A high-throughput erosion-corrosion test method

Abstract

The present invention relates to a high-throughput erosion corrosion test method, which arranges metal wires in a square matrix form and inserts them into metal wire positioning holes on a test module, then uses a nozzle to scour the metal wires on the test module for a set time, and then uses a three-dimensional optical surface profiler to perform non-contact scanning on each metal wire after scouring and construct a three-dimensional surface image model, and then obtains the surface corrosion pit volume V of each metal wire through software, thereby obtaining the corrosion rate of the metal wire, and then uses software to create a geometric model of the test module and the metal wire array, and uses a Fluent solver to calculate and obtain fluid parameter information on the surface of each metal wire, and finally integrates the scouring corrosion rate of each metal wire with the fluid parameter information on the surface of each metal wire, thereby obtaining the corrosion rate of the metal scour under different fluid conditions. The present invention improves test efficiency, shortens test cycle, and also reduces experimental costs.

Description

Technical Field

[0001] The invention relates to the technical field of metal erosion corrosion testing, in particular to a high-throughput erosion corrosion testing method. Background Art

[0002] Metal materials are prone to erosion corrosion under the action of fluids, and this type of corrosion is very common in marine environments, oil pipeline transportation and other fields. Some erosion corrosion testing methods have appeared in the prior art.

[0003] For example, a Chinese invention patent with authorization announcement number CN109359431B discloses a method for simulating pitting corrosion on the surface of materials in flowing seawater. This method can obtain the process of how the pitting morphology on the surface of the material changes with simulation time, and has a good simulation effect on the diffusion and corrosion process of the physical system. At the same time, the corrosion process is computerized, providing a good technical solution for subsequent analysis and summary.

[0004] For example, a Chinese invention patent with authorization announcement number CN112414935B discloses a desalination corrosion test method, which uses three sets of hanging plate assemblies to be placed in gas phase, gas-liquid phase, and liquid phase environments respectively to test the corrosion rate of the test piece.

[0005] For example, a Chinese invention patent with authorization announcement number CN114791401B discloses a pressurized large-diameter pipe flow variable-diameter erosion-corrosion testing device, which can detect the erosion-corrosion rate at different positions of the variable-diameter section of the oil and gas pipeline under real working conditions, and can evaluate the influence of various factors on the erosion-corrosion mechanism, providing valuable theoretical guidance for high-pressure erosion-corrosion protection of variable-diameter pipe sections.

[0006] The Chinese invention patent with authorization announcement number CN110132715B discloses an adjustable symmetrical multi-channel diversion erosion corrosion test system and test method, which can ensure that two symmetrical specimens can be subjected to erosion tests in exactly the same system, thereby avoiding errors in the system.

[0007] A Chinese invention patent with authorization announcement number CN107328707B discloses a method and device for testing high-temperature and high-pressure erosion-corrosion rate components. The method uses a multi-stage pipeline pump and a high-temperature and high-pressure autoclave to provide a corrosive solid-liquid two-phase flow with a certain temperature, pressure and speed and can be circulated, and the solid-liquid two-phase flow is used to flush the test elbow. At the same time, the total erosion-corrosion rate and each erosion / corrosion rate component in the erosion-corrosion process are tested by combining electrochemical methods, weight loss methods and cathodic protection methods. According to the relationship between the total erosion-corrosion rate and each erosion / corrosion rate component, each erosion / corrosion rate component is determined, which provides a technical basis for separately clarifying the mechanism of action of key factors such as corrosive media, fluid flow characteristics, and solid phase particle properties on erosion corrosion, as well as the selection and optimization design of oil pipe materials.

[0008] However, the metal erosion corrosion test methods in the prior art can usually only test a small number of samples at a time, so there are problems such as low test efficiency, long test cycle, and high cost. In the prior art, there is still a lack of effective test analysis means or methods for high-throughput erosion corrosion experiments. High-throughput experiments refer to experimental methods that complete the preparation or characterization of a large number of samples in a short period of time. The core of high-throughput experiments is to prepare or characterize samples under multiple conditions in parallel, complete the experimental data processing of multiple conditions at the same time, and ultimately improve the efficiency of material research. Summary of the invention

[0009] The purpose of the present invention is to provide a high-throughput erosion-corrosion testing method, which can obtain a large number of metal erosion-corrosion rates under different fluid conditions through a single injection experiment, thereby greatly improving the test efficiency, significantly shortening the test cycle, and also reducing the experimental cost.

[0010] The objective of the present invention is achieved through the following technical solutions:

[0011] A high-throughput erosion-corrosion testing method comprises the following steps:

[0012] Step 1: Arrange the metal wires in a square matrix and insert them into the corresponding metal wire positioning holes on the test module;

[0013] Step 2: Place the test module into the test device, then adjust the nozzle position and flushing flow rate in the test device, and control the spray solution temperature of the nozzle to reach the set value. After the adjustment is completed, open the nozzle and set the time for flushing the metal wire on the test module;

[0014] Step 3: Use a 3D optical surface profiler to perform non-contact scanning on the metal wire and construct a 3D surface image model. Then, the surface corrosion pit volume V of each metal wire is calculated by software, and the corrosion rate R of the metal wire is calculated by the following formula (1):

[0015]

[0016] In the above formula (1), S is the area of ​​the wire and T is the test time;

[0017] Step 4: Use the software to create the geometric model of the test module and the metal wire array, then use the ANSYSMeshing tool to generate a computational mesh for the geometric model, and import the generated mesh model into the Fluent solver, set the turbulence model of the Fluent solver to the SST Kw model, select the multiphase flow model as the VOF model, and set the flow rate and temperature to be consistent with the flushing flow rate and injection solution temperature in step 2, then enable the adaptive mesh model in the Fluent solver, and set the maximum refinement level to 2, the minimum mesh size to 0.00001m, and the maximum mesh size to 0.001m. Finally, run the Fluent solver to calculate and obtain the fluid parameter information on the surface of each metal wire;

[0018] Step 5: Integrate the erosion corrosion rate of each metal wire obtained in step 3 with the fluid parameter information on the surface of each metal wire obtained in step 4, so as to obtain the erosion corrosion rate of the metal material under different fluid conditions.

[0019] The test module includes an insulating plate and an insulating tube, wherein the insulating plate is provided with a plurality of metal wire positioning holes in a square matrix form. During installation, each metal wire is first inserted into the corresponding metal wire positioning hole on the insulating plate, and then the insulating plate is placed in the insulating tube and fixed, and then each metal wire is polished step by step with sandpaper.

[0020] In step three, after the three-dimensional surface image model of each metal wire is constructed, MATLAB is used to read the three-dimensional point cloud data of the metal wire surface, and then the K-means clustering function is called and the number of clusters and the Euclidean distance are defined. Then the K-means clustering function is executed. After the execution is completed, the clustered metal wire surface point cloud is extracted, and the boundary function is called to search for the boundary of the clustered metal wire surface point cloud. Then the volume calculation is performed to obtain the surface corrosion pit volume V of each metal wire sample.

[0021] In step 2, the test device includes a solution barrel, an input pump and an impact container, wherein the solution barrel is connected to the input pump through a first pipeline, the input pump is connected to the impact container through a second pipeline, and the end of the second pipeline is provided with a water inlet pipe driven to rise and fall by a lifting device, and the lower end of the water inlet pipe is provided with a rotatable and adjustable nozzle, the solution barrel is provided with a first thermocouple, the impact container is provided with a second thermocouple, and the test module is placed in the impact container and arranged below the nozzle.

[0022] The second pipeline is provided with an input flow meter.

[0023] The impact container is provided with an impact angle meter, the nozzle is rotatably mounted on the lower end of the water inlet pipe, and the nozzle is connected to the impact angle meter and driven to rotate by the impact angle meter.

[0024] A heater is arranged at the lower side of the solution barrel, and a cooling water pipe is arranged at one side of the solution barrel.

[0025] A water outlet pipe is provided at the lower end of the impact container and is communicated with the solution barrel.

[0026] The advantages and positive effects of the present invention are:

[0027] 1. The present invention can obtain a large number of metal erosion corrosion rates under different fluid conditions through a single injection experiment, thereby greatly improving the test efficiency, significantly shortening the test cycle, and also reducing the experimental cost.

[0028] 2. The test module for holding the metal wire used in the present invention is simple and convenient to manufacture and will not increase the test cost.

[0029] 3. The present invention arranges and positions each metal wire to be tested in a square matrix form, which can not only ensure the test quality, but also facilitate subsequent software analysis, thereby ensuring the test speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the relationship between the test module and the nozzle position of the present invention.

[0031] Figure 2 for Figure 1 Top view of the test module in

[0032] Figure 3 The present invention is a schematic diagram of the process of using a three-dimensional optical surface profiler to perform non-contact scanning on a metal wire and construct a three-dimensional surface image model.

[0033] Figure 4 This is a schematic diagram of the process of using software to obtain the fluid parameter information on the surface of the metal wire in the present invention.

[0034] Figure 5 The present invention is a schematic diagram of a test device structure for implementing the method of the present invention.

[0035] Among them, 1 is a wire positioning hole, 2 is a nozzle, 3 is a test module, 4 is a solution barrel, 401 is a first thermocouple, 402 is a heater, 403 is a cooling water pipe, 5 is a stirring pump, 6 is an input pump, 7 is an input flow meter, 8 is an impact container, 801 is a second thermocouple, 802 is an impact angle meter, 803 is a water outlet pipe, 9 is a water inlet pipe, and 10 is a lifting device. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] like Figures 1-2 As shown, the present invention includes a test module 3 and a position-adjustable nozzle 2, wherein the test module 3 is provided with a plurality of metal wire positioning holes 1 arranged in a square matrix. During the test, each metal wire is inserted into the corresponding metal wire positioning hole 1, and then the nozzle 2 starts to spray the solution and start the test.

[0038] The testing method of the present invention comprises the following steps:

[0039] Step 1: Insert each metal wire into the corresponding metal wire positioning hole 1 on the test module 3. In this embodiment, 49 metal wires with a diameter of 1 mm and a length of 5 cm are obtained by wire cutting of copper alloy, and then the 49 metal wires are inserted into the metal wire positioning holes 1 arranged in a 7×7 square matrix.

[0040] The present invention adopts a square matrix form to position each metal wire for the following purposes:

[0041] 1. Make the flow distribution uniform: The square arrangement enables the fluid to be evenly distributed between each metal wire, reducing the local high or low flow velocity areas generated during the flow of the fluid. This uniform flow distribution helps to provide consistent experimental conditions, thereby ensuring the repeatability and reliability of the experimental data.

[0042] 2. Covering a wide range of flow rate conditions: Since each metal wire is in a different position in the square array, the flow rate and angle of impact conditions they are in will also be different. This arrangement can cover different ranges of flow rates and angles of impact. In this way, the method of the present invention can capture a variety of fluid conditions from high flow rates (angles of impact) to low flow rates (angles of impact).

[0043] 3. Controllability: The present invention can control the flow velocity distribution in the experimental area by adjusting the arrangement density of the metal wire, so that different fluid conditions can be simulated to meet different experimental requirements, and the operation is also simple and convenient.

[0044] 4. Reduce boundary effects: The metal wire in the middle of this arrangement is less affected by boundary effects. Compared with other arrangements (such as linear arrangements), this method can better simulate the fluid conditions in actual working conditions and provide more realistic experimental results.

[0045] 5. Fluid dynamics advantage: In computational fluid dynamics simulation, the meshing and fluid dynamics calculations of this arrangement are relatively simple and effective, providing accurate predictions of flow velocity and pressure distribution, which helps to optimize experimental design.

[0046] In addition, in this embodiment, the test module 3 includes an insulating board with multiple metal wire positioning holes 1 and an insulating tube made of PVC plastic material. During installation, each metal wire is first inserted into the corresponding metal wire positioning hole 1 on the insulating board, and then the insulating board is placed in the insulating tube and fixed. The inner diameter of the insulating tube is equal to the outer diameter of the insulating board. Finally, each metal wire in the metal wire array is polished step by step to 800 mesh using sandpaper.

[0047] Step 2: Place the test module 3 into the test device, then adjust the position and flushing flow rate of the nozzle 2 in the test device, and control the spray solution temperature of the nozzle 2 to reach the set value. After the adjustment is completed, open the nozzle 2 and set the flushing time for the metal wire on the test module 3.

[0048] In this embodiment, the diameter of the nozzle 2 is 3 mm, the vertical distance between the nozzle 2 and the surface of the test module 3 is 5 mm, the flushing angle of the nozzle 2 is 30°, the flushing flow rate is 1 m / s, the flushing solution uses an artificial seawater solution, the temperature of the artificial seawater solution is controlled to 35°C, and the flushing test cycle is set to 7 days.

[0049] Step 3: If Figure 3 As shown, a three-dimensional optical surface profiler is used to perform non-contact scanning on the metal wire and construct a three-dimensional surface image model. Then, the surface corrosion pit volume V of each metal wire is calculated by software, and then the corrosion rate R of the sample is calculated by the following formula (1):

[0050]

[0051] In the above formula (1), S is the area of ​​the wire (in cm 2 ), T is the test time (in hours).

[0052] The above formula (1) is obtained according to the following formula (2) in the standard "JB / T 7901-2001 Metal Materials Laboratory Uniform Corrosion Full Immersion Test Method":

[0053]

[0054] V in formula (1) is equivalent to (M-M1) / D in formula (2), wherein M is the mass of the sample before the test, M1 is the mass of the sample after the test, and D is the density of the sample material. (M-M1) / D is the change in sample volume before and after the test, which is also V in formula (1). However, the method of the present invention uses software to calculate the V value.

[0055] like Figure 3As shown, after the three-dimensional surface image model is constructed, in this step, MATLAB software is used to read the three-dimensional point cloud data of the metal wire surface, and the K-means clustering function is called, wherein the number of clusters is defined as 1 and the Euclidean distance is 1, and then the K-means clustering function is executed. After the execution is completed, the clustered metal wire surface point cloud is extracted, and the boundary function is called to search for the clustered metal wire surface point cloud boundary, and then the volume calculation is performed to obtain the surface corrosion pit volume V of each metal wire, and finally the corrosion rate R of the sample is obtained by the above formula (1), wherein the K-means clustering function, the boundary function, etc. are all functions provided by the MATLAB software, and the three-dimensional optical surface profiler is a well-known technology in the art and is a commercially available product, for example, a three-dimensional optical surface profiler of the KathMatic brand can be used.

[0056] Step 4: Use software (such as Solidworks) to create a geometric model of the test module 3 and the wire array. To ensure the accuracy of the calculation, the geometric parameters in the geometric model are consistent with the object sizes in steps 1 and 2.

[0057] Then, the ANSYS Meshing tool is used to generate a computational mesh for the geometric model, and the generated mesh model is imported into the Fluent solver. The turbulence model is set to the SST Kw model, the multiphase flow model is selected to be the VOF model, and the flow rate and temperature are set to be consistent with the flushing flow rate and injection solution temperature in step 2.

[0058] Considering the particularity of the metal wire array, especially the diameter and spacing of the filaments, conventional processing methods will not be able to generate a sufficiently fine grid, and it is difficult to accurately capture the complex interactions and flow characteristics between the metal wire surface and the jet fluid. Therefore, the present invention uses the adaptive grid model in the Fluent solver to improve the accuracy and reliability of the simulation, sets the maximum refinement level to 2, the minimum grid size to 0.00001m, and the maximum grid scale to 0.001m, and finally runs the Fluent solver to calculate and obtain the fluid parameter information of each metal wire surface. In this embodiment, the fluid parameter information includes flow velocity and angle of attack.

[0059] The ANSYS Meshing tool and Fluent solver are both well-known technologies in the art.

[0060] Step 5: Use software to integrate the erosion corrosion rate of each metal wire obtained in step 3 with the fluid parameter information on the surface of each metal wire obtained in step 4, so as to obtain the corrosion rate of the metal material under different fluid conditions, where the different fluid conditions are the fluid parameter information on the surface of each metal wire obtained in step 4. For example, in this embodiment, 49 metal wires can be numbered from 1 to 49 in sequence, and the erosion corrosion rate of metal wire No. 1 corresponding to step 3 corresponds to the fluid parameter information of metal wire No. 1 corresponding to step 4.

[0061] From the above, it can be seen that the testing method of the present invention can obtain a large amount of metal erosion corrosion rate data under different fluid conditions (different flow rates and injection angles) at one time through a single injection test of nozzle 2, wherein the fluid parameter information on the surface of each metal wire represents a fluid condition. In this embodiment, there are 49 metal wires, so the metal wire erosion corrosion rates under 49 different fluid conditions can be obtained at one time through a single injection test of nozzle 2, thereby greatly improving the test efficiency.

[0062] In addition, Figure 5As shown, a test device that can be used in the method of the present invention includes a solution barrel 4, an input pump 6 and an impact container 8, wherein the solution barrel 4 is connected to the input pump 6 through a first pipeline, the input pump 6 is connected to the impact container 8 through a second pipeline, and the end of the second pipeline is provided with a water inlet pipe 9 driven to rise and fall by a lifting device 10, the lifting device 10 can adopt a linear drive device such as an electric push rod, a cylinder, and an oil cylinder, and the power shaft end of the linear drive device is connected to the water inlet pipe 9 through a cross bar, the lower end of the water inlet pipe 9 is provided with the nozzle 2, the nozzle 2 is driven to rise and fall through the water inlet pipe 9 and changes the distance between it and the upper surface of the test module 3, in addition, the input pump 6 controls the input solution flow through the equipment control system, and the second pipeline is provided with an input flowmeter 7 for real-time detection of whether the input solution flow meets the requirements. The impact container 8 is provided with a rotatable impact angle meter 802, the nozzle 2 is rotatably installed at the lower end of the water inlet pipe 9, and the nozzle 2 is connected to the impact angle meter 802. The operator can drive the nozzle 2 to rotate by rotating the impact angle meter 802 to change the spray angle. The solution barrel 4 is provided with a first thermocouple 401 for real-time monitoring of the liquid temperature in the barrel, and the impact container 8 is provided with a second thermocouple 801 for real-time detection of the liquid temperature in the container, so as to ensure that the temperature of the sprayed solution meets the test requirements. The lower side of the solution barrel 4 is provided with a heater 402, and one side of the solution barrel 4 is provided with a cooling water pipe 403. If the solution temperature does not meet the requirements, the equipment control system adjusts the solution temperature to meet the requirements by controlling the heater 402 to heat or controlling the cooling water pipe 403 to input cooling water. In addition, a water outlet pipe 803 is provided at the lower end of the impact container 8 to communicate with the solution barrel 4, and a control valve is provided on the water outlet pipe 803. The solution in the impact container 8 can be discharged into the solution barrel 4 through the water outlet pipe 803. A stirring pump 5 is also provided on one side of the solution barrel 4. After the stirring pump 5 is started, it can play a role in stirring the solution in the solution barrel 4.

[0063] The present invention can also use other suitable test devices to complete the test according to actual needs.

Claims

1. A high-throughput erosion-corrosion testing method, characterized in that: The steps include: Step 1: Arrange the metal wires in a square matrix and insert them into the corresponding metal wire positioning holes (1) on the test module (3); Step 2: Place the test module (3) into the test device, then adjust the position and flushing flow rate of the nozzle (2) in the test device, and control the temperature of the spray solution of the nozzle (2) to reach a set value. After the adjustment is completed, open the nozzle (2) and set the flushing time for the metal wire on the test module (3); Step 3: Use a 3D optical surface profiler to perform non-contact scanning on the metal wire and construct a 3D surface image model. Then, the surface corrosion pit volume V of each metal wire is calculated by software, and the corrosion rate R of the metal wire is calculated by the following formula (1): （1）； In the above formula (1), S is the area of ​​the wire and T is the test time; In this step, after the three-dimensional surface image model of each metal wire is constructed, MATLAB is used to read the three-dimensional point cloud data of the metal wire surface, and then the K-means clustering function is called and the number of clusters and the Euclidean distance are defined, and then the K-means clustering function is executed. After the execution is completed, the clustered metal wire surface point cloud is extracted, and the boundary function is called to search for the boundary of the clustered metal wire surface point cloud, and then the volume is calculated to obtain the surface corrosion pit volume V of each metal wire sample; Step 4: Use software to create the geometric model of the test module (3) and the metal wire array, then use the ANSYSMeshing tool to generate a computational mesh for the geometric model, and import the generated mesh model into the Fluent solver, set the turbulence model of the Fluent solver to the SST Kw model, select the multiphase flow model as the VOF model, and set the flow rate and temperature to be consistent with the flushing flow rate and injection solution temperature in step 2, then enable the adaptive mesh model in the Fluent solver, and set the maximum refinement level to 2, the minimum mesh size to 0.00001m, and the maximum mesh size to 0.001m. Finally, run the Fluent solver to calculate and obtain the flow rate and angle of attack information on the surface of each metal wire; Step 5: Integrate the erosion corrosion rate of each metal wire obtained in step 3 with the fluid parameter information on the surface of each metal wire obtained in step 4, so as to obtain the erosion corrosion rate of the metal wire under different flow rate conditions and different impact angle conditions.

2. The high-throughput erosion-corrosion testing method according to claim 1, characterized in that: The test module (3) comprises an insulating plate and an insulating tube, wherein the insulating plate is provided with a plurality of metal wire positioning holes (1) in the form of a square matrix. During installation, each metal wire is first inserted into the corresponding metal wire positioning hole (1) on the insulating plate, then the insulating plate is placed in the insulating tube and fixed, and then each metal wire is polished step by step with sandpaper.

3. The high-throughput erosion-corrosion testing method according to claim 1, characterized in that: In step 2, the test device comprises a solution barrel (4), an input pump (6) and an impact container (8), wherein the solution barrel (4) is connected to the input pump (6) via a first pipeline, the input pump (6) is connected to the impact container (8) via a second pipeline, and a water inlet pipe (9) driven to be raised and lowered by a lifting device (10) is provided at the end of the second pipeline, a rotatably adjustable nozzle (2) is provided at the lower end of the water inlet pipe (9), a first thermocouple (401) is provided in the solution barrel (4), a second thermocouple (801) is provided in the impact container (8), and the test module (3) is placed in the impact container (8) and arranged below the nozzle (2).

4. The high-throughput erosion-corrosion testing method according to claim 3, characterized in that: An input flow meter (7) is provided on the second pipeline.

5. The high throughput erosion corrosion testing method according to claim 3, characterized in that: An impact angle meter (802) is provided on the impact container (8), the nozzle (2) is rotatably mounted on the lower end of the water inlet pipe (9), and the nozzle (2) is connected to the impact angle meter (802) and is driven to rotate by the impact angle meter (802).

6. The high throughput erosion corrosion testing method according to claim 3, characterized in that: A heater (402) is provided on the lower side of the solution barrel (4), and a cooling water pipe (403) is provided on one side of the solution barrel (4).

7. The high throughput erosion corrosion testing method according to claim 3, characterized in that: A water outlet pipe (803) is provided at the lower end of the impact container (8) and is connected to the solution barrel (4).

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