Nickel plating process and application for carbon steel wire

Abstract

The application relates to the technical field of steel anticorrosion, in particular to a carbon steel wire surface nickel plating process and application. The carbon steel wire surface nickel plating process comprises the following steps: step one, surface impurity removal treatment and drying treatment of the carbon steel wire in an ultrasonic cleaner; step two, nickel plating treatment of the carbon steel wire after the surface impurity removal treatment and drying treatment in a B cell of an AB type electrolytic cell, the carbon steel wire serving as a cathode, an inert electrode serving as an anode, pH value being 3.5-4.0, temperature being 20-60 DEG C, current density being 0.5-3 A / dm 2 , time being 30-1800 s, and water washing and drying; ions in the electrolytic cell in the A cell are used for regulating and controlling the concentration of nickel ions and hydrogen ions in the electrolyte in the B cell through a cation membrane between the A cell and the B cell. The nickel plating process can obtain a high-quality nickel plating layer with excellent bonding force and high density, and overcomes the problem of quality deviation of the traditional electroplating process.

Description

Technical Field

[0001] This invention relates to the field of steel corrosion protection technology, and in particular to a nickel plating process and application for carbon steel wire. Background Technology

[0002] Carbon steel wire is a metal wire primarily composed of iron and carbon, widely used in industries such as construction, manufacturing, agriculture, transportation, and power. In construction, it is commonly used to make reinforcing bars to enhance the load-bearing capacity of concrete structures. The elasticity and toughness of carbon steel wire give it an advantage in manufacturing springs and other mechanical components. Its excellent machinability allows it to be processed into various shapes and sizes (such as common iron wire, hooks, and clothes hangers) through drawing and bending processes to meet diverse application needs. In agriculture, carbon steel wire can be used to build greenhouses and support plants. In transportation, it is used as a component of vehicle suspension and braking systems. In the power industry, it is frequently used for the erection and support of power lines.

[0003] However, carbon steel wire has relatively poor corrosion resistance. When exposed to humid environments, iron reacts with oxygen to form loose iron oxide (rust), leading to gradual corrosion and limiting its applications. Nickel plating on the surface of carbon steel wire can slow down corrosion, effectively improving the corrosion resistance of the resulting nickel-plated carbon steel wire and expanding its application range.

[0004] The existing production methods for nickel-plated carbon steel wire are mainly electroless nickel plating and electroless nickel plating. Electroless nickel plating has problems such as high brittleness and high porosity of the coating, which leads to poor bonding strength between the nickel plating layer and the base steel. In addition, the porosity of the nickel plating layer causes it to bend and crack, and its corrosion resistance is not as good as that of electroless nickel plating.

[0005] In the nickel electroplating process, high-purity nickel is used as the anode, and the carbon steel workpiece to be plated is used as the cathode, containing plating metal cations (Ni). 2+ Ni 2+ A nickel plating layer is formed on the surface of the carbon steel workpiece to be plated by reduction.

[0006] Pure nickel anodes have the advantage of good dissolution uniformity and can stabilize Ni in the electroplating solution. 2+ Concentration improves the quality of nickel plating. However, during electroplating, pure nickel anodes may develop oxides such as Ni2O3 on the surface due to excessively high current density, changes in electrolyte composition, or improper operation, leading to anode passivation. This manifests as abnormally high tank voltage and decreased anode current efficiency, which, if not addressed promptly, will affect the plating quality. Furthermore, pure nickel anodes are expensive to manufacture and may experience selective dissolution during electroplating, causing fluctuations in electrolyte composition. This necessitates frequent adjustments or replenishment of metal salts, resulting in high maintenance costs and complex operating procedures, making them unsuitable for large-scale production.

[0007] Platinum is also used as the anode in nickel electroplating processes. However, using a platinum anode requires adding water-soluble nickel salts to the plating bath. Since the electroplating environment tends towards stable flow conditions, the added water-soluble nickel salts disrupt this flow stability, thus affecting the quality of the nickel plating layer. Furthermore, water near the platinum anode loses electrons to produce H... + This can cause the system's pH value to drop, deviating from the optimal pH conditions for nickel plating (3.8±0.1). Maintaining the plating pH requires adding more pH stabilizer (by choosing boric acid), which increases plating costs. If the system's pH value drops too quickly, an additional pH adjuster (alkaline water) is needed for pH regulation. However, the added alkaline water disrupts the stable flow of the plating system and also affects the quality of the nickel plating layer. Therefore, the inventors provide a nickel plating process and application for carbon steel wire. Summary of the Invention

[0008] To address the problems of high maintenance costs, complex operation processes, and unsuitability for large-scale production caused by using pure nickel anodes in existing nickel plating processes, and the need to add water-soluble nickel salts and / or pH adjusters to the electroplating solution when using platinum anodes, which can disrupt the stable flow state of the electroplating system and affect the quality of the nickel plating layer, this invention provides a nickel plating process for carbon steel wire.

[0009] The present invention provides a nickel plating process for carbon steel wire, which is achieved through the following scheme:

[0010] A nickel plating process for carbon steel wire includes the following steps:

[0011] Step 1: Place the carbon steel wire in an ultrasonic cleaning machine for surface cleaning and drying to obtain the treated carbon steel wire.

[0012] Step two: The electroplating equipment is an AB-type electrolytic cell, which includes cell A and cell B, separated by a cation exchange membrane. Cell A is equipped with an electrolysis device, which uses an inert electrode as the cathode and an inert electrode or a nickel rod as the anode, placed in the electrolyte of cell A. The electrolyte in cell A has a pH of 3.8–4.2 and a temperature of 20–60°C. Cell B is equipped with an electroplating device, which performs nickel plating on the carbon steel wire treated in step one. The carbon steel wire serves as the cathode in the electrolyte of cell B, and the inert electrode serves as the anode. The electrolyte in cell B has a pH of 3.5–4.0, a temperature of 20–60°C, and a current density of 0.5–3 A / dm³. 2 The time is 30 to 1800 seconds. The ratio of the current density of the electroplating device to the current density of the electrolysis device is 1:(1.0-1.05). After washing and drying, it is ready.

[0013] In this invention, pool A is used as a "buffer pool." The concentration of nickel ions in the electrolyte of pool A is higher than that in the electrolyte of pool B. Nickel ions from the electrolyte of pool A are replenished into the electrolyte of pool B through a cation exchange membrane, thereby regulating the nickel ion concentration in the electrolyte of pool B. The concentration of hydrogen ions in the electrolyte of pool B is higher than that in the electrolyte of pool A. Hydrogen ions from the electrolyte of pool B are replenished into the electrolyte of pool A through a cation exchange membrane. This ensures that the electrolyte in pool B is always in a stable flow environment for nickel plating. Through the selective permeation of hydrogen and nickel ions by the cation exchange membrane (Fick's First Law: diffusion from high concentration to low concentration), the hydrogen and nickel ion concentrations in the electrolyte of pool B are regulated, keeping the electrolyte in pool B within the optimal nickel plating parameter range. This ensures that the nickel plating layer on the surface of the carbon steel wire has excellent adhesion and high density, overcoming the problem of nickel plating layer quality deviation in traditional electroplating processes.

[0014] Preferably, in step two, the electrolyte in cell A has a pH of 4.0 ± 0.1 and a temperature of 50-60°C.

[0015] Preferably, in step two, the electrolyte in cell B has a pH of 3.8 ± 0.1 and a temperature of 50–60°C.

[0016] The selective permeation of hydrogen and nickel ions is influenced by Fick's first law. The diffusion rate depends on the concentration difference between the two ions and the temperature of the solution. That is, the greater the concentration difference between hydrogen and nickel ions in cells A and B, the faster the diffusion rate. Higher electrolyte temperatures in cells A and B intensify molecular thermal motion, accelerating the diffusion rate and leading to an increase in entropy, ultimately causing the system to approach equilibrium. In actual experiments, the pH value of the electrolyte in cell A is always higher than that in cell B. The pH difference (ΔpH) between cells A and B should ideally be controlled at around 0.2. Excessive ΔpH is detrimental to adjusting the pH stability of cell B. Therefore, adjusting the temperature of the electrolyte in cells A and B can effectively increase the diffusion rate and regulate the concentration of hydrogen and nickel ions in the electrolyte of cell B, ensuring that the electrolyte in cell B is within the optimal nickel plating parameter range for electroplating and guaranteeing the quality of the final nickel plating layer.

[0017] Preferably, the electrolyte in cell B comprises a water-soluble nickel salt, boric acid, a grain refiner, a terminal acid value adjuster, and pure water. The water-soluble nickel salt is at least one of nickel sulfate, nickel chloride, and nickel aminosulfonate. The grain refiner is at least one of tartaric acid, citric acid, gluconic acid, and phytic acid. The terminal acid value adjuster is ammonia. The conductivity of the pure water is 1.0 < μS / cm.

[0018] Preferably, the water-soluble nickel salts in the electrolyte of cell B are nickel sulfate, nickel chloride, and nickel sulfamate, with a total concentration of 200-300 g / L; the concentrations of nickel sulfate, nickel chloride, sulfamate, boric acid, and acid value adjuster are 50-100 g / L, 50-100 g / L, 100-200 g / L, 40-60 g / L, and 40-60 g / L. The pH of the electrolyte in cell B is adjusted to 3.8 ± 0.1 with ammonia water, which ensures excellent adhesion and high density of the nickel plating layer.

[0019] Preferably, when the electrolysis device uses a nickel rod as the anode, a sodium chloride aqueous solution needs to be continuously added to the electrolyte in cell A at a constant flow rate. The concentration of the sodium chloride aqueous solution is 0.01-0.1 mol / L, and the temperature is 50-60℃. The electrolyte in cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH value of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

[0020] Adding sodium chloride solution maintains the chloride ion concentration balance in the electrolyte of cell A. Sodium ions in cell A also diffuse through the cation exchange membrane to cell B, improving the conductivity of the electrolyte in cell B. This helps ensure a uniform current distribution in the electrolyte, resulting in a more consistent deposition rate across the plating layer and ultimately improving the quality of the nickel plating. The advantages of using a nickel rod as the anode are: no hydrogen evolution, resulting in better safety during nickel plating; and relatively better control over the stability of the nickel ion concentration in the electrolyte of cell A. The disadvantage is the higher cost of pure nickel anodes.

[0021] When the electrolysis device uses an inert electrode as the anode, a nickel chloride aqueous solution needs to be continuously added to the electrolyte of cell A at a constant flow rate. The concentration of nickel ions in the nickel chloride aqueous solution is 1.2-2.0 times that in the electrolyte of cell A. The electrolyte of cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH value of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

[0022] Preferably, the nickel chloride aqueous solution has a pH of 4.0±0.1 and a temperature of 50-60℃; the concentration of nickel ions in the nickel chloride aqueous solution is 1.6-1.8 times that in the electrolyte of cell A.

[0023] The concentration of nickel ions in the electrolyte of cell A is higher than that in the electrolyte of cell B. Nickel ions from the electrolyte of cell A are replenished into the electrolyte of cell B through the cation exchange membrane, thereby regulating the nickel ion concentration in the electrolyte of cell B. The concentration of hydrogen ions in the electrolyte of cell B is higher than that in the electrolyte of cell A. Hydrogen ions from the electrolyte of cell B are replenished into the electrolyte of cell A through the cation exchange membrane, thereby regulating the hydrogen ion concentration in the electrolyte of cell B. This ensures that the nickel plating layer has excellent adhesion and high density.

[0024] The hydrogen produced by electrolysis in cell A can be recycled and reused. It can be used as a reducing atmosphere for the protective atmosphere in cell B, or mixed with nitrogen for the same purpose. The chlorine produced by electrolysis in cell A can be used to prepare a hydrochloric acid solution. This solution can then be used for low-concentration acid ultrasonic rinsing in tanks #9 and #13, thereby reducing the overall cost of nickel plating.

[0025] Preferably, in step one, the carbon steel wire is placed in tank #1 of an ultrasonic cleaner for surfactant-based degreasing and ultrasonic washing, then in tanks #2-4 of the ultrasonic cleaner for deionized water ultrasonic rinsing, then in tank #5 of the ultrasonic cleaner for surfactant-based degreasing and ultrasonic washing, then in tanks #6-8 of the ultrasonic cleaner for deionized water ultrasonic rinsing, then in tank #9 of the ultrasonic cleaner for low-concentration acid ultrasonic rinsing, then in tanks #10-12 of the ultrasonic cleaner for deionized water ultrasonic rinsing, then in tank #13 of the ultrasonic cleaner for low-concentration acid ultrasonic rinsing, and finally in tanks #13-15 of the ultrasonic cleaner for deionized water ultrasonic rinsing. Afterward, it is placed in an oven for drying, thus completing the impurity removal and drying treatment of the carbon steel wire surface.

[0026] In this invention, an ultrasonic cleaning machine is used to perform large-scale surface cleaning and drying of carbon steel wires. This effectively removes organic pollutants and oxide film from the surface of the carbon steel wires, thereby improving the bonding strength between the coating and the substrate and ensuring the bonding quality of the nickel plating layer.

[0027] This invention provides a nickel plating process for carbon steel wire to prepare nickel-plated carbon steel wire for applications requiring high corrosion resistance.

[0028] In summary, the present invention has the following advantages:

[0029] 1. The nickel plating process provided in this invention can obtain a high-quality nickel plating layer with excellent adhesion and high density, which can effectively improve the corrosion resistance of nickel-plated carbon steel wire and expand its application range.

[0030] 2. The equipment structure in this nickel plating process is simple and the operation is relatively easy. It can ensure that the electrolyte in the B cell is always in a stable flow environment for nickel plating. Through the selective permeation of hydrogen ions and nickel ions by the cation membrane (Fick's first law: diffusion from high concentration to low concentration), the hydrogen ions and nickel ions in the electrolyte in the B cell can be regulated, so that the electrolyte in the B cell is within the optimal nickel plating parameter range. This ensures that the nickel plating layer on the surface of the carbon steel wire has excellent adhesion and high density, which is conducive to the large-scale production of the nickel plating process. Attached Figure Description

[0031] Figure 1This is a schematic diagram of the overall structure of the AB-type electrolytic cell in this invention. Detailed Implementation

[0032] To further understand the inventiveness and technical advancements of this invention, the preferred embodiments of this invention will be discussed in detail below with reference to examples and comparative examples.

[0033] Example: The nickel plating process in this invention requires an AB-type electrolytic cell. The AB-type electrolytic cell includes cell A and cell B, separated by a cation exchange membrane. Specifically, cell A is a titanium alloy cylinder with an outer diameter of 800 mm, a wall thickness of D = 1 mm, and a height of 600 mm. Cell B is a titanium alloy cylinder with an outer diameter of 450 mm, a wall thickness of D = 1 mm, and a height of 600 mm. The bottom of cell B is a solid titanium alloy circular plate, and the sidewalls of cell B have a mesh structure with a porosity of 50%. The outer sidewalls of cell B are coated with a cation exchange membrane, which seals the mesh structure, allowing only cations to diffuse between cells A and B via Fick's first law. This adjusts the hydrogen ion concentration (H₂O) in the electrolytes of cells A and B. + and nickel ions Ni 2+ Concentration balance.

[0034] Pool B is the main site for nickel electroplating. The electroplating equipment in Pool B consists of a conventional constant voltage DC power supply, two power connection lines, an inert electrode (anode), and the workpiece to be plated (cathode).

[0035] Pool A is a buffer pool, and an electrolysis device is installed in Pool A. The electroplating device consists of a conventional constant voltage DC power supply, two power connection lines, an inert electrode A (anode) or a pure nickel rod (anode), and an inert electrode B (cathode).

[0036] A nickel plating process for carbon steel wire includes the following steps:

[0037] Step 1: Place the carbon steel wire in an ultrasonic cleaning machine for surface cleaning and drying.

[0038] Specifically, in step one, the carbon steel wire is placed in tank #1 of an ultrasonic cleaner for ultrasonic cleaning with surfactant degreasing. The cleaning concentration is 5-15 g / L NaOH and 3-8 g / L AQUA-SOL, the temperature is 40-60℃, the cleaning time is 3-5 minutes, the ultrasonic power is 800-1200W, and the ultrasonic frequency is 20-40kHz. Then, it is placed in tanks #2-4 of the ultrasonic cleaner for ultrasonic rinsing with deionized water. The temperature is 20-60℃, the cleaning time is 3-5 minutes, the ultrasonic power is 800-1200W, and the ultrasonic frequency is 20-40kHz. Finally, it is placed in... The ultrasonic cleaner performs ultrasonic cleaning with surfactant degreasing in tank #5, using a washing concentration of 5g / L NaOH and 3g / L AQUA-SOL, at a temperature of 40-60℃ for 3-5 minutes, with an ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Following this, the ultrasonic cleaner performs ultrasonic rinsing with deionized water in tanks #6-8, at a temperature of 20-60℃ for 3-5 minutes, with an ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Finally, the ultrasonic cleaner performs ultrasonic cleaning with a low-concentration acid in tank #9. Rinse with low-concentration acid (0.1-5 g / L hydrochloric acid, 0.1-5 g / L sulfuric acid), at a temperature of 40-60℃ for 3-5 minutes, using ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Then, place the sample in tanks 10-12 of an ultrasonic cleaner for ultrasonic rinsing with deionized water at a temperature of 20-60℃ for 3-5 minutes, using ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Finally, place the sample in tank 13 of the ultrasonic cleaner for ultrasonic rinsing with low-concentration acid (0.1-5 g / L hydrochloric acid). The carbon steel wire is washed with 0.1-5 g / L sulfuric acid at a temperature of 40-60℃ for 3-5 minutes, using an ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Then, it is placed in tank 13-15 of an ultrasonic cleaner for ultrasonic rinsing with deionized water at a temperature of 20-60℃ for 3-5 minutes, using an ultrasonic power of 800-1200W and an ultrasonic frequency of 20-40kHz. Finally, it is placed in an oven for drying under nitrogen protection at a temperature of 80-120℃ for 4-6 hours. This completes the impurity removal and drying process on the surface of the carbon steel wire.

[0039] Step two: The electroplating equipment is an AB type electrolytic cell. The electrolytic device uses an inert electrode as the cathode and an inert electrode or a nickel rod as the anode, placed in the electrolyte of cell A. The electrolyte in cell A has a pH of 3.8–4.2 and a temperature of 20–60°C. Preferably, the electrolyte in cell A has a pH of 4.0 ± 0.1 and a temperature of 50–60°C. The electroplating device then performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed as the cathode in the electrolyte of cell B, and the inert electrode is placed as the anode in the electrolyte of cell B. The electrolyte in cell B has a pH of 3.5–4.0 and a temperature of 20–60°C. Preferably, the electrolyte in cell B has a pH of 3.8 ± 0.1 and a temperature of 50–60°C, and the current density is 0.5–3 A / dm³. 2 The time is 30 to 1800 seconds. The ratio of the current density of the electroplating device to the current density of the electrolysis device is 1:(1.0-1.05). After washing and drying, it is ready.

[0040] The electrolyte in cell B includes a water-soluble nickel salt, boric acid, a grain refiner, a terminal acid value adjuster, and pure water. The water-soluble nickel salt is at least one of nickel sulfate, nickel chloride, and nickel sulfamate. The grain refiner is at least one of tartaric acid, citric acid, gluconic acid, and phytic acid. The terminal acid value adjuster is ammonia. The conductivity of the pure water is 1.0 < μS / cm; specifically, it is high-purity water.

[0041] Preferably, the water-soluble nickel salts in the electrolyte of cell B are nickel sulfate, nickel chloride, and nickel sulfamate, with a total concentration of 200-300 g / L. The electrolyte in cell B contains 50-100 g / L nickel sulfate, 50-100 g / L nickel chloride, 100-200 g / L sulfamate, 40-60 g / L boric acid, and 40-60 g / L acid value adjuster. The pH of the electrolyte in cell B is adjusted to 3.8 ± 0.1 using ammonia.

[0042] When the electrolysis device uses a nickel rod as the anode, a sodium chloride aqueous solution needs to be continuously added to the electrolyte in cell A at a constant flow rate. The concentration of the sodium chloride aqueous solution is 0.01-0.1 mol / L, and the temperature is 50-60℃. The electrolyte in cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH value of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

[0043] When the electrolysis device uses an inert electrode as the anode, a nickel chloride aqueous solution needs to be continuously added to the electrolyte in cell A at a constant flow rate. The nickel chloride aqueous solution has a pH of 4.0±0.1 and a temperature of 50-60℃. The concentration of nickel ions in the nickel chloride aqueous solution is 1.2-2.0 times that in the electrolyte in cell A. Preferably, the concentration of nickel ions in the nickel chloride aqueous solution is 1.6-1.8 times that in the electrolyte in cell A. The electrolyte in cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

[0044] The electrolyte in cells A and B is prepared using high-purity water with a conductivity of 0.1-1 μS / cm.

[0045] Example 1: A nickel plating process for carbon steel wire, comprising the following steps:

[0046] Step 1: Place the carbon steel wire in an ultrasonic cleaning machine for surface cleaning and drying.

[0047] Carbon steel wire was placed in tank #1 of an ultrasonic cleaner for ultrasonic cleaning with surfactant degreasing. The cleaning concentration was 5 g / L NaOH and 3 g / L AQUA-SOL, the temperature was 60℃, the cleaning time was 3 minutes, the ultrasonic power was 1200W, and the ultrasonic frequency was 40kHz. It was then sequentially ultrasonically rinsed with deionized water in tanks #2-4 of the ultrasonic cleaner at 25℃ for 3 minutes, the ultrasonic power was 1200W, and the ultrasonic frequency was 40kHz. Next, it was placed in tank #5 for ultrasonic cleaning with surfactant degreasing. The cleaning concentration was 5 g / L NaOH and 3 g / L AQUA-SOL, the temperature was 60℃, the cleaning time was 3 minutes, the ultrasonic power was 1200W, and the ultrasonic frequency was 40kHz. Then, it was sequentially ultrasonically rinsed with deionized water in tanks #6-8 of the ultrasonic cleaner at 25℃ for 3 minutes, the ultrasonic power was 1200W, and the ultrasonic frequency was 40kHz. Finally, it was placed in tank #9 of the ultrasonic cleaner for low-concentration... The ultrasonic cleaner first performs ultrasonic rinsing with low-concentration acids: 2 g / L hydrochloric acid and 2 g / L sulfuric acid, at a temperature of 60°C for 3 minutes, with an ultrasonic power of 1200W and an ultrasonic frequency of 40kHz. Then, it sequentially undergoes ultrasonic rinsing with deionized water in tanks 10-12 of the ultrasonic cleaner at a temperature of 25°C for 5 minutes, with an ultrasonic power of 1200W and an ultrasonic frequency of 40kHz. Finally, it is placed in tank 13 of the ultrasonic cleaner for ultrasonic rinsing with low-concentration acids: 2 g / L hydrochloric acid. The steel wire is washed with 2 g / L sulfuric acid at 60°C for 3 minutes, with an ultrasonic power of 1200W and an ultrasonic frequency of 40kHz. It is then ultrasonically rinsed with deionized water in tanks 13-15 of an ultrasonic cleaner at 25°C for 3 minutes, with an ultrasonic power of 1200W and an ultrasonic frequency of 40kHz. Finally, it is placed in an oven for drying under nitrogen protection at 105°C for 4 hours, thus completing the impurity removal and drying process on the surface of the carbon steel wire.

[0048] Step two: The electroplating equipment is an AB type electrolytic cell. The electrolytic device uses graphite electrodes as cathodes and anodes, placed in the electrolyte of cell A. A nickel chloride aqueous solution at 55℃ is continuously added to the electrolyte of cell A at a constant flow rate of 180g / 450s. The concentration of the nickel chloride aqueous solution is: 300g / L nickel chloride, 50g / L boric acid, and 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte concentration in cell A is: 50g / L nickel sulfate, 100g / L nickel chloride, 100g / L sulfamic acid, 50g / L boric acid, 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 55℃, and the current density is 2.05A / dm³. 2The time is 450s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentrations of the electrolyte in cell B are: nickel sulfate 50g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, and citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 55℃, and the current density is 2A / dm³. 2 The process involves washing the wire three times with deionized water for 450 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0049] The difference between Example 2 and Example 1 is as follows: In step two, the electroplating equipment is an AB-type electrolytic cell. The electrolytic device uses a graphite electrode as the cathode and a graphite electrode as the anode, placed in the electrolyte of cell A. A nickel chloride aqueous solution at a temperature of 55°C is continuously added to the electrolyte of cell A at a constant flow rate of 180g / 900s. The concentration of the nickel chloride aqueous solution is: 300g / L nickel chloride, 50g / L boric acid, and 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The concentration of the electrolyte in cell A is: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 50g / L. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 55°C, and the current density is 1.03A / dm³. 2 The time is 900s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentration of the electrolyte in cell B is as follows: nickel sulfate 50g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 55℃, and the current density is 1A / dm³. 2 The process involves washing the wire three times with deionized water for 900 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0050] The difference between Example 3 and Example 1 is as follows: In step two, the electroplating equipment is an AB-type electrolytic cell. The electrolytic device uses a graphite electrode as the cathode and a graphite electrode as the anode, placed in the electrolyte of cell A. A nickel chloride aqueous solution at 55°C is continuously added to the electrolyte of cell A at a constant flow rate of 180g / 300s. The concentration of the nickel chloride aqueous solution is: 300g / L nickel chloride, 50g / L boric acid, and 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The concentration of the electrolyte in cell A is: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 50g / L. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 55°C, and the current density is 3.1A / dm³. 2 The time is 300s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentrations of the electrolyte in cell B are: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, and citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 55℃, and the current density is 3A / dm³. 2 The process involves washing the wire three times with deionized water for 300 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0051] The difference between Example 4 and Example 1 is as follows: In step two, the electroplating equipment is an AB-type electrolytic cell. The electrolytic device uses a graphite electrode as the cathode and a graphite electrode as the anode, placed in the electrolyte of cell A. A nickel chloride aqueous solution at a temperature of 25°C is continuously added to the electrolyte of cell A at a constant flow rate of 180g / 450s. The concentration of the nickel chloride aqueous solution is: 300g / L nickel chloride, 50g / L boric acid, and 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The concentration of the electrolyte in cell A is: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 50g / L. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 25°C, and the current density is 2.05A / dm³. 2The time is 450s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentrations of the electrolyte in cell B are: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, and citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 25℃, and the current density is 2A / dm³. 2 The process involves washing the wire three times with deionized water for 450 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0052] The difference between Example 5 and Example 1 is as follows: In step two, the electroplating equipment is an AB-type electrolytic cell. The electrolytic device uses a graphite electrode as the cathode and a graphite electrode as the anode, placed in the electrolyte of cell A. A nickel chloride aqueous solution at 40°C is continuously added to the electrolyte of cell A at a constant flow rate of 180g / 450s. The concentration of the nickel chloride aqueous solution is: 300g / L nickel chloride, 50g / L boric acid, and 50g / L tartaric acid. The pH of the electrolyte is adjusted to 4.0 with ammonia. The concentration of the electrolyte in cell A is: nickel sulfate 50g / L, nickel chloride 100g / L, sulfamic acid 100g / L, boric acid 50g / L, tartaric acid 50g / L. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 40°C, and the current density is 2.05A / dm³. 2 The time is 450s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentration of the electrolyte in cell B is as follows: nickel sulfate 50g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 40℃, and the current density is 2A / dm³. 2 The process involves washing the wire three times with deionized water for 450 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0053] The difference between Example 6 and Example 1 is as follows: In step two, the electroplating equipment is an AB-type electrolytic cell. The electrolytic device uses a graphite electrode as the cathode and a pure nickel rod as the anode, placed in the electrolyte of cell A. A 10wt% sodium chloride aqueous solution at a constant flow rate of 58.44g / 450s is continuously added to the electrolyte of cell A at a temperature of 55℃. The concentrations of the electrolyte in cell A are: nickel sulfate 50g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 50g / L. The pH of the electrolyte is adjusted to 4.0 with ammonia. The electrolyte temperature is 55℃, and the current density is 2.05A / dm³. 2 The time is 450s; the electroplating device performs nickel plating on the carbon steel wire from step one. The carbon steel wire is placed in the electrolyte of cell B as the cathode, and the inert electrode is placed in the electrolyte of cell B as the anode. The concentrations of the electrolyte in cell B are: nickel sulfate 50g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, and citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in cell B is 3.8, the temperature is 55℃, and the current density is 2A / dm³. 2 The process involves washing the wire three times with deionized water for 450 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0054] The difference between Comparative Example 1 and Example 1 is that the electroplating equipment is a single-chamber electrolytic cell, which is equipped with an electroplating device. The electroplating device performs nickel plating on the carbon steel wire in step one. The carbon steel wire serves as the cathode and is placed in the electrolyte of the single-chamber electrolytic cell. The graphite electrode serves as the anode and is placed in the electrolyte of the single-chamber electrolytic cell. The concentrations of the electrolyte in the single-chamber electrolytic cell are as follows: nickel sulfate 50 g / L, nickel chloride 100 g / L, sulfamic acid 100 g / L, boric acid 50 g / L, tartaric acid 30 g / L, gluconic acid 10 g / L, and citric acid 10 g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in the single-chamber electrolytic cell is 3.8, the temperature is 55°C, and the current density is 2 A / dm³. 2The electroplating process takes 450 seconds. During the electroplating process, nickel-replenishing electrolyte at a constant flow rate of 180g / 450s is continuously added to the electrolyte in the single-chamber electrolytic cell. The concentrations of the nickel-replenishing electrolyte are as follows: nickel sulfate 100g / L, nickel chloride 100g / L, aminosulfonic acid 100g / L, boric acid 50g / L, tartaric acid 30g / L, gluconic acid 10g / L, and citric acid 10g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. After washing three times with deionized water, the electrolyte is placed in an oven and dried at 100℃ for 2 hours to obtain nickel-platable carbon steel wire.

[0055] The difference between Comparative Example 2 and Example 1 is that the electroplating equipment is a single-chamber electrolytic cell, which is equipped with an electroplating device. The electroplating device electroplats nickel onto the carbon steel wire in step one. The carbon steel wire serves as the cathode and is placed in the electrolyte of the single-chamber electrolytic cell. The pure nickel rod serves as the anode and is placed in the electrolyte of the single-chamber electrolytic cell. The concentrations of the electrolyte in the single-chamber electrolytic cell are as follows: nickel sulfate 50 g / L, nickel chloride 100 g / L, sulfamic acid 100 g / L, boric acid 50 g / L, tartaric acid 30 g / L, gluconic acid 10 g / L, and citric acid 10 g / L. The pH of the electrolyte is adjusted to 3.8 with ammonia. The pH of the electrolyte in the single-chamber electrolytic cell is 3.8, the temperature is 55°C, and the current density is 2 A / dm³. 2 The process involves washing the wire three times with deionized water for 450 seconds, then drying it in an oven at 100°C for 2 hours to obtain nickel-platable carbon steel wire.

[0056] Performance testing: 1. Evaluation of coating adhesion: The coating adhesion is evaluated using the thermal shock test standard (ASTM B571). The sample is heated in a furnace at 300°C, with an allowable temperature error of ±10°C, for 1 hour. Then it is placed in room temperature water, and the coating is observed for defects such as blistering and peeling. 2. Corrosion resistance was assessed according to QB / T3826-1999 "Neutral Salt Spray Test (NSS) for Corrosion Resistance of Metal Coatings and Chemically Treated Layers of Light Industrial Products". At 35±2℃, a 5wt% sodium chloride aqueous solution (pH adjusted to 6.5-7.2) was continuously sprayed onto each nickel-plated carbon steel wire. The salt spray deposition rate was 1-2 mL / (h·80cm). Continuous spraying was performed for 168 hours, 180 hours, 192 hours, and 204 hours. After the test, the samples were carefully removed from the salt spray chamber and gently rinsed with running cold water (below 35℃) or with a sponge to remove salt deposits. Immediately afterward, the samples were dried at 80-100℃ for approximately 30 minutes (unless drying is necessary for accurate assessment, except by inspectors). The degree of corrosion and other defects were promptly checked. The degree of corrosion was rated according to GB5 944-1986 - Evaluation of Corrosion Test Results of Metal Coatings of Light Industrial Products - Table 2: Rating Based on the Number of Rust Spots.

[0057] Table 1: Test parameters of nickel-plated carbon steel wires in Examples 1-6 and Comparative Examples 1-2

[0058]

[0059] As can be seen from Examples 1-6 and Comparative Examples 1-2, and Table 1, the nickel-plated carbon steel wire prepared by the nickel plating process of the present invention did not show rust spots after 180 hours of neutral salt spray treatment, while the nickel-plated carbon steel wire in Comparative Examples 1-2 showed rust spots after 24*7=168 hours of neutral salt spray treatment. Therefore, the nickel plating process of the present invention can obtain a high-quality nickel plating layer with excellent adhesion, high density, and better corrosion resistance.

[0060] Combining Examples 1 and 4-5 with Table 1, it can be seen that the nickel-plated carbon steel wire in Example 1 did not show any rust spots after 192 hours of neutral salt spray treatment, and the nickel-plated carbon steel wire in Examples 4-5 did not show any rust spots after 180 hours of neutral salt spray treatment. The nickel-plated carbon steel wire in Example 1 has relatively better corrosion resistance. The electrolyte temperature should be controlled at 55±5℃ to ensure the density of the nickel plating layer and improve the overall corrosion resistance of the nickel-plated carbon steel wire.

[0061] It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A nickel plating process for carbon steel wire, characterized in that: Includes the following steps: Step 1: Place the carbon steel wire in an ultrasonic cleaning machine for surface cleaning and drying to obtain the treated carbon steel wire. Step 2: The electroplating equipment is an AB type electrolytic cell, which includes cell A and cell B, separated by a cation exchange membrane. The A cell is equipped with an electrolysis device, which uses an inert electrode as the cathode and an inert electrode or a nickel rod as the anode, and is placed in the electrolyte of the A cell. The electrolyte in the A cell has a pH value of 3.8 to 4.2 and a temperature of 20 to 60°C. The B pool is equipped with an electroplating device; The electroplating apparatus performs nickel plating on the carbon steel wire processed in step one. The carbon steel wire serves as the cathode and is placed in the electrolyte of cell B. An inert electrode serves as the anode and is also placed in the electrolyte of cell B. The electrolyte in cell B has a pH of 3.5–4.0, a temperature of 20–60°C, and a current density of 0.5–3 A / dm³. 2 The time is 30 to 1800 seconds. The ratio of the current density of the electroplating device to the current density of the electrolysis device is 1:(1.0-1.05). After washing and drying, it is ready.

2. The nickel plating process for carbon steel wire according to claim 1, characterized in that: In step two, the electrolyte in cell A has a pH of 4.0 ± 0.1 and a temperature of 50-60℃.

3. The nickel plating process for carbon steel wire according to claim 1, characterized in that: In step two, the electrolyte in cell B has a pH of 3.8 ± 0.1 and a temperature of 50–60°C.

4. The nickel plating process for carbon steel wire according to claim 1, characterized in that: The electrolyte in cell B includes a water-soluble nickel salt, boric acid, a grain refiner, a terminal acid value adjuster, and pure water. The water-soluble nickel salt is at least one of nickel sulfate, nickel chloride, and nickel aminosulfonate. The grain refiner is at least one of tartaric acid, citric acid, gluconic acid, and phytic acid. The terminal acid value adjuster is ammonia. The conductivity of the pure water is 1.0 < μS / cm.

5. The nickel plating process for carbon steel wire according to claim 4, characterized in that: The electrolyte in cell B contains water-soluble nickel salts, namely nickel sulfate, nickel chloride, and nickel sulfamate, with a total concentration of 200-300 g / L. The concentrations of the nickel sulfate, nickel chloride, sulfamate, boric acid, and terminal acid value adjuster are 50-100 g / L, 100-200 g / L, 40-60 g / L, and 40-60 g / L. The pH of the electrolyte in cell B is adjusted to 3.8 ± 0.1 using ammonia.

6. The nickel plating process for carbon steel wire according to claim 1, characterized in that: When the electrolysis device uses a nickel rod as the anode, a sodium chloride aqueous solution needs to be continuously added to the electrolyte in cell A at a constant flow rate. The concentration of the sodium chloride aqueous solution is 0.01-0.1 mol / L, and the temperature is 50-60℃. The electrolyte in cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH value of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

7. The nickel plating process for carbon steel wire according to claim 1, characterized in that: When the electrolysis device uses an inert electrode as the anode, a nickel chloride aqueous solution needs to be continuously added to the electrolyte of cell A at a constant flow rate. The concentration of nickel ions in the nickel chloride aqueous solution is 1.2-2.0 times that in the electrolyte of cell A. The electrolyte of cell A includes nickel chloride, boric acid, tartaric acid, ammonia, and pure water. The pH value of the electrolyte in cell A is adjusted to 4.0±0.1 by ammonia.

8. The nickel plating process for carbon steel wire according to claim 7, characterized in that: The nickel chloride aqueous solution has a pH of 4.0±0.1 and a temperature of 50-60℃; the concentration of nickel ions in the nickel chloride aqueous solution is 1.6-1.8 times that in the electrolyte of cell A.

9. The nickel plating process for carbon steel wire according to claim 1, characterized in that: In step one, the carbon steel wire is placed in tank #1 of the ultrasonic cleaner for ultrasonic cleaning with surfactant to remove oil, then in tanks #2-4 for ultrasonic rinsing with deionized water, then in tank #5 for ultrasonic cleaning with surfactant to remove oil, then in tanks #6-8 for ultrasonic rinsing with deionized water, then in tank #9 for ultrasonic rinsing with low-concentration acid, then in tanks #10-12 for ultrasonic rinsing with deionized water, then in tank #13 for ultrasonic rinsing with low-concentration acid, and finally in tanks #13-15 for ultrasonic rinsing with deionized water. Afterward, it is placed in an oven for drying, thus completing the impurity removal and drying treatment of the carbon steel wire surface.

10. The application of the nickel plating process for carbon steel wire according to any one of claims 1-9 in the preparation of nickel-plated carbon steel wire.

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