A nickel electroplating anti-corrosion process for alkaline electrolytic cell plates

Abstract

The present invention relates to the technical field of electroplating corrosion protection of electrolytic cell plates, and specifically to a nickel electroplating corrosion protection process for alkaline electrolytic cell plates, comprising: electrolytic degreasing treatment of the cathode surface and the anode surface of the plate; and electroplating nickel on the entire plate, wherein the nickel electroplating includes first using the top hanging point of the plate as the cathode current input contact position, and then using the bottom hanging point of the plate as the cathode current input contact position. The present invention performs electrolytic degreasing treatment in the electrolytic cell, which is easy to operate, removes oil stains on the surface of the plate by electrolytic degreasing, and enhances the adhesion of the electroplated nickel layer to the surface of the plate. The present invention uses the top hanging point and the bottom hanging point of the plate as the cathode in turn, and changes the contact position of the current input, which is conducive to solving the phenomenon of uneven thickness of the electroplated nickel layer caused by uneven current density distribution.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cell plate electroplating anti-corrosion, and in particular to a nickel electroplating anti-corrosion process for an alkaline electrolytic cell plate. Background Art

[0002] As a secondary energy source with abundant sources, green and low carbon, and wide applications, hydrogen energy can build a clean, low-carbon, safe and efficient energy system. However, with the rapid growth of green hydrogen demand in various industries, the rapid and efficient production of high-purity and high-yield hydrogen has become one of the main problems currently faced. In this context, vigorously promoting water electrolysis hydrogen production technology can effectively solve the technical problems of high-purity and high-yield hydrogen production.

[0003] The raw material for hydrogen production by water electrolysis is water, and the input energy is electricity. Alkaline water electrolysis hydrogen production equipment has high commercial maturity, rich operating experience, and a large amount of hydrogen production per tank, which is easy to apply to large-scale hydrogen production. 3 / h and above alkaline water electrolysis hydrogen production equipment core component plate needs to be treated with nickel electroplating to improve the corrosion resistance of the plate during use. The quality of the nickel electroplating anti-corrosion process has a direct impact on the service life, stability, safety and reliability of the alkaline electrolytic cell.

[0004] In the prior art, the pretreatment effect of the plate surface before electroplating is not good, resulting in poor adhesion of the nickel-plated layer after the nickel-plating process; at the same time, since the current input position of the nickel-plating process is fixed, the thickness error of the nickel-plated layer at the top and bottom of the hanging point is 30~100μm, and the thickness of the nickel-plated layer is uneven, which brings unstable factors to the nickel-plating anti-corrosion process of the alkaline electrolytic cell plate. Summary of the invention

[0005] Aiming at the technical problems of poor adhesion and uneven thickness of the nickel-plated layer, the present invention provides a nickel-plating anti-corrosion process for an alkaline electrolytic cell plate, wherein the obtained nickel-plated layer has strong adhesion and uniform thickness, thereby improving the yield of the product.

[0006] The present invention provides an electroplating nickel anti-corrosion process for an alkaline electrolytic cell plate, comprising:

[0007] Electrolytic degreasing treatment of the cathode surface and anode surface of the plate;

[0008] The entire electrode plate is electroplated with nickel, and the electroplating includes firstly using the top hanging point of the electrode plate as the cathode current input contact position, and then using the bottom hanging point of the electrode plate as the cathode current input contact position.

[0009] Furthermore, before the electrolytic degreasing treatment, the electrode plates and the hangers for nickel electroplating are inspected, including inspecting the electrode plate surface for appearance defects, and inspecting the conductivity of the hangers for nickel electroplating and whether there is an oxide layer on the hanging contact parts.

[0010] Further, the cathode surface of the plate is electrolytically degreased by placing the plate in an electrolytic cell with a bath solution, attaching the hanger to the cathode and applying electricity for 60 minutes, with a cathode current of 0.8A / dm 2 , the bath liquid temperature is 40±5℃; the bath liquid includes the following concentrations of components: NaOH 10~25g / L, Na2CO325~50g / L, Na2SiO325~50g / L.

[0011] Further, the electrolytic degreasing treatment of the anode surface of the electrode plate includes placing the electrode plate in an electrolytic cell with a bath solution, connecting the hanger to the anode and applying electricity for 30 minutes, and the cathode current is 0.8A / dm 2 , the bath liquid temperature is 40±5℃; the bath liquid includes the following concentrations of components: NaOH 10~25g / L, Na2CO325~50g / L, Na2SiO325~50g / L.

[0012] Furthermore, the nickel electroplating process conditions include a current density of 0.9A / dm 2 , temperature is 35±5℃, pH value of nickel solution is 4.1~4.8.

[0013] Furthermore, the time for using the top hanging point of the electrode plate as the cathode current input contact position for nickel electroplating is half of the total nickel electroplating time.

[0014] Furthermore, the bottom hanging point of the electrode plate is used as the cathode current input contact position and then the current control is performed in segments, including first electroplating at 200A for 2 minutes, then electroplating at 600A for 3 minutes, and finally electroplating at 1200A for 5 minutes.

[0015] Furthermore, after the plate is electroplated, it is subjected to a passivation treatment in a passivation solution for 60 minutes. The passivation solution is at a temperature of >60°C. The passivation solution includes components of the following concentrations: NaOH 15 g / L, Na2CO3 15 g / L, Na3PO4·12H2O 50 g / L, Na2SiO3 15 g / L, and KMnO4 5 g / L.

[0016] The beneficial effects of the present invention are:

[0017] (1) The present invention performs electrolytic degreasing in an electrolytic cell, which is easy to operate. The electrolytic degreasing removes oil stains on the surface of the electrode plate, thereby enhancing the adhesion of the electroplated nickel layer to the surface of the electrode plate.

[0018] (2) The present invention adopts the top hanging point and the bottom hanging point of the electrode plate as the cathode in turn, changing the contact position of the current input, which is conducive to solving the problem of uneven thickness of the electroplated nickel layer caused by uneven current density distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the plate structure of a specific embodiment of the present invention.

[0021] In the figure, 1-first plate frame thickness measurement point, 2-second plate frame thickness measurement point, 3-third plate frame thickness measurement point, 4-fourth plate frame thickness measurement point, 5-first plate main body thickness measurement point, 6-second plate main body thickness measurement point, 7-third plate main body thickness measurement point, 8-fourth plate main body thickness measurement point, 9-plate top hanging point, 10-plate bottom hanging point. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] Example 1

[0024] A nickel electroplating anti-corrosion process for an alkaline electrolytic cell plate comprises the following steps:

[0025] Step 1: Check components before electroplating; check whether there are serious bumps, scratches, rust spots, sand holes and other appearance defects on the surface of the plate;

[0026] Step 2: Check the tooling and lifting equipment; check whether the tooling and lifting equipment is conductive and whether there is an oxide layer on the contact part;

[0027] Step 3: Place the plate in an electrolytic cell with bath solution and perform cathode electrolytic degreasing treatment on the plate; cathode current: 0.8A / dm 2 , bath temperature: 40±5℃, treatment time: 60min; the bath contains the following concentrations: NaOH 20g / L, Na2CO3 40g / L, Na2SiO3 40g / L. Use a hanger to overlap the plate on the cathode and power on for 60min.

[0028] Step 4: Rinse, pickle and rinse again the cathode surface of the plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 60 minutes.

[0029] Step 5: Place the electrode plate in an electrolytic cell with bath solution to perform anode electrolysis degreasing of the electrode plate; current density: 0.8A / dm 2 , bath temperature: 40±5℃, treatment time: 30min, bath composition: NaOH concentration 20g / L, Na2CO3 concentration 40g / L, Na2SiO3 concentration 40g / L. Use a hanger to overlap the electrode plate on the anode and power on for 30min.

[0030] Step 6: Rinse, pickle, soak and rinse the surface of the anode plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 2 minutes.

[0031] Step 7: Start nickel plating; Figure 1 First, the top hanging point 9 of the electrode plate is used as the cathode current input contact position. The nickel electroplating process conditions include a current density of 0.9A / dm 2 , the temperature is 35±5℃, the pH value of the nickel solution is 4.1~4.8. When the nickel plating time is half of the total plating time, the hanging point 10 at the bottom of the plate is used as the cathode current input contact position to check the plate for blistering, burrs, burning, leakage and other phenomena. If the problem can be cleared on the spot, continue plating after clearing; if it cannot be cleared, re-plating is performed after the repair is completed; the maximum current is applied when entering the tank for the first time; the hanging point at the bottom of the plate is used as the cathode current input contact position and the current is controlled in stages, including first plating at 200A for 2 minutes, then at 600A for 3 minutes, and finally at 1200A for 5 minutes.

[0032] Step 8: Recycling; out of the tank, into the tank, and out of the tank are performed once.

[0033] Step 9: Rinse after electroplating; use a water gun to rinse twice in the tank and twice out of the tank; visually check whether there is any nickel solution residue.

[0034] Step 10: After the plate is electroplated, it enters the passivation solution for passivation treatment; the passivation solution environment temperature is > 60°C, and the treatment time is 60 minutes. The passivation solution includes the following concentration components: NaOH 15g / L, Na2CO3 15g / L, Na3PO4•12H2O 50g / L, Na2SiO3 15g / L, KMnO4 5g / L.

[0035] Step 11: Rinse after passivation treatment; use a water gun to rinse twice in the tank and twice out of the tank; check with the naked eye to see if there is any passivation liquid left.

[0036] Step 12: Surface neutralization treatment after electroplating; neutralization time 5 minutes; the bath solution includes the following concentration components: NaOH 10~25g / L.

[0037] Step 13: Spray the plates to clean the alkali and acid residues; visually check whether there is any alkali residue.

[0038] Step 14: Dry the electrode plate with hot air for 2 minutes to ensure that all residual liquid on the components is removed.

[0039] Step 15: Prepare and store after electroplating; check whether the parts have quality problems such as blistering, burrs, burning (too much current, burning the plating), water stains, etc., and store them in a dry place.

[0040] like Figure 1 The thickness was measured at the first plate frame thickness measurement point 1, the second plate frame thickness measurement point 2, the third plate frame thickness measurement point 3, and the fourth plate frame thickness measurement point 4, and the actual thickness was 70~80μm; the thickness was measured at the first plate main body thickness measurement point 5, the second plate main body thickness measurement point 6, the third plate main body thickness measurement point 7, and the fourth plate main body thickness measurement point 8, and the actual thickness was 60~70μm; which meets the requirements for the electrolytic cell plate plating thickness.

[0041] Example 2

[0042] A nickel electroplating anti-corrosion process for an alkaline electrolytic cell plate comprises the following steps:

[0043] Step 1: Check components before electroplating; check whether there are serious bumps, scratches, rust spots, sand holes and other appearance defects on the surface of the plate;

[0044] Step 2: Check the tooling and lifting equipment; check whether the tooling and lifting equipment is conductive and whether there is an oxide layer on the contact part;

[0045] Step 3: Place the plate in an electrolytic cell with bath solution and perform cathode electrolytic degreasing treatment on the plate; cathode current: 0.8A / dm 2 , bath temperature: 40±5℃, treatment time: 60min; the bath contains the following concentrations: NaOH 10g / L, Na2CO3 25g / L, Na2SiO3 25g / L. Use a hanger to overlap the plate on the cathode and power on for 60min.

[0046] Step 4: Rinse, pickle and rinse again the cathode surface of the plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 60 minutes.

[0047] Step 5: Place the electrode plate in an electrolytic cell with bath solution to perform anode electrolysis degreasing of the electrode plate; current density: 0.8A / dm 2, bath temperature: 40±5℃, treatment time: 30min, bath composition: NaOH concentration 10g / L, Na2CO3 concentration 25g / L, Na2SiO3 concentration 25g / L. Use a hanger to overlap the electrode plate on the anode and power on for 30min.

[0048] Step 6: Rinse, pickle, soak and rinse the surface of the anode plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 2 minutes.

[0049] Step 7: Start nickel electroplating; first, the top hanging point of the plate is used as the cathode current input contact position. The nickel electroplating process conditions include a current density of 0.9A / dm 2 , the temperature is 35±5℃, the pH value of the nickel solution is 4.1~4.8. When the nickel plating time is half of the total plating time, the hanging point at the bottom of the plate is used as the cathode current input contact position to check the plate for blistering, burrs, burning, leakage and other phenomena. If the problem can be cleared on the spot, continue plating after clearing; if it cannot be cleared, re-electroplate after the repair is completed; give the maximum current when entering the tank for the first time; use the hanging point at the bottom of the plate as the cathode current input contact position and then perform current control in stages, including first plating at 200A for 2 minutes, then at 600A for 3 minutes, and finally at 1200A for 5 minutes.

[0050] Step 8: Recycling; out of the tank, into the tank, and out of the tank are performed once.

[0051] Step 9: Rinse after electroplating; use a water gun to rinse twice in the tank and twice out of the tank; visually check whether there is any nickel solution residue.

[0052] Step 10: After the plate is electroplated, it enters the passivation solution for passivation treatment; the passivation solution environment temperature is > 60°C, and the treatment time is 60 minutes. The passivation solution includes the following concentration components: NaOH 15g / L, Na2CO3 15g / L, Na3PO4•12H2O 50g / L, Na2SiO3 15g / L, KMnO4 5g / L.

[0053] Step 11: Rinse after passivation treatment; use a water gun to rinse twice in the tank and twice out of the tank; check with the naked eye to see if there is any passivation liquid left.

[0054] Step 12: Surface neutralization treatment after electroplating; neutralization time 5 minutes; the bath solution includes the following concentration components: NaOH 10g / L.

[0055] Step 13: Spray the plates to clean the alkali and acid residues; visually check whether there is any alkali residue.

[0056] Step 14: Dry the electrode plate with hot air for 2 minutes to ensure that all residual liquid on the components is removed.

[0057] Step 15: Prepare and store after electroplating; check whether the parts have quality problems such as blistering, burrs, burning (too much current, burning the plating), water stains, etc., and store them in a dry place.

[0058] In Example 2, the actual measured thickness of the plate frame is 75-85 μm; the actual measured thickness of the plate main body is 65-75 μm, which meets the requirements for the thickness of the electrolytic cell plate coating.

[0059] Example 3

[0060] A nickel electroplating anti-corrosion process for an alkaline electrolytic cell plate comprises the following steps:

[0061] Step 1: Check components before electroplating; check whether there are serious bumps, scratches, rust spots, sand holes and other appearance defects on the surface of the plate;

[0062] Step 2: Check the tooling and lifting equipment; check whether the tooling and lifting equipment is conductive and whether there is an oxide layer on the contact part;

[0063] Step 3: Place the plate in an electrolytic cell with bath solution and perform cathode electrolytic degreasing treatment on the plate; cathode current: 0.8A / dm 2 , bath temperature: 40±5℃, treatment time: 60min; the bath contains the following concentrations: NaOH 25g / L, Na2CO3 50g / L, Na2SiO3 50g / L. Use a hanger to overlap the plate on the cathode and power on for 60min.

[0064] Step 4: Rinse, pickle and rinse again the cathode surface of the plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 60 minutes.

[0065] Step 5: Place the electrode plate in an electrolytic cell with bath solution to perform anode electrolysis degreasing of the electrode plate; current density: 0.8A / dm 2 , bath temperature: 40±5℃, treatment time: 30min, bath composition: NaOH concentration 25g / L, Na2CO3 concentration 50g / L, Na2SiO3 concentration 50g / L. Use a hanger to overlap the electrode plate on the anode and power on for 30min.

[0066] Step 6: Rinse, pickle, soak and rinse the surface of the anode plate; visually inspect twice before and after pickling to see if there is any alkali residue. The pickling time is 2 minutes.

[0067] Step 7: Start nickel electroplating; first, the top hanging point of the plate is used as the cathode current input contact position. The nickel electroplating process conditions include a current density of 0.9A / dm2 , the temperature is 35±5℃, the pH value of the nickel solution is 4.1~4.8. When the nickel plating time is half of the total plating time, the hanging point at the bottom of the plate is used as the cathode current input contact position to check the plate for blistering, burrs, burning, leakage and other phenomena. If the problem can be cleared on the spot, continue plating after clearing; if it cannot be cleared, re-electroplate after the repair is completed; give the maximum current when entering the tank for the first time; use the hanging point at the bottom of the plate as the cathode current input contact position and then perform current control in stages, including first plating at 200A for 2 minutes, then at 600A for 3 minutes, and finally at 1200A for 5 minutes.

[0068] Step 8: Recycling; out of the tank, into the tank, and out of the tank are performed once.

[0069] Step 9: Rinse after electroplating; use a water gun to rinse twice in the tank and twice out of the tank; visually check whether there is any nickel solution residue.

[0070] Step 10: After the plate is electroplated, it enters the passivation solution for passivation treatment; the passivation solution environment temperature is > 60°C, and the treatment time is 60 minutes. The passivation solution includes the following concentration components: NaOH 15g / L, Na2CO3 15g / L, Na3PO4•12H2O 50g / L, Na2SiO3 15g / L, KMnO4 5g / L.

[0071] Step 11: Rinse after passivation treatment; use a water gun to rinse twice in the tank and twice out of the tank; check with the naked eye to see if there is any passivation liquid left.

[0072] Step 12: Surface neutralization treatment after electroplating; neutralization time 5 minutes; the bath solution includes the following concentration components: NaOH 25g / L.

[0073] Step 13: Spray the plates to clean the alkali and acid residues; visually check whether there is any alkali residue.

[0074] Step 14: Dry the electrode plate with hot air for 2 minutes to ensure that all residual liquid on the components is removed.

[0075] Step 15: Prepare and store after electroplating; check whether the parts have quality problems such as blistering, burrs, burning (too much current, burning the plating), water stains, etc., and store them in a dry place.

[0076] In Example 3, the actual measured thickness of the plate frame is 70-85 μm; the actual measured thickness of the plate main body is 65-80 μm, which meets the requirements for the thickness of the electrolytic cell plate coating.

[0077] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A nickel electroplating anti-corrosion process for alkaline electrolytic cell plates, characterized in that: include: Electrolytic degreasing treatment of the cathode surface and anode surface of the plate; The entire plate is electroplated with nickel, wherein the electroplating includes firstly using the top hanging point of the plate as a cathode current input contact position, and then using the bottom hanging point of the plate as a cathode current input contact position; The cathode surface electrolytic degreasing treatment of the plate includes placing the plate in an electrolytic tank with bath solution, connecting the hanger to the cathode and applying electricity for 60 minutes, with the cathode current of 0.8A / dm 2 , the bath temperature is 40±5℃; the bath includes the following components in concentration: NaOH 10~25g / L, Na2CO3 25~50g / L, Na2SiO325~50g / L; The electrolytic degreasing treatment of the anode surface of the electrode plate includes placing the electrode plate in an electrolytic tank with a bath solution, connecting the hanger to the anode and applying electricity for 30 minutes, and the anode current is 0.8A / dm 2 , the bath temperature is 40±5℃; the bath includes the following components in concentration: NaOH 10~25g / L, Na2CO3 25~50g / L, Na2SiO3 25~50g / L; The time for nickel electroplating with the top hanging point of the electrode plate as the cathode current input contact position is half of the total nickel electroplating time; after the bottom hanging point of the electrode plate is used as the cathode current input contact position, the current is controlled in segments, including first electroplating at 200A for 2 minutes, then electroplating at 600A for 3 minutes, and finally electroplating at 1200A for 5 minutes.

2. The nickel electroplating anti-corrosion process for alkaline electrolytic cell plates according to claim 1, characterized in that: Before the electrolytic degreasing treatment, the plate and the nickel electroplating hanger are inspected, including checking the surface of the plate for appearance defects, and checking the conductivity of the nickel electroplating hanger and whether there is an oxide layer on the hanging contact part.

3. The electroplating nickel anticorrosion process for alkaline electrolytic cell plates according to claim 1, characterized in that: The nickel electroplating process conditions include a current density of 0.9A / dm 2 , temperature is 35±5℃, pH value of nickel solution is 4.1~4.

8.

4. The nickel electroplating anti-corrosion process for alkaline electrolytic cell plates according to claim 1, characterized in that: After electroplating, the plate enters the passivation solution for passivation treatment for 60 minutes. The passivation solution is greater than 60°C. The passivation solution includes the following concentrations of components: NaOH 15g / L, Na2CO3 15g / L, Na3PO4·12H2O 50g / L, Na2SiO3 15g / L, and KMnO4 5g / L.

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