Treatment method for improving stray current corrosion resistance of power grid grounding copper-clad steel material in acid soil

Abstract

The invention discloses a treatment method for improving stray current corrosion resistance of a power grid grounding copper-clad steel material in acid soil, and relates to the field of corrosion prevention of metal materials, the treatment method comprises the following steps: S1, collecting a soil leachate, and preparing the soil leachate into an electrolyte solution; s2, electrifying the copper-clad steel material in an electrolyte solution, and cleaning and drying the copper-clad steel material after electrifying; s3, burying the copper-clad steel material treated in the step S2 into soil for a period of time, then taking out the copper-clad steel material, cleaning the surface and drying the copper-clad steel material; and S4, repeating the steps S2-S3 for 2-6 times. Under the action of alternating current, a loose corrosion product initially grows on the surface of the copper layer, then the corrosion product grows compactly through soil burying, a protective film layer is formed, and the stray current corrosion resistance of the copper-clad steel material in acid soil can be remarkably improved through the film layer.

Description

Technical Field

[0001] The invention relates to the field of metal material corrosion prevention, and in particular to a treatment method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil. Background Art

[0002] Copper Clad Steel (CCS) is widely used in power grid grounding systems because it combines the high conductivity of copper with the high strength of steel. The main function of the power grid grounding system is to provide a low impedance path to safely conduct fault current into the ground, thereby protecting the safety of equipment and personnel. The copper layer of CCS provides excellent conductivity, ensuring efficient power transmission, while its internal steel core gives it excellent mechanical strength and stability, making it an ideal material for power grid grounding systems.

[0003] However, the grid grounding materials are buried underground for a long time, facing complex soil environment and are easily affected by corrosion. Although copper shows excellent corrosion resistance in natural environment, its corrosion rate may still be fast in some acidic or other harsh environments, affecting the stability and life of the grounding system. Therefore, how to improve the corrosion resistance of copper-clad steel grounding materials in complex soil environment has become an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a treatment method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil.

[0005] The technical solution of the present invention is as follows:

[0006] A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil comprises the following steps:

[0007] S1: Collect soil leachate and prepare it into electrolyte solution;

[0008] S2: subjecting the copper-clad steel material to an energizing treatment in an electrolyte solution, and then cleaning and drying the material after the energizing treatment is completed;

[0009] S3: The copper-clad steel material treated by S2 is buried in the soil for a period of time, then taken out, the surface is cleaned and dried;

[0010] S4: Repeat steps S2-S3 2-6 times.

[0011] As a preferred embodiment of the present invention, in step S1, the soil leachate is acidic red soil leachate.

[0012] As a preferred embodiment of the present invention, the pH value of the electrolyte solution is 5-6.

[0013] As a preferred embodiment of the present invention, the electrolyte solution also includes NaCl and / or KCl.

[0014] As a preferred embodiment of the present invention, the concentration range of the NaCl is 0.5 g / mL to 1 g / mL, and the concentration of the KCl is 0.5 g / mL to 1 g / mL.

[0015] As a preferred embodiment of the present invention, in step S2, the energization treatment is carried out under alternating current with a frequency of 40-60 Hz and a current density of 1 A / dm 2 ~2A / dm 2 , the power-on time is 24-48 hours.

[0016] As a preferred embodiment of the present invention, in step S2, the copper-clad steel material is subjected to end sealing treatment before being energized.

[0017] As a preferred embodiment of the present invention, in step S3, the soil is acidic red soil obtained from a natural environment, and the water content is controlled at 20-30% and the pH is controlled at 5.5-6.5.

[0018] As a preferred embodiment of the present invention, in step S4, steps S2-S3 are repeated 2-4 times.

[0019] The invention also discloses a power grid grounding copper-clad steel material, which is obtained by using any of the above-mentioned processing methods.

[0020] The beneficial effects of the present invention are:

[0021] The invention discloses a treatment method for improving the stray current corrosion resistance of a copper-clad steel material for grounding a power grid in acidic soil. By configuring an electrolyte solution containing soil leachate and under the action of an alternating current, loose corrosion products are initially grown on the surface of the copper-clad steel material, and then the corrosion products are further grown by burying the material in soil, thereby forming a dense protective film layer. The film layer can significantly improve the ability of the copper-clad steel material to resist stray current corrosion in acidic soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the corrosion appearance of copper-clad steel material under different conditions;

[0023] Figure 2 The corrosion SEM images of copper-clad steel materials under different conditions. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0025] In order to enhance the anti-corrosion performance of copper-clad steel in soil, a method of using alternating current to oxidize the surface of copper-clad steel in soil leachate was proposed. The core idea of ​​this method is to initially grow loose corrosion products on the surface of the copper layer under the action of alternating current, and then bury the corrosion products in the soil to make them grow densely, forming a protective film layer, which can significantly improve the ability of copper-clad steel materials to resist stray current corrosion in acidic soil.

[0026] This method can not only effectively improve the corrosion resistance of copper-clad steel materials, but also extend their service life in the grounding system, reduce maintenance costs, and ensure the safety and stability of power grid operation. Through laboratory simulation and actual application tests, the effectiveness of this method in enhancing the soil corrosion resistance of copper-clad steel grounding materials has been verified, providing new ideas and scientific basis for the design and material selection of power grid grounding systems.

[0027] A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil comprises the following steps:

[0028] S1: Collect soil leachate and prepare it into electrolyte solution;

[0029] S2: subjecting the copper-clad steel material to an energizing treatment in an electrolyte solution, and then cleaning and drying the material after the energizing treatment is completed;

[0030] S3: The copper-clad steel material treated by S2 is buried in the soil for a period of time, then taken out, the surface is cleaned and dried;

[0031] S4: Repeat steps S2-S3 2-6 times.

[0032] The present invention configures an electrolyte solution containing soil leachate under the action of alternating current, and under the action of alternating current, initially grows loose corrosion products on the surface of the copper-clad steel material, and then buries the corrosion products in the soil to make them grow densely, forming a protective film layer. The film layer can significantly improve the ability of the copper-clad steel material to resist stray current corrosion in acidic soil.

[0033] Further, in step S1, the soil leachate is an acidic red soil leachate, and the pH value of the electrolyte solution is 5-6, specifically, it can be 5, 5.1, 5.2, 5.3, 5.5, 5.6, 5.7, 5.8, 5.9 or 6.

[0034] Furthermore, the electrolyte solution also includes NaCl and / or KCl, and the concentration range of the NaCl and / or KCl is 0.5 g / mL to 1 g / mL, specifically, they can be independently 0.5 g / mL, 0.6 g / mL, 0.7 g / mL, 0.8 g / mL, 0.9 g / mL or 1 g / mL.

[0035] Furthermore, in step S2, the energization treatment is performed under alternating current with a frequency of 40-60 Hz and a current density of 1 A / dm 2 ~2A / dm 2 , the power-on time is 24-48 hours.

[0036] Furthermore, in step S2, the copper-clad steel material is subjected to end sealing treatment before power is supplied. Specifically, two groups of copper-clad steel grounding materials can be polished in turn using 350-mesh and 1000-mesh sandpaper to remove surface oxides and impurities, increase surface roughness, and improve subsequent treatment effects. Then, cold mounting resin is used to seal both ends of the copper-clad steel material to ensure that the electrode portion is exposed to the treatment solution.

[0037] Furthermore, in step S3, the soil is acidic red soil obtained from a natural environment, with a water content of 20-30% and a pH of 5.5-6.5.

[0038] Further, in step S4, steps S2-S3 are repeated 2-4 times.

[0039] The present invention obtains a power grid grounding copper-clad steel material through any of the above methods.

[0040] The present invention firstly grows loose corrosion products on the surface of the copper layer under the action of alternating current, and then makes the corrosion products grow densely by burying in soil to form a protective film layer, which can significantly improve the ability of the copper-clad steel material to resist stray current corrosion in acidic soil.

[0041] The technical solution of the present invention is further described below in the form of specific embodiments.

[0042] Example 1

[0043] S1: Collect soil leachate, add NaCl and KCl, control pH=6, and prepare electrolyte solution with the concentration of NaCl and KCl both at 0.05 g / mL;

[0044] S2: First, use 350-mesh and 1000-mesh sandpaper to grind the copper-clad steel material in turn (see the appearance Figure 1 a, SEM image, see Figure 2a), then weld a copper wire at one end; use cold mounting resin to seal both ends of the copper-clad steel material; finally, energize the copper-clad steel material in an electrolyte solution, turn on the power supply, and apply 1A / dm 2 The current density of alternating current is continuously treated for 24 hours. After the power is turned off, it is cleaned and dried. Figure 1 b, SEM image Figure 2 b;

[0045] S3: The copper-clad steel material treated by S2 was buried in the acidic red soil (pH=6) obtained from the natural environment for natural corrosion for 7 days, and the water content of the red soil was controlled to 25%. Then it was taken out, the surface was cleaned and dried, and the appearance was shown in FIG. Figure 1 c, SEM image Figure 2 c;

[0046] S4: Repeat steps S2-S3 3 times.

[0047] Example 2

[0048] S1: Collect soil leachate, add NaCl and KCl, control pH=6, and prepare electrolyte solution with the concentration of NaCl and KCl both at 0.05 g / mL;

[0049] S2: First, use 350-mesh and 1000-mesh sandpaper to grind the copper-clad steel material in turn, then weld a copper wire at one end; use cold mounting resin to seal both ends of the copper-clad steel material; finally, energize the copper-clad steel material in an electrolyte solution, turn on the power supply, and apply 1A / dm 2 Alternating current with a current density of , and continue to process for 36 hours, and then clean and dry after the power is turned off;

[0050] S3: The copper-clad steel material treated by S2 is buried in acidic red soil (pH=6) obtained from the natural environment for natural corrosion for 7 days, and the water content of the red soil is controlled to 25%, and then taken out, the surface is cleaned and dried;

[0051] S4: Repeat steps S2-S3 3 times.

[0052] Example 3

[0053] S1: Collect soil leachate, add NaCl and KCl, control pH=6, and prepare electrolyte solution with the concentration of NaCl and KCl both at 0.05 g / mL;

[0054] S2: First, use 350-mesh and 1000-mesh sandpaper to grind the copper-clad steel material in turn, then weld a copper wire at one end; use cold mounting resin to seal both ends of the copper-clad steel material; finally, energize the copper-clad steel material in an electrolyte solution, turn on the power supply, and apply 1A / dm 2Alternating current with a current density of , and continue to process for 48 hours, and then clean and dry after the power is turned off;

[0055] S3: The copper-clad steel material treated by S2 is buried in acidic red soil (pH=6) obtained from the natural environment for natural corrosion for 7 days, and the water content of the red soil is controlled to 25%, and then taken out, the surface is cleaned and dried;

[0056] S4: Repeat steps S2-S3 3 times.

[0057] Comparative Example 1

[0058] This comparative example is a variation of Example 1, specifically, there is no S2 step, and the rest is the same as Example 1.

[0059] The above embodiments and comparative examples were subjected to performance tests, and the test results are as follows:

[0060] (1) Corrosion rate

[0061] The weight loss method is used to measure the corrosion rate of the material, and the corrosion rate of the sample is calculated by the following formula:

[0062]

[0063] Where:

[0064] v-corrosion rate of the sample;

[0065] m1-mass of the sample after corrosion;

[0066] m0-mass of the specimen before corrosion;

[0067] t-corrosion time of the sample;

[0068] S-surface area of ​​the specimen.

[0069] (2) Scanning electron microscope (SEM) was used for observation.

[0070] (3) Resistance value test.

[0071] The resistance can be calculated by the following formula:

[0072]

[0073] R-resistance of the material being tested;

[0074] ρ - resistivity of the material;

[0075] L - length of the material;

[0076] S- cross-sectional area of ​​the material.

[0077] (4) Surface hardness test

[0078] Nine points were evenly selected on the surface of the sample for hardness measurement using a micro Vickers hardness tester, and the average value was taken.

[0079] Sample Corrosion rate (mm / year) Resistance value increase (%) Hardness increase (%) Example 1 0.01 0.5 10 Example 2 0.008 0.4 11 Example 3 0.007 0.3 12 Comparative Example 1 0.04 0.9 5

[0080] Note: The added value is compared with the original copper-clad steel material.

[0081] As can be seen from the above table, the corrosion rate of the copper-clad steel grounding material treated with electrostatic film formation is 0.01 mm / year, which is 75% lower than that of the untreated copper-clad steel material, and the resistance value is only increased by 0.5%, which can still meet the requirements of the power grid grounding system. Figure 2 ), a dense and uniform oxide film is formed on the surface of the treated copper-clad steel material, the film thickness is about 10μm, there are no obvious cracks and holes on the surface, the surface hardness increases by about 10%, and there is no obvious decrease in mechanical strength, indicating that the surface oxide film has no adverse effect on the mechanical properties of the material, and has good application prospects and economic benefits

[0082] It can be seen from Examples 1-3 that the corrosion rates of the copper-clad steel material after power-on for 24 hours, 36 hours and 48 hours are 0.01 mm / year, 0.008 mm / year and 0.007 mm / year respectively, the resistance values ​​increase by 0.5%, 0.4% and 0.3% respectively, and the surface hardness increases by 10%, 11% and 12% respectively. Among them, the copper-clad steel material after power-on for 24 hours can still meet the requirements of the grid grounding system and there is no obvious decrease in mechanical strength.

[0083] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the scope of protection of the claims of the present invention.

Claims

1. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil, characterized in that: The following steps are involved: S1: Collect soil leachate and prepare it into electrolyte solution; S2: subjecting the copper-clad steel material to an energizing treatment in an electrolyte solution, and then cleaning and drying the material after the energizing treatment is completed; S3: The copper-clad steel material treated by S2 is buried in the soil for a period of time, then taken out, the surface is cleaned and dried; S4: Repeat steps S2-S3 2-6 times.

2. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: In step S1, the soil leachate is acidic red soil leachate.

3. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: The pH value of the electrolyte solution is 5-6.

4. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: The electrolyte solution also includes NaCl and / or KCl.

5. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 4, characterized in that: The concentration range of the NaCl is 0.5 g / mL to 1 g / mL, and the concentration of the KCl is 0.5 g / mL to 1 g / mL.

6. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: In step S2, the energization treatment is performed under alternating current with a frequency of 40-60 Hz and a current density of 1 A / dm 2 ~2A / dm 2 , the power-on time is 24-48 hours.

7. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: In step S2, the copper-clad steel material is subjected to end sealing treatment before being energized.

8. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: In step S3, the soil is acidic red soil obtained from the natural environment, with the water content controlled at 20-30% and the pH at 5.5-6.

5.

9. A method for improving the resistance of power grid grounding copper-clad steel materials to stray current corrosion in acidic soil according to claim 1, characterized in that: In step S4, steps S2-S3 are repeated 2-4 times.

10. A copper-clad steel material for power grid grounding, characterized in that: The method is obtained by using any one of claims 1 to 9.

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