CN115537698B - Hot dip galvanizing smokeless plating aid and hot dip galvanizing method - Google Patents

Abstract

The invention discloses a hot-dip galvanizing smokeless plating aid and a hot-dip galvanizing method. The hot-dip galvanizing smokeless plating aid of the invention comprises the following components in mass percentage: sulfate: 5% to 15%; stabilizer: 0.1% to 1%; corrosion inhibitor: 0.1% to 0.5%; surfactant: 0.05% to 3%; water: the balance. The hot-dip galvanizing smokeless plating aid of the invention uses sulfate as the main salt, has a simple formula, low cost, no smoke is generated during the hot-dip galvanizing process, has a good galvanizing effect, and is suitable for large-scale industrial applications.

Description

Hot dip galvanizing smokeless plating aid and hot dip galvanizing method

Technical Field

The invention relates to the technical field of hot-dip galvanizing, and in particular to a hot-dip galvanizing smokeless plating aid and a hot-dip galvanizing method.

Background technique

Steel exposed to the natural environment is easily corroded by corrosive media, which damages its performance. Hot-dip galvanizing technology can provide barrier protection and sacrificial anode protection for steel, greatly improving the corrosion resistance of steel. It has become the most widely used steel corrosion protection technology and is widely used in power, transportation, communications, home appliances and other fields (for example: highway guardrails, UHV transmission towers, communication towers, light poles, etc.).

Plating aid is an important pre-treatment process in hot-dip galvanizing technology. It can not only remove the oxide on the surface of the workpiece and protect the surface of the workpiece from oxidation before immersion plating, but also activate the surface of the workpiece and improve the wetting ability of the zinc liquid on the workpiece, thereby improving the quality of the coating. The aqueous solution of zinc chloride and ammonium chloride is currently a commonly used plating aid, but the workpiece treated with the plating aid will produce a large amount of smoke during hot-dip galvanizing (the source of the smoke is mainly two aspects: on the one hand, the ammonium chloride in the plating aid will decompose to produce hydrogen chloride and ammonia during the immersion plating process, and the two gases will meet in the air to generate white smoke of ammonium chloride; on the other hand, the chloride ions in the plating aid will react with the aluminum in the zinc bath to generate cyan aluminum chloride), which will not only cause serious pollution to the environment, but also cause harm to human health, which is not in line with the concept of green development. Therefore, smokeless plating aid has become one of the research hotspots in the current hot-dip galvanizing industry.

CN 103173706 A discloses a smokeless plating aid for batch hot-dip galvanizing, CN 108179368 A discloses a smokeless plating aid for hot-dip galvanizing without zinc ammonium, and CN 103834888 A discloses an ammonia-free plating aid for hot-dip galvanizing. These plating aids generate less smoke during the galvanizing process, but because these plating aids use chloride salt as the main salt of the plating aid, aluminum chloride smoke cannot be removed from the root, and smokeless hot-dip galvanizing cannot be truly achieved.

Therefore, it is of great significance to develop a plating aid that has no smoke generation during hot-dip galvanizing, has good galvanizing effect, and can effectively solve the smoke pollution problem during the galvanizing process.

Summary of the invention

The purpose of the present invention is to provide a hot-dip galvanizing smokeless plating aid and a hot-dip galvanizing method.

The technical solution adopted by the present invention is:

A hot-dip galvanizing smokeless plating aid comprises the following components in percentage by mass:

Sulfate: 5% to 15%;

Stabilizer: 0.1%~1%;

Corrosion inhibitor: 0.1%~0.5%;

Surfactant: 0.05% to 3%;

Water: Balance.

Preferably, the sulfate is at least two of zinc sulfate, ammonium sulfate, sodium sulfate, potassium sulfate, aluminum sulfate, magnesium sulfate, manganese sulfate, and copper sulfate, and must contain zinc sulfate and ammonium sulfate.

Preferably, the total mass percentage of zinc sulfate and ammonium sulfate in the sulfate is ≥50%.

Preferably, the mass ratio of zinc sulfate to ammonium sulfate is 1:1-5.

Preferably, the stabilizer is at least one of sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride, and nickel fluoride.

Preferably, the corrosion inhibitor is at least one of disodium hydroxyethylidene diphosphonate, hexamethylenetetramine, benzotriazole, and imidazoline.

Preferably, the surfactant is at least one of N-dodecyl dimethyl betaine, fatty alcohol polyoxyethylene ether, dioctadecyl dimethyl ammonium chloride, sodium lauryl sulfate, phosphate, and alkyl glycoside.

A hot-dip galvanizing method, wherein the plating aid used in the plating aid process is the above-mentioned hot-dip galvanizing smokeless plating aid.

Preferably, a hot-dip galvanizing method comprises the following steps: adjusting the pH value of the plating agent to 3.5-5.5, immersing the degreased and rust-removed steel plated parts in the plating agent for plating, taking out the steel plated parts and drying them, then immersing them in zinc liquid for dip plating, and then taking out the steel plated parts.

Preferably, the assist plating is carried out at 20°C to 80°C, and the assist plating time is 10s to 180s.

The invention has the beneficial effects that the hot-dip galvanizing smokeless plating aid of the invention uses sulfate as the main salt, has a simple formula, is low in cost, generates no smoke at all during the hot-dip galvanizing process, has a good galvanizing effect, and is suitable for large-scale industrial applications.

Specifically:

1) The hot-dip galvanizing smokeless plating agent of the present invention uses sulfate to replace zinc chloride and ammonium chloride in traditional plating agents, and also has the functions of cleaning, protecting and activating the surface of the plated parts, and no smoke is generated during the immersion plating process, which can solve the smoke pollution problem in the immersion plating process of traditional plating agents;

2) The price and dosage of the sulfate in the hot-dip galvanizing smokeless plating aid of the present invention are much lower than the zinc chloride and ammonium chloride in the traditional plating aid, which can reduce the production cost;

3) The stabilizer in the hot-dip galvanizing smokeless plating aid of the present invention can form a dense protective film on the surface of the plated part, thereby preventing the plated part from being oxidized before immersion plating and preventing the plated part from leaking after immersion plating;

4) A small amount of corrosion inhibitor is added to the hot-dip galvanizing smokeless plating agent of the present invention, which can slow down the corrosion of the plating agent on the steel, and at the same time can also reduce the iron ion content in the plating agent, thereby enhancing the plating effect;

5) The surfactant in the hot-dip galvanizing smokeless plating agent of the present invention can greatly reduce the surface tension of the plating agent, thereby improving the uniformity and coverage of the salt film formed on the surface of the plated piece, and ultimately improving the wetting ability of the plating agent on the surface of the plated piece;

6) Compared with the traditional hot-dip galvanizing agent, the smokeless plating agent of the present invention forms a more uniform and dense plating salt film, which is beneficial to prevent the plated parts from being oxidized before immersion plating, thereby obtaining a flat, smooth, and leak-free galvanized layer;

7) The preparation method of the hot-dip galvanizing smokeless plating aid of the present invention is simple, and the sulfate, stabilizer, corrosion inhibitor and surfactant are uniformly dispersed in water to obtain the smokeless plating aid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an appearance diagram of a coating formed on the surface of a steel sheet after assist plating in an embodiment.

Detailed ways

The present invention will be further explained and illustrated below in conjunction with specific embodiments.

Embodiment 1:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 1 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 3 Potassium sulfate 3 Sodium fluoride 1 Imidazolin 0.1 Fatty alcohol polyoxyethylene ether 0.1 water 90.8

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 5.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 25°C for 180s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (the appearance of the coating formed on the surface of the steel plate is shown in Figure 1, and the surface of the steel plate obtains a bright and flat zinc coating without missing plating).

Embodiment 2:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 2 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 8 Sodium sulfate 1 Potassium fluoride 0.5 Benzotriazole 0.2 Dioctadecyl dimethyl ammonium chloride 2 water 86.3

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 3.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 40°C for 90s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 3:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 3 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 3 Ammonium sulfate 5 Potassium sulfate 2 Aluminum sulfate 1 Sodium fluoride 0.2 Potassium fluoride 0.3 Disodium Hydroxyethyl Phosphonate 0.1 Benzotriazole 0.2 N-Dodecyl dimethyl betaine 3 water 85.2

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 60°C for 60 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 4:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 4 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 5 Ammonium sulfate 5 Sodium sulfate 2 Magnesium sulfate 1 Ammonium bifluoride 0.3 Hexamethylenetetramine 0.5 Sodium dodecyl sulfate 2.5 water 83.7

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 30°C for 180s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 5:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 5 Composition of a hot dip galvanizing smokeless plating agent

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled, pickled and rust-removed is immersed in the plating agent at 70°C for 150s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 6:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 6 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 4 Ammonium sulfate 5 Aluminum sulfate 1 Manganese sulfate 3 Sodium fluoride 0.1 Nickel fluoride 0.5 Hexamethylenetetramine 0.2 Benzotriazole 0.1 Alkyl glycoside 1 water 85.1

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 5.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 80°C for 80 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 7:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 7 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 5 Ammonium sulfate 8 Sodium sulfate 1 Copper sulfate 1 Ammonium fluoride 0.2 Ammonium bifluoride 0.5 Disodium Hydroxyethyl Phosphonate 0.3 Sodium dodecyl sulfate 0.5 Phosphate 0.5 water 83

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled, pickled and rust-removed is immersed in the plating agent at 75°C for 90s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 8:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 8 Composition of a hot dip galvanizing smokeless plating agent

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 3.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 65°C for 120s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 9:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 9 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 4 Potassium sulfate 1 Magnesium sulfate 3 Nickel fluoride 0.1 Disodium Hydroxyethyl Phosphonate 0.3 N-Dodecyl dimethyl betaine 0.05 water 89.55

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 60°C for 70s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 10:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 10 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 3 Ammonium sulfate 3 Sodium sulfate 3 Potassium sulfate 3 Sodium fluoride 0.1 Disodium Hydroxyethyl Phosphonate 0.1 Hexamethylenetetramine 0.1 Benzotriazole 0.1 Fatty alcohol polyoxyethylene ether 0.03 Dioctadecyl dimethyl ammonium chloride 0.02 Sodium dodecyl sulfate 0.04 water 87.51

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled, pickled and rust-removed is immersed in the plating agent at 50°C for 60 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 11:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 11 Composition of a hot dip galvanizing smokeless plating agent

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 70°C for 10 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Embodiment 12:

A hot-dip galvanizing smokeless plating aid, the composition of which is shown in the following table:

Table 12 Composition of a hot dip galvanizing smokeless plating agent

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 10 Magnesium sulfate 1 Manganese sulfate 2 Sodium fluoride 0.1 Potassium fluoride 0.1 Ammonium fluoride 0.1 Disodium Hydroxyethyl Phosphonate 0.3 N-Dodecyl dimethyl betaine 1.5 Fatty alcohol polyoxyethylene ether 1.5 water 81.4

A hot-dip galvanizing method comprises the following steps:

The pH value of the above-mentioned hot-dip galvanizing smokeless plating agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled and derusted is immersed in the plating agent at 60°C for 20s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (a bright and flat zinc plating layer is obtained on the surface of the steel plate, and there is no leakage plating phenomenon).

Comparative Example 1:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 13 Composition of a hot dip galvanizing flux

Components Mass percentage (%) Zinc chloride 12 Ammonium chloride 14 water 74

A hot-dip galvanizing method comprises the following steps:

The degreased, deoiled and pickled steel plates were immersed in the above hot-dip galvanizing agent at 60°C for 60 seconds, then the steel plates were taken out and dried at 80°C, then immersed in zinc liquid at 450°C for 60 seconds (a large amount of smoke and slag were generated during the immersion process), then the steel plates were taken out and cooled to room temperature (a bright and smooth zinc coating was obtained on the surface of the steel plates without missing coating).

Comparative Example 2:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 14 Composition of a hot dip galvanizing flux

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 12 Sodium sulfate 1 Potassium fluoride 0.5 Benzotriazole 0.2 Dioctadecyl dimethyl ammonium chloride 2 water 82.3

A hot-dip galvanizing method comprises the following steps:

The pH value of the hot-dip galvanizing agent is adjusted to 3.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled, pickled and derusted is immersed in the plating agent at 40°C for 90 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (the zinc layer on the surface of the steel plate is incomplete and rough, and about 70% of the area is not plated).

Comparative Example 3:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 15 Composition of a hot dip galvanizing additive

Components Mass percentage (%) Zinc sulfate 2 Ammonium sulfate 3 Potassium sulfate 5 Aluminum sulfate 5 Sodium fluoride 1 Imidazolin 0.1 Fatty alcohol polyoxyethylene ether 1 water 82.9

A hot-dip galvanizing method comprises the following steps:

The pH value of the hot-dip galvanizing agent is adjusted to 5.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 25°C for 180s, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (the zinc layer on the surface of the steel plate is incomplete and rough, and about 60% of the area is not plated).

Comparative Example 4:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 16 Composition of a hot dip galvanizing flux

Components Mass percentage (%) Zinc sulfate 10 Ammonium sulfate 8 Sodium sulfate 5 Sodium fluoride 1 Imidazolin 0.1 Sodium dodecyl sulfate 0.05 Alkyl glycoside 0.05 water 75.8

A hot-dip galvanizing method comprises the following steps:

The pH value of the hot-dip galvanizing agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 60°C for 60 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and more scum is generated), and then the steel plate is taken out and cooled to room temperature (the zinc layer on the surface of the steel plate is incomplete and rough, and about 50% of the area is not plated).

Comparative Example 5:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 17 Composition of a hot dip galvanizing additive

Components Mass percentage (%) Zinc sulfate 3 Ammonium sulfate 9 Manganese sulfate 1 Copper sulfate 1 Potassium fluoride 0.4 Benzotriazole 0.2 water 85.4

A hot-dip galvanizing method comprises the following steps:

The pH value of the hot-dip galvanizing agent is adjusted to 3.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled is immersed in the plating agent at 65°C for 120s. The steel plate is then taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60s (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (the zinc layer on the surface of the steel plate is incomplete and rough, and about 60% of the area is not plated).

Comparative Example 6:

A hot dip galvanizing auxiliary agent, the composition of which is shown in the following table:

Table 18 Composition of a hot dip galvanizing flux

Components Mass percentage (%) Zinc sulfate 3 Ammonium sulfate 3 Sodium sulfate 3 Potassium sulfate 3 Disodium 2-HEPDP 0.1 Hexamethylenetetramine 0.1

Benzotriazole 0.1 Fatty alcohol polyoxyethylene ether 0.03 Dioctadecyl dimethyl ammonium chloride 0.02 Sodium dodecyl sulfate 0.04 water 87.61

A hot-dip galvanizing method comprises the following steps:

The pH value of the hot-dip galvanizing agent is adjusted to 4.5 with 98% by mass industrial sulfuric acid, and then the steel plate that has been degreased, deoiled and pickled for rust removal is immersed in the plating agent at 50°C for 60 seconds, and then the steel plate is taken out and dried at 80°C, and then immersed in zinc liquid at 450°C for 60 seconds (no smoke is generated during the immersion plating process, and a small amount of scum is generated), and then the steel plate is taken out and cooled to room temperature (the zinc layer on the surface of the steel plate is incomplete and rough, and about 40% of the area is not plated).

Note:

The summary table of the hot-dip galvanizing auxiliary plating and immersion plating effects of Examples 1 to 12 and Comparative Examples 1 to 6 is as follows:

Table 19 Summary of the effects of hot-dip galvanizing agents and immersion plating of Examples 1 to 12 and Comparative Examples 1 to 6

It can be seen from Table 19 that the hot-dip galvanizing aids of Examples 1 to 12 generate no smoke at all during the hot-dip galvanizing process, have good galvanizing effects, and are suitable for large-scale industrial applications.

The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims (6)

1. A smokeless plating aid for hot-dip galvanizing, characterized in that it is composed of the following components in percentage by mass: Sulfate: 5% to 15%; Stabilizer: 0.1%~1%; Corrosion inhibitor: 0.1%~0.5%; Surfactant: 0.05% to 3%; Water: balance; The sulfate is at least two of zinc sulfate, ammonium sulfate, sodium sulfate, potassium sulfate, aluminum sulfate, magnesium sulfate, manganese sulfate, and copper sulfate, and must contain zinc sulfate and ammonium sulfate; The total mass percentage of zinc sulfate and ammonium sulfate in the sulfate is ≥50%; The mass ratio of zinc sulfate to ammonium sulfate is 1:1-5; The stabilizer is at least one of sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and nickel fluoride. 2. The hot-dip galvanizing smokeless plating aid according to claim 1, characterized in that the corrosion inhibitor is at least one of disodium hydroxyethylidene diphosphonate, hexamethylenetetramine, benzotriazole, and imidazoline. 3. The hot-dip galvanizing smokeless plating aid according to claim 1, characterized in that the surfactant is at least one of N-dodecyl dimethyl betaine, fatty alcohol polyoxyethylene ether, dioctadecyl dimethyl ammonium chloride, sodium lauryl sulfate, phosphate, and alkyl glycoside. 4. A hot-dip galvanizing method, characterized in that the plating aid used in the plating aid process is the hot-dip galvanizing smokeless plating aid as claimed in any one of claims 1 to 3. 5. The hot-dip galvanizing method according to claim 4 is characterized in that it comprises the following steps: adjusting the pH value of the plating agent to 3.5-5.5, immersing the degreased and rust-removed steel plated parts in the plating agent for plating, taking out the steel plated parts and drying them, then immersing them in zinc liquid for dip plating, and then taking out the steel plated parts. 6. The hot-dip galvanizing method according to claim 5, characterized in that the assist plating is carried out at 20°C to 80°C and the assist plating time is 10s to 180s.