Anticorrosion processing technology for automobile precision part

Abstract

The invention belongs to the technical field of anti-corrosion processing, and discloses an anti-corrosion processing technology for automobile precision parts, which comprises the following steps: S1, pre-cleaning; s2, carrying out phosphating treatment; s3, chemical nickel plating; s4, primer coating; s5, coating a floating coat; s6, finish paint coating; and S7, inspection and quality control. Through accurate control of the concentration of each component in the plating solution and strict management of the temperature, the time and the pH value in the nickel plating process, the stability and the consistency of the quality of a plating layer are ensured, and the nickel plating layer not only improves the corrosion resistance of a part, but also enhances the hardness and the wear resistance of the part, so that the part can better adapt to a severe use environment, and the service life of the part is prolonged. By selecting a high-performance coating formula and combining an electrostatic spraying technology, uniform coating coverage, accurate thickness control and setting of multiple drying steps are realized, full curing of each layer of coating and good combination of the coatings are ensured, and thus the corrosion resistance and durability of the whole coating system are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-corrosion processing, and specifically relates to an anti-corrosion processing technology for automobile precision parts. Background Art

[0002] Anti-corrosion processing for automotive precision parts aims to improve the durability and corrosion resistance of automotive parts in harsh environments, typically achieved through various surface treatment techniques. These technologies prevent corrosion caused by factors such as climate, moisture, salt, acidity, and alkali during use, thereby extending the service life of the parts.

[0003] However, the actual anti-corrosion processing technology for automotive precision parts still has many shortcomings. For example, the anti-corrosion coating has insufficient adhesion and is prone to falling off or peeling during the use of automotive parts. When applying the anti-corrosion material, problems such as uneven coating thickness, bubbles, and scratches may occur. The anti-corrosion treatment of the components may not take into account the differences in specific usage environments, such as high humidity, high temperature, or acidic / alkaline environments, resulting in reduced anti-corrosion effectiveness. The complex surface shape of precision parts may lead to uneven surface treatment during the anti-corrosion process. Certain anti-corrosion processes (such as hot-dip galvanizing and electroplating) require precise control of temperature, time, and other factors. If the treatment time is too long or the temperature is too high, it will result in poor coating quality and even damage the material itself. Some anti-corrosion processes (such as chemical plating and painting) may use harmful chemicals, increasing environmental risks and control costs. Although the anti-corrosion coating can provide some protection in the early stage, over time, especially in high temperature, high humidity, or highly corrosive environments, the coating may lose its original effectiveness, leading to corrosion of the parts. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-corrosion processing technology for automobile precision parts to solve the problems raised in the above background technology.

[0005] In order to achieve the above-mentioned object, the present invention provides the following technical solution: a process for anti-corrosion processing of automobile precision parts, comprising the following steps:

[0006] S1: pre-cleaning;

[0007] S2: phosphating treatment;

[0008] S3: chemical nickel plating;

[0009] S4: Primer coating;

[0010] S5: mid-coat painting;

[0011] S6: topcoat painting;

[0012] S7: Inspection and quality control;

[0013] The pre-cleaning includes ultrasonic cleaning, rinsing and drying, the phosphating treatment includes phosphating solution preparation, phosphating and rinsing, the chemical nickel plating includes plating solution preparation, chemical plating and testing, the primer coating includes primer preparation and coating, and primary drying, the mid-coat coating includes mid-coat preparation and coating, and secondary drying, the topcoat coating includes topcoat preparation and coating, and tertiary drying, and the inspection and quality control include coating thickness and adhesion test, smoke test and appearance inspection.

[0014] As a further technical solution of the present invention, the ultrasonic cleaning includes using an ultrasonic cleaning machine to clean the parts, and selecting a cleaning solution to ensure surface cleaning. The formula of the cleaning solution is a mixture of 5-10% alkylbenzene, fatty acid solvent and deionized water. The cleaning temperature is 60°C and the cleaning time is 15 minutes. The rinsing and drying include multiple rinsings with deionized water to ensure that no cleaning agent residue is left, and the parts are blown dry with compressed air.

[0015] As a further technical solution of the present invention, the phosphating solution preparation includes preparing the phosphating solution and preparing the required solution, wherein the phosphating solution is a mixture of a zinc phosphating solution and phosphoric acid, the concentration of the zinc phosphating solution is 15-20 g / L, and the concentration of the phosphoric acid is 10-15%. The phosphating and rinsing includes immersing the parts in the phosphating solution for 5-7 minutes, and then rinsing with deionized water multiple times to ensure that no phosphoric acid residue is left. The temperature of the phosphating tank is 50°C-60°C, and the immersion time is 5-7 minutes.

[0016] As a further technical solution of the present invention, the plating solution preparation includes preparing a chemical nickel plating solution to ensure the accuracy of the solution composition. The plating solution formula is nickel chloride (concentration: 40-50g / L), sodium chloride (concentration: 20g / L), and sodium gluconate (reducing agent, concentration: 10g / L). The chemical plating and testing include immersing the parts in the plating solution, controlling the nickel plating time and temperature, and completing the nickel plating operation. The plating tank temperature is 90℃±5℃, the pH value is 4.0-5.0, the nickel plating time is 30-40 minutes, and the coating thickness is 8-12μm.

[0017] As a further technical solution of the present invention, the primer preparation and coating include the use of epoxy resin primer for coating to ensure uniform coating. The primer formula is epoxy resin (solid content: 60%) + amine curing agent (10%) + solvent (alcohol solvent). The coating method adopts electrostatic spraying, and the coating thickness is 30-40 μm. The one-time drying includes drying after coating to ensure that the primer is completely cured. The drying temperature is 120°C and the drying time is 30 minutes.

[0018] As a further technical solution of the present invention, the intermediate preparation and coating include coating with a polyurethane resin mid-coat to ensure uniform coating. The intermediate formula is polyurethane resin (solid content: 55%) + curing agent (10%) + solvent, and the coating method is electrostatic spraying. The coating thickness is 40-50 μm. The secondary drying includes drying after coating to ensure that the mid-coat is completely cured. The drying temperature is 130°C and the drying time is 20 minutes.

[0019] As a further technical solution of the present invention, the topcoat preparation and coating include the use of fluoride resin topcoat for coating to ensure that the coating is uniform and the surface is smooth. The topcoat formula is fluoride resin (solid content: 50%) + pigment + solvent, the coating method is electrostatic spraying, and the coating thickness is 50-60 μm. The secondary drying includes drying after coating to ensure that the topcoat is cured. The drying temperature is 150°C and the drying time is 30 minutes.

[0020] As a further technical solution of the present invention, the coating thickness and adhesion test includes using a coating thickness gauge to check the coating thickness and perform an adhesion test. The coating thickness must be maintained at 30-60 μm and comply with the ISO2409 standard. The salt spray test and appearance inspection include performing a salt spray test and an appearance inspection to ensure that the parts meet the corrosion resistance and appearance requirements and ensure that there is no corrosion, bubbles, or cracks for 96 hours.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) The present invention effectively removes stains and grease on the surface of parts by optimizing the pre-cleaning step, especially adopting ultrasonic cleaning technology, combined with specific cleaning solution formula and process parameters, laying a solid foundation for subsequent treatment. The high-frequency vibration of ultrasonic waves can penetrate into the tiny gaps on the surface of parts to achieve comprehensive and thorough cleaning. The improvement of the phosphating treatment step further enhances the bonding strength between the coating and the substrate. By accurately preparing the phosphating solution and strictly controlling the temperature and immersion time of the phosphating tank, a uniform and dense phosphating film is formed. This film not only improves the adhesion of the coating, but also provides a good adhesion foundation for subsequent coating. The phosphating treatment can also effectively inhibit the penetration of corrosive media, thereby extending the life of the parts. To extend the service life of components, the application of chemical nickel plating technology provides components with a uniform and corrosion-resistant protective layer. The precise control of the concentration of each component in the plating solution and the strict management of temperature, time and pH value during the nickel plating process ensure the stability and consistency of the coating quality. This nickel plating layer not only improves the corrosion resistance of components, but also enhances its hardness and wear resistance, enabling it to better adapt to harsh use environments. By selecting high-performance coating formulas and combining electrostatic spraying technology, uniform coating coverage and precise thickness control are achieved. The setting of multiple drying steps ensures the full curing of each layer of coating and good bonding between coatings, thereby improving the corrosion resistance and durability of the entire coating system.

[0023] (2) The present invention reduces the risk of environmental pollution in the production process by optimizing the coating formula and reducing the use of harmful chemicals. At the same time, the fine process control and efficient resource utilization also reduce the consumption of energy and raw materials, which is in line with the concept of sustainable development. The combination of salt spray test and appearance inspection not only verifies the corrosion resistance of parts, but also ensures that they maintain a good appearance during long-term use. This process can significantly improve the corrosion resistance and durability of automotive parts, extend their service life, and reduce the maintenance and replacement costs caused by corrosion. At the same time, this process is also applicable to other precision parts processing fields that require high precision and high corrosion resistance, and has broad application prospects and market potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the overall process of the present invention;

[0025] Figure 2 Schematic diagram of the pre-cleaning process of the present invention;

[0026] Figure 3 Schematic diagram of the phosphating process of the present invention;

[0027] Figure 4 Schematic diagram of the process of chemical nickel plating of the present invention;

[0028] Figure 5Schematic diagram of the primer coating process of the present invention;

[0029] Figure 6 Schematic diagram of the coating process of the present invention;

[0030] Figure 7 Schematic diagram of the topcoat coating process of the present invention;

[0031] Figure 8 Schematic diagram of the process for inspection and quality control of the present invention. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0033] like Figures 1 to 8 As shown, in an embodiment of the present invention, a corrosion protection process for automobile precision parts includes the following steps:

[0034] S1: pre-cleaning;

[0035] S2: phosphating treatment;

[0036] S3: chemical nickel plating;

[0037] S4: Primer coating;

[0038] S5: mid-coat painting;

[0039] S6: topcoat painting;

[0040] S7: Inspection and quality control;

[0041] Pre-cleaning includes ultrasonic cleaning, rinsing and drying; phosphating includes phosphating solution preparation, phosphating and rinsing; chemical nickel plating includes plating solution preparation, chemical plating and testing; primer coating includes primer preparation and coating, and primary drying; mid-coat coating includes mid-coat preparation and coating, and secondary drying; topcoat coating includes topcoat preparation and coating, and tertiary drying; inspection and quality control include coating thickness and adhesion test, smoke test and appearance inspection.

[0042] like Figure 2As shown, ultrasonic cleaning includes using an ultrasonic cleaning machine to clean parts and selecting a cleaning solution to ensure surface cleaning. The cleaning solution is a mixture of 5-10% alkylbenzene, fatty acid solvents and deionized water. The cleaning temperature is 60°C and the cleaning time is 15 minutes. Rinsing and drying include multiple rinsings with deionized water to ensure that no cleaning agent residues are left, and compressed air is used to blow the parts dry.

[0043] A specially formulated ultrasonic cleaning process provides deep cleaning of precision automotive parts, significantly improving cleaning efficiency and quality. By optimizing the cleaning fluid composition and temperature control, it effectively removes surface dirt and grease, ensuring adhesion and uniformity for subsequent anti-corrosion treatment. Multiple deionized water rinses and compressed air drying steps completely eliminate residual cleaning agents, preventing secondary contamination and further ensuring processing quality. This process not only enhances the corrosion resistance of precision parts but also reduces rework due to incomplete cleaning, contributing to overall production efficiency and cost reduction.

[0044] like Figure 3 As shown, the phosphating solution preparation includes preparing the phosphating solution and preparing the required solution. The phosphating solution is a mixture of zinc phosphating solution and phosphoric acid. The concentration of the zinc phosphating solution is 15-20g / L, and the concentration of phosphoric acid is 10-15%. Phosphating and rinsing include immersing the parts in the phosphating solution for 5-7 minutes, and then rinsing with deionized water multiple times to ensure that there is no phosphoric acid residue. The phosphating tank temperature is 50℃-60℃, and the soaking time is 5-7 minutes.

[0045] The phosphating process, through the precise formulation of a zinc phosphating solution and phosphoric acid mixture, provides an excellent corrosion protection foundation for automotive precision parts. The optimal zinc phosphating solution concentration and phosphoric acid ratio, combined with appropriate temperature and immersion time, ensures a uniform and dense phosphating layer, effectively enhancing the corrosion resistance of the parts. Multiple deionized water rinses thoroughly remove residual phosphoric acid, preventing adverse effects and further improving phosphating quality. This process not only enhances the corrosion protection of precision parts but also strengthens the coating's adhesion.

[0046] like Figure 4 As shown, the plating solution preparation includes preparing a chemical nickel plating solution to ensure the accuracy of the solution composition. The plating solution formula is nickel chloride (concentration: 40-50g / L), sodium chloride (concentration: 20g / L), and sodium gluconate (reducing agent, concentration: 10g / L). Chemical plating and testing include immersing the parts in the plating solution, controlling the nickel plating time and temperature, and completing the nickel plating operation. The plating tank temperature is 90℃±5℃, the pH value is 4.0-5.0, the nickel plating time is 30-40 minutes, and the coating thickness is 8-12μm.

[0047] The chemical nickel plating process achieves high-quality nickel plating on the surface of automotive precision parts through precise formulation of the plating solution. The optimized plating solution formula, including appropriate concentrations of nickel chloride, sodium chloride and sodium gluconate, ensures the uniformity and density of the coating. Strict control of nickel plating conditions, such as plating tank temperature, pH value and nickel plating time, ensures precise control of the coating thickness, reaching the ideal range of 8-12μm. This process not only significantly improves the corrosion resistance and wear resistance of precision parts, but also enhances the bonding strength between the coating and the substrate.

[0048] like Figure 5 As shown, the primer preparation and coating include the use of epoxy resin primer for coating to ensure uniform coating. The primer formula is epoxy resin (solid content: 60%) + amine curing agent (10%) + solvent (alcohol solvent). The coating method adopts electrostatic spraying, and the coating thickness is 30-40μm. One-time drying includes drying after coating to ensure that the primer is completely cured. The drying temperature is 120℃ and the drying time is 30 minutes.

[0049] The use of epoxy resin primer for coating, combined with an optimized formula and electrostatic spraying technology, provides a high-quality anti-corrosion base layer for automotive precision parts. Electrostatic spraying ensures uniform coverage of the coating and achieves an ideal coating thickness of 30-40μm, effectively enhancing the anti-corrosion performance of the primer. Appropriate primary drying conditions, such as a drying temperature of 120°C and a drying time of 30 minutes, ensure the complete curing of the primer and further enhance the adhesion and durability of the coating. This process not only improves the anti-corrosion effect of precision parts.

[0050] like Figure 6 As shown, the intermediate preparation and coating include the use of a polyurethane resin mid-coat for coating to ensure uniform coating. The intermediate formula is polyurethane resin (solid content: 55%) + curing agent (10%) + solvent. The coating method is electrostatic spraying. The coating thickness is 40-50 μm. The secondary drying includes drying after coating to ensure that the mid-coat is completely cured. The drying temperature is 130°C and the drying time is 20 minutes.

[0051] The application of a polyurethane resin midcoat, combined with an optimized formulation and electrostatic spraying technology, significantly improves the coating performance of automotive precision parts. Uniform coating coverage and an ideal coating thickness of 40-50μm effectively enhance the coating's corrosion and wear resistance. Appropriate secondary drying conditions, such as a temperature of 130°C and a drying time of 20 minutes, ensure complete curing of the midcoat, further enhancing the coating's overall strength and adhesion.

[0052] like Figure 7As shown, the topcoat preparation and coating include the use of fluoride resin topcoat for coating to ensure that the coating is uniform and the surface is smooth. The topcoat formula is fluoride resin (solid content: 50%) + pigment + solvent, and the coating method is electrostatic spraying. The coating thickness is 50-60μm. The secondary drying includes drying after coating to ensure that the topcoat is cured. The drying temperature is 150°C and the drying time is 30 minutes.

[0053] The application of fluoride resin topcoat, combined with an optimized formula and electrostatic spraying technology, provides a high-performance anti-corrosion and decorative coating for automotive precision parts. The uniform coating coverage, smooth surface and ideal coating thickness of 50-60μm significantly enhance the coating's weather resistance, corrosion resistance and aesthetics. Suitable drying conditions, such as a drying temperature of 150°C and a drying time of 30 minutes, ensure the complete curing of the topcoat, further improving the coating's hardness and durability.

[0054] like Figure 8 As shown, the coating thickness and adhesion test includes checking the coating thickness with a coating thickness gauge and performing an adhesion test. The coating thickness must be maintained at 30-60μm and comply with the ISO2409 standard. The salt spray test and appearance inspection include performing a salt spray test and appearance inspection to ensure that the parts meet the corrosion resistance and appearance requirements and ensure that there is no corrosion, bubbles, or cracks for 96 hours.

[0055] Coating thickness and adhesion tests, as well as salt spray tests and appearance inspections, constitute key quality control links in the anti-corrosion processing of automotive precision parts. Strict coating thickness control ensures the stability of anti-corrosion performance, while adhesion tests verify the strong bond between the coating and the substrate. Salt spray tests verify the corrosion resistance of the coating in harsh environments. The 96-hour corrosion-free standard ensures the long-term reliability of the product. Appearance inspections ensure that the coating is smooth and defect-free, improving the overall aesthetics of the product.

[0056] By optimizing the pre-cleaning steps, especially adopting ultrasonic cleaning technology, combined with specific cleaning solution formula and process parameters, the stains and grease on the surface of parts are effectively removed, laying a solid foundation for subsequent treatment. The high-frequency vibration of ultrasound can penetrate into the tiny gaps on the surface of parts to achieve comprehensive and thorough cleaning. The improvement of the phosphating treatment step further enhances the bonding strength between the coating and the substrate. By accurately preparing the phosphating solution and strictly controlling the temperature and immersion time of the phosphating tank, a uniform and dense phosphating film is formed. This film not only improves the adhesion of the coating, but also provides a good adhesion foundation for subsequent coating. Phosphating treatment can also effectively inhibit the penetration of corrosive media, thereby extending the life of parts. Service life, the application of chemical nickel plating technology provides parts with a uniform and corrosion-resistant protective layer, the precise control of the concentration of each component in the plating solution, and the strict management of temperature, time and pH value during the nickel plating process ensure the stability and consistency of the plating quality. This nickel plating layer not only improves the corrosion resistance of parts, but also enhances its hardness and wear resistance, enabling it to better adapt to harsh use environments. By selecting high-performance paint formulas and combining electrostatic spraying technology, uniform coverage of the coating and precise control of thickness are achieved. The setting of multiple drying steps ensures the full curing of each layer of paint and the good bonding between the coatings, thereby improving the corrosion resistance and durability of the entire coating system.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A corrosion protection process for automotive precision parts, characterized by: The following steps are involved: S1: pre-cleaning; S2: phosphating treatment; S3: chemical nickel plating; S4: Primer coating; S5: mid-coat painting; S6: topcoat painting; S7: Inspection and quality control; The pre-cleaning includes ultrasonic cleaning, rinsing and drying, the phosphating treatment includes phosphating solution preparation, phosphating and rinsing, the chemical nickel plating includes plating solution preparation, chemical plating and testing, the primer coating includes primer preparation and coating, and primary drying, the mid-coat coating includes mid-coat preparation and coating, and secondary drying, the topcoat coating includes topcoat preparation and coating, and tertiary drying, and the inspection and quality control include coating thickness and adhesion test, smoke test and appearance inspection.

2. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The ultrasonic cleaning includes using an ultrasonic cleaning machine to clean the parts and selecting a cleaning solution to ensure surface cleaning. The cleaning solution is a mixture of 5-10% alkylbenzene, fatty acid solvent and deionized water. The cleaning temperature is 60°C and the cleaning time is 15 minutes. The rinsing and drying include multiple rinsings with deionized water to ensure that no cleaning agent residue is left, and the parts are blown dry with compressed air.

3. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The phosphating solution preparation includes preparing the phosphating solution and preparing the required solution. The phosphating solution is a mixture of zinc phosphating solution and phosphoric acid. The concentration of the zinc phosphating solution is 15-20g / L, and the concentration of the phosphoric acid is 10-15%. The phosphating and rinsing includes immersing the parts in the phosphating solution for 5-7 minutes, and then rinsing with deionized water multiple times to ensure that no phosphoric acid residue is left. The temperature of the phosphating tank is 50°C-60°C, and the immersion time is 5-7 minutes.

4. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The plating solution preparation includes preparing a chemical nickel plating solution to ensure the accuracy of the solution composition. The plating solution formula is nickel chloride (concentration: 40-50g / L), sodium chloride (concentration: 20g / L), and sodium gluconate (reducing agent, concentration: 10g / L). The chemical plating and testing include immersing the parts in the plating solution, controlling the nickel plating time and temperature, and completing the nickel plating operation. The plating tank temperature is 90℃±5℃, the pH value is 4.0-5.0, the nickel plating time is 30-40 minutes, and the coating thickness is 8-12μm.

5. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The primer preparation and coating include using epoxy resin primer for coating to ensure uniform coating. The primer formula is epoxy resin (solid content: 60%) + amine curing agent (10%) + solvent (alcohol solvent). The coating method adopts electrostatic spraying, and the coating thickness is 30-40μm. The one-time drying includes drying after coating to ensure that the primer is completely cured. The drying temperature is 120°C and the drying time is 30 minutes.

6. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The intermediate preparation and coating include coating with a polyurethane resin mid-coat to ensure uniform coating. The intermediate formula is polyurethane resin (solid content: 55%) + curing agent (10%) + solvent. The coating method is electrostatic spraying. The coating thickness is 40-50 μm. The secondary drying includes drying after coating to ensure that the mid-coat is completely cured. The drying temperature is 130°C and the drying time is 20 minutes.

7. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The topcoat preparation and coating include the use of fluoride resin topcoat for coating to ensure that the coating is uniform and the surface is smooth. The topcoat formula is fluoride resin (solid content: 50%) + pigment + solvent, the coating method is electrostatic spraying, and the coating thickness is 50-60 μm. The secondary drying includes drying after coating to ensure that the topcoat is cured. The drying temperature is 150°C and the drying time is 30 minutes.

8. The anti-corrosion processing technology for automobile precision parts according to claim 1 is characterized in that: The coating thickness and adhesion test includes using a coating thickness gauge to check the coating thickness and perform an adhesion test. The coating thickness must be maintained at 30-60 μm and comply with the ISO2409 standard. The salt spray test and appearance inspection include performing a salt spray test and appearance inspection to ensure that the parts meet the corrosion resistance and appearance requirements and ensure that there is no corrosion, bubbles, or cracks for 96 hours.

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