A hot-dip galvanizing anti-leakage additive, a preparation method and application thereof

Abstract

The present application relates to the technical field of steel surface hot galvanizing, and proposes a hot galvanizing anti-leakage additive, a preparation method and application thereof, which comprises the following components in parts by weight: chloride 22-40 parts, surfactant 0.8-2.4 parts, complexing agent 0.5-1.5 parts, and deionized water 98-102 parts; the preparation method comprises the following steps: S1, heating the deionized water to a constant temperature, adding the chloride, and stirring and dissolving; S2, continuously adding the surfactant, stirring and dissolving at the constant temperature; S3, continuously adding the complexing agent, stirring and dissolving at the constant temperature, stopping heating, and cooling to room temperature to obtain the hot galvanizing anti-leakage additive; the constant temperature is 50-60 DEG C; and the hot galvanizing anti-leakage additive is applied in steel surface hot galvanizing. Through the above technical solution, the problems of leakage, zinc explosion and smoke during hot galvanizing in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of hot-dip galvanizing technology for steel surfaces, specifically to a hot-dip galvanizing anti-leakage additive, its preparation method, and its application. Background Technology

[0002] Steel is widely used in human production and construction activities due to its excellent comprehensive mechanical properties, but it is easily corroded and fails due to complex service environments. Hot-dip galvanizing, which involves immersing steel in molten zinc to obtain a zinc coating on the steel surface with strong corrosion resistance, controllable thickness and surface morphology, and relatively low process cost, has become an effective method for steel corrosion protection.

[0003] Incomplete galvanizing is a common problem. Incomplete galvanizing refers to the intermittent, localized, spot-like or irregular black areas appearing in the zinc coating. It is generally related to the physicochemical state of the steel workpiece surface. When the workpiece surface hinders the wetting of the molten zinc, it affects the galvanizing reaction, leading to incomplete galvanizing. Currently, fluxing is required before immersing the workpiece in the zinc bath to prevent incomplete galvanizing. The quality of the anti-incomplete galvanizing additive directly determines the quality of the galvanizing process.

[0004] Traditional hot-dip galvanizing involves immersing steel parts in a flux solution containing zinc chloride and ammonium chloride to form a thin zinc chloride-ammonium salt film. However, during hot-dip galvanizing, when the surface temperature exceeds 200°C, the ammonium chloride in the flux film decomposes, forming HCl and NH3. Upon contact with room temperature air, these HCl and NH3 recombine to form NH4Cl particles, generating a large amount of fumes and causing issues such as incomplete galvanizing and zinc bursting, severely impacting workpiece quality. Therefore, there is an urgent need to explore a novel hot-dip galvanizing anti-incomplete galvanizing additive to solve these problems. Summary of the Invention

[0005] This invention proposes a hot-dip galvanizing anti-leakage additive, its preparation method and application, which solves the problems of leakage, zinc explosion and smoke in related technologies during hot-dip galvanizing.

[0006] The technical solution of the present invention is as follows:

[0007] This invention proposes a hot-dip galvanizing anti-leakage additive comprising the following components in parts by weight: 22-40 parts of chloride, 0.8-2.4 parts of surfactant, 0.5-1.5 parts of complexing agent, and 98-102 parts of deionized water. The chloride comprises zinc chloride, sodium chloride, scandium chloride, and yttrium chloride in a mass ratio of 13-17:2-5:4-6:3-12.

[0008] As a further technical solution, the mass ratio of scandium chloride to yttrium chloride in the chloride is 1:1-1.5.

[0009] As a further technical solution, the surfactant includes sodium lauroyl glutamate and dodecyl glucoside.

[0010] As a further technical solution, the mass ratio of sodium lauroyl glutamate to dodecyl glucoside is 1:1-2.

[0011] As a further technical solution, the complexing agent is malonic acid.

[0012] This invention also proposes a method for preparing a hot-dip galvanizing anti-leakage additive, comprising the following steps:

[0013] S1. Heat deionized water to a constant temperature, add the chloride, and stir until completely dissolved;

[0014] S2. Continue adding the surfactant and stir at the constant temperature until completely dissolved;

[0015] S3. Continue to add the complexing agent, stir at the constant temperature until completely dissolved, stop heating, and cool to room temperature to obtain the hot-dip galvanizing anti-leakage additive.

[0016] The constant temperature is 50-60℃.

[0017] The present invention also proposes the application of the hot-dip galvanizing anti-leakage additive in hot-dip galvanizing of steel surfaces.

[0018] As a further technical solution, the following steps are included: degreasing, derusting, and washing the workpiece to obtain the part to be galvanized; immersing the part to be galvanized in the hot-dip galvanizing anti-leakage additive; controlling the pH value of the hot-dip galvanizing anti-leakage additive; soaking for 5-10 minutes; removing the part; allowing it to air dry for 3-10 minutes; and then galvanizing.

[0019] As a further technical solution, the pH value of the hot-dip galvanizing anti-leakage additive is 3-5.

[0020] As a further technical solution, the soaking temperature is 40-80℃.

[0021] The working principle and beneficial effects of this invention are as follows:

[0022] 1. The chlorides in the hot-dip galvanizing anti-leakage additive of this invention include zinc chloride, sodium chloride, scandium chloride, and yttrium chloride, but do not contain ammonium chloride. This effectively inhibits problems such as missed plating, zinc bursting, and fumes that occur during hot-dip galvanizing of steel workpieces, significantly improving the surface quality of hot-dip galvanized workpieces and meeting the needs of actual industrial production. Furthermore, the combined use of scandium chloride and yttrium chloride in the chlorides improves the fluxing effect, effectively preventing missed plating. In addition, it improves the uniformity of the coating, thereby enhancing the quality of the galvanized layer.

[0023] 2. The surfactant in this invention improves the wettability and flowability of the hot-dip galvanizing anti-leakage additive, increases the drying rate and uniformity of the flux film, and inhibits the occurrence of zinc explosion.

[0024] 3. The complexing agent in this invention can both activate the surface of steel workpieces and coordinate with ferrous ions to form complexes, preventing excessive ferrous ions from entering the zinc bath during hot-dip galvanizing and forming zinc dross that reduces the fluidity of the zinc bath, thereby improving the overall quality of the hot-dip galvanized workpiece surface. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] In the following examples and comparative examples, the specific operation during galvanizing is as follows: at 450°C, the workpiece is immersed in the zinc pot at a speed of 2 m / min and removed from the zinc pot at a speed of 10 m / min.

[0027] Example 1

[0028] A hot-dip galvanizing anti-leakage additive and its preparation method, comprising the following steps:

[0029] S1. Add 98 parts of deionized water to the reactor, heat to 50°C, add 13 parts of zinc chloride, 2 parts of sodium chloride, 4 parts of scandium chloride, and 4 parts of yttrium chloride, and stir until completely dissolved;

[0030] S2. Continue to add 0.4 parts of sodium lauroyl glutamate and 0.4 parts of dodecyl glucoside, and stir at 50°C until completely dissolved;

[0031] S3. Continue to add 0.5 parts of malonic acid, stir at 50°C until completely dissolved, stop heating, and cool to room temperature to obtain the hot-dip galvanizing anti-leakage additive.

[0032] The application of hot-dip galvanizing anti-leakage additive includes the following steps: degreasing, derusting, and washing the workpiece to obtain the workpiece to be galvanized; immersing the workpiece to be galvanized in the hot-dip galvanizing anti-leakage additive; controlling the pH value of the hot-dip galvanizing anti-leakage additive to 3; soaking at 40°C for 10 minutes; removing the workpiece; allowing it to air dry for 10 minutes; and then galvanizing.

[0033] Example 2

[0034] A hot-dip galvanizing anti-leakage additive and its preparation method, comprising the following steps:

[0035] S1. Add 100 parts of deionized water to the reactor, heat to 55°C, add 15 parts of zinc chloride, 3.5 parts of sodium chloride, 5 parts of scandium chloride, and 8 parts of yttrium chloride, and stir until completely dissolved;

[0036] S2. Continue to add 0.6 parts of sodium lauroyl glutamate and 0.9 parts of dodecyl glucoside, and stir at 55°C until completely dissolved;

[0037] S3. Continue to add 1.0 part of malonic acid, stir at 55°C until completely dissolved, stop heating, and cool to room temperature to obtain the hot-dip galvanizing anti-leakage additive.

[0038] The application of hot-dip galvanizing anti-leakage additive includes the following steps: degreasing, derusting, and washing the workpiece to obtain the workpiece to be galvanized; immersing the workpiece to be galvanized in the hot-dip galvanizing anti-leakage additive; controlling the pH value of the hot-dip galvanizing anti-leakage additive to 4; soaking at 60°C for 8 minutes; removing the workpiece; allowing it to air dry for 7 minutes; and then galvanizing.

[0039] Example 3

[0040] A hot-dip galvanizing anti-leakage additive and its preparation method, comprising the following steps:

[0041] S1. Add 102 parts of deionized water to the reactor, heat to 60°C, add 17 parts of zinc chloride, 5 parts of sodium chloride, 6 parts of scandium chloride, and 9 parts of yttrium chloride, and stir until completely dissolved;

[0042] S2. Continue to add 0.8 parts of sodium lauroyl glutamate and 1.6 parts of dodecyl glucoside, and stir at 60°C until completely dissolved;

[0043] S3. Continue to add 1.0 part of malonic acid, stir at 60°C until completely dissolved, stop heating, and cool to room temperature to obtain the hot-dip galvanizing anti-leakage additive.

[0044] The application of hot-dip galvanizing anti-leakage additive includes the following steps: degreasing, derusting, and washing the workpiece to obtain the workpiece to be galvanized; immersing the workpiece to be galvanized in the hot-dip galvanizing anti-leakage additive; controlling the pH value of the hot-dip galvanizing anti-leakage additive to be 5; soaking at 80°C for 5 minutes; removing the workpiece; allowing it to air dry for 3 minutes; and then galvanizing.

[0045] Example 4

[0046] The only difference between this embodiment and Embodiment 2 is that, in the hot-dip galvanizing anti-leakage additive and its preparation method, the weight parts of scandium chloride and yttrium chloride in step S1 are different. In this embodiment, there are 4 parts of scandium chloride and 3 parts of yttrium chloride.

[0047] Example 5

[0048] The only difference between this embodiment and Embodiment 2 is that, in the hot-dip galvanizing anti-leakage additive and its preparation method, the weight parts of scandium chloride and yttrium chloride in step S1 are different. In this embodiment, there are 6 parts of scandium chloride and 12 parts of yttrium chloride.

[0049] Example 6

[0050] The only difference between this embodiment and Embodiment 2 is that, in the hot-dip galvanizing anti-leakage additive and its preparation method, the weight parts of sodium lauroyl glutamate and dodecyl glucoside in step S2 are different. In this embodiment, sodium lauroyl glutamate is 0.4 parts and dodecyl glucoside is 1.6 parts.

[0051] Example 7

[0052] The only difference between this embodiment and Embodiment 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, sodium lauroyl glutamate in step S2 is replaced with an equal amount of dodecyl glucoside.

[0053] Example 8

[0054] The only difference between this embodiment and Embodiment 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, the dodecyl glucoside in step S2 is replaced with an equal amount of sodium lauroyl glutamate.

[0055] Example 9

[0056] The only difference between this embodiment and Embodiment 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, sodium lauroyl glutamate in step S2 is replaced with an equal amount of sodium dodecylbenzenesulfonate.

[0057] Example 10

[0058] The only difference between this embodiment and Embodiment 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, the dodecyl glucoside in step S2 is replaced with an equal amount of fatty alcohol polyoxyethylene ether.

[0059] Example 11

[0060] The only difference between this embodiment and Embodiment 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, sodium lauroyl glutamate in step S2 is replaced with an equal amount of sodium dodecylbenzenesulfonate, and dodecyl glucoside is replaced with an equal amount of fatty alcohol polyoxyethylene ether.

[0061] Comparative Example 1

[0062] The only difference between this comparative example and Example 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, scandium chloride in step S1 is replaced with an equal amount of yttrium chloride.

[0063] Comparative Example 2

[0064] The only difference between this comparative example and Example 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, yttrium chloride in step S1 is replaced with an equal amount of scandium chloride.

[0065] Comparative Example 3

[0066] The only difference between this comparative example and Example 2 is that in the hot-dip galvanizing anti-leakage additive and its preparation method, yttrium chloride and scandium chloride in step S1 are replaced with an equal amount of ammonium chloride.

[0067] The galvanized parts in Examples 1-11 and Comparative Examples 1-3 were evaluated as follows:

[0068] ① Incomplete plating: Use fine sandpaper to polish the small black spots on the surface of the zinc plating layer and observe whether the black spots can be easily removed. Check whether there is an obvious depression between the black spots and the surrounding zinc plating layer to determine whether there is incomplete plating.

[0069] ② Zinc splattering: Visually inspect whether zinc splattering occurs on the galvanized parts during hot-dip galvanizing;

[0070] ③ Smoke situation: Visually inspect whether smoke appears on the galvanized parts during hot-dip galvanizing.

[0071] The evaluation results are shown in Table 1 below.

[0072] Table 1. Incomplete galvanizing, zinc bursting, and smoke conditions of galvanized parts in Examples 1-11 and Comparative Examples 1-3.

[0073]

[0074] As can be seen from the evaluation results of Examples 1-3 and Comparative Example 3 in the table, the hot-dip galvanizing anti-leakage additive prepared by the present invention effectively suppresses the problems of incomplete galvanizing, zinc bursting, and fumes that occur during hot-dip galvanizing of steel workpieces, significantly improving the surface quality of hot-dip galvanized workpieces and meeting the needs of actual industrial production. Compared with Examples 1-3, the evaluation results of Examples 4-6 show that, within the weight range of the components described in the present invention, when the mass ratio of scandium chloride to yttrium chloride in the chloride is 1:1-1.5 and the mass ratio of sodium lauroyl glutamate to dodecyl glucoside is 1:1-2, the prepared hot-dip galvanizing anti-leakage additive is more effective in solving the problems of incomplete galvanizing, zinc bursting, and fumes.

[0075] The evaluation results of Examples 7-11 show that the specific combination of sodium lauroyl glutamate and dodecyl glucoside in the surfactant of the present invention can significantly inhibit the occurrence of zinc explosion. Furthermore, the evaluation results of Comparative Examples 1-3 show that the combined use of scandium chloride and yttrium chloride in the present invention improves the fluxing effect and effectively avoids the occurrence of incomplete plating.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hot dip galvanizing leak-proofing additive, characterized by, The hot-dip galvanizing anti-leakage plating additive is prepared from the following components by weight: chlorides 22-40 parts, surfactants 0.8-2.4 parts, complexing agents 0.5-1.5 parts, and deionized water 98-102 parts, wherein the chlorides are zinc chloride, sodium chloride, scandium chloride and yttrium chloride with a mass ratio of (13-17):(2-5):(4-6):(3-12); the mass ratio of the scandium chloride to the yttrium chloride in the chlorides is 1:1-1.5; the surfactants include sodium lauroyl glutamate and dodecyl glucoside; the mass ratio of the sodium lauroyl glutamate to the dodecyl glucoside is 1:1-2.

2. A leak-proofing additive for hot-dip galvanizing according to claim 1, characterized by, the complexing agent is malonic acid.

3. A process for the preparation of a hot dip galvanizing anti-leakage additive according to any one of claims 1-2, characterized in that, The method comprises the following steps: S1, heating deionized water to a constant temperature, adding the chlorides, and stirring until completely dissolved; S2, continuously adding the surfactants, and stirring at the constant temperature until completely dissolved; S3, continuously adding the complexing agents, and stirring at the constant temperature until completely dissolved, stopping heating, and cooling to room temperature to obtain the hot-dip galvanizing anti-leakage plating additive; the constant temperature is 50-60℃.

4. The hot-dip galvanizing anti-leakage plating additive according to any one of claims 1-2 or prepared by the method of claim 3 is applied in hot-dip galvanizing of a steel surface.

5. Use according to claim 4, characterized in that, The method comprises the following steps: oil and rust removal, water washing to obtain a workpiece to be plated, immersing the workpiece to be plated in the hot-dip galvanizing anti-leakage plating additive, controlling the pH value of the hot-dip galvanizing anti-leakage plating additive, taking out after soaking for 5-10 min, and naturally drying for 3-10 min before galvanizing.

6. Use according to claim 5, characterized in that, the pH value of the hot-dip galvanizing anti-leakage plating additive is 3-5.

7. Use according to claim 5, characterized in that, the temperature during soaking is 40-80℃.

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