Chemical nickel plating solution containing oxidizing agent and method for improving corrosion resistance of chemical nickel plating

Abstract

The invention relates to the technical field of electroplating, in particular to a chemical nickel plating solution containing an oxidizing agent and a method for improving the corrosion resistance of chemical nickel plating. The chemical nickel plating solution comprises the following raw materials: nickel salt, a reducing agent, an oxidizing agent and a solvent; the oxidizing agent at least comprises hydrogen peroxide. It is creatively found that the oxidizing agent is introduced into the chemical nickel plating solution, the oxidizing agent comprises hydrogen peroxide or a combination of hydrogen peroxide and other oxidizing agents, and the corrosion resistance of a chemical nickel plating layer can be effectively improved. By means of the well-designed technological process and the specific chemical nickel plating solution, a brand-new and efficient thought is provided for electroplating surface treatment, and the problems that the chemical nickel plating process is difficult to control, energy consumption is large, and the nickel plating solution is poor in stability, prone to volatilization, short in service life and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of electroplating, and in particular to a chemical nickel plating solution containing an oxidant and a method for improving the corrosion resistance of chemical nickel plating. Background Art

[0002] Chemical nickel plating technology has become an important technical choice in the manufacture of many industrial and consumer products due to its good corrosion resistance, good throwing power and ability to enhance the hardness and wear resistance of the substrate. However, the current industrial application of chemical nickel plating technology has a temperature between 85 and 95°C, which is difficult to control the process, consumes a lot of energy, and has poor plating solution stability, is easy to volatilize, and has a short service life.

[0003] In order to improve the corrosion resistance of the chemical nickel layer, Chinese patent CN202310818483.5 discloses a corrosion-resistant chemical nickel plating solution and a preparation method thereof, and proposes to use a chemical nickel plating solution and a combined stabilizer to improve the corrosion resistance of the chemical nickel plating layer, wherein the combined stabilizer includes modified binaphthylthiourea, chromium sulfate and thiodipropionic acid, but the preparation process of modified binaphthylthiourea is complicated, and the substances such as chloroform and dichloromethane used in the preparation process are toxic and not environmentally friendly. Chinese patent application CN202410633397.1 discloses a high-phosphorus chemical nickel-phosphorus alloy plating solution and a chemical plating method thereof, and proposes to use a composite complexing agent, iodate and rare earth compound to improve the corrosion resistance of the chemical nickel plating layer, but the plating temperature needs to be 85 to 90°C, which consumes a lot of energy and the nickel plating solution is volatile.

[0004] Under such circumstances, there is an urgent need to provide a simple and easy technical solution that can effectively improve the effect of chemical nickel plating. Summary of the invention

[0005] In view of the defects of chemical nickel plating technology, the present invention aims to simplify the operation while improving the corrosion resistance of the chemical nickel plating layer and the stability of the plating solution. It is unexpectedly found that adding a small amount of oxidant substance to the chemical nickel plating solution can enhance the corrosion resistance of the chemical nickel plating layer without producing harmful by-products; and the operation is simple, the practicability is strong, and it has broad application prospects.

[0006] A first aspect of the present invention provides a chemical nickel plating solution containing an oxidant, wherein raw materials of the chemical nickel plating solution include a nickel salt, a reducing agent, an oxidant and a solvent.

[0007] In some preferred embodiments, the oxidant includes a combination of one or more of organic peroxides, permanganates, and ozone.

[0008] Preferably, the organic peroxide includes one or more combinations of hydrogen peroxide, meta-chloroperbenzoic acid, peracetic acid, and tert-butyl peroxide.

[0009] More preferably, the oxidant comprises hydrogen peroxide.

[0010] In some preferred embodiments, the concentration of hydrogen peroxide in the hydrogen peroxide is 5-35 wt %, more preferably 30 wt %.

[0011] In some preferred embodiments, the amount of hydrogen peroxide added to the chemical nickel plating solution is 0-2 mL / L, excluding endpoint values.

[0012] More preferably, the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.2-1 mL / L; it can be listed as 0.2 mL / L, 0.3 mL / L, 0.4 mL / L, 0.5 mL / L, 0.6 mL / L, 0.7 mL / L, 0.8 mL / L, 0.9 mL / L, 1 mL / L; further preferably, it is 0.2-0.6 mL / L.

[0013] The present invention innovatively finds that introducing an oxidant into a chemical nickel plating solution, wherein the oxidant includes hydrogen peroxide or a combination of hydrogen peroxide and other oxidants, preferably hydrogen peroxide, can effectively improve the corrosion resistance of the chemical nickel plating layer; in particular, the concentration of the hydrogen peroxide is set to 30wt%, and the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.2-1mL / L, which can effectively prolong the time for the plating layer to turn black and bubble to appear after contacting nitric acid, and the chemical nickel plating layer has reliable corrosion resistance.

[0014] The present invention has no special restrictions on nickel salts, as long as they can provide a source of nickel ions to achieve the purpose of chemical nickel plating, such as nickel sulfate, nickel chloride, nickel acetate, nickel hypophosphite, nickel nitrate, nickel carbonate, etc.; preferably nickel sulfate.

[0015] In some preferred embodiments, the reducing agent can be listed as hypophosphite, hypophosphite, sodium borohydride, borane, hydrazine, etc., preferably hypophosphite, such as NaH2PO2.

[0016] Preferably, the reducing agent is added in an amount of 10-40 g / L in the chemical nickel plating solution.

[0017] In some preferred embodiments, the raw materials of the chemical nickel plating solution further include a complexing agent and a stabilizer.

[0018] The complexing agent can be listed as sodium succinate, malic acid, sodium acetate, lactic acid, citric acid, glycolic acid, aminoacetic acid, ethylenediaminetetraacetic acid, hydroxyethylidene diphosphonic acid, aminotri(methylene)phosphonic acid, etc., preferably a combination of sodium succinate, malic acid, sodium acetate and lactic acid.

[0019] In some preferred embodiments, the dosage ratio of sodium succinate, malic acid, sodium acetate and lactic acid is (3-20): (2-15): (2-20): (3-25); in this dosage ratio, the dosage unit of sodium succinate, malic acid and sodium acetate is g / L, and the dosage unit of lactic acid is mL / L.

[0020] In some preferred embodiments, the complexing agent is added in an amount of 5-70 g / L, preferably 20-55 g / L, to the chemical nickel plating solution.

[0021] The stabilizer may be exemplified by heavy metal compounds, thiocyanates, thiourea and derivatives thereof, oxygen-containing acid radical compounds, etc., preferably heavy metal compounds, and heavy metals may be exemplified by tin, antimony, cadmium, and lead.

[0022] In some preferred embodiments, the stabilizer includes lead acetate.

[0023] In some preferred embodiments, the stabilizer is added in an amount of 0.1-2 mg / L in the chemical nickel plating solution.

[0024] Most preferably, the chemical nickel plating solution comprises: NiSO4·6H2O 18-25g / L, NaH2PO2·H2O 20-30g / L, sodium succinate 5-15g / L, malic acid 5-10g / L, sodium acetate 5-15g / L, lactic acid 5-15mL / L, lead acetate 0.5-1mg / L, hydrogen peroxide (30wt%%) 0.2-1mL / L, and the solvent is water.

[0025] The present invention does not impose any particular limitation on the solvent of the chemical nickel plating solution, as long as it can achieve the purpose of dissolution, such as water.

[0026] The present invention has no particular limitation on the preparation method of the chemical nickel plating solution, and the solution can be prepared by conventional methods in the art, for example, by uniformly mixing the raw materials.

[0027] Preferably, the pH of the chemical nickel plating solution is 4-6.5, more preferably 4.8. The pH of the chemical nickel plating solution can be adjusted by H2SO4 or NaOH.

[0028] In order to facilitate the chemical nickel plating operation, preferably, the preparation steps of the chemical nickel plating solution are: firstly mix the raw materials except hydrogen peroxide, and then add hydrogen peroxide when using (ie, performing the chemical nickel plating operation).

[0029] In some preferred embodiments, the working temperature of the chemical nickel plating solution is 70-95°C, more preferably 75-85°C; most preferably 80°C.

[0030] The working temperature of the chemical nickel plating solution of the present invention is relatively low, and a chemical nickel plating layer with excellent corrosion resistance can be obtained when operated at 80° C., which improves the quality of manufactured parts while reducing energy consumption, and has great advantages over existing products.

[0031] The second aspect of the present invention provides a method for improving the corrosion resistance of chemical nickel plating, which at least comprises the steps of: using a chemical nickel plating solution to perform chemical nickel plating on a workpiece to be plated.

[0032] In some preferred embodiments, the part to be plated is pre-treated before chemical nickel plating is performed on the part to be plated using a chemical nickel plating solution.

[0033] In some preferred embodiments, the pre-treatment includes degreasing, and the workpiece to be plated is immersed in a degreasing liquid for degreasing treatment.

[0034] Preferably, the degreasing treatment is carried out at a temperature of 40-60°C and a treatment time of 3-10 minutes.

[0035] More preferably, the concentration is 50°C, and the degreasing treatment temperature is 50°C, and the treatment time is 5 minutes.

[0036] In some preferred embodiments, the degreasing liquid includes NaOH 2-15 g / L, Na2CO3 2-25 g / L, Na3PO4 10-35 g / L, and the solvent is water.

[0037] More preferably, the degreasing liquid comprises NaOH 5-10 g / L, Na2CO3 5-15 g / L, Na3PO4 15-25 g / L, and the solvent is water.

[0038] In some preferred embodiments, the pre-treatment further includes micro-etching, wherein the degreased workpiece to be plated is immersed in a micro-etching solution for micro-etching.

[0039] Preferably, the micro-etching treatment is performed at a temperature of 15-40° C. and a treatment time of 1-3 min.

[0040] In some preferred embodiments, the micro-etching solution includes 15-45 g / L of peroxodisulfate, 40-120 mL / L of acid, and the solvent is water.

[0041] More preferably, the micro-etching solution includes 25-35 g / L Na2S2O8, 50-100 mL / L concentrated sulfuric acid, and the solvent is water.

[0042] Preferably, the concentration of the concentrated sulfuric acid is 98wt%.

[0043] In some preferred embodiments, the pre-treatment further comprises activation, wherein the micro-etched workpiece is immersed in an activation solution for activation treatment.

[0044] Preferably, the activation treatment temperature is 15-40° C., and the treatment time is 1-3 min.

[0045] In some preferred embodiments, the activation solution includes PdCl2 0.1-1 g / L, NH4Cl 0.1-3.0 g / L, and the solvent is water.

[0046] More preferably, the activation solution comprises PdCl2 0.1-0.5 g / L, NH4Cl 0.5-2.0 g / L, and the solvent is water.

[0047] The present invention does not impose any special restrictions on the material of the piece to be plated, and it can be flexibly selected according to the needs; for example, copper.

[0048] Most preferably, the method for improving the corrosion resistance of chemical nickel plating comprises the steps of:

[0049] S1. Degreasing: Immerse the plated piece in degreasing liquid at 40-60℃ for 3-10min for degreasing treatment, then wash the plated piece with water and set aside for the next step;

[0050] S2. Micro-etching: Immerse the plated piece in the micro-etching solution at 15-40℃ for 1-3min for micro-etching, then wash the plated piece with water and set aside for the next step;

[0051] S3. Activation: Immerse the plated piece in the activation solution at 15-40°C for 1-3 minutes for activation treatment, then wash the plated piece with water and set aside for the next step;

[0052] S4. Chemical nickel plating: immerse the workpiece to be plated in the above-mentioned chemical nickel plating solution for chemical nickel plating for 10-30 minutes.

[0053] The present invention designs a series of process flows of degreasing → micro-etching → activation → chemical nickel plating, aiming to generate a uniform and dense chemical nickel plating layer on the surface of the part to be plated, and improve the corrosion resistance of the plating layer. The process flow first degreasing the part to be plated to thoroughly remove impurities such as grease, dirt, etc. on the surface of the part to be plated, laying a good foundation for subsequent treatment. Then enter the micro-etching link, which uses a micro-etching liquid to slightly corrode the surface of the part to be plated to remove defects such as oxide layer and rust on the surface, and at the same time increase the surface roughness, which is conducive to the adhesion of the subsequent plating layer. Next, the activation step is carried out, and the chemical activity of the surface of the part to be plated is further improved through the action of the activation liquid, so that it is easier to react with the subsequent plating solution, thereby ensuring the uniformity and density of the plating layer. And after each step of treatment, a water washing step is followed to remove impurities or residues in the treatment process of each step to ensure the cleanliness of the surface of the part to be plated. After the pre-treatment, the chemical nickel plating link is entered, and a specific chemical nickel plating solution is used for nickel plating operation to form a uniform and dense nickel plating layer on the surface of the part to be plated. This nickel plating layer not only has excellent corrosion resistance and wear resistance, but also can significantly improve the hardness and service life of the plated parts.

[0054] Beneficial effects:

[0055] The present invention provides a chemical nickel plating solution containing an oxidant and a method for improving the corrosion resistance of chemical nickel plating, which has the following advantages:

[0056] (1) The present invention innovatively finds that introducing an oxidant into the chemical nickel plating solution, wherein the oxidant includes hydrogen peroxide or a combination of hydrogen peroxide and other oxidants, preferably hydrogen peroxide, can effectively improve the corrosion resistance of the chemical nickel plating layer.

[0057] (2) The concentration of hydrogen peroxide in the chemical nickel plating solution is preferably 30wt%, and the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.2-1mL / L. Only a very low amount of addition is required, which can not only improve the stability of the nickel plating solution, but also effectively prolong the time for the coating to turn black and bubble to appear after contacting nitric acid, and the chemical nickel plating layer has reliable corrosion resistance.

[0058] (3) The process flow of the present invention is as follows: degreasing → micro-etching → activation → chemical nickel plating. Through a specific chemical nickel plating solution and pre-treatment process, a uniform and dense chemical nickel plating layer can be generated on the surface of the workpiece to be plated, thereby improving the quality of the workpiece.

[0059] (4) The present invention provides a new and efficient idea for electroplating surface treatment through a carefully designed process flow and a specific chemical nickel plating solution, which solves the problems of difficult chemical nickel plating process control, high energy consumption, poor stability of the nickel plating solution, easy volatility, and short service life.

[0060] (5) The working temperature of the chemical nickel plating solution of the present invention is relatively low. A chemical nickel plating layer with excellent corrosion resistance can be obtained when operated at 80°C, thereby reducing energy consumption and improving the quality of the product, which has great advantages over existing products.

[0061] (6) The process of the present invention is simple, has low energy consumption, readily available raw materials, low cost, and strong operability; and the overall operation process does not produce harmful by-products, is safe and pollution-free, can meet the requirements of industrial production, and has extremely high application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 . Tafel polarization curve of chemical nickel plating layer, where a is a comparative example, and b~e correspond to Examples 1~4 respectively. DETAILED DESCRIPTION

[0063] The present invention can be further illustrated by the following examples, but the examples are not intended to limit the scope of protection of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] In order to solve the problems of difficult control of chemical nickel plating process, high energy consumption, poor stability of nickel plating solution, easy volatility, short service life, etc., the present invention provides a chemical nickel plating solution containing an oxidant and a method for improving the corrosion resistance of chemical nickel plating.

[0065] Preferably, the composition of the chemical nickel plating solution is shown in Table 1 below.

[0066] Table 1 Chemical nickel plating solution composition

[0067]

[0068] The preparation steps of the chemical nickel plating solution are as follows: firstly, the raw materials except hydrogen peroxide are mixed, the pH value is adjusted to 4.8, and when it is used (i.e., chemical nickel plating operation is performed), hydrogen peroxide is added to obtain the solution.

[0069] Preferably, the method for improving the corrosion resistance of chemical nickel plating comprises the steps of:

[0070] S1. Degreasing: Immerse the plated piece in degreasing liquid at 40-60℃ for 3-10min for degreasing treatment, then wash the plated piece with water and set aside for the next step;

[0071] The degreasing liquid comprises NaOH 5-10 g / L, Na2CO3 5-15 g / L, Na3PO4 15-25 g / L, and the solvent is water.

[0072] S2. Micro-etching: Immerse the plated piece in the micro-etching solution at 15-40℃ for 1-3min for micro-etching, then wash the plated piece with water and set aside for the next step;

[0073] The micro-etching solution includes 25-35 g / L Na2S2O8, 50-100 mL / L concentrated sulfuric acid, and the solvent is water.

[0074] S3. Activation: Immerse the plated piece in the activation solution at 15-40°C for 1-3 minutes for activation treatment, then wash the plated piece with water and set aside for the next step;

[0075] The activation solution comprises PdCl2 0.1-0.5 g / L, NH4Cl 0.5-2.0 g / L, and the solvent is water.

[0076] S4. Chemical nickel plating: immerse the workpiece to be plated in the above-mentioned chemical nickel plating solution containing an oxidant for chemical nickel plating for 10-30 minutes.

[0077] Note: Unless otherwise specified, the solvents of the solutions involved in the present invention are all water; the concentrations involved are all mass concentrations; and the raw materials used are all commercially available.

[0078] Example

[0079] Example 1

[0080] This embodiment provides a chemical nickel plating solution containing an oxidant and a method for improving the corrosion resistance of chemical nickel plating.

[0081] The chemical nickel plating solution comprises: NiSO4·6H2O 20g / L, NaH2PO2·H2O 25g / L, sodium succinate 10g / L, malic acid 5g / L, sodium acetate 15g / L, lactic acid 8mL / L, lead acetate 0.8mg / L, hydrogen peroxide (30wt%) 0.2mL / L, and the solvent is water.

[0082] The preparation steps of the chemical nickel plating solution are as follows: firstly, raw materials except hydrogen peroxide are mixed, pH is adjusted to 4.8, a basic chemical nickel plating solution is prepared, and hydrogen peroxide is added when the solution is used (i.e., chemical nickel plating operation is performed).

[0083] The working temperature of the chemical nickel plating solution is 80°C.

[0084] The method for improving the corrosion resistance of chemical nickel plating comprises the steps of:

[0085] S1. Degreasing: Immerse the plated piece (copper sheet, 2cm×2cm) in degreasing liquid at 50℃ for 5min for degreasing treatment, then wash the plated piece with water and set aside for the next step;

[0086] The degreasing liquid is composed of: NaOH 5g / L, Na2CO3 10g / L, Na3PO4 20g / L, and the solvent is water.

[0087] S2. Micro-etching: Immerse the workpiece to be plated in the micro-etching solution and soak it at room temperature for 1 minute for micro-etching. Then wash the workpiece to be plated with water and set aside for the next step.

[0088] The micro-etching solution has the following composition: Na2S2O8 30 g / L, concentrated sulfuric acid (98 wt%) 50 mL / L, and the solvent is water.

[0089] S3. Activation: Immerse the plated piece in the activation solution and soak it at room temperature for 1 minute for activation treatment, then wash the plated piece with water and set aside for the next step;

[0090] The composition of the activation solution is: PdCl2 0.1g / L, NH4Cl 1g / L, and the solvent is water.

[0091] S4. Chemical nickel plating: immerse the piece to be plated in the above-mentioned chemical nickel plating solution containing an oxidant (80°C) for chemical nickel plating for 20 minutes, and then wash it with water and store it in a dry place.

[0092] Example 2

[0093] This embodiment provides an oxidant-containing chemical nickel plating solution and a method for improving the corrosion resistance of chemical nickel plating. The specific implementation method is the same as that of Example 1; the difference is that the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.4 mL / L.

[0094] Example 3

[0095] This embodiment provides an oxidant-containing chemical nickel plating solution and a method for improving the corrosion resistance of chemical nickel plating. The specific implementation method is the same as that of Example 1; the difference is that the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.6 mL / L.

[0096] Example 4

[0097] This embodiment provides an oxidant-containing chemical nickel plating solution and a method for improving the corrosion resistance of chemical nickel plating. The specific implementation method is the same as that of Example 1; the difference is that the amount of hydrogen peroxide added to the chemical nickel plating solution is 0.8 mL / L.

[0098] Comparative Example

[0099] This comparative example provides an oxidant-containing chemical nickel plating solution and a method for improving the corrosion resistance of chemical nickel plating. The specific implementation method is the same as that of Example 1; the difference is that no hydrogen peroxide is added to the chemical nickel plating solution.

[0100] Performance Testing Methods

[0101] The chemically plated nickel layers obtained after being treated in steps S1 to S4 in Examples 1 to 4 and the comparative example were used as test samples, and the corrosion resistance of the chemically plated nickel layers was tested by an electrochemical method using a three-electrode system.

[0102] The working electrode is the chemically plated nickel layer obtained in the comparative example and Examples 1 to 4 (effective area is 1 cm 2 ), the auxiliary electrode was a platinum electrode, the reference electrode was a saturated calomel electrode (SCE); the electrolyte was a 3.5wt% NaCl aqueous solution, and the test temperature was 25°C.

[0103] Performance Test Results

[0104] 1. Tafel polarization curve

[0105] The Tafel polarization curves of the chemical nickel plating layers of Examples 1 to 4 and the comparative example are as follows: Figure 1 The Tafel polarization curve analysis results are shown in Table 2.

[0106] Table 2 Tafel polarization curve analysis results

[0107]

[0108] 2. Nitric acid spot corrosion test results

[0109] A nitric acid aqueous solution (30wt%) was added dropwise to the surface of the chemically plated nickel layer treated by steps S1 to S4 in Examples 1 to 4 and the comparative example to carry out a nitric acid spot corrosion test. During the test, a drop of nitric acid aqueous solution was added to the surface of the plated sample, and the changes in the chemically plated nickel layer were observed. The time when the chemically plated nickel layer turned black and the time when bubbles appeared were recorded as shown in Table 3.

[0110] Table 3 Occurrence time of nitric acid drop corrosion test phenomenon

[0111]

[0112] Depend on Figure 1 It can be seen from the test data in Tables 2 and 3 that the chemical nickel plating method of the present invention can improve the corrosion resistance of the chemical nickel plating layer. After adding a specific amount of oxidant (hydrogen peroxide) to the chemical nickel plating solution, the time for the obtained coating to turn black and bubble to appear after nitric acid dripping is significantly prolonged, and the coating quality is significantly improved. In addition, the overall process is simple to operate, low in energy consumption, pollution-free, can meet the requirements of mass production, and has good application prospects.

Claims

1. A chemical nickel plating solution containing an oxidant, characterized in that The raw materials of the chemical nickel plating solution include nickel salt, reducing agent, oxidizing agent and solvent; The oxidant includes one or more combinations of organic peroxides, permanganates, and ozone.

2. The chemical nickel plating solution containing an oxidant according to claim 1, characterized in that The organic peroxide includes one or more of hydrogen peroxide, meta-chloroperbenzoic acid, peracetic acid, and tert-butyl peroxide.

3. The chemical nickel plating solution containing an oxidant according to claim 2, characterized in that The oxidant includes hydrogen peroxide.

4. The chemical nickel plating solution containing an oxidant according to claim 3, characterized in that: The concentration of hydrogen peroxide in the hydrogen peroxide is 5-35wt%.

5. The chemical nickel plating solution containing an oxidant according to claim 4, characterized in that: The amount of hydrogen peroxide added to the chemical nickel plating solution is 0-2 mL / L, excluding endpoint values.

6. The chemical nickel plating solution containing an oxidant according to claim 1, characterized in that The raw materials of the chemical nickel plating solution also include a complexing agent and a stabilizer.

7. A method for improving the corrosion resistance of chemical nickel plating, comprising at least the steps of: using the chemical nickel plating solution containing an oxidant as claimed in any one of claims 1 to 6 to perform chemical nickel plating on a workpiece to be plated.

8. The method for improving the corrosion resistance of chemical nickel plating according to claim 7, characterized in that: Before the chemical nickel plating, the part to be plated is pre-treated; The pre-treatment includes degreasing, and the plated piece is immersed in a degreasing liquid for degreasing treatment; The temperature of the degreasing treatment is 40-60° C., and the treatment time is 3-10 minutes.

9. The method for improving the corrosion resistance of chemical nickel plating according to claim 8, characterized in that: The pre-treatment also includes micro-etching, wherein the degreased workpiece to be plated is immersed in a micro-etching liquid for micro-etching; The micro-etching treatment has a temperature of 15-40° C. and a treatment time of 1-3 min.

10. The method for improving the corrosion resistance of chemical nickel plating according to claim 9, characterized in that: The pre-treatment also includes activation, wherein the micro-etched part to be plated is immersed in an activation solution for activation treatment; Preferably, the activation solution comprises PdCl2 0.1-1 g / L, NH4Cl 0.1-3.0 g / L, and the solvent is water.

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