrosion environment of oil and gas pipelines, the reaction kettle 1 can reproduce the high-temperature and high-pressure state inside the oil and gas pipelines by heating up and pressurizing, so that the test medium is in a physical state similar to that inside the actual pipeline. The rotatable part of the stirrer 2 is located inside the reaction kettle 1 and is used to stir the test medium in the reaction kettle 1. Through stirring, the test medium can be evenly mixed, and the flow state of the actual fluid can be simulated, so that the test medium generates a similar flow rate and flow pattern, thereby making the hydrodynamic action on the test piece 4 closer to the actual situation. The test rack 3 is also located inside the reaction kettle 1 and is used to place the test piece 4. The test piece 4 represents the metal structure in the object to be evaluated, that is, the pipeline components in the oil and gas pipelines. In practical applications, the test rack 3 is provided with three layers in the vertical direction, and the liquid level of the test medium is accurately controlled at the middle layer position of the test rack 3, which can achieve a full-range simulation of the corrosion environment at different positions. Specifically, the upper layer of the test rack 3 is in a gaseous test medium environment, which can simulate the corrosion situation of pipeline components in the gas phase space part of oil and gas pipelines, such as some pipeline components above the liquid level or in the gas accumulation area; the middle layer of the test rack 3 is at the gas-liquid interface, which is a very special corrosion environment. It is wetted by the liquid test medium and contacts the gaseous test medium, and unique corrosion reactions will occur, corresponding to simulating the corrosion condition of pipeline components exactly at the gas-liquid interface position in the actual pipeline; the lower layer of the test rack 3 is completely immersed in the liquid test medium, which can simulate the corrosion situation of pipeline components that are long-term underwater or in a liquid environment. Through the setting of these three different environments, the corrosion behavior of the test piece 4 in test media with different phases can be comprehensively studied, and richer and more accurate corrosion data can be obtained, thus providing strong support for more accurately evaluating the corrosion risk. In addition, the test piece 4 is placed on the test rack 3, and the test piece 4 is fixed. By driving the test medium to flow by the stirrer 2, the actual situation inside the industrial pipeline can be simulated more purely. Compared with rotating the test piece 4 in the test medium, the additional mechanical stress introduced by the rotation of the test piece 4 itself is avoided, which may cause the test results to be difficult to be simply attributed to the corrosion effect between the test medium and the test piece 4, thus interfering with the accurate evaluation of the corrosion risk.

[0045] In this embodiment, first, before starting multiple groups of simulation tests, the temperature, pressure, and flow rate of the test medium in the reaction kettle 1 are adjusted to normal temperature and pressure. For the temperature, it can be stabilized at about 25 °C through heating elements such as the heater 9 of the reaction kettle 1; for the pressure, a pressure regulating device such as a booster pump is used to make the pressure in the reaction kettle 1 reach about 101.325 kPa; for the flow rate of the test medium, it can be controlled at a very low flow rate level by adjusting the rotation speed of the stirrer 2 to simulate a static or nearly static medium state. Then, a gradient is set according to the design parameters of the object to be evaluated, and the influence of different operating conditions on the corrosion of the specimen 4 is systematically studied. By gradually increasing these parameters, various working conditions that may be encountered in actual use can be simulated, which helps to comprehensively evaluate the corrosion risk of the object to be evaluated under different working conditions. It should be noted that the preset gradient can be determined according to actual experience, industry standards, or theoretical calculations to ensure that it covers the possible operating range of the object to be evaluated. Conducting multiple groups of simulation tests can obtain corrosion data under different working conditions. By comparing the data of different groups, the influence law of different parameter combinations on the corrosion of the specimen 4 can be analyzed, providing more comprehensive and detailed data support for corrosion risk assessment. In addition, the parameter combinations of different groups of tests form a parameter matrix, which helps researchers discover the interactive effects of various parameters on corrosion.

[0046] Step S102: Collect the corresponding reference corrosion parameters of the specimens 4 on each layer of the test rack 3 in multiple groups of simulation tests respectively, and select the characteristic parameters from the multiple groups of reference corrosion parameters.

[0047] In this embodiment, after each group of simulation tests, relevant corrosion data of each specimen 4 on the three layers of the test rack 3 are collected. These data are the reference corrosion parameters, such as the corrosion rate of the specimen 4, etc. From the numerous reference corrosion parameters, the characteristic parameters that can best represent the overall corrosion characteristics are selected. For example, the maximum corrosion rate can be selected as the characteristic parameter to characterize the most severe corrosion situation for subsequent comparative analysis.

[0048] Here, after each group of simulation tests, the relevant corrosion data of each specimen 4 on the three layers of the test rack 3 can be collected by various methods such as the weight loss method, electrochemical methods (such as using the galvanic corrosion sensor 5), etc.

[0049] Step S103: Replace the specimens 4 on each layer of the test rack 3, and set the temperature, pressure in the reaction kettle 1, and the flow rate of the test medium in the reaction kettle 1 with reference to the actual operating parameters of the object to be evaluated, and conduct comparative tests.

[0050] In this embodiment, according to the operating parameters of the object to be evaluated during actual operation, the temperature, pressure, and flow rate of the test medium in the reaction kettle 1 are adjusted to a range consistent with or similar to that of the actual pipeline, simulating the real working scenario of the object to be evaluated, so that the results of the comparative test are more in line with the actual situation. For example, if a certain section of the petroleum and natural gas pipeline to be evaluated is in a high-temperature operation state with an operating temperature between 80 °C and 120 °C, the temperature in the reaction kettle 1 needs to be precisely adjusted to this range. Specifically, in practical applications, heating elements such as heaters 9 can be set on the outer wall of the reaction kettle 1. According to the set target temperature, the heaters 9 and other heating elements keep the temperature in the reaction kettle 1 within the target range by heating or cooling. At the same time, the inner cavity of the reaction kettle 1 can be connected to a pressure regulating device such as a booster pump to adjust the pressure in the reaction kettle 1 to match the pressure level of the actual pipeline. At the same time, the rotation speed of the stirrer 2 in the reaction kettle 1 is adjusted so that the flow rate of the test medium in the reaction kettle 1 reaches a level similar to that of the actual pipeline. When the above temperature, pressure, and flow rate parameters are set, the comparative test is started. It should be noted that through the implementation of step S103, a corrosion test scenario highly similar to the actual operating environment of the petroleum and natural gas pipeline can be constructed in the laboratory environment, providing the basis and prerequisite for subsequent corrosion risk assessment, etc., so that the corrosion problems that the petroleum and natural gas pipeline may face under actual working conditions can be grasped in advance at a relatively low cost and with high safety, and provide a basis for optimizing the design, operation, and maintenance of the pipeline.

[0051] Here, in order to ensure the independence and reliability of the comparative test and avoid the influence of the simulation test on the results of the subsequent comparative test, the specimens 4 on each layer of the test rack 3 need to be replaced. The simulation test may cause certain physical and chemical changes on the surface of the specimens 4, such as the formation of corrosion products and the change of surface roughness. These changes will interfere with the accuracy of the subsequent comparative test. Therefore, using new specimens 4 that have not been affected by the simulation test can ensure that the comparative test starts under the same initial conditions and guarantee the comparability of the results of the comparative test.

[0052] Step S104: Collect the actual corrosion parameters corresponding to the specimens 4 on each layer of the test rack 3 in the comparative test. The actual corrosion parameters include the actual corrosion rate of the specimens 4 in the gaseous test medium, the actual corrosion rate in the liquid test medium, and the actual corrosion rate in the gas-liquid two-phase test medium.

[0053] In this embodiment, after the comparative test in step S103 is completed, it is necessary to quantitatively analyze the test results. Collecting the actual corrosion parameters of the specimen 4 under different medium states is a key link in evaluating the corrosion degree and risk. These parameters can directly reflect the corrosion rate of the specimen 4, which represents the pipeline components in oil and gas pipelines, under different environmental conditions in actual working conditions, providing important data support for comprehensively understanding the corrosion situation of the pipeline, analyzing the corrosion mechanism, and formulating protection measures in the follow-up. Specifically, the test rack 3 is arranged in three layers in the vertical direction, and the test medium environments where the specimens 4 are located in each layer are different. The upper specimens 4 are in a gaseous test medium environment, simulating the pipeline components in the gas phase space of oil and gas pipelines, such as the pipeline parts above the liquid level or in the gas accumulation area; the middle specimens 4 are at the gas-liquid interface, which is a special corrosion environment and is affected by both liquid and gaseous test media, corresponding to simulating the pipeline components at the gas-liquid junction position of the actual pipeline; the lower specimens 4 are completely immersed in the liquid test medium, simulating the pipeline components that are long-term underwater or in a liquid environment.

[0054] Here, by collecting data from the specimens 4 in each layer respectively, that is, collecting the corrosion rates in different phases, the corrosion situation of the specimens 4 in various actual environments can be comprehensively understood, providing richer data for subsequent evaluation.

[0055] Step S105: Classify and compare the actual corrosion parameters with the characteristic parameters according to the phase state, and adjust the actual operating parameters of the object to be evaluated based on the comparison results.

[0056] In this embodiment, the actual corrosion parameters obtained in the comparative test are classified according to gaseous, liquid, and gas-liquid states, and then compared with the characteristic parameters selected in step S102 respectively.

[0057] Here, the characteristic parameter is the maximum value of multiple reference corrosion parameters, which is used to characterize the most severe corrosion situation. Thus, by comparing the characteristic parameters and the actual corrosion parameters with the same phase state, it can be evaluated whether the actual operating parameters corresponding to the actual corrosion parameters need to be adjusted.

[0058] By applying the technical solution of this embodiment, the test rack 3 is arranged in three layers in the vertical direction, and the liquid level of the test medium is controlled at the middle position, so that the corrosion conditions of the test pieces 4 at different height positions in different gas-liquid phases and the gas-liquid interface can be simulated, more comprehensively reflecting the different corrosion environments that may exist in metal structures in actual applications. In multiple groups of simulation tests, starting from normal temperature and pressure, according to the preset gradient, the temperature, pressure and flow rate of the test medium in the reaction kettle 1 are gradually increased according to the design parameters, and the corresponding reference corrosion parameters are collected, so as to systematically study the influence law of different operating parameters on the corrosion rate and provide a scientific basis for determining the optimal operating parameters. By selecting the characteristic parameters from multiple groups of reference corrosion parameters, the combination of operating parameters such as the temperature, pressure and flow rate of the test medium in the reaction kettle 1 that causes the most serious corrosion can be determined. By referring to the actual operating parameters of the object to be evaluated, setting the temperature, pressure and flow rate of the test medium in the reaction kettle 1 can highly restore the real working environment of the object to be evaluated, so that the comparison test results carried out in the corrosion test system can truly reflect the corrosion conditions of the metal structures in the object to be evaluated under actual working conditions, improving the accuracy and reliability of the test results. By collecting the actual corrosion parameters of the test pieces 4 in the gaseous, liquid and gas-liquid two-phase test media during the test, a rich and detailed data basis is provided for subsequent corrosion risk assessment, which can comprehensively display the corrosion characteristics of metal structures in different medium phases and help to deeply understand the corrosion mechanism. By comparing the actual corrosion parameters with the characteristic parameters according to the phase state classification, the change trend and difference of the corrosion rate under different operating parameter conditions can be clearly analyzed, and based on this comparison result, the actual operating parameters of the object to be evaluated can be adjusted, which has strong pertinence and scientificity. By optimizing the actual operating parameters, on the premise of ensuring production efficiency, the corrosion risk of the metal structures in the object to be evaluated can be effectively reduced, the service life of the object to be evaluated can be extended, the maintenance and replacement costs of the object to be evaluated can be reduced, and the safety and stability of production can be improved, thus bringing significant economic and social benefits to the enterprise.

[0059] Further, as a refinement and extension of the specific implementation manner of the above embodiment, in order to completely illustrate the specific implementation process of this embodiment, another corrosion risk assessment method is provided, and this method includes:

[0060] Step S201: Starting from normal temperature and pressure, according to the preset gradient, in accordance with the design parameters of the object to be evaluated, gradually increase the temperature, pressure and the flow rate of the test medium in the reaction kettle 1, and conduct multiple groups of simulation tests;

[0061] Step S202: Respectively collect the corresponding reference corrosion parameters of the test pieces 4 on each layer of the test rack 3 in multiple groups of simulation tests, and select the characteristic parameters from multiple groups of reference corrosion parameters;

[0062] Step S203: Replace the test pieces 4 in each layer of the test rack 3, set the temperature, pressure inside the reaction kettle 1, and the flow rate of the test medium inside the reaction kettle 1 with reference to the actual operating parameters of the object to be evaluated, and conduct a comparative test;

[0063] Step S204: Collect the actual corrosion parameters corresponding to the test pieces 4 in each layer of the test rack 3 during the comparative test. The actual corrosion parameters include the actual corrosion rate of the test piece 4 in the gaseous test medium, the actual corrosion rate in the liquid test medium, and the actual corrosion rate in the gas-liquid two-phase test medium;

[0064] Step S205: Compare the actual corrosion parameters with the characteristic parameters according to the phase classification, and adjust the actual operating parameters of the object to be evaluated based on the comparison results.

[0065] Among them, step S202 includes:

[0066] Step S2021: Before conducting multiple groups of simulation tests, for each group of simulation tests, weigh each test piece 4 in each layer of the test rack 3 in turn, and record the initial weight of each test piece 4 in each layer of the test rack 3 in each group of simulation tests.

[0067] In this embodiment, before each group of simulation tests, it is necessary to weigh each test piece 4 placed on the three layers of the test rack 3 to obtain the initial weight of each test piece 4 before the test, which provides basic data for calculating the corrosion degree later and ensures that the weight change of the test piece 4 caused by corrosion and other factors during the simulation test can be accurately measured.

[0068] Here, a high-precision weighing device, such as an electronic balance, can be used to accurately weigh each test piece 4 placed on each layer of the test rack 3, and then record the initial weight of each test piece 4 on each layer of the test rack 3 in detail, including the layer number of the test rack 3 where the test piece 4 is located, the corresponding position number, and the accurate weight value.

[0069] Step S2022: After multiple groups of simulation tests are completed, for each group of simulation tests, weigh each test piece 4 in each layer of the test rack 3 in turn again, and record the final weight of each test piece 4 in each layer of the test rack 3 in each group of simulation tests.

[0070] In this embodiment, when all multiple groups of simulation tests are completed, weigh each test piece 4 on each layer of the test rack 3 in turn again. At this time, the recorded is the final weight of each test piece 4 after the simulation test. By comparing with the initial weight, the weight change of the test piece 4 during the simulation test can be known.

[0071] Here, using the same weighing equipment as before the simulation test, weigh each specimen 4 on each layer of the test rack 3 again, and record the final weight. Similarly, the records should be detailed and accurate, corresponding to the specific positions and numbers of each specimen 4.

[0072] Step S2023: Calculate the corrosion rate of each specimen 4 on each layer of the test rack 3 in each group of simulation tests based on the weight loss method, and obtain multiple groups of reference corrosion parameters.

[0073] In this embodiment, the weight loss method is used to calculate the corrosion rate of each specimen 4. The weight loss method is to calculate the corrosion rate of the specimen 4 in the simulated test environment based on the weight difference of the specimen 4 before and after the simulation test, combined with factors such as the test time and the area of the specimen 4. These corrosion rate data constitute multiple groups of reference corrosion parameters to reflect the corrosion conditions of the specimen 4 under different simulation test conditions.

[0074] Here, substitute the initial weight (m0) of the specimen 4, the final weight (m1) of the specimen 4, the surface area (S) of the specimen 4, and the time (t) of the simulation test into the formula v = (m0 - m1) / St for calculating the corrosion rate by the weight loss method, and obtain the corrosion rate of each specimen 4 on each layer of the test rack 3 under the simulation test, providing key data for subsequent corrosion risk assessment.

[0075] Step S2024: Screen and determine the reference corrosion parameter with the largest value among multiple groups of reference corrosion parameters, and use it as the characteristic parameter.

[0076] In this embodiment, select the reference corrosion parameter with the largest value from multiple groups of reference corrosion parameters and determine it as the characteristic parameter. Because the corrosion rate with the largest value can represent the most severe corrosion condition under these simulation test conditions, using it as the characteristic parameter helps subsequent analysis such as comparison with actual corrosion parameters to determine the differences in corrosion conditions between actual operating parameters and design parameters.

[0077] Among them, the corrosion test system further includes a galvanic corrosion sensor 5. At least three galvanic corrosion sensors 5 are provided, and at least three galvanic corrosion sensors 5 are arranged corresponding to the three layers of the test rack 3 one by one; the corrosion risk assessment method further includes:

[0078] Step S2025: During the continuous progress of each group of simulation tests, obtain the real-time corrosion current data output by the galvanic corrosion sensors 5 corresponding to each layer of the test rack 3 in real time.

[0079] In this embodiment, during the continuous progress of the entire simulation test, it is necessary to monitor the corrosion conditions of each layer of the test rack 3 in real time. The role of the galvanic corrosion sensor 5 is to obtain corrosion-related data to more comprehensively and timely understand the corrosion status during the test process.

[0080] Here, the electrodes of the galvanic corrosion sensor 5 are composed of a metal (anode) of the same material as the specimen and another metal or non-metal (cathode) with an obvious potential difference from the metal of the specimen material. In practical applications, since a thin liquid film is formed on the surface of the galvanic corrosion sensor 5 or it is completely covered by the corrosive medium, a circuit is formed. Due to the potential difference between the two electrodes, a primary battery effect occurs, resulting in electrochemical corrosion and generating a corrosion current. Since the anode is of the same material as the specimen 4, the magnitude of the corrosion current flowing through the galvanic corrosion sensor 5 can indirectly reflect the corrosion rate and degree of the specimen 4. The galvanic corrosion sensor 5 monitors the corrosion condition of the specimen 4 by detecting the change in the corrosion current. Moreover, since at least three galvanic corrosion sensors 5 are provided and correspond to the three layers of the test rack 3 one by one, the corrosion conditions of the specimens 4 in different positions, that is, different phases, can be monitored, ensuring the comprehensiveness and reliability of the data. Further, for real-time monitoring, refer to Figure 2 As shown, the corrosion test system further includes a data collector 12, and the galvanic corrosion sensor 5 is connected to the data collector 12. After the actual working condition simulation test starts, the galvanic corrosion sensor 5 continuously transmits the detected corrosion current data to the data acquisition system. For example, in the actual working condition simulation test, when the temperature, pressure, and flow rate of the test medium are stable according to the actual operating parameters of the object to be evaluated, the galvanic corrosion sensor 5 can collect data at a certain time interval (such as every second, every minute, or according to the accuracy requirements of the test). This time interval depends on the sampling frequency setting of the data acquisition system, and then transmits the sensed corrosion current data to the data collector 12 through the signal amplifier 11. Thus, in the actual working condition simulation test, the real-time corrosion current data of the galvanic corrosion sensor 5 at different times and different phases of the test medium can be obtained, providing a rich data source for the subsequent calculation of the real-time corrosion rate.

[0081] Step S2026: Calculate the corrosion rate of the galvanic corrosion sensor 5 corresponding to each layer of the test rack 3 based on the real-time corrosion current data.

[0082] In this embodiment, after obtaining the real-time corrosion current data, it is necessary to convert it into a corrosion rate that can directly reflect the corrosion degree, so as to more intuitively understand the corrosion conditions of each layer of the test rack 3 and provide a more valuable quantitative index for corrosion risk assessment.

[0083] Here, refer to Figure 2As shown, the corrosion test system further includes a computer 13, which is connected to the data acquisition instrument 12. The computer 13 is used to receive the real-time corrosion current data transmitted by the data acquisition instrument 12 and calculate the real-time corrosion rate of the galvanic corrosion sensor 5. Specifically, in practical applications, after the data acquisition instrument 12 obtains the real-time corrosion current data in step S2025, it then uploads it to the computer 13. The computer 13 pre-stores the Faraday's law algorithm and processes the real-time corrosion current data based on Faraday's law. That is to say, first, the real-time corrosion current data is converted into the mass loss of the galvanic corrosion sensor 5, and then further converted into the real-time corrosion rate, so as to indirectly reflect the corrosion situation of the test piece 4.

[0084] Among them, step S2026 includes:

[0085] Step S20261: Draw a curve graph of the mass loss of material corrosion, with the reaction time as the independent variable and the total mass loss of the material at different reaction times as the dependent variable, and visually display the change of the total mass loss of the material with the reaction time.

[0086] In this embodiment, the data from step S2025 is the basis for drawing the curve graph of the mass loss of material corrosion. In the simulation test, by continuously monitoring the real-time corrosion current data of multiple galvanic corrosion sensors 5 in different phases and at different times, and then calculating through the Faraday's law algorithm to convert these real-time corrosion current data into the total mass loss of the material at different reaction times. With the reaction time as the independent variable and the total mass loss of the material at different reaction times as the dependent variable, draw a curve graph of the mass loss of material corrosion. The tangent slope of each reaction time point in the curve graph of the mass loss of material corrosion is the real-time corrosion rate corresponding to each reaction time. For each galvanic corrosion sensor 5 corresponding to each layer of the test rack 3, there is a corresponding real-time corrosion rate value at different reaction time points. These data include the real-time corrosion rate of the galvanic corrosion sensor 5 in the gaseous, liquid, and gas-liquid two-phase test media at each time point during the entire test process. Then, take the reaction time of the test piece 4 in different phases as the x-axis data and the total mass loss of the material at different reaction times as the y-axis data and input them into the plotting tool. For example, for the galvanic corrosion sensor 5 in the gaseous test medium, input the data at different time points (starting from the 0 moment at the beginning of the test, increasing sequentially at a certain time interval until the end of the test), and at the same time input the total mass loss of the material of the corresponding galvanic corrosion sensor 5 at each time point. During this process, in order to distinguish the galvanic corrosion sensors 5 in different phases, it is necessary to group and draw the data in different phases. For example, use different colors or marks to distinguish the data of the galvanic corrosion sensors 5 in the gaseous, liquid, and gas-liquid two-phase states, and add a legend in the graph to clearly identify the phases represented by different curves.

[0087] Step S20262: Based on the material corrosion mass loss curve graph, calculate the corrosion rate of the galvanic corrosion sensors 5 corresponding to each layer of the test rack 3.

[0088] In this embodiment, from the material corrosion mass loss curve graph plotted in step S20261, extract the total material mass loss at different reaction times and the corresponding reaction time data of the galvanic corrosion sensors 5 in different phases. For each phase, there is a series of total material mass loss data, which correspond to different total reaction times. For the galvanic corrosion sensors 5 in the gaseous test medium, divide the total material mass loss during the entire test period by the total reaction time to obtain the corrosion rate of the galvanic corrosion sensors 5 in this phase. Similarly, the calculation methods for the corrosion rates of the galvanic corrosion sensors 5 in the liquid test medium and the gas-liquid two-phase test medium are the same as that of the galvanic corrosion sensors 5 in the gaseous test medium. Thus, it can be determined in which environment, namely the gaseous, liquid or gas-liquid two-phase test medium, the galvanic corrosion sensors 5, that is, the test pieces 4, are more likely to be corroded, providing guidance for subsequent corrosion risk assessment and actual operation parameter adjustment. It should be noted that since the corrosion process is a dynamic process, its corrosion rate may fluctuate at different time points. By calculating the average value, an index that can comprehensively reflect the corrosion situation of the galvanic corrosion sensors 5, that is, the test pieces 4, in this phase can be obtained, facilitating comparison and evaluation between different phases.

[0089] Among them, in view of the relatively cumbersome operation process of the weight loss method, and the corrosion rate of the galvanic corrosion sensors 5 can only indirectly reflect the corrosion rate of the test pieces 4. To achieve a more accurate and comprehensive corrosion risk assessment, the corrosion risk assessment method further includes:

[0090] Step S2027: For multiple groups of simulation tests, respectively organize the corrosion rate data of the test pieces 4 on each layer of the test rack 3 in each group of simulation tests, and the corresponding corrosion rate data of the galvanic corrosion sensors 5 on each layer.

[0091] In this embodiment, work is carried out for multiple groups of simulation tests. Each group of simulation tests here includes the corrosion rate data of the test pieces 4 on each layer of the test rack 3 and the corrosion rate data of the corresponding layer of the galvanic corrosion sensors 5. The corrosion rate data of the test pieces 4 on each layer of the test rack 3 are calculated based on the weight loss method in the previous steps; the corrosion rate data of the galvanic corrosion sensors 5 are calculated based on the real-time corrosion current data output by them.

[0092] Here, the data of each group of simulation tests are processed separately. The data can be sorted according to the groups of the simulation tests and the number of layers of the test rack 3. For example, it can be made into a table, with each row representing a group of simulation tests, and each column recording the corrosion rate of each layer of the test piece 4 and the corrosion rate of the corresponding galvanic corrosion sensor 5 in this group of tests. This can intuitively present the corresponding relationship of the data and facilitate subsequent analysis.

[0093] Step S2028: Using data analysis methods, based on the sorted corrosion rate data of multiple groups of test pieces 4 and the corrosion rate data of multiple groups of galvanic corrosion sensors 5, determine the conversion relationship between the corrosion rate of the galvanic corrosion sensor 5 and the corrosion rate of the test piece 4.

[0094] In this embodiment, by establishing a conversion relationship, a quantitative connection can be established between the corrosion rate of the galvanic corrosion sensor 5 and the corrosion rate of the test piece 4. This conversion relationship can comprehensively consider the characteristic differences between the galvanic corrosion sensor 5 and the test piece 4 under different test conditions, as well as the similarities and differences in the corrosion effects suffered by both. Specifically, in the process of determining the conversion relationship, first, a deep analysis of a large amount of test data is required. These data cover the real-time corrosion current data of the galvanic corrosion sensor 5, the corrosion rate calculated based on this, and the corrosion rate of the test piece 4 measured by the weight loss method under simulation tests with different operating parameter conditions. Through mathematical tools such as multiple linear regression analysis and neural network algorithms, combined with physical and chemical principles, a mathematical expression that can accurately reflect the relationship between the two is fitted. Subsequently, in actual applications, when only the corrosion rate of the galvanic corrosion sensor 5 can be obtained, the corrosion rate of the test piece 4 can be accurately calculated according to this conversion relationship, effectively making up for the defect that the galvanic corrosion sensor 5 cannot directly measure the corrosion rate of the test piece 4. At the same time, during the test process, if it is impossible to measure the corrosion rate of the test piece 4 by the weight loss method due to certain special circumstances, the conversion relationship can also provide key data support for corrosion risk assessment. Moreover, with the continuous accumulation of test data and the continuous expansion of test conditions, the conversion relationship can be optimized and updated to make it more in line with the actual situation, further improving the accuracy and reliability of corrosion risk assessment, providing stronger guarantee for the safe operation of oil and gas pipelines, and helping relevant enterprises make more scientific and reasonable decisions in pipeline design, maintenance strategy formulation, etc.

[0095] Among them, step S205 includes:

[0096] Step S2051: When the absolute value difference between the actual corrosion parameter and the characteristic parameter is within the preset interval, during actual operation, reduce the temperature and / or pressure and / or the flow rate of the test medium inside the object to be evaluated.

[0097] Here, the actual corrosion parameters are the corrosion rate data of specimen 4 measured by various methods (such as weight loss method, electrochemical method, etc.) in the comparative test under different phases, which reflect the corrosion situation of specimen 4 under the current actual operating parameters. The characteristic parameter is the maximum value of the reference corrosion parameters collected in multiple groups of simulation tests, representing the most severe corrosion situation. When calculating the absolute value difference between these two parameters and finding that it is within the preset setting range, it indicates that the corrosion situation under the actual operating parameters has approached the most severe corrosion situation, and there may be a relatively high corrosion risk, and measures need to be taken for adjustment. It should be noted that the preset setting range is determined according to specific industry standards, test experience or safety requirements, and this application does not limit it. For example, for some high-precision equipment or important industrial pipelines, the preset setting range may be set relatively narrow to ensure the long-term stable operation and safety of the equipment or pipeline; while for some relatively less sensitive application scenarios, the preset setting range can be relatively loose.

[0098] In this embodiment, in order to reduce the corrosion risk, it is necessary to adjust the parameters during the actual operation process. Since temperature, pressure and flow rate are the key factors affecting the corrosion rate, reducing these parameters can change the environment where specimen 4 is located, thereby changing the kinetic and thermodynamic conditions of the corrosion process, and further reducing the corrosion rate.

[0099] Furthermore, as a refinement and extension of the specific implementation manner of the above embodiment, in order to completely illustrate the specific implementation process of this embodiment, see Figure 2 As shown, the corrosion test system further includes a pressure sensor 6, a temperature sensor 7 and a flow rate sensor 8. The pressure sensor 6 is arranged on the top cover of the reaction kettle 1, the temperature sensor 7 is arranged on the bottom wall of the reaction kettle 1, and there are three flow rate sensors 8. The three flow rate sensors 8 are all arranged on the outer wall of the reaction kettle 1 and are arranged corresponding to the three layers of the test rack 3 one by one.

[0100] Among them, the pressure sensor 6 is used to obtain the pressure information in the reaction kettle 1 in real time to ensure the accuracy of the pressure during the test process. The temperature sensor 7 is used to obtain the pressure information in the reaction kettle 1 in real time to ensure the accuracy of the temperature during the test process. The flow rate sensor 8 is used to obtain the flow rate information of the test medium in the reaction kettle 1 in real time to ensure the accuracy of the flow rate during the test process.

[0101] Specifically, in practical applications, there are three flow rate sensors 8, and the three flow rate sensors 8 are arranged corresponding to the three layers of the test rack 3 one by one, which can respectively measure the flow rates of the test medium around the specimens 4 at different layers, and realize the precise monitoring of the flow rates of the test medium at different positions.

[0102] Furthermore, as a refinement and extension of the specific implementation manner of the above embodiment, in order to completely illustrate the specific implementation process of this embodiment, seeFigure 4 As shown, a ceramic gasket 10 is provided at the connection between the test piece 4 and the test rack 3. The ceramic gasket 10 is used to isolate the test piece 4 from the test rack 3. Thus, it is possible to prevent the formation of a galvanic couple between the test piece 4 and the test rack 3, protecting the test piece 4 from additional corrosion damage caused by galvanic corrosion with the test rack 3, thereby ensuring that the corrosion test system can create an environment similar to the actual working conditions and improving the accuracy of the test results.

[0103] Among them, the test rack 3 includes a column and a mounting ring. The mounting ring presents a three-layer structure layout in the vertical direction. The three-layer mounting ring is fixed on the column, forming a stable framework and providing a reliable support structure for the subsequent installed test piece 4.

[0104] Specifically, each layer of the mounting ring is equipped with a ceramic block, and the ceramic block is used to connect the test piece 4. In practical applications, the ceramic block is connected to the test piece 4 through a ceramic bolt, and the ceramic gasket 10 is arranged between the ceramic block and the test piece 4.

[0105] Furthermore, as a refinement and extension of the specific implementation manner of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, refer to Figure 3 As shown, multiple test pieces 4 are fixed on each layer of the test rack 3, enabling the corrosion test system to verify the relationship between the flow rate of the test medium and the corrosion rate under different phases.

[0106] Among them, by fixing multiple test pieces 4 on each layer, it is possible to simultaneously study the corrosion conditions of different test pieces 4 under the same flow rate conditions, or study the corrosion changes of the same test piece 4 under different flow rate conditions, providing multi-dimensional data support for the study of corrosion laws.

[0107] Specifically, multiple test pieces 4 are arranged on each layer of the test rack 3. When the multiple test pieces 4 have the same material, shape, size, and initial state, by changing the flow rate of the test medium, since the multiple test pieces 4 are in the same phase environment (such as gaseous, liquid, or gas-liquid two-phase) and the same flow rate conditions, the corrosion conditions of the multiple test pieces 4 can be observed simultaneously. For example, by methods such as the weight loss method or the galvanic corrosion sensor 5, the corrosion rate of each test piece 4 is measured. If the corrosion rates of the multiple test pieces 4 are similar at a certain specific flow rate, this enhances the reliability of the corrosion rate data at this flow rate. Moreover, by changing the flow rate, corresponding multiple corrosion rate data points at different flow rates can be obtained, and these data points are helpful for plotting the flow rate-corrosion rate curve to more accurately verify the relationship between the two.

[0108] Those skilled in the art can understand that the attached drawings are only schematic diagrams of a preferred implementation scenario, and the modules or processes in the attached drawings are not necessarily essential for implementing the present application. Those skilled in the art can understand that the modules in the devices in the implementation scenario can be distributed in the devices of the implementation scenario according to the description of the implementation scenario, or can be correspondingly changed and located in one or more devices different from this implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple sub-modules.

[0109] The above serial numbers of the present application are only for description and do not represent the advantages or disadvantages of the implementation scenarios. The above disclosure is only several specific implementation scenarios of the present application. However, the present application is not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of the present application.

Claims

1. A corrosion risk assessment method, applied to a corrosion test system, characterized in that: The corrosion test system comprises a reactor, a stirrer and a test stand, wherein the rotatable part of the stirrer and the test stand are both arranged in the reactor, the test stand is used to fix the test piece, the test stand is vertically arranged with three layers, the reactor is used to inject the test medium, and the liquid level of the test medium is controlled at the middle layer of the test stand; The corrosion risk assessment method comprises: Starting from normal temperature and pressure, according to a preset gradient and in accordance with the design parameters of the object to be evaluated, the temperature and pressure in the reactor and the flow rate of the test medium in the reactor are gradually increased to carry out multiple groups of simulation tests; Collecting a plurality of groups of reference corrosion parameters corresponding to the test pieces in each layer of the test frame in the simulation test respectively, and selecting characteristic parameters from the plurality of groups of reference corrosion parameters; Replace the test pieces in each layer of the test rack, set the temperature and pressure in the reactor and the flow rate of the test medium in the reactor with reference to the actual operating parameters of the object to be evaluated, and conduct a comparative test; Collecting actual corrosion parameters corresponding to the test pieces in each layer of the test rack in the comparative test, the actual corrosion parameters including the actual corrosion rate of the test pieces in the gaseous test medium, the actual corrosion rate in the liquid test medium, and the actual corrosion rate in the test medium in both gas and liquid states; Comparing the actual corrosion parameter with the characteristic parameter according to phase classification, and adjusting the actual operating parameter of the object to be evaluated based on the comparison result; The characteristic parameter is a parameter with the largest corrosion rate among the multiple groups of reference corrosion parameters.

2. The corrosion risk assessment method according to claim 1, characterized in that: The collecting of multiple groups of reference corrosion parameters corresponding to the test pieces in each layer of the test frame in the simulation test and selecting characteristic parameters from the multiple groups of reference corrosion parameters includes: Before carrying out multiple groups of simulation tests, for each group of simulation tests, weigh each of the test pieces in each layer of the test rack in turn, and record the initial weight of each of the test pieces in each layer of the test rack in each group of simulation tests; After the multiple groups of simulation tests are completed, for each group of simulation tests, each of the test pieces in each layer of the test rack is weighed again in turn, and the final weight of each of the test pieces in each layer of the test rack in each group of simulation tests is recorded; Calculate the corrosion rate of each test piece on each layer of the test frame in each group of simulation tests based on the weight loss method to obtain multiple groups of reference corrosion parameters; The parameter with the largest corrosion rate among the multiple groups of reference corrosion parameters is screened and determined, and is used as the characteristic parameter.

3. The corrosion risk assessment method according to claim 2, characterized in that: The corrosion test system further includes a galvanic corrosion sensor, at least three of which are provided, and the at least three galvanic corrosion sensors are provided in one-to-one correspondence with the three layers of the test frame; the corrosion risk assessment method further includes: During the continuous process of each group of simulation tests, real-time corrosion current data output by the galvanic corrosion sensors corresponding to each layer of the test frame are obtained in real time; The corrosion rates of the galvanic corrosion sensors corresponding to each layer of the test frame are calculated based on the real-time corrosion current data.

4. The corrosion risk assessment method according to claim 3, characterized in that: The calculating the corrosion rate of the galvanic corrosion sensor corresponding to each layer of the test frame based on the real-time corrosion current data includes: Draw a material corrosion mass loss curve graph, with reaction time as the independent variable and total material mass loss at different reaction times as the dependent variable, and visualize the change of total material mass loss with the reaction time; Based on the material corrosion mass loss curve, the corrosion rate of the galvanic corrosion sensor corresponding to each layer of the test frame is calculated.

5. The corrosion risk assessment method according to claim 3, characterized in that: After calculating the corrosion rate of the galvanic corrosion sensor corresponding to each layer of the test frame based on the real-time corrosion current data, the corrosion risk assessment method further includes: For the plurality of groups of simulation tests, respectively sorting out the corrosion rate data of the test pieces on each layer of the test rack in each group of simulation tests and the corresponding corrosion rate data of the galvanic corrosion sensors on each layer; Using a data analysis method, based on the sorted corrosion rate data of multiple groups of the test pieces and the corrosion rate data of multiple groups of the galvanic corrosion sensors, a conversion relationship between the corrosion rate of the galvanic corrosion sensor and the corrosion rate of the test piece is determined.

6. The corrosion risk assessment method according to claim 1, characterized in that: The comparing the actual corrosion parameter with the characteristic parameter according to the phase classification and adjusting the actual operating parameter of the object to be evaluated based on the comparison result comprises: When the difference between the absolute value of the actual corrosion parameter and the characteristic parameter is within a preset setting interval, during actual operation, the temperature and / or pressure inside the object to be evaluated and / or the flow rate of the test medium are reduced.

7. The corrosion risk assessment method according to claim 1, characterized in that: A plurality of the test pieces are fixed on each layer of the test rack, so that the corrosion test system can verify the relationship between the flow rate of the test medium and the corrosion rate of the test piece in different phases.

8. The corrosion risk assessment method according to claim 1, characterized in that: The corrosion test system also includes a pressure sensor, a temperature sensor and a flow rate sensor. The pressure sensor is arranged on the top cover of the reactor, the temperature sensor is arranged on the bottom wall of the reactor, and three flow rate sensors are arranged. The three flow rate sensors are all arranged on the outer wall of the reactor and are arranged one by one corresponding to the three layers of the test frame.

9. The corrosion risk assessment method according to claim 1, characterized in that: The corrosion test system also includes a booster pump and a heater. The booster pump is connected to the inner cavity of the reactor and is used to adjust the pressure inside the reactor. The heater is arranged on the outer wall of the reactor and is used to adjust the temperature inside the reactor.

10. The corrosion risk assessment method according to claim 1, characterized in that: A ceramic gasket is provided at the connection between the test piece and the test frame, and the ceramic gasket is used to isolate the test piece from the test frame.

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