阅读说明：本技术 一种天然气管道内壁冲刷腐蚀实验装置及方法 (Natural gas pipeline inner wall erosion corrosion experimental device and method ) 是由 李恩田 齐磊 祝晓杰 李莹屏 王钰颖 周诗岽 吕晓方 于 2021-08-04 设计创作，主要内容包括：本发明涉及一种天然气管道内壁冲刷腐蚀实验装置及方法,具有密封房,密封房外设有自控单元,所述自控单元包括计算机、电化学工作站以及控制柜,所述密封房内设有气体供应单元、液体气化单元、气液混合单元、温度控制单元、冲刷腐蚀实验单元以及有害气体回收单元,密封房的墙壁和地面均设有有害气体探测仪。本发明通过调节腐蚀性气体种类和含量、湿度、温度等条件,可以高度模仿天然气管道内的冲刷腐蚀过程,另外可以控制流体的流速、实验系统的压力等参数,对金属试样进行冲刷腐蚀实验,并可以进行电化学腐蚀测试。实验结束后可以对金属试样多方位内壁的冲刷腐蚀程度进行形貌观察,通过计算得出金属试样的冲刷腐蚀速率。(The invention relates to a natural gas pipeline inner wall erosion corrosion experiment device and a method, which comprises a sealed room, wherein an automatic control unit is arranged outside the sealed room, the automatic control unit comprises a computer, an electrochemical workstation and a control cabinet, a gas supply unit, a liquid gasification unit, a gas-liquid mixing unit, a temperature control unit, an erosion corrosion experiment unit and a harmful gas recovery unit are arranged in the sealed room, and harmful gas detectors are arranged on the wall and the ground of the sealed room. The invention can highly imitate the erosion corrosion process in the natural gas pipeline by adjusting the type and content of corrosive gas, humidity, temperature and other conditions, and can control the parameters of the flow rate of fluid, the pressure of an experimental system and the like, carry out erosion corrosion experiments on metal samples and carry out electrochemical corrosion tests. After the experiment is finished, the appearance of the erosion corrosion degree of the multi-azimuth inner wall of the metal sample can be observed, and the erosion corrosion rate of the metal sample can be obtained through calculation.)

1. The utility model provides a natural gas line inner wall erodees and corrodes experimental apparatus, has sealed room, and sealed room is equipped with the automatic control unit outward, the automatic control unit includes computer, electrochemistry workstation and switch board, characterized by: the sealed room is internally provided with a gas supply unit, a liquid gasification unit, a gas-liquid mixing unit, a temperature control unit, a scouring corrosion experiment unit and a harmful gas recovery unit, and the wall and the ground of the sealed room are respectively provided with a harmful gas detector;

a gas supply unit: the device is provided with a gas mixing tank, wherein the gas mixing tank is communicated with a carbon dioxide gas cylinder, a hydrogen sulfide gas cylinder and a sulfur dioxide gas cylinder, the outer bottom of the gas mixing tank is provided with an electromagnetic rotator, and the gas outlet end of the gas mixing tank is connected with a gas-liquid mixing unit;

a liquid gasification unit: the automatic water replenishing device is provided with an automatic water replenishing device and a liquid vaporization tank, wherein the water inlet end of the automatic water replenishing device is connected with an external tap water pipe, the water outlet end of the automatic water replenishing device is communicated with the liquid vaporization tank, an electric heating pipe is arranged at the bottom in the liquid vaporization tank, and the outlet end of the liquid vaporization tank is connected with a gas-liquid mixing unit;

a gas-liquid mixing unit: the device is provided with a gas-liquid mixing tank, an electromagnetic rotator is arranged outside the bottom of the gas-liquid mixing tank, the left side of the gas-liquid mixing tank is connected with the gas mixing tank and corrosive mixed gas is introduced, water vapor from a liquid vaporization tank enters the gas-liquid mixing tank from the upper edge of the left side of the gas-liquid mixing tank, and the outlet end of the right side of the gas-liquid mixing tank is connected with a temperature control unit;

a temperature control unit: the device is provided with a constant-temperature water bath tank connected with a gas-liquid mixing tank pipeline, and the outlet end of the constant-temperature water bath tank is connected to a scouring corrosion experiment unit;

erosion corrosion experiment unit: the device is provided with two flanges which are arranged at a distance, a metal sample is hermetically arranged between the flanges, a reference electrode, an auxiliary electrode and a temperature probe are radially arranged in the flanges, and a gas-liquid mixture transmitted by a constant temperature water bath tank is introduced into the metal sample;

a harmful gas recovery unit: the device is provided with two harmful gas recovery tanks which are arranged side by side, wherein the harmful gas recovery tanks are filled with harmful gas absorption liquid, a gas-liquid mixture flowing through a metal sample is introduced into the previous harmful gas recovery tank and then flows into the next harmful gas recovery tank, and the next harmful gas recovery tank is connected with a purified gas recovery tank through a pipeline.

2. The natural gas pipeline inner wall erosion corrosion experimental device of claim 1, characterized in that: the gas mixing tank is connected with an air compressor for improving the gas mixing effect.

3. The natural gas pipeline inner wall erosion corrosion experimental device of claim 1, characterized in that: the bottom of the inner cavities of the gas mixing tank and the gas-liquid mixing tank are respectively provided with a rubber fan fin matched with the electromagnetic rotator for use.

4. The natural gas pipeline inner wall erosion corrosion experimental device of claim 1, characterized in that: the constant-temperature water bath box is communicated with the metal sample through a heat-insulating pipeline.

5. The natural gas pipeline inner wall erosion corrosion experimental device of claim 1, characterized in that: rubber gaskets are respectively arranged between two ends of the metal sample and the flanges, and a working electrode jacket is sleeved on the metal sample.

6. The natural gas pipeline inner wall erosion corrosion experimental device of claim 1, characterized in that: and a baffling baffle for delaying the gas flowing time is arranged in the harmful gas recovery tank.

7. An experimental method of the natural gas pipeline erosion corrosion experimental device according to claim 1, comprising the following steps:

s1, polishing and smoothing the metal sample, weighing, and recording M₀(ii) a The metal sample is hermetically arranged between the two flanges, and the electrochemical workstation is respectively connected with the reference electrode, the auxiliary electrode and the metal sample line;

s2, according to corrosive gas components contained in the natural gas conveying pipeline, configuring mixed gas used for experiments in a gas mixing tank, adjusting the proportion of the mixed gas to be simulated, opening an electromagnetic rotator at the bottom of the gas mixing tank to fully mix the mixed gas in the gas mixing tank, and adding a harmful gas absorption liquid into a harmful gas recovery tank;

s3, starting the automatic water replenishing device to introduce tap water into the liquid vaporization tank, simultaneously starting the electric heating pipe to heat the tap water, and introducing the generated water vapor into the gas-liquid mixing tank;

s4, opening an electromagnetic rotator at the bottom of the gas-liquid mixing tank to fully mix gas and water vapor in the gas-liquid mixing tank, and enabling the mixed gas-liquid mixture to flow out from the right side of the gas-liquid mixing tank;

s5, adjusting the temperature of the gas-liquid mixture flowing through the thermostatic water bath box;

s6, allowing the temperature-adjusted gas-liquid mixture to flow through the metal sample, starting the erosion corrosion test, and recording the start time T of the test₀Opening the electrochemical workstation to test the open-circuit potential;

s7, carrying out interval test on potential and impedance in the experiment process, carrying out Tafel curve test when the experiment is finished, and recording the end time of the experiment as T₁Closing all instruments, checking whether harmful gas exists in the sealed room through a harmful gas detector, if not, opening a door and a window after entering the room, and taking down the metal sample;

s8, observing the appearance of the metal sample after the experiment, removing corrosion products, weighing, and recording M₁The average erosion corrosion rate V of the sample can be obtained according to the following formula:

Technical Field

The invention relates to the technical field of petroleum and natural gas, in particular to a natural gas pipeline inner wall erosion corrosion experimental device and method.

Background

In the process of natural gas exploitation, associated gases such as carbon dioxide, hydrogen sulfide, sulfur dioxide, water vapor and the like often exist, the heat value of natural gas is reduced, scouring corrosion effects on pipelines, equipment and the like are generated, perforation, fracture and the like are caused on the natural gas pipelines, normal and stable gas supply is damaged, production and life of users are affected, and damage caused by scouring corrosion causes great economic loss to the country and also threatens life safety of workers. Therefore, it is necessary to design a simple, efficient, pollution-free and high-safety device and study the erosion corrosion mechanism and influencing factors in the natural gas pipeline.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to overcome the defects in the prior art, the invention provides a natural gas pipeline inner wall erosion corrosion experimental device and an experimental method, which aim to solve the following problems: (1) the influence of the type and the content of corrosive gas in the fluid on the erosion corrosion process of the pipeline cannot be determined; (2) the problem of erosion corrosion degree of the inner wall of the multi-position pipeline cannot be fully reflected in the traditional hanging piece experiment; (3) the influence of water content (water vapor) on the flushing corrosion process.

The technical scheme adopted by the invention for solving the technical problems is as follows: a natural gas pipeline inner wall erosion corrosion experiment device and a method are provided with a sealed room, an automatic control unit is arranged outside the sealed room and comprises a computer, an electrochemical workstation and a control cabinet, a gas supply unit, a liquid gasification unit, a gas-liquid mixing unit, a temperature control unit, an erosion corrosion experiment unit and a harmful gas recovery unit are arranged in the sealed room, and harmful gas detectors are arranged on the wall and the ground of the sealed room;

a gas supply unit: the device is provided with a gas mixing tank, wherein the gas mixing tank is communicated with a carbon dioxide gas cylinder, a hydrogen sulfide gas cylinder and a sulfur dioxide gas cylinder, the outer bottom of the gas mixing tank is provided with an electromagnetic rotator, and the gas outlet end of the gas mixing tank is connected with a gas-liquid mixing unit;

a liquid gasification unit: the automatic water replenishing device is provided with an automatic water replenishing device and a liquid vaporization tank, wherein the water inlet end of the automatic water replenishing device is connected with an external tap water pipe, the water outlet end of the automatic water replenishing device is communicated with the liquid vaporization tank, an electric heating pipe is arranged at the bottom in the liquid vaporization tank, and the outlet end of the liquid vaporization tank is connected with a gas-liquid mixing unit;

a gas-liquid mixing unit: the device is provided with a gas-liquid mixing tank, an electromagnetic rotator is arranged outside the bottom of the gas-liquid mixing tank, the left side of the gas-liquid mixing tank is connected with the gas mixing tank and corrosive mixed gas is introduced, water vapor from a liquid vaporization tank enters the gas-liquid mixing tank from the upper edge of the left side of the gas-liquid mixing tank, and the outlet end of the right side of the gas-liquid mixing tank is connected with a temperature control unit;

a temperature control unit: the device is provided with a constant-temperature water bath tank connected with a gas-liquid mixing tank pipeline, and the outlet end of the constant-temperature water bath tank is connected to a scouring corrosion experiment unit;

erosion corrosion experiment unit: the device is provided with two flanges which are arranged at a distance, a metal sample is hermetically arranged between the flanges, a reference electrode, an auxiliary electrode and a temperature probe are radially arranged in the flanges, and a gas-liquid mixture transmitted by a constant temperature water bath tank is introduced into the metal sample;

a harmful gas recovery unit: the device is provided with two harmful gas recovery tanks which are arranged side by side, wherein the harmful gas recovery tanks are filled with harmful gas absorption liquid, a gas-liquid mixture flowing through a metal sample is introduced into the previous harmful gas recovery tank and then flows into the next harmful gas recovery tank, and the next harmful gas recovery tank is connected with a purified gas recovery tank through a pipeline.

In order to improve the air quantity in the gas mixing tank and realize sufficient gas mixing, the gas mixing tank is connected with an air compressor.

In order to improve the mixing effect of the gas, rubber fan fins matched with the electromagnetic rotator are arranged at the bottoms of the inner cavities of the gas mixing tank and the gas-liquid mixing tank.

The constant-temperature water bath box is communicated with the metal sample through a heat insulation pipeline so as to ensure that the temperature of the transmitted gas-liquid mixture is constant and meet the experimental requirements.

In order to improve the tightness of the metal sample during testing, rubber gaskets are respectively arranged between the two ends of the metal sample and the flange, and a working electrode jacket is sleeved on the metal sample.

The inside of the harmful gas recovery tank is provided with a baffle plate for delaying the gas flow time, so that the acid gas can be fully absorbed.

A method for carrying out a natural gas pipeline erosion corrosion experiment by adopting the experimental device comprises the following steps:

s1, polishing and smoothing the metal sample, weighing, and recording M₀(ii) a The metal sample is hermetically arranged between the two flanges, and the electrochemical workstation is respectively connected with the reference electrode, the auxiliary electrode and the metal sample line;

s2, according to corrosive gas components contained in the natural gas conveying pipeline, configuring mixed gas used for experiments in a gas mixing tank, adjusting the proportion of the mixed gas to be simulated, opening an electromagnetic rotator at the bottom of the gas mixing tank to fully mix the mixed gas in the gas mixing tank, and adding a harmful gas absorption liquid into a harmful gas recovery tank;

s3, starting the automatic water replenishing device to introduce tap water into the liquid vaporization tank, simultaneously starting the electric heating pipe to heat the tap water, and introducing the generated water vapor into the gas-liquid mixing tank;

s4, opening an electromagnetic rotator at the bottom of the gas-liquid mixing tank to fully mix gas and water vapor in the gas-liquid mixing tank, and enabling the mixed gas-liquid mixture to flow out from the right side of the gas-liquid mixing tank;

s5, adjusting the temperature of the gas-liquid mixture flowing through the thermostatic water bath box;

s6, allowing the temperature-adjusted gas-liquid mixture to flow through the metal sample, starting the erosion corrosion test, and recording the start time of the testT₀Opening the electrochemical workstation to test the open-circuit potential;

s7, carrying out interval test on potential and impedance in the experiment process, carrying out Tafel curve test when the experiment is finished, and recording the end time of the experiment as T₁Closing all instruments, checking whether harmful gas exists in the sealed room through a harmful gas detector, if not, opening a door and a window after entering the room, and taking down the metal sample;

s8, observing the appearance of the metal sample after the experiment, removing corrosion products, weighing, and recording M₁The average erosion corrosion rate V of the sample can be obtained according to the following formula:

the invention has the beneficial effects that: the invention

Drawings

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a schematic structural diagram of a erosion corrosion test unit according to the present invention.

FIG. 3 is a schematic structural diagram of a metal coupon according to the present invention.

Fig. 4 is a schematic structural view of a harmful gas recovery tank according to the present invention.

In the figure:

1. the system comprises an automatic control unit, 1-1 a computer, 1-2 an electrochemical workstation, and 1-3 a control box;

2. the gas supply unit comprises 2-1 parts of a carbon dioxide gas cylinder, 2-2 parts of a sulfur dioxide gas cylinder, 2-3 parts of a hydrogen sulfide gas cylinder, 2-4 parts of a gas mixing tank, 2-5 parts of an air compressor and 2-6 parts of an electromagnetic rotator;

3. liquid vaporization unit, 3-1 automatic water replenishing device, 3-2 liquid vaporization tank, 3-3 electric heating tube,

4. the device comprises a gas-liquid mixing unit, 4-1. a gas-liquid mixing tank, 4-2. an anticorrosive coating, 4-3. an electromagnetic rotator and 4-4. a gas-liquid mixing and conveying pump;

5. a temperature control unit, 5-1, a constant temperature water bath box, 5-2, a heat preservation pipeline;

6. the method comprises the following steps of (1) a scouring corrosion test unit, 6-1 a flange, 6-2 a reference electrode, 6-3 an auxiliary electrode, 6-4 a metal sample, 6-5 a rubber gasket and 6-6 a working electrode jacket;

7. a harmful gas recovery unit, 7-1. a harmful gas recovery tank, 7-2. a harmful gas absorption liquid, 7-3. a deflection baffle, and 7-4. a purified gas recovery tank;

8. and 9, a sealed room and a harmful gas detector.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

The natural gas pipeline inner wall erosion corrosion experiment device shown in fig. 1-4 is installed in a sealed room 8, an automatic control unit 1 for an operator to perform experiment control is arranged in a control chamber outside the sealed room 8, and the automatic control unit 1 comprises a computer 1-1, an electrochemical workstation 1-2 and a control box 1-3.

Two sets of harmful gas detectors 9 are installed in the sealed room 8, one set of harmful gas detectors 9 is arranged on the inner wall of one side of the sealed room 8, and the other set of harmful gas detectors 9 is arranged on the ground on the other side of the sealed room 8.

The sealed room 8 is internally provided with: a gas supply unit 2, a liquid vaporization unit 3, a gas-liquid mixing unit 4, a temperature control unit 5, a erosion corrosion test unit 6, and a harmful gas recovery unit 7.

The gas supply unit 2: the device is provided with a carbon dioxide gas cylinder 2-1, a hydrogen sulfide gas cylinder 2-2 and a sulfur dioxide gas cylinder 2-3, wherein the carbon dioxide gas cylinder 2-1, the hydrogen sulfide gas cylinder 2-2 and the sulfur dioxide gas cylinder 2-3 are sequentially connected with a gas mixing tank 2-4 through electric valves, gas booster pumps and gas flow meters on respective pipelines, an air compressor 2-5 is sequentially connected with the gas mixing tank 2-4 through a gas flow meter and a check valve on the pipelines, the inner wall of the gas mixing tank 2-4 is coated with an anticorrosive coating, an electromagnetic rotator 2-6 is arranged at the outer bottom of the gas mixing tank 2-4, a rubber fan fin matched with the electromagnetic rotator 2-6 is arranged at the inner bottom of the gas mixing tank 2-4, the wall of the gas mixing tank 2-4 is provided with a device for measuring the internal pressure of the gas mixing tank 2-4, A pressure probe for temperature and a temperature probe for temperature.

The liquid vaporization unit 3: the automatic water replenishing device is provided with an automatic water replenishing device 3-1 connected with a tap water inlet, the automatic water replenishing device 3-1 is communicated with a liquid vaporization tank 3-2 through an electric valve, an electric heating pipe 3-3 is installed at the bottom of the liquid vaporization tank 3-2, a pressure probe and a liquid level detector are installed on the inner wall of the liquid vaporization tank 3-2, and water vapor generated after heating flows to a gas-liquid mixing unit 4 from the top of the liquid vaporization tank 3-2 through the electric valve.

The gas-liquid mixing unit 4 is provided with a gas-liquid mixing tank 4-1, corrosive mixed gas from a gas mixing tank 2-4 enters the gas-liquid mixing tank 4-1 from the left side end of the gas-liquid mixing tank 4-1 through a check valve, water vapor from a liquid vaporization tank 3-2 enters the gas-liquid mixing tank 4-1 from the upper edge of the gas-liquid mixing tank 4-1 through the check valve, an anticorrosive coating 4-2 is coated on the inner wall of the gas-liquid mixing tank 4-1, an electromagnetic rotator 4-3 is installed outside the bottom of the gas-liquid mixing tank 4-1, a rubber fan fin matched with the electromagnetic rotator 4-3 is arranged inside the bottom of the gas-liquid mixing tank 4-1, a humidity probe is installed on the wall surface of the gas-liquid mixing tank 4-1, the gas and the liquid are fully mixed in the gas-liquid mixing tank 4-1 and then flow out from the right side of the gas-liquid mixing tank 4-1, and is transmitted to the temperature control unit 5 through the electric valve and the gas-liquid mixed transmission pump 4-4 in sequence.

The temperature control unit 5: the device is provided with a constant-temperature water bath box 5-1, a gas-liquid mixture transmitted from a gas-liquid mixed transmission pump 4-4 transversely penetrates through the constant-temperature water bath box 5-1 in a pipeline, the constant-temperature water bath box 5-1 regulates the temperature of the gas-liquid mixture passing through the constant-temperature water bath box and then flows into a heat insulation pipeline 5-2 provided with heat insulation cotton, and the heat insulation pipeline 5-2 is always connected to a scouring corrosion test unit 6 for testing a sample.

The erosion corrosion test unit 6: the flange structure is provided with two flanges 6-1 which are arranged at a distance, and the two flanges 6-1 are connected and fixed with nuts through screws; the flange 6-1 is internally provided with a reference electrode 6-2, an auxiliary electrode 6-3 and a temperature probe to avoid damage and air leakage caused by repeated disassembly, the metal sample 6-4 is positioned between the inner side surfaces of the flange 6-1, rubber gaskets 6-5 are respectively arranged between the two ends of the metal sample 6-4 and the flange 6-1, and the metal sample 6-4 is sleeved with a working electrode jacket 6-6.

The harmful gas recovery unit 7 is provided with two sets of harmful gas recovery tanks 7-1 with the same structure, a gas-liquid mixture after an experiment flows into the previous set of harmful gas recovery tank 7-1 from the tank bottom after passing through a check valve, and harmful gas absorption liquid 7-2 (such as concentrated sodium hydroxide solution, which can absorb CO) is filled in the harmful gas recovery tank 7-1₂、SO₂、H₂S) and a baffle 7-3 is arranged to delay the time of gas flowing through so as to ensure that the acid gas is fully absorbed; then the gas-liquid mixture flows through the next set of harmful gas recovery tank 7-1 from the upper part of the previous set of harmful gas recovery tank 7-1 again, and finally the residual non-harmful gas (air) enters the purified gas recovery tank 7-4.

A test method of a natural gas pipeline erosion corrosion experimental device comprises the following steps:

s1, polishing and smoothing the metal sample 6-4, weighing, and recording M₀(ii) a Entering a sealing room 8, installing a metal sample 6-4 on a flange 6-1 for testing, and then installing a rubber gasket 6-5 at the interface of the metal sample 6-4 and the flange 6-1 to ensure that the sealing performance of the two ends is good; connecting the connecting wire of the electrochemical workstation 1-2 with the reference electrode 6-2, the auxiliary electrode 6-3 and the metal sample 6-4 respectively, closing the door and the window, and going to a control room for operation;

s2, configuring mixed gas required by an experiment according to corrosive gas components contained in the natural gas transmission pipeline, and digitally displaying data such as gas flow, pressure in a gas mixing tank 2-4 and the like through a computer 1-1 so as to adjust the proportion of the gas required to be simulated; and opening the electromagnetic rotator 2-6 to match with the rubber fan wing to fully mix the mixed gas in the gas mixing tank 2-4, and then adding a harmful gas absorption liquid 7-2 (such as concentrated sodium hydroxide solution) into the harmful gas recovery tank 7-1.

S3, opening a faucet, starting an automatic water replenishing device 3-1, digitally displaying a pressure probe on a computer 1-1 according to the pressure in a liquid vaporization tank 3-2, opening a pressure release valve when the pressure does not reach a safety value, releasing certain gas to reduce the pressure, and closing the pressure release valve when the pressure is reduced to the safety value; the automatic water replenishing device 3-1 can automatically work according to the height of the liquid level, the liquid level can be displayed by a liquid level detector, when the liquid level reaches a specified value, the automatic water replenishing device 3-1 stops working, and when the liquid level is reduced to a set value, the automatic water replenishing device 3-1 is automatically started and repeatedly carried out; meanwhile, an electric heating pipe 3-3 with an electric heating wire therein is started to heat water, and the generated water vapor enters a gas-liquid mixing tank 4-1 through an electric valve and a check valve.

Description of the drawings: the automatic water replenishing device 3-1 works according to the liquid level and the pressure in the liquid vaporization tank 3-2, when the pressure is too high and water is deficient, the pressure is reduced by releasing gas through the pressure release valve, and then water is replenished.

S4, opening the electromagnetic rotator 4-3 at the bottom of the gas-liquid mixing tank 4-1 to fully mix the gas and the liquid (water vapor) in the gas-liquid mixing tank 4-1, and displaying the water content in the gas-liquid mixing tank 4-1 through a humidity probe so as to adjust the size of the electric valve and control the water vapor content in the gas-liquid mixing tank 4-1; after being fully mixed, the mixture flows out from the right side of the gas-liquid mixing tank 4-1, and the temperature of the mixture is controlled.

S5, opening the constant temperature water bath box 5-1, adjusting and controlling the temperature of the flowing gas-liquid mixture, and conveying the gas-liquid mixture with constant temperature to the metal sample 6-4 through the heat preservation pipeline 5-2.

S6, enabling the gas-liquid mixture to flow through the metal sample 6-4 to enter a erosion corrosion testing section, and recording the starting time T of the experiment₀And opening the electrochemical workstation 1-2 to test the open circuit potential.

S7, carrying out interval test on the potential and the impedance of the metal sample 6-4 in the experimental process, carrying out Tafel curve test when the experiment is finished, and recording the time T of the end of the experiment₁And closing all the instruments, checking whether harmful gas still exists in the sealed room 8 through the harmful gas detector 9, if not, opening a door and a window after entering the room, and taking down the metal sample 6-4.

S8, observing the appearance of the metal sample 6-4 after the experiment, and then cleaningRemoving corrosion products, weighing, and recording M₁. The average erosion corrosion rate V of the metal coupon 6-4 can be obtained according to the following formula:

expanding:

in terms of mechanism, erosive corrosion is a combination of erosion and corrosion:

T＝C+E

in the formula, T is total mass loss, C is mass loss caused by corrosion, E is mass loss caused by scouring, but the mechanism of scouring corrosion is not sufficiently explained by only considering scouring and corrosion, so that T is further subdivided:

T＝C₀+C_E+E₀+E_C

wherein: c₀Is mass loss due to pure corrosion, E₀Is mass loss due to pure scouring, Ce is mass loss due to scouring-promoted corrosion (promoting effect), and Ec is mass loss due to corrosion-promoted scouring (synergistic effect).

In the formula: j is the current density, A/cm 2; w is atomic weight, g/mol; a is the area of the sample, cm 2; t is time, s; f is a Faraday constant, and 96485C/mol is taken; n is atomic number and is 2.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.