Silver plating method for conductive part of outdoor high-voltage switch

Abstract

The invention relates to the field of surface treatment of electrical materials for electric power system application equipment, and discloses a silver plating method for an outdoor high-voltage switch conductive part. The invention relates to a silver plating method for a conductive part of an outdoor high-voltage switch. The silver plating method comprises the steps of pre-plating treatment, organic solvent oil removal, chemical oil removal, acid etching, acid pickling passivation, wax brushing (soaking), acid pickling and film removal, cleaning and polishing of a to-be-plated surface, silver pre-plating, cyaniding silver plating, alkali boiling for wax removal, acid etching for bright dipping, acrylic varnish coating of a non-silver-plated part and silver layer anti-discoloration treatment. By optimizing the silver plating step and the formula of the silver plating electroplating solution, the hardness, adhesive force and weather resistance of the silver plating layer of the copper base material and copper alloy base material conductive part of the high-voltage switch are improved, so that the high-voltage switch can adapt to different working conditions and environments.

Description

Technical Field

[0001] The invention relates to the field of surface treatment of electrical materials in power system application equipment, in particular to a silver plating method for conductive parts of outdoor high-voltage switches. Background Art

[0002] In recent years, with the development of the national smart grid, the demand for outdoor high-voltage switches has increased day by day. The electrical contact parts of outdoor high-voltage switch conductive parts are mostly made of copper or aluminum substrates, and surface treatments such as silver plating or tin plating are performed on their surfaces to obtain good conductivity. In the past, the materials of conductive parts were mostly powder metallurgy, which uses silver as raw material, has high manufacturing costs and limited manufacturing shapes.

[0003] The working environment of outdoor high-voltage switches is very harsh. The traditional copper substrate silver plating process is used. The conductive parts are exposed to the outdoors for a long time and are corroded by the natural environment. The silver plating layer of the conductive parts will rust and fall off. The thickness, hardness, adhesion, weather resistance and corrosion resistance of the plating are still unstable, resulting in poor conductive contact and excessive contact resistance, which affects the safety of outdoor high-voltage switchgear and seriously affects the reliable operation of the power system.

[0004] Therefore, based on the above problems, the present invention provides a silver plating method for outdoor high-voltage switch conductive parts, which not only ensures the economy of the conductive parts, but also improves their stability. Summary of the invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a silver plating method for outdoor high-voltage switch conductive parts. By optimizing the silver plating steps and the silver plating solution formula, the hardness, adhesion and weather resistance of the silver plating layer of the copper substrate and copper alloy substrate conductive parts of the high-voltage switch are improved, so that they can adapt to different working conditions.

[0006] The present invention adopts the following technical solution: A silver plating method for an outdoor high-voltage switch conductive part comprises the following steps: S1: pre-plating treatment; S2: degreasing with organic solvents; S3: Chemical degreasing: Dissolve 100-150 g / L sodium hydroxide NaOH, 20-40 g / L sodium carbonate Na2CO3·10H2O, and 20-40 g / L sodium phosphate Na3PO4·12H2O in water, soak for 10-20 minutes at 70-90°C, rinse, and dry; S4: acid etching; S5: Pickling and passivation: Add 2 / 3 of the total volume of water to the pickling and passivation tank. While stirring continuously, slowly add sulfuric acid H2SO4 15~25g / L, slowly add nitric acid HNO3 30~45g / L, add chromic anhydride CrO3 150~180g / L, stir thoroughly until completely dissolved, add water to 100mm away from the tank surface and stir evenly; put the parts to be plated in and soak for 10~30 minutes, rinse with cold water first, then rinse with 70~80℃ hot water, and then blow dry with compressed air; S6: Brush (dip) wax: melt semi-refined paraffin at a temperature of 100-120°C, add rosin and stir evenly; for partially silver-plated parts, wax is applied to protect the non-electroplated surface, leaving a 2-3mm transition zone between the electroplated surface and the non-electroplated surface; S7: acid removal; S8: Clean and polish the surface to be plated: Use 00# sandpaper and 240# water sandpaper to polish the surface to be plated until it feels fine and smooth, and there is no water droplets on the surface to be plated after soaking in water, and a continuous water film is formed; S9: Pre-silver plating: The pre-silver plating solution is prepared by dissolving 1~2g / L of metallic silver Ag and 100~120g / L of free potassium cyanide KCN. At room temperature, the treated parts to be plated are placed in the silver plating solution for silver plating. The cathode current density is 1~2A / dm 2 , the time is 1~2 hours, the cathode material is stainless steel 1Cr18Ni9Ti, and the cation and cathode area ratio is 1:1~2; S10. Cyanide silver plating: add 1 / 3 of the solution volume of pure water to the cyanide silver plating tank; add free potassium cyanide KCN120~150g / L, stir to completely dissolve; slowly add the calculated amount of silver cyanide to the potassium cyanide solution under constant stirring, stir to completely dissolve; add water to 100mm away from the tank surface and stir evenly; use 0.2~0.3A / dm 2 The current density is energized for 4 to 8 hours, and 3KMK-A brightener 8 to 12 ml / L and 3KMK-B cylinder opener 8 to 12 ml / L are added; S11. Alkali boiling to remove wax; S12. Acid etching to reveal light; S13. Apply acrylic varnish to non-silver-plated areas: the paint ratio is B01-3 or B01-5 acrylic varnish: X-5 acrylic thinner = 1:2.5~3.5 (weight ratio), construction viscosity 5~10S; protect the unpainted area and apply evenly by brush, then dry at room temperature 20℃ for 2 hours; S14. Silver layer anti-tarnishing treatment.

[0007] Preferably, step S1 includes checking that the parts have no obvious cracks, pores, mechanical deformation, damage, scratches and other defects, and polishing with sandpaper when the surface roughness of the surface to be plated is greater than 1.6.

[0008] Preferably, step S2 includes soaking in industrial gasoline for 10 to 20 minutes at room temperature and then drying naturally in air.

[0009] Preferably, step S4 comprises soaking in an aqueous solution prepared with 140-200 g / L hydrochloric acid HCL and 100-150 g / L sulfuric acid H2SO4 for 10-60 minutes at room temperature, and then rinsing and drying.

[0010] Preferably, step S7 includes soaking in a ratio of hydrochloric acid HCL: water = 1:1 for 10 to 30 minutes at room temperature, and then rinsing with cold water.

[0011] Preferably, step S11 includes preparing an alkali dewaxing solution by dissolving 80-120 g / L of sodium hydroxide NaOH, 10-25 g / L of sodium carbonate Na2CO3·10H2O, and 15-35 g / L of sodium phosphate Na3PO4·12H2O, and removing all the wax at a temperature of 80-100°C.

[0012] Preferably, step S12 includes: removing the film by acid immersion in an acid etching solution prepared by dissolving 100-150 g / L of hydrochloric acid HCL in water for 5-10 minutes, then rinsing with cold water, and drying at 60-80°C.

[0013] Preferably, step S14 includes polishing the silver layer with a scouring pad to a fine and smooth silver-white color, wiping the metal dust on the surface of the silver layer with industrial alcohol, and after the alcohol on the surface of the silver layer evaporates, brushing or dipping the silver-plated part with a silver-plating protective agent, and drying it at room temperature for 3 to 5 minutes; after it is completely dry, wrap the silver-plated layer with a plastic bag and tie it with paper tape.

[0014] Preferably, the high-voltage switch conductive component is a copper substrate or a copper alloy substrate.

[0015] Compared with the prior art, the technical effects of the present invention are: less silver is used for surface silver plating, saving costs; the design of the silver plating steps is optimized, so that the plated parts have better performance advantages; the formula of the silver plating liquid is optimized, so that the outdoor high-voltage switch conductive parts can adapt to different working conditions and have better resistance to harsh environments. DETAILED DESCRIPTION

[0016] The following examples are further detailed descriptions of the present invention, but they are not intended to limit the present invention. The descriptions of the following examples are only intended to help understand the present invention. It should be noted that, for those of ordinary skill in the art, without departing from the principles of the present invention, the present invention may also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0017] The invention discloses a silver plating method for an outdoor high-voltage switch conductive part, which comprises the following steps: S1: Pre-plating treatment: Check that the parts have no obvious cracks, pores, mechanical deformation, damage, scratches and other defects. If the surface roughness of the surface to be plated is greater than 1.6, polish it with sandpaper.

[0018] S2: Organic solvent degreasing: Soak in industrial gasoline for 10 to 20 minutes at room temperature, then dry naturally in the air.

[0019] S3: Chemical degreasing: Prepared with 100~150g / L sodium hydroxide NaOH, 20~40g / L sodium carbonate Na2CO3·10H2O, and 20~40g / L sodium phosphate Na3PO4·12H2O, soaked at 70~90℃ for 10~20 minutes. First, add 2 / 3 of the tank volume of tap water to the chemical degreasing tank, and then use a hanging basket to hold the calculated amount of sodium hydroxide and place it in the degreasing tank to completely dissolve it. Add sodium carbonate (only added when preparing the solution, no need to add it in subsequent production) and sodium phosphate directly into the tank, stir thoroughly until completely dissolved. Add the liquid level to 100mm from the tank surface, stir evenly, then rinse with hot water, rinse with cold water, and air dry.

[0020] S4: Acid etching: Soak in a solution prepared with 140~200g / L hydrochloric acid HCL and 100~150g / L sulfuric acid H2SO4 for 10~60 minutes at room temperature. Add 1 / 3 of the total volume of water to the acid etching tank; slowly add the calculated amount of sulfuric acid under constant stirring; after the temperature drops to room temperature, add the calculated amount of hydrochloric acid and stir evenly; add water to 100° from the tank surface, stir evenly, and then rinse with tap water.

[0021] S5: Pickling passivation: Soak in chromic anhydride CrO3150~180g / L, sulfuric acid H2SO415~25g / L, nitric acid HNO330~45g / L solution for 10~30 minutes at room temperature. Add 2 / 3 of the total volume of water to the pickling tank; slowly add the calculated amount of sulfuric acid while stirring continuously; slowly add the calculated amount of nitric acid; add the calculated amount of chromic anhydride to the tank and stir thoroughly until it is completely dissolved; add water to 100mm from the tank surface and stir evenly; rinse with cold water; rinse with hot water at 70~80℃ and blow dry.

[0022] S6: Brush (dip) wax: melt semi-refined paraffin at a temperature of 100~120℃, add rosin and stir evenly; for partially silver-plated parts, apply wax to the non-electroplated surface for protection, and allow a 2~3mm transition zone between the electroplated and non-electroplated surfaces.

[0023] S7 Acid immersion to remove the membrane: soak in hydrochloric acid HCL: water in a ratio of 1:1 for 10 to 30 minutes at room temperature, then rinse with cold water.

[0024] S8: Clean and polish the surface to be plated: Use 00# sandpaper or 240# water sandpaper to polish the surface to be plated until it feels fine and smooth, and there is no water droplets on the surface to be plated after soaking in water, and it presents a continuous water film.

[0025] S9: Pre-silver plating. The pre-silver plating solution is prepared by dissolving 1~2g / L of metallic silver Ag and 100~120g / L of free potassium cyanide KCN. At room temperature, the treated parts to be plated are placed in the silver plating solution for silver plating. The cathode current density is 1~2A / dm 2 , the time is 1~2 hours, the cathode material is stainless steel 1Cr18Ni9Ti, and the positive and negative area ratio is 1:1~2. Add 1 / 3 of the solution volume of pure water to the pre-silver plating tank, add the calculated amount of potassium cyanide and stir to dissolve it completely; add the calculated amount of silver cyanide (1 gram of silver nitrate and 0.38 grams of potassium cyanide are required to produce 1 gram of silver cyanide. Dissolve the silver nitrate and potassium cyanide in water respectively. Under stirring, slowly add the potassium cyanide solution to the silver nitrate solution until the reaction is complete, filter, and wash the precipitate with pure water; the operation process should be protected from light.) Slowly add it to the potassium cyanide solution under constant stirring, add water to 100mm from the tank surface after it is completely dissolved, and stir evenly.

[0026] S10: Cyanide silver plating: The silver plating solution is prepared by dissolving metallic silver Ag 22~28g / L, free potassium cyanide KCN 120~150g / L, 3KMK-A brightener 8~12ml / L, 3KMK-B opener 8~12ml / L, and the current density is 0.5~2A / dm 2 , the anode material is Ag-1, and the ratio of the cathode and anode areas is 1:2. Add 1 / 3 of the volume of the solution into the cyanide silver plating tank; add the calculated amount of potassium cyanide and stir to dissolve it completely; add the calculated amount of silver cyanide (1 gram of silver nitrate and 0.38 grams of potassium cyanide are required to produce 1 gram of silver cyanide. Dissolve the silver nitrate and potassium cyanide in water respectively. Under stirring, slowly add the potassium cyanide solution to the silver nitrate solution until the reaction is complete, filter, and wash the precipitate with pure water; the operation should be protected from light.) Slowly add it to the potassium cyanide solution under constant stirring, stir to dissolve it completely; add water to 100mm from the tank surface and stir evenly; use 0.2~0.3A / dm 2 The current density is energized for 4 to 8 hours, and then the calculated amount of 3KMK-A and 3KMK-B is added. When preparing, it is strictly forbidden to mix silver nitrate and potassium cyanide together before dissolving them in the tank to avoid danger. Then rinse with cold water.

[0027] S11 Alkali dewaxing: Alkali dewaxing solution is prepared by dissolving 80~120g / L sodium hydroxide NaOH, 10~25g / L sodium carbonate Na2CO3·10H2O, and 15~35g / L sodium phosphate Na3PO4·12H2O, and the wax is completely removed at a temperature of 80~100℃. Add 2 / 3 of the total volume of water to the alkali dewaxing tank; use a hanging basket to hold the calculated amount of sodium hydroxide and place it in the degreasing tank to completely dissolve the sodium hydroxide; add the calculated amount of sodium phosphate and sodium carbonate, and stir thoroughly until they are completely dissolved; add water to 100mm from the tank surface and stir evenly.

[0028] S12 acid etching: At room temperature, use hydrochloric acid HCL100~150 g / L acid etching solution to remove the film for 5~10 minutes, then rinse with cold water and dry at 60~80℃.

[0029] S13: Apply acrylic varnish to non-silver-plated areas. The paint mixing ratio is: B01-3 (or B01-5) acrylic varnish: X-5 acrylic thinner = 1:2.5~3.5 (weight ratio). The construction viscosity is 5~10S (measured by Tu-4 viscometer). After protecting the unpainted parts, apply evenly by brush, and then dry at room temperature 20℃ for 2 hours.

[0030] S14 Silver layer anti-tarnishing treatment: Use a scouring pad to rub the silver layer until it is fine and smooth silver-white, wipe the metal dust on the surface of the silver layer with industrial alcohol, and after the alcohol on the surface of the silver layer evaporates, brush or dip a layer of silver plating protective agent on the silver-plated part, and dry it at room temperature for 3 to 5 minutes. After it is completely dry, wrap the silver-plated part with a plastic bag and tie it with paper tape.

[0031] It should be understood that the specific embodiments described above are only used to explain the present invention and are only used to cooperate with the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention without affecting the effects and purposes that can be achieved by the present invention.

Claims

1. A silver plating method for outdoor high-voltage switch conductive parts, characterized in that: The following steps are involved: S1: pre-plating treatment; S2: degreasing with organic solvents; S3: Chemical degreasing: Dissolve 100-150 g / L sodium hydroxide NaOH, 20-40 g / L sodium carbonate Na2CO3·10H2O, and 20-40 g / L sodium phosphate Na3PO4·12H2O in water, soak for 10-20 minutes at 70-90°C, rinse, and dry; S4: acid etching; S5: Pickling and passivation: Add 2 / 3 of the total volume of water to the pickling and passivation tank. While stirring continuously, slowly add 15-25 g / L sulfuric acid H2SO4, 30-45 g / L nitric acid HNO3, and 150-180 g / L chromic anhydride CrO3. Stir thoroughly until completely dissolved. Add water to a distance of 100 mm from the tank surface and stir evenly. Soak the parts to be plated for 10-30 minutes, rinse with cold water first, then rinse with 70-80 ° C hot water, and then blow dry with compressed air. S6: Brush (dip) wax: melt semi-refined paraffin at a temperature of 100-120°C, add rosin and stir evenly; for partially silver-plated parts, wax is applied to protect the non-electroplated surface, leaving a 2-3mm transition zone between the electroplated surface and the non-electroplated surface; S7: acid removal; S8: Clean and polish the surface to be plated: Use 00# sandpaper and 240# water sandpaper to polish the surface to be plated until it feels fine and smooth, and there is no water droplets on the surface to be plated after soaking in water, and a continuous water film is formed; S9: Pre-silver plating: The pre-silver plating solution is prepared by dissolving 1~2g / L of metallic silver Ag and 100~120g / L of free potassium cyanide KCN. At room temperature, the treated parts to be plated are placed in the silver plating solution for silver plating. The cathode current density is 1~2A / dm 2 , the time is 1~2 hours, the cathode material is stainless steel 1Cr18Ni9Ti, and the cation and cathode area ratio is 1:1~2; S10. Cyanide silver plating: add 1 / 3 of the solution volume of pure water to the cyanide silver plating tank; add 120~150g / L of free potassium cyanide KCN and stir to completely dissolve it; slowly add the calculated amount of silver cyanide to the potassium cyanide solution while stirring continuously and stir to completely dissolve it; add water to 100mm from the tank surface and stir evenly; use 0.2~0.3A / dm 2 The current density is energized for 4 to 8 hours, and 3KMK-A brightener 8 to 12 ml / L and 3KMK-B cylinder opener 8 to 12 ml / L are added; S11. Alkali boiling to remove wax; S12. Acid etching to reveal light; S13. Apply acrylic varnish to non-silver-plated areas: the paint ratio is B01-3 or B01-5 acrylic varnish: X-5 acrylic thinner = 1:2.5~3.5 (weight ratio), construction viscosity 5~10S; protect the unpainted area and apply evenly by brush, then dry at room temperature 20℃ for 2 hours; S14. Silver layer anti-tarnishing treatment.

2. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S1 includes checking that the parts do not have obvious cracks, pores, mechanical deformation, damage, scratches and other defects. When the surface roughness of the surface to be plated is greater than 1.6, it is polished with sandpaper.

3. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S2 includes soaking the mixture in industrial gasoline for 10 to 20 minutes at room temperature and then drying the mixture naturally in air.

4. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S4 includes soaking in an aqueous solution prepared with 140-200 g / L hydrochloric acid HCL and 100-150 g / L sulfuric acid H2SO4 for 10-60 minutes at room temperature, and then rinsing and drying.

5. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S7 includes soaking the mixture in a ratio of hydrochloric acid (HCl) to water (1:1) for 10 to 30 minutes at room temperature and then rinsing with cold water.

6. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S11 includes preparing an alkali dewaxing solution by dissolving 80-120 g / L of sodium hydroxide NaOH, 10-25 g / L of sodium carbonate Na2CO3·10H2O, and 15-35 g / L of sodium phosphate Na3PO4·12H2O, and heating the solution at a temperature of 80-100°C until the wax is completely removed.

7. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S12 includes: removing the film by acid immersion in an acid etching solution prepared by dissolving 100-150 g / L of hydrochloric acid HCL in water for 5-10 minutes, then rinsing with cold water, and drying at 60-80°C.

8. The silver plating method for outdoor high-voltage switch conductive parts according to claim 1, characterized in that: Step S14 includes polishing the silver layer with a scouring pad to a fine and smooth silver-white color, wiping the metal dust on the surface of the silver layer with industrial alcohol, and after the alcohol on the surface of the silver layer evaporates, brushing or dipping the silver-plated part with a silver-plating protective agent, and drying it at room temperature for 3 to 5 minutes; after it is completely dry, wrap the silver-plated part with a plastic bag and tie it with paper tape.

9. A silver plating method for outdoor high-voltage switch conductive parts according to any one of claims 1 to 8, characterized in that: The high-voltage switch conductive component is a copper substrate or a copper alloy substrate.