A metal hanging plate accelerated corrosion test device and test method in marine environment

Abstract

The present invention discloses an accelerated corrosion test device and test method for metal hanging plates in a marine environment. The accelerated corrosion test device for metal hanging plates in a marine environment comprises a base, a support column, a sample rack for placing metal samples, and two metal meshes connected to high voltage electricity. The lower end of the support column is fixed on the base. The sample rack and the metal mesh are inclined and are both arranged on the support column. The two metal meshes are respectively located above and below the sample rack so that the sample rack is located between the two. The present invention uses high voltage electricity to pass through the metal mesh and uses the electric field to accelerate the corrosion of the metal plate, which not only ensures that the corrosion rate of the metal sample is accelerated and the test cycle is shortened, but also maintains the variable corrosion factors of the outdoor natural environment, which is more in line with the actual environment and improves the accuracy of the test results. In addition, the present invention has a simple structure, low cost, easy operation, and strong practicality, and can be widely promoted and used.

Description

Technical Field

[0001] The invention relates to a metal hanging plate accelerated corrosion test device under marine environment, and also relates to a test method using the metal hanging plate accelerated corrosion test device under marine environment. Background Art

[0002] In a corrosive medium environment, metal materials are very prone to corrosion, which not only affects the appearance, but also affects the service life, posing a huge safety hazard to the safe operation of equipment. Therefore, the study of the corrosion rate of metal materials is extremely important.

[0003] Commonly used methods for studying metal corrosion rates include natural exposure and artificial accelerated corrosion. The natural exposure method is to expose metal materials to a pre-operation environment, and measure the corrosion rate in the environment by studying the quality difference before and after long-term exposure. Although this method has intuitive data and is closer to the actual environmental corrosion situation, metal materials usually need to be exposed for at least half a year. Therefore, the natural exposure method has the disadvantages of long test cycle and low timeliness. The artificial accelerated corrosion test method has become the current mainstream test method because it can greatly reduce the corrosion test cycle. This method mainly places metal materials in an artificial simulation test box, and concentrates and continuously delivers high-concentration corrosive media (such as salt spray, hydrogen sulfide, sulfur dioxide, etc., single or mixed) to the environment where the metal materials are located, thereby achieving the effect of accelerated corrosion. However, it is difficult for environmental simulation to completely match the actual environment, which affects the accuracy of the test results. Summary of the invention

[0004] The first object of the present invention is to provide a metal hanging plate accelerated corrosion test device in a marine environment which has a simple structure, low cost, easy operation, can shorten the test cycle, and improve the accuracy of the test results.

[0005] The first object of the present invention is achieved through the following technical solution: a metal hanging plate accelerated corrosion test device in a marine environment, characterized in that it includes a base, a support column, a sample rack for placing metal samples and two metal meshes connected to high voltage electricity, the lower end of the support column is fixed to the base, the sample rack and the metal mesh are inclined and are both arranged on the support column, the two metal meshes are respectively located above and below the sample rack so that the sample rack is located between the two.

[0006] The present invention uses high voltage electricity to pass through the metal mesh and uses the electric field to accelerate the corrosion of the metal plate, which not only ensures that the corrosion rate of the metal sample is accelerated, shortens the test period, but also maintains the variable corrosion factors of the outdoor natural environment, is more in line with the actual environment, and improves the accuracy of the test results. In addition, the present invention has a simple structure, low cost, easy operation, strong practicality, and can be widely promoted and used.

[0007] In the present invention, an IP protection box with a power supply system installed is arranged on the base, and the metal mesh is connected to the power supply system through a wire to provide high voltage electricity.

[0008] The sample holder and the metal mesh of the present invention are parallel to each other.

[0009] The sample rack and the metal mesh of the present invention are connected to the support column through a bracket respectively. The sample rack and the metal mesh can be installed on the bracket in a transverse sliding manner, so that the sample rack can be fully exposed, which is convenient for installing and fixing the metal sample on the sample rack.

[0010] The sample rack and the metal mesh support of the present invention are both made of non-conductive light-resistant polymer materials.

[0011] The metal mesh of the present invention is made of corrosion-resistant metal or metal with a coating treatment on the surface.

[0012] The second object of the present invention is to provide a test method using the above copper hanging plate accelerated corrosion test device in a marine environment.

[0013] The second object of the present invention is achieved by the following technical solution: a test method using the above-mentioned copper hanging plate accelerated corrosion test device under marine environment, characterized by comprising the following steps:

[0014] S1. Fixing the metal sample on the sample rack of the metal hanging plate accelerated corrosion test device under the marine environment;

[0015] S2, turning on high voltage electricity to form a high voltage electric field between the two metal meshes, so that the metal sample is in the high voltage electric field, accelerating the corrosion of the metal sample in the atmospheric environment;

[0016] S3, real-time recording of the average ambient temperature, average relative humidity, ambient salt spray and hydrogen sulfide content;

[0017] S4. Calculate the accelerated corrosion rate of metal samples.

[0018] The accelerated corrosion rate of the metal sample of the present invention is calculated by the following steps:

[0019] ⑴ Establish a mathematical model of the correlation between the accelerated corrosion rate of metal samples and the environment:

[0020]

[0021] Among them, r corr is the average annual corrosion rate under accelerated conditions, in g / (m 2 .a); a, m, n are environmental factor coefficients; RH represents the average relative humidity of the environment; T is the ambient temperature; C is the deposition concentration of soluble pollutants; f(E) is the electric field acceleration function; t is the corrosion exposure time; A is the time coefficient;

[0022] (2) Obtain environmental factor coefficients a, m, n, time coefficient A and electric field acceleration function f(E) = 0.00225E + 0.9294, where f(0) = 1;

[0023] ⑶ Substitute the environmental factor coefficient and time coefficient obtained into formula ⑴ to obtain the accelerated corrosion rate of the metal sample:

[0024]

[0025] Wherein, electric field acceleration function f(E)=0.00225E+0.9294, where f(0)=1;

[0026] Where, T is the ambient temperature; RH is the average relative humidity of the environment; C H2S is the hydrogen sulfide deposition concentration, in ppm; is the chloride ion deposition concentration, in g / (m 2 .d); a, m, n are environmental factor coefficients; A is the time coefficient; E is the electric field strength; f(E) is the electric field acceleration function; t is the corrosion exposure time.

[0027] The present invention places metal samples in single pollutant environments respectively, calculates environmental factor coefficients a, m and n under various environments by changing the environmental temperature T, the average relative humidity RH and the soluble pollutant deposition concentration C; obtains the time coefficient A by changing the corrosion exposure time t; and obtains f(E) by changing the electric field strength.

[0028] In the step S4 of the present invention, the calculated accelerated corrosion rate of the metal sample is corrected.

[0029] Compared with the prior art, the present invention has the following significant effects:

[0030] (1) The test device of the present invention passes high voltage electricity to the metal mesh and utilizes the electric field to accelerate the corrosion of the metal plate, which not only ensures that the corrosion rate of the metal sample is accelerated and the test period is shortened, but also maintains the changeable corrosion factors of the outdoor natural environment, which is more in line with the actual environment and improves the accuracy of the test results.

[0031] (2) The test method of the present invention provides a method for calculating the corrosion rate under electric field accelerated corrosion, and the current corrosion rate can be obtained according to environmental related parameters.

[0032] ⑶ The present invention has the advantages of simple structure, low cost, easy operation and strong practicability, and can be widely promoted and used. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Figure 1 is a side view schematic diagram of the test device of the present invention;

[0035] Figure 2 1 is a schematic diagram of the front view of the test device of the present invention (the metal mesh above is not drawn);

[0036] Figure 3 It is a schematic diagram of the metal mesh structure of the present invention.

[0037] In the figure, 1-base, 2-support column, 3-wire, 4-second metal mesh, 5-sample rack, 6-first metal mesh, 7-IP protection box, 8-power supply system, 9-card slot, 10-pollutant and temperature and humidity sensor, 11-metal sample. DETAILED DESCRIPTION

[0038] like Figure 1 , 2 As shown, it is an accelerated corrosion test device for metal hanging plates in a marine environment of the present invention, which includes a base 1, a support column 2, a sample rack 5 for placing a metal sample 11, two metal meshes connected to high voltage electricity and an IP protection box 7 with a power supply system 8 installed. The lower end of the support column 2 is fixed on the base 1, and the IP protection box 7 is arranged on the base 1. The power supply system 8 of the IP protection box 7 provides high voltage electricity to the two metal meshes through a wire 3. The sample rack 5 and the metal mesh are both arranged on the support column 2 through a bracket. The sample rack 5 and the metal mesh are inclined and parallel to each other. The two metal meshes are respectively located above and below the sample rack 5 so that the sample rack 5 is located between the two. Among them, the metal mesh located above the sample rack 5 is a first metal mesh 6, and the metal mesh located below the sample rack 5 is a second metal mesh 4. The sample rack 5 is connected to the support column 2 through the first bracket 12, the first metal mesh 6 is connected to the support column 2 through the second bracket 13, and the second metal mesh 4 is connected to the support column 2 through the third bracket 14. The sample rack 5 and the metal mesh can be installed on their respective brackets by horizontal sliding. Specifically, a sliding structure can be set between the frames of the sample rack and the metal mesh and their respective brackets. The sliding structure can specifically use a structure in which a slide groove and a slider cooperate to enable the sample rack and the metal mesh to move left and right (laterally), so that the sample rack can be completely exposed, which is convenient for installing and fixing the metal sample 11 on the sample rack 5, specifically, the metal sample 11 is engaged by the card slot 9 on the sample rack.

[0039] The sample holder 5 and the brackets of the first metal mesh 6 and the second metal mesh 4 are all made of non-conductive light-resistant polymer materials. The first metal mesh 6 and the second metal mesh 4 are made of corrosion-resistant metal or metal with a coating treatment on the surface.

[0040] like Figure 3As shown, the first metal mesh 6 and the second metal mesh 4 both include an outer frame and a mesh portion located within the outer frame. The present invention uses two metal meshes, which can achieve the effect of applying high voltage electricity without hindering the exchange of air pollutants with the air between the plates. If two solid flat plates that usually apply voltage are used, the solid flat plates will hinder the air flow in the front direction of the plates, which is equivalent to reducing the contact between air pollutants in the atmosphere (including salt spray, sulfur dioxide gas, nitrogen dioxide gas and other pollutants that affect metal corrosion) and the metal sample. For example, the direction of the sea breeze happens to be in the front direction of the plate, and the solid flat plate blocks the sea breeze in this direction from contacting the metal sample, while the meshed one will not.

[0041] The use process of the present invention is:

[0042] After the metal sample 11 is fixed on the slot 9 on the sample rack, the positions of the sample rack 5, the first metal mesh 6 and the second metal mesh 4 are adjusted so that the first metal mesh 6, the sample rack 5 and the second metal mesh 4 are parallel to each other. Subsequently, high voltage electricity is applied to the first metal mesh 6 and the second metal mesh 4 to concentrate the positive charge of the second metal mesh 4 and the negative charge of the first metal mesh 6. A stable electric field is formed between the second metal mesh 4 and the first metal mesh 6 by applying high voltage electricity, so that the corrosion of the metal sample on the sample rack in the atmospheric environment is accelerated under the action of the electric field.

[0043] A test method using the above-mentioned accelerated corrosion test device for metal hanging plates in a marine environment, the accelerated corrosion test device is installed at an experimental site in Qionghai, Hainan, and a pollutant and temperature and humidity sensor 10 is also used. The metal sample 11 is a copper sheet, which is two pieces. The test method includes the following steps:

[0044] S1, fix the metal sample 11 on the sample rack 5 of the metal hanging plate accelerated corrosion test device in the marine environment, adjust the positions of the sample rack 5, the first metal mesh 6 and the second metal mesh 4, so that the first metal mesh 6, the sample rack 5 and the second metal mesh 4 are parallel to each other;

[0045] S2, turning on high voltage electricity to concentrate the positive charge of the second metal mesh 4 and the negative charge of the first metal mesh 6, forming a high voltage electric field between the second metal mesh 4 and the first metal mesh 6, and placing the metal sample 11 in a 100 kV / m high voltage electric field, accelerating the corrosion of the metal sample 11 in the atmospheric environment;

[0046] S3, monitor and record the average temperature, average relative humidity, environmental salt spray and hydrogen sulfide content in real time through temperature, humidity and pollutant monitoring equipment, and take metal samples 11 every 30 days and 60 days;

[0047] S4. Calculate the accelerated corrosion rate of the metal sample 11.

[0048] When specifically calculating the accelerated corrosion rate of the metal sample 11, the accelerated corrosion rate of the metal sample 11 is calculated by the calculation formula of the present invention, and the data model of the present invention is corrected according to the measured data of the weight loss method. The average ambient temperature is 26.3°C, the humidity is 81RH%, the chloride ion sedimentation rate is 33.8mg / m2.d, and the ambient hydrogen sulfide sedimentation rate is 0.005ppm. According to the formula:

[0049]

[0050] The accelerated corrosion rates of the two copper sheets calculated by the above formula are 11.3114 g / m2.a and 9.928 g / m2.a, respectively. The average corrosion rates calculated by weight loss method are 13.426 g / m2.a and 11.554 g / m2.a, respectively. It can be seen that the deviation of the calculated results of the present invention and the calculated results by weight loss method is less than 20%, and the correction coefficient is 1.353.

[0051] The implementation modes of the present invention are not limited to these. Based on the above contents of the present invention, according to the common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, the present invention may also make other various forms of modification, replacement or change, all of which fall within the scope of protection of the present invention.

Claims

1. A method for accelerating corrosion test of metal cladding in marine environment, wherein the method uses an accelerated corrosion test device for metal cladding in marine environment to conduct the test, and the method is characterized in that: The test device comprises a base, a support column, a sample rack for placing metal samples and two metal nets connected to high voltage, the lower end of the support column is fixed on the base, the sample rack and the two metal nets are both inclined and arranged on the support column, the two metal nets are respectively located above and below the sample rack so that the sample rack is located between the two; the sample rack and the two metal nets are parallel to each other; The sample rack and the two metal meshes are respectively connected to the support column through a bracket, and the sample rack and the two metal meshes can be installed on the bracket in a transverse sliding manner; The test method comprises the following steps: S1. Fixing the metal sample on the sample rack of the metal hanging plate accelerated corrosion test device under the marine environment; S2, turning on high voltage electricity to form a high voltage electric field between the two metal meshes, so that the metal sample is in the high voltage electric field, accelerating the corrosion of the metal sample in the atmospheric environment; S3, real-time recording of the average ambient temperature, average relative humidity, ambient salt spray and hydrogen sulfide content; S4. Calculate the accelerated corrosion rate of metal samples; The accelerated corrosion rate of the metal sample in step S4 is calculated by the following steps: ⑴ Establish a mathematical model of the correlation between the accelerated corrosion rate of metal samples and the environment: Among them, r corr is the average annual corrosion rate under accelerated conditions, in g / (m 2 .a); a, m, n are environmental factor coefficients; RH represents the average relative humidity of the environment; T is the ambient temperature; C is the deposition concentration of soluble pollutants; f(E) is the electric field acceleration function; t is the corrosion exposure time; A is the time coefficient; (2) Obtain environmental factor coefficients a, m, n, time coefficient A and electric field acceleration function f(E)=0.00225E+0.9294, where f(0)=0.9294; ⑶ Substitute the environmental factor coefficient and time coefficient obtained into formula ⑴ to obtain the accelerated corrosion rate of the metal sample: Wherein, electric field acceleration function f(E)=0.00225E+0.9294, where f(0)=0.9294; Among them, r corr is the average annual corrosion rate under accelerated conditions, in g / (m 2 .a); T is the ambient temperature; RH is the average relative humidity of the environment; C H2S is the hydrogen sulfide deposition concentration, in ppm; is the chloride ion deposition concentration, in g / (m 2 .d); a, m, n are environmental factor coefficients; A is the time coefficient; E is the electric field strength; f(E) is the electric field acceleration function; t is the corrosion exposure time; The metal sample is placed in a single pollutant environment, and the environmental factor coefficients a, m and n under each environment are calculated by changing the ambient temperature T, the average relative humidity RH and the soluble pollutant deposition concentration C; the time coefficient A is obtained by changing the corrosion exposure time t; and f(E) is obtained by changing the electric field strength.

2. The accelerated corrosion test method for metal cladding in marine environment according to claim 1, characterized in that: An IP protection box with a power supply system installed is arranged on the base, and the two metal meshes are connected to the power supply system through wires to provide high voltage electricity.

3. The accelerated corrosion test method for metal cladding in marine environment according to claim 2, characterized in that: The sample rack and the brackets of the two metal meshes are both made of non-conductive light-resistant polymer materials.

4. The accelerated corrosion test method for metal cladding in marine environment according to claim 3, characterized in that: The two metal meshes are made of corrosion-resistant metal or metal with a coating treatment on the surface.

5. The accelerated corrosion test method for metal cladding in marine environment according to claim 4, characterized in that: In step S4, the calculated accelerated corrosion rate of the metal sample is corrected.

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