Environment-friendly passivation solution for metal component and preparation method and passivation process of environment-friendly passivation solution

Abstract

The invention relates to a metal passivator, and particularly discloses an environment-friendly passivation solution for a metal component and a preparation method and a passivation process of the environment-friendly passivation solution. The passivation solution comprises 1%-5% of trivalent chromium salt, 1%-5% of silicon-containing compound modified alkyd resin, 2%-15% of a film forming accelerant, 5%-15% of a complexing agent, 1.5%-2% of a hole sealing agent and the balance deionized water. The low-content trivalent chromium salt is adopted to replace traditional hexavalent chromium salt, the toxicity of trivalent chromium is far lower than that of hexavalent chromium, heavy metal pollution hazards are effectively reduced, and by adding assistants such as the silicon-containing compound modified alkyd resin, the hole sealing agent, the film forming accelerant and the complexing agent, through the synergistic effect of all the components, the corrosion resistance of the coating is improved, and the service life of the coating is prolonged. A compact, uniform and stable passivation film is formed on the surface of the sherardizing steel part, the probability of rusting and corrosion of the sherardizing steel part is remarkably reduced, the service life of the sherardizing steel part in severe environments such as high humidity and high salinity is prolonged, and high practical value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of metal passivators, and in particular to an environmentally friendly passivation solution for metal components and a preparation method and a passivation process thereof. Background Art

[0002] Steel products play an indispensable role in many areas of today's industrial production and daily life. As an important steel surface protection process, sherardizing can significantly improve the corrosion resistance of steel parts and extend their service life. Therefore, it is widely used in many industries such as construction, machinery manufacturing, and automotive parts.

[0003] After treatment, the surface activity of traditional zinc-diffused steel parts is still high. If they are directly exposed to the air, they are easily oxidized and corroded, resulting in deterioration of the appearance of the workpiece and a decrease in mechanical properties, which cannot meet the needs of long-term use. To solve this problem, passivation treatment came into being. However, most of the existing steel passivation solutions have many disadvantages. On the one hand, the traditional passivation solution contains hexavalent chromate. Although it has high corrosion resistance and self-repairing ability, during use, these heavy metals will enter the natural environment with wastewater discharge, causing serious pollution to the soil and water bodies, and will be enriched through the food chain, endangering the health of organisms and causing a series of ecological and environmental problems. On the other hand, the passivation film formed by some conventional passivation solutions has poor density and uniformity, resulting in poor durability of the passivation effect. After being treated with it, the zinc-diffused steel parts may develop rust spots in a short period of time under relatively harsh environmental conditions, such as high humidity and high salinity environments, and it is difficult to guarantee the long-term and stable protection needs of steel parts. This not only increases maintenance costs and wastes resources, but also limits the expansion of the application scenarios of zinc-diffused steel parts.

[0004] As the world's attention to environmental protection increases, and the demand for high-quality, long-life steel parts in various industries continues to grow, the development of a zinc-plated steel passivation solution that has both excellent passivation effect and meets environmental protection requirements has become a key technical problem that needs to be overcome in the field of metal surface treatment. Summary of the invention

[0005] In view of the problems of poor environmental protection and poor passivation effect of steel component passivation liquid in the prior art, the present invention provides an environmentally friendly passivation liquid for metal components and a preparation method and a passivation process thereof.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] In a first aspect, the present invention provides an environmentally friendly passivation solution for metal components, comprising the following raw material components in percentage by weight: 1% to 5% of trivalent chromium salt, 1% to 5% of silicon-containing compound-modified alkyd resin, 2% to 15% of film-forming promoter, 5% to 15% of complexing agent, 1.5% to 2% of sealing agent, and the balance being deionized water.

[0008] Compared with the prior art, the environmentally friendly passivation liquid for metal components provided by the present invention uses a low-content trivalent chromium salt as the main film-forming agent, and forms a dense and uniform dark gray passivation film on the surface of the galvanized steel part through the synergistic effect of the sealing agent and the alkyd resin modified by the silicon compound, so as to effectively block the invasion of corrosive media such as external water vapor and oxygen. In addition, the introduction of silicon element further enhances the hardness, wear resistance and weather resistance of the film, so that the steel parts can still maintain the good appearance and structural integrity of the film layer under the harsh conditions of long-term outdoor exposure, wind, sun and rain, and extend the service life; adding a film-forming promoter can significantly accelerate the formation speed of the passivation film, and help optimize the microstructure of the film, make the film layer more uniform and dense, and improve the film and the galvanized steel substrate. The adhesion between the two components is improved to ensure that the protective film exists stably on the surface of the steel parts for a long time and is not easy to peel off; a chelating agent is added to form a stable complex with the metal ions (such as trivalent chromium ions, etc.) in the system, adjust the release rate of metal ions, and continuously provide active ingredients for the passivation reaction to ensure the durability of the passivation effect; a sealing agent is added to fill the tiny pores on the surface of the passivation film to further block the penetration channel of corrosive substances. At the same time, the alkyd resin modified by the silicon compound and the sealing agent are cross-linked to form a network structure, which ensures the density and uniformity of the final film layer. When the film layer is slightly damaged, the damaged film layer can release the sealing agent, which synergistically acts with the alkyd resin modified by the silicon compound to repair the film layer, thereby playing a certain self-repairing role and further improving the corrosion resistance of the zinc-plated steel parts.

[0009] The zinc-plated steel passivation liquid provided by the present invention adopts a low-content trivalent chromium salt instead of a traditional hexavalent chromium salt. The toxicity of trivalent chromium is much lower than that of hexavalent chromium, and its mobility and bioavailability in the environment are relatively small, which greatly reduces the pollution risk to the ecological environment such as soil and water bodies, and effectively reduces the harm of heavy metal pollution. By adding auxiliary agents such as silicon-containing compound-modified alkyd resin, sealing agent, film-forming promoter and complexing agent, a dense, uniform and stable passivation film is formed on the surface of the zinc-plated steel part through the synergistic effect of each component, which significantly reduces the probability of rust and corrosion of the zinc-plated steel part, and increases the service life of the zinc-plated steel part in harsh environments such as high humidity and high salinity, and has high practical value.

[0010] Furthermore, the silicon-containing compound modified alkyd resin is nano-silicon dioxide modified alkyd resin.

[0011] Furthermore, the preparation method of the nano-silica modified alkyd resin comprises the following steps:

[0012] Add nano-silicon dioxide, water-based alkyd resin and p-toluenesulfonic acid into deionized water, mix evenly, and react by stirring at 60° C. to 80° C. to obtain nano-silicon dioxide modified alkyd resin.

[0013] The compatibility of silica with water-based alkyd resin is relatively poor. The present invention adopts p-toluenesulfonic acid as a catalyst, which can react with the hydroxyl groups on the surface of silica, introduce organic groups on the surface of silica, so that it can be better integrated into the alkyd resin system, reduce the occurrence of phase separation, and improve the uniformity and stability of the modified material; at the same time, by controlling the reaction temperature, the reaction degree between silica and alkyd resin is adjusted, so that appropriate chemical bonds and interactions are formed between silica and alkyd resin, thereby improving the performance of the modified alkyd resin, such as hardness, flexibility, corrosion resistance, etc.

[0014] Furthermore, the mass ratio of the nano-silicon dioxide to the water-based alkyd resin is (5-9):(95-91).

[0015] Furthermore, the added amount of the p-toluenesulfonic acid is 0.3% to 0.5% of the total mass of the nano-silicon dioxide and the water-based alkyd resin.

[0016] Furthermore, the stirring reaction time is 20h to 25h.

[0017] Furthermore, the trivalent chromium salt includes at least one of chromium sulfate, chromium nitrate, chromium chloride, chromium carbonate, chromium oxalate or potassium chromium sulfate.

[0018] Furthermore, the film-forming promoter includes at least one of sodium nitrate, sodium chloride, potassium dihydrogen phosphate, cerium sulfate or manganese chloride.

[0019] The preferred film-forming promoter can significantly accelerate the formation speed of the passivation film and improve production efficiency. At the same time, it helps to optimize the microstructure of the film, make the film layer more uniform and dense, enhance the adhesion between the film and the zinc-diffused steel substrate, and ensure that the protective film exists stably on the surface of the steel for a long time and is not easy to peel off.

[0020] Furthermore, the complexing agent includes at least one of malonic acid, glycine, glutamic acid, glycolic acid, oxalic acid, ammonium bifluoride, sodium fluorosilicate or glacial acetic acid.

[0021] The preferred complexing agent can, on the one hand, adjust the release rate of metal ions (such as trivalent chromium ions), continuously provide active ingredients for the passivation reaction, and ensure the durability of the passivation effect; on the other hand, the complex formed in the system can improve the chemical stability of the passivation solution, prevent the precipitation and precipitation of components, ensure the performance consistency of the passivating agent during storage and use, and improve the reliability of product quality.

[0022] Furthermore, the sealing agent is selected from at least one of nano-silicon dioxide, acidic silica sol or nano-scale silicate.

[0023] The preferred sealing agent can fill the tiny pores on the surface of the passivation film, further block the penetration channels of corrosive substances, and effectively improve the passivation effect.

[0024] In a second aspect, the present invention further provides a method for preparing an environmentally friendly passivation solution for metal components, comprising the following steps:

[0025] S1, adding trivalent chromium salt, film-forming accelerator and complexing agent into part of deionized water, mixing evenly, to obtain solution A;

[0026] S2, adding the sealing agent and the silicon-containing compound modified alkyd resin to the remaining deionized water, mixing them evenly, to obtain solution B;

[0027] S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

[0028] It should be noted that, in S1, the partial deionized water accounts for 2 / 3 of the total amount.

[0029] The method for preparing the environment-friendly passivation liquid for metal components provided by the present invention is simple, and the prepared passivation liquid has good stability and is still a uniform and transparent dark green color after being stored for two years, and has a stable use effect.

[0030] In a third aspect, the present invention provides a passivation process using the environmentally friendly passivation solution for metal components, comprising the following steps:

[0031] Add the environmentally friendly passivation solution for metal components into deionized water, mix well, and adjust the pH to 2-3 to obtain a diluted solution;

[0032] The zinc-diffused steel part is immersed in the diluent for passivation to obtain the passivated zinc-diffused steel part.

[0033] It should be noted that before passivation, the galvanized steel parts need to be washed twice to ensure that the surface of the galvanized steel parts is clean. After passivation, the surface of the galvanized steel parts also needs to be washed twice, and then hot air drying is performed after washing. For example, the temperature of hot air drying is 60°C to 80°C, and the drying time is 8min to 12min.

[0034] Furthermore, the volume ratio of the environmentally friendly passivation solution for metal components to deionized water is 1:(2-4).

[0035] Furthermore, the immersion temperature of the zinc-diffused steel part in the diluent is 20° C. to 30° C., and the immersion time is 90s to 180s.

[0036] It should be noted that, in actual use, due to the different number of workpieces produced every day, the pH of the passivation tank liquid will also increase to varying degrees. The pH of the passivation tank liquid can be controlled to be maintained between 2 and 4 by appropriately adding passivation stock solution to the passivation tank. The liquid in the passivation tank can be used for a long time, and there is no need to extract and replace the entire liquid in the passivation tank every time. This method can greatly simplify the production operation links and save use costs.

[0037] The present invention uses low-toxic trivalent chromium salt as raw material, abandons traditional highly polluting heavy metal components, greatly reduces the harm to the environment from the source, and through the synergistic effect of film-forming promoter and silicon-containing compound modified alkyd resin, the passivation liquid can not only quickly form a film on the surface of the zinc-diffused steel part, but also ensure the density and uniformity of the film layer, thereby creating a solid barrier for the zinc-diffused steel part to resist external corrosion and extend the service life of the workpiece; by adding a chelating agent, the release of metal ions is regulated to ensure long-term and durable passivation; by adding a sealing agent, the corrosion resistance effect is enhanced, and the zinc-diffused steel part is protected in all directions, so that it can maintain a good state under various complex working conditions. The passivated galvanized steel parts provided by the present invention have no white rust for 1200 hours and still no red rust after 4 months in a neutral salt spray corrosion resistance test according to the national standard GB / T 10125-2012 artificial atmosphere corrosion test measurement standard. The galvanized steel parts provided by the present invention are suitable for the passivation of galvanized steel parts or galvanized steel parts, and provide a passivation liquid for galvanized or galvanized steel parts that has both excellent passivation effect and meets environmental protection requirements, and has good economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the infrared absorption spectrum of the nano-silicon dioxide modified alkyd resin prepared in Example 1;

[0039] Figure 2 This is a thermal gravimetric curve of the nano-silica modified alkyd resin prepared in Example 1. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] In order to better illustrate the present invention, further examples are given below.

[0042] Example 1

[0043] This embodiment provides a method for preparing a nano-silicon dioxide modified alkyd resin, which specifically comprises the following steps:

[0044] Add nano-silica and water-based alkyd resin in a mass ratio of 7:93, and p-toluenesulfonic acid (the added amount is 0.4% of the total mass of the nano-silica and the water-based alkyd resin) into deionized water of the same mass as the total mass of the nano-silica and the water-based alkyd resin, mix well, stir and react at 70°C for 24 hours, and dry to obtain nano-silica modified alkyd resin.

[0045] Figure 1 This is the infrared absorption spectrum of the nano-silicon dioxide modified alkyd resin prepared in this example. It can be seen from the figure that at 3440cm -1 The absorption peak at is the characteristic peak of -COOH; the stretching vibration peak of saturated CH is located at 2975cm -1 Nearby, 1740cm -1 It is the characteristic peak of C=O at 797cm -1 、469cm -1 The attached absorption bands are attributed to the characteristic peaks of Si-O bonds, proving that nano-silica has been successfully introduced into alkyd resin.

[0046] Figure 2 The thermogravimetric curve of the nano-silicon dioxide modified alkyd resin prepared in this example when heated from room temperature to 800°C under an inert atmosphere. As can be seen from the figure, the nano-silicon dioxide modified alkyd resin begins to decompose at around 200°C and is completely decomposed at around 500°C, while silicon dioxide is not decomposed, indicating that the grafting rate of silicon dioxide on the alkyd resin is 6.6%.

[0047] Nano-silicon dioxide modified alkyd resins prepared under other conditions specified in the present invention can achieve effects equivalent to the above.

[0048] Example 2

[0049] The present embodiment provides an environmentally friendly passivation solution for metal components, comprising the following raw material components in percentage by weight: 1% chromium sulfate, 1% nano-silicon dioxide modified alkyd resin, 2% sodium nitrate, 5% alanine, 1.5% nano-silicon dioxide, and the balance being deionized water.

[0050] The method for preparing the environmentally friendly passivation solution for metal components comprises the following steps:

[0051] S1, adding chromium sulfate, sodium nitrate and alanine into 2 / 3 of deionized water, mixing well to obtain solution A;

[0052] S2, adding nano-silica and nano-silica modified alkyd resin to the remaining deionized water, mixing evenly, to obtain solution B;

[0053] S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

[0054] Example 3

[0055] The present embodiment provides an environmentally friendly passivation solution for metal components, comprising the following raw material components in percentage by weight: 3% chromium nitrate, 3% nano-silicon dioxide modified alkyd resin, 8% sodium chloride, 10% glacial acetic acid, 2% nano-sodium silicate, and the balance being deionized water.

[0056] The method for preparing the environmentally friendly passivation solution for metal components comprises the following steps:

[0057] S1, adding chromium nitrate, sodium chloride and glacial acetic acid into 2 / 3 of deionized water, mixing well to obtain solution A;

[0058] S2, adding nano sodium silicate and nano silicon dioxide modified alkyd resin into the remaining deionized water, mixing evenly, to obtain solution B;

[0059] S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

[0060] Example 4

[0061] The present embodiment provides an environmentally friendly passivation solution for metal components, comprising the following raw material components in percentage by weight: 5% chromium chloride, 5% nano-silicon dioxide modified alkyd resin, 15% potassium dihydrogen phosphate, 15% oxalic acid, 1.6% acidic silica sol, and the balance being deionized water.

[0062] The method for preparing the environmentally friendly passivation solution for metal components comprises the following steps:

[0063] S1, adding chromium chloride, potassium dihydrogen phosphate and oxalic acid into 2 / 3 of deionized water, mixing well, to obtain solution A;

[0064] S2, adding the acidic silica sol and the nano-silica modified alkyd resin into the remaining deionized water, and mixing them evenly to obtain a solution B;

[0065] S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

[0066] Example 5

[0067] The present embodiment provides an environmentally friendly passivation solution for metal components, comprising the following raw material components in percentage by weight: 4% chromium carbonate, 2% nano-silicon dioxide modified alkyd resin, 10% cerium sulfate, 12% malonic acid, 1.8% nano-silicon dioxide, and the balance being deionized water.

[0068] The method for preparing the environmentally friendly passivation solution for metal components comprises the following steps:

[0069] S1, adding chromium carbonate, cerium sulfate and malonic acid into 2 / 3 of deionized water, mixing well, to obtain solution A;

[0070] S2, adding nano-silica and nano-silica modified alkyd resin to the remaining deionized water, mixing evenly, to obtain solution B;

[0071] S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

[0072] After the passivation solutions prepared in Examples 2 to 4 were placed for two years, they still remained a uniform and transparent solution.

[0073] The passivation solutions prepared in Examples 2 to 4 were used to passivate the zinc-plated steel parts according to the following process:

[0074] The zinc-drenched steel parts are washed twice to remove surface contaminants;

[0075] Add 100L of the passivation solution prepared in Examples 2 to 4 into 300L of deionized water, mix well, and adjust the pH to 2 to 3 with nitric acid to obtain a diluted solution; immerse the washed galvanized steel parts in the above diluted solution at room temperature (25°C), tumble the galvanized steel parts during the immersion process, soak for 120s, take out, wash twice, and dry with hot air at 70°C to obtain the passivated galvanized steel parts.

[0076] The passivated galvanized steel parts were tested according to the national standard GB / T 10125-2012 artificial atmosphere corrosion test. In the neutral salt spray corrosion test, there was no white rust after 1200 hours and no red rust after 4 months.

[0077] By replacing the film-forming promoter, complexing agent and sealing agent in the above embodiments with other substances defined in the present invention, as long as they are within the scope defined in the present invention, the technical effects equivalent to those of the corresponding embodiments can be achieved.

[0078] Comparative Example 1

[0079] This comparative example provides a passivation solution for metal components, which is different from Example 5 only in that no nano-silicon dioxide-modified alkyd resin is added, and specifically includes the following raw material components in percentage by weight:

[0080] Chromium carbonate 4%, cerium sulfate 10%, malonic acid 12%, nano silicon dioxide 1.8%, and the balance is deionized water.

[0081] The passivation solution was prepared in the same manner as in Example 5, which will not be described in detail here.

[0082] The passivating solution was used to passivate the galvanized steel parts in the same manner as in Example 5, and the test was carried out in accordance with the national standard GB / T 10125-2012 artificial atmosphere corrosion test determination standard. In the neutral salt spray corrosion resistance test, white rust began to form after 96 hours, and red rust began to form after 7 days.

[0083] Comparative Example 2

[0084] This comparative example provides a passivation solution for metal components, which is different from Example 5 in that the nano-silicon dioxide modified alkyd resin is replaced with an equal amount of water-based alkyd resin, and specifically includes the following raw material components in percentage by weight:

[0085] Chromium carbonate 4%, water-based alkyd resin 2%, cerium sulfate 10%, malonic acid 12%, nano-silicon dioxide 1.8%, and the balance is deionized water.

[0086] The passivation solution was prepared in the same manner as in Example 5, which will not be described in detail here.

[0087] After the passivation solution prepared in this comparative example was placed for 6 months, the viscosity began to increase, and a small amount of particles precipitated, leading to failure.

[0088] The passivation solution was used to passivate the galvanized steel parts in the same manner as in Example 5, and the test was carried out in accordance with the national standard GB / T 10125-2012 artificial atmosphere corrosion test determination standard. In the neutral salt spray corrosion resistance test, there was no white rust for 120 hours, and red rust began to form after 15 days.

[0089] Comparative Example 3

[0090] This comparative example provides a passivation solution for metal components, which is different from Example 5 in that the nano-silicon dioxide-modified alkyd resin is replaced with an equal amount of nano-silicon dioxide-modified acrylic resin, and specifically includes the following raw material components in percentage by weight:

[0091] Chromium carbonate 4%, nano-silicon dioxide modified acrylic resin 2%, cerium sulfate 10%, malonic acid 12%, nano-silicon dioxide 1.8%, and the balance is deionized water.

[0092] The preparation method of the nano-silicon dioxide modified acrylic resin comprises the following steps:

[0093] Add nano-silica and water-based acrylic resin in a mass ratio of 7:93, and p-toluenesulfonic acid (the added amount is 0.4% of the total mass of the nano-silica and the water-based acrylic resin) into deionized water of the same mass as the total mass of the nano-silica and the water-based acrylic resin, mix well, stir and react at 70° C. for 24 hours, and dry to obtain nano-silica modified acrylic resin.

[0094] The passivation solution was prepared in the same manner as in Example 5, which will not be described in detail here.

[0095] After the passivation solution prepared in this comparative example was placed for 1 month, the viscosity began to increase, and floccules were precipitated, and then it became ineffective.

[0096] The passivation solution was used to passivate the galvanized steel parts in the same manner as in Example 5, and the test was carried out in accordance with the national standard GB / T 10125-2012 artificial atmosphere corrosion test determination standard. In the neutral salt spray corrosion resistance test, there was no white rust in 48 hours, but red rust began to form after 5 days.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An environmentally friendly passivation solution for metal components, characterized in that: The invention comprises the following raw material components in percentage by weight: 1% to 5% of trivalent chromium salt, 1% to 5% of silicon-containing compound-modified alkyd resin, 2% to 15% of film-forming accelerator, 5% to 15% of complexing agent, 1.5% to 2% of sealing agent, and the balance is deionized water.

2. The environmentally friendly passivation solution for metal components according to claim 1, characterized in that: The silicon-containing compound modified alkyd resin is nano-silicon dioxide modified alkyd resin.

3. The environmentally friendly passivation solution for metal components according to claim 2, characterized in that: The preparation method of the nano-silicon dioxide modified alkyd resin comprises the following steps: Add nano-silicon dioxide, water-based alkyd resin and p-toluenesulfonic acid into deionized water, mix evenly, and react by stirring at 60° C. to 80° C. to obtain nano-silicon dioxide modified alkyd resin.

4. The environmentally friendly passivation solution for metal components according to claim 3, characterized in that: The mass ratio of the nano-silicon dioxide to the water-based alkyd resin is (5-9):(95-91); and / or The added amount of the p-toluenesulfonic acid is 0.3% to 0.5% of the total mass of the nano-silicon dioxide and the water-based alkyd resin.

5. The environmentally friendly passivation solution for metal components according to claim 3, characterized in that: The stirring reaction time is 20h to 25h.

6. The environmentally friendly passivation solution for metal components according to claim 1, characterized in that: The trivalent chromium salt comprises at least one of chromium sulfate, chromium nitrate, chromium chloride, chromium carbonate, chromium oxalate or potassium chromium sulfate; and / or The film-forming promoter includes at least one of sodium nitrate, sodium chloride, potassium dihydrogen phosphate, cerium sulfate or manganese chloride.

7. The environmentally friendly passivation solution for metal components according to claim 1, characterized in that: The complexing agent includes at least one of malonic acid, glycine, glutamic acid, glycolic acid, oxalic acid, ammonium bifluoride, sodium fluorosilicate or glacial acetic acid; and / or The sealing agent is selected from at least one of nano silicon dioxide, acidic silica sol or nano silicate.

8. The method for preparing the environmentally friendly passivation solution for metal components according to any one of claims 1 to 7, characterized in that: The steps include: S1, adding trivalent chromium salt, film-forming accelerator and complexing agent into part of deionized water, mixing evenly, to obtain solution A; S2, adding the sealing agent and the silicon-containing compound modified alkyd resin to the remaining deionized water, mixing them evenly, to obtain solution B; S3, mixing the solution A and the solution B evenly to obtain an environmentally friendly passivation solution for metal components.

9. A passivation process using the environmentally friendly passivation solution for metal components according to any one of claims 1 to 7, characterized in that: The steps include: Add the environmentally friendly passivation solution for metal components into deionized water, mix well, and adjust the pH to 2-3 to obtain a diluted solution; The zinc-diffused steel part is immersed in the diluent for passivation to obtain the passivated zinc-diffused steel part.

10. The passivation process according to claim 9, characterized in that: The volume ratio of the environmentally friendly passivation solution for metal components to deionized water is 1:(2-4); and / or The immersion temperature of the zinc-diffused steel part in the diluent is 20° C. to 30° C., and the immersion time is 90s to 180s.

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