Multi-effect explosion-proof additive solution for hot-dip galvanizing as well as preparation method and use method of multi-effect explosion-proof additive solution

Abstract

The invention provides a multi-effect explosion-proof additive solution for hot-dip galvanizing as well as a preparation method and a use method of the multi-effect explosion-proof additive solution, and belongs to the technical field of hot-dip galvanizing. Wherein the multi-effect explosion-proof additive solution comprises the following components in percentage by mass: 25-35% of a double-chain quaternary ammonium salt type cationic surface active agent, 1-5% of a surfactant, 1-5% of a solvent and the balance of water. 2%-8% of a nonionic surfactant; and the balance of deionized water. The multi-effect explosion-proof additive solution provided by the invention has simple components and multiple effects on the basis of meeting the basic explosion-proof effect, does not contain any organic solvent, and is healthy to human bodies and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of hot-dip galvanizing, and in particular to a multi-effect explosion-proof additive solution for hot-dip galvanizing, and a preparation method and a use method thereof. Background Art

[0002] Hot-dip galvanizing is one of the most commonly used and economical anti-corrosion methods for steel surfaces. It is done by immersing steel workpieces in molten zinc liquid. Through the iron-zinc reaction, a zinc coating with excellent adhesion is formed on the surface of the workpiece, thereby playing the role of electrochemical protection and physical protection. Workpieces galvanized in this way need to be pre-treated with plating aids. This pre-treatment process is extremely important for hot-dip galvanizing, which is directly related to the appearance quality of the finished workpiece, the consumption of plating aids, as well as safety issues during the galvanizing process and production costs caused by zinc ash output. In order to solve the above problems, industry insiders have conducted a lot of research on hot-dip galvanizing aids.

[0003] For example, Chinese patent: CN 101126142A (Additives for hot-dip galvanizing flux) invented an explosion-proof agent comprising an organic solvent and a long-chain alkyl cationic surfactant. Through the synergistic effect of the cationic surfactant and the non-ionic surfactant, the interfacial compatibility and wettability between the steel and the flux are improved, the occurrence of zinc explosion is reduced, the flux effect is improved, and the amount of flux used is reduced.

[0004] Chinese patent: CN 101597732A (Plating aid additive for preventing hot-dip galvanizing of steel wire from leaking out), using fatty alcohol polyoxyethylene ether (RO(CH2 CH2O)nH), dodecylphenol polyoxyethylene ether (C42H78O13) and octylphenol polyoxyethylene ether (C16 H26 O2), which helps the rapid drying of the plating aid, effectively reduces the surface tension of the plating solution, and improves the coverage of the surfactant component, effectively preventing zinc liquid from splashing.

[0005] However, the auxiliary agents and additives mentioned in the above patents have relatively simple functions, are basically limited to explosion-proof effects, and contain organic solvents.

[0006] Therefore, it is necessary to study an environmentally friendly auxiliary additive, which has multiple properties in addition to reducing the surface tension of the plating agent and improving the wetting effect of the workpiece surface. Summary of the invention

[0007] In order to solve the problems mentioned in the background technology, the present invention provides a multi-effect explosion-proof additive solution for hot-dip galvanizing, which, on the basis of meeting the basic explosion-proof effect, has simple ingredients, multiple functions, does not contain any organic solvents, and is friendly to human health and the environment.

[0008] Specifically:

[0009] A multi-effect explosion-proof additive solution for hot-dip galvanizing comprises, by mass percentage, 25%-35% of a double-chain quaternary ammonium salt type cationic surfactant, 2%-8% of a nonionic surfactant, and the balance being deionized water.

[0010] Furthermore, the double-chain quaternary ammonium salt type cationic surfactant is selected from one or a mixture of didecyl dimethyl ammonium bromide and dodecyl bis (hydroxyethyl) methyl ammonium chloride.

[0011] Furthermore, the nonionic surfactant is selected from one or a mixture of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

[0012] Furthermore, the solution has a pH value of 5 to 7 and a solid content of 25% to 35%.

[0013] The multi-effect explosion-proof additive solution prepared by the present invention has simple ingredients but multiple and excellent effects. The solvent in the multi-effect explosion-proof agent stock solution is only deionized water, does not contain any organic solvent, and is friendly to the human body and the environment.

[0014] Specifically, (1) a double-chain quaternary ammonium salt type cationic surfactant is used. Because it has two carbon chains, this special structure makes it have extremely strong surface activity at low concentrations, which can greatly reduce the surface tension of the additive and improve the wettability of the workpiece surface. At the same time, the double carbon chain can give the multi-effect explosion-proof additive solution prepared by the present invention a good effect in various complex environments, reflecting extremely high stability and decontamination ability. Specifically, it is not affected by factors such as organic matter that slowly grows in the additive tank, pH value, water quality and temperature. Even in the face of fluctuations in the temperature and pH of the additive tank liquid, as well as impurity ions brought in, the agent can be kept intact and the use effect is not reduced.

[0015] (2) Introducing a small amount of non-ionic surfactant can further improve the penetration, wetting and partial hydrophobicity of the agent. The multiple effects make the additive salt film generated on the surface of the workpiece more uniform and dense, while the excess water flows quickly to keep the surface of the workpiece dry, ultimately bringing excellent explosion-proof effect in the subsequent galvanizing process.

[0016] (3) By compounding the double-chain quaternary ammonium salt cationic surfactant with the non-ionic surfactant, the advantages of the two different types of surfactants are retained while compensating for their respective deficiencies, thereby ultimately achieving a synergistic effect. This allows the multi-effect explosion-proof additive solution prepared by the present invention to significantly reduce the surface tension of the additive even at a relatively low addition amount, thereby bringing about multiple effects.

[0017] The technical indicators of the multi-effect explosion-proof additive solution prepared by the present invention are shown in the following table:

[0018]

[0019] In addition, the present invention also provides a method for preparing the above-mentioned multi-effect explosion-proof additive solution for hot-dip galvanizing, the steps of which include:

[0020] Step 1, weighing a double-chain quaternary ammonium salt cationic surfactant, a nonionic surfactant and deionized water;

[0021] Step 2: Add a nonionic surfactant to 2 / 3 of deionized water and stir thoroughly;

[0022] Step 3, continue to add double-chain quaternary ammonium salt cationic surfactant and stir thoroughly;

[0023] Step 4: Add the remaining amount of deionized water and stir evenly to obtain a multi-effect explosion-proof additive solution.

[0024] Furthermore, in step 2, stirring is performed until the liquid becomes transparent and clear.

[0025] Furthermore, in step three, stirring is performed until the liquid becomes transparent and clear.

[0026] In addition, the present invention also provides a method for using the above-mentioned multi-effect explosion-proof additive solution for hot-dip galvanizing, characterized in that the steps include: directly adding the multi-effect explosion-proof additive solution into the workshop auxiliary agent tank, and stirring it evenly through the explosion equipment in the tank.

[0027] Furthermore, the multi-effect explosion-proof additive solution is initially added in an amount of 0.1%-0.5% by volume of the plating aid.

[0028] Furthermore, the daily addition amount of the multi-effect explosion-proof additive solution is 25 kg of the multi-effect explosion-proof additive solution for every 250-350 tons of output.

[0029] Compared with the prior art, the present invention has the following beneficial features:

[0030] (1) Reduce the consumption of ammonium chloride and zinc chloride in the plating solution, that is, greatly reduce the consumption of additives;

[0031] (2) Enhance the leveling uniformity of the additive on the workpiece surface to ensure that the workpiece is drained of water in a very short time; on the one hand, this can save plating time and improve production efficiency, and on the other hand, it can ensure that zinc explosion does not occur during the subsequent galvanizing process;

[0032] (3) Effectively improve the working environment of hot-dip galvanizing; when the workpiece is put into the zinc pot, the chloride in the salt film will decompose to produce ammonia and hydrogen chloride gas. Since the auxiliary salt film on the surface of the workpiece is evenly covered and thin, the amount of gas is reduced, thus improving the production environment;

[0033] (4) Reduce the output of zinc ash; the output of zinc ash is positively correlated with the amount of salt film enrichment on the workpiece surface. Therefore, when the amount of salt film is reduced, the amount of zinc ash is reduced accordingly, achieving the effect of saving zinc;

[0034] (5) The finished workpiece has a bright and smooth appearance without any quality defects. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0036] The invention provides a multi-effect explosion-proof additive solution for hot-dip galvanizing, which comprises, by mass percentage, 25%-35% of a double-chain quaternary ammonium salt type cationic surfactant, 2%-8% of a nonionic surfactant, and the balance being deionized water.

[0037] Furthermore, the double-chain quaternary ammonium salt type cationic surfactant is selected from one or a mixture of didecyl dimethyl ammonium bromide (abbreviated as DDAB) and dodecyl bis(hydroxyethyl) methyl ammonium chloride (abbreviated as 2HEAC-12).

[0038] Furthermore, the nonionic surfactant is selected from one or a mixture of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

[0039] Furthermore, the solution has a pH value of 5 to 7 and a solid content of 25% to 35%.

[0040] In addition, the present invention also provides a method for preparing the above-mentioned multi-effect explosion-proof additive solution for hot-dip galvanizing, the steps of which include:

[0041] Step 1, weighing a double-chain quaternary ammonium salt cationic surfactant, a nonionic surfactant and deionized water;

[0042] Step 2: Add a nonionic surfactant to 2 / 3 of deionized water and stir thoroughly;

[0043] Step 3, continue to add double-chain quaternary ammonium salt cationic surfactant and stir thoroughly;

[0044] Step 4: Add the remaining amount of deionized water and stir evenly to obtain a multi-effect explosion-proof additive solution.

[0045] Furthermore, in step 2, stirring is performed until the liquid becomes transparent and clear.

[0046] Furthermore, in step three, stirring is performed until the liquid becomes transparent and clear.

[0047] In addition, the present invention also provides a method for using the above-mentioned multi-effect explosion-proof additive solution for hot-dip galvanizing, characterized in that the steps include: directly adding the multi-effect explosion-proof additive solution into the workshop auxiliary agent tank, and stirring it evenly through the explosion equipment in the tank.

[0048] Furthermore, the multi-effect explosion-proof additive solution is initially added in an amount of 0.1%-0.5% by volume of the plating aid.

[0049] Furthermore, the daily addition amount of the multi-effect explosion-proof additive solution is 25 kg of the multi-effect explosion-proof additive solution for every 250-350 tons of output.

[0050] In order to verify the beneficial effects of the present invention, the following Examples 1-6 and Comparative Examples 1-3 were designed for comparative experimental verification.

[0051] The plating aid additives of Examples 1-6 and Comparative Examples 1-3 were prepared according to the following steps: 2 / 3 of the calculated amount of deionized water was added to a reaction kettle at room temperature, and then a nonionic surfactant was added thereto, and stirred until the liquid was transparent and clear; a double-chain quaternary ammonium salt cationic surfactant was added, and stirred until the liquid was transparent and clear; finally, the remaining amount of deionized water was added and stirred evenly.

[0052] The composition ratios (mass percentages) of Examples 1-6 and Comparative Examples 1-3 in the above-mentioned preparation method are shown in the following table:

[0053]

[0054]

[0055] The plating aid additives prepared in Examples 1-6 and Comparative Examples 1-3 were added to the plating aid in an amount of 0.5%, stirred evenly, and then the performance was evaluated.

[0056] The evaluation test methods used this time are mainly the following 7 kinds:

[0057] (1) Surface tension of additives: Use a static surface tension meter to test the surface tension of the additive solution and record the value;

[0058] (2) Uniformity of additive salt film: Use a glass slide, immerse it in an additive solution at 70°C, take it out after 1 minute, blow it dry with a hair dryer and record the uniformity of the salt film on the surface of the glass slide;

[0059] (3) The amount of additive salt film on the steel plate surface: A small steel plate of 50mm×80mm×5.7mm was used. After pickling for 1 hour, it was washed with water and then dried with cold air from a hair dryer. The weight of the steel plate before the test was weighed and recorded as w1. Then it was immersed in an additive solution at 70°C, taken out after 1 minute and dried with cold water from a hair dryer. The weight of the steel plate after immersion was weighed and recorded as w2. The salt film increment on the steel plate surface / mg was calculated, i.e. w2-w1. The amount of salt film = (w2-w1) / S, where S is the surface area of ​​the steel plate, fixed at 92cm 2 Each test needs to be conducted in three groups in parallel, and the average of the three tests is taken as the result value.

[0060] (4) Compatibility: Take the common high-aluminum leak-proof agent and explosion-proof agent on the market and the multi-effect explosion-proof agent of this invention, add them to the additives at a dosage of 1%, and observe whether adverse phenomena such as stratification, precipitation, etc. will occur;

[0061] (5) Explosion-proof effect: Slowly immerse the steel plate after the plating into the molten zinc solution, and record the sound and explosion-proof conditions during the process.

[0062] (6) Appearance quality: Observe the appearance quality of the steel plate after galvanizing and record whether there are any quality defects such as missing plating, streaks, zinc layer loss of gloss, roughness, etc.

[0063] (7) Zinc ash amount: Prepare 25 small steel plates of 70 mm × 80 mm × 5.7 mm and simulate the on-site galvanizing process in the laboratory resistance furnace. Follow the procedure of pickling → water washing → auxiliary plating → galvanizing to complete the galvanizing. Collect the amount of zinc ash on the surface of the zinc solution during and after the galvanizing process of the steel plate, weigh it with a 1 / 10,000 balance, and record the value.

[0064] The final test results are shown in the following table:

[0065]

[0066] Note: The basic additive composition used in this test is: 170g / L NH4Cl+100g / L ZnCl2, pH: 3-4, temperature 70℃, auxiliary plating time 1 minute; galvanizing process: 440-450℃, time 1 minute; the test sample is a small steel plate of 70mm×80mm×5.7mm, Q235 material.

[0067] According to the test results of the above-mentioned Examples 1-6 and Comparative Examples 1-3, it can be determined that the multi-effect explosion-proof additive solution provided by the present invention, although having simple ingredients, can achieve the following functions by compounding a double-chain quaternary ammonium salt type cationic surfactant with a nonionic surfactant:

[0068] (1) Greatly reduce the surface tension of the additive, improve the wettability between the workpiece and the additive, and ensure the uniformity of the salt film;

[0069] (2) On the basis of ensuring the uniformity of the salt film on the workpiece surface, the amount of salt film is further reduced, which greatly reduces the consumption of additives and saves production costs;

[0070] (3) By reducing the amount of salt film on the workpiece surface, the amount of zinc ash produced during the galvanizing process is reduced, achieving a zinc-saving effect;

[0071] (4) By improving the leveling property of the workpiece surface additive, the workpiece is ensured to drain water in a very short time, thereby improving production efficiency;

[0072] (5) It has excellent explosion-proof effect, and the finished plated parts have a bright and smooth appearance without any quality defects.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-effect explosion-proof additive solution for hot-dip galvanizing, characterized in that: Calculated by mass percentage, the components include: 25%-35% of double-chain quaternary ammonium salt type cationic surfactant; 2%-8% of non-ionic surfactant; and the balance is deionized water.

2. The multi-effect explosion-proof additive solution according to claim 1, characterized in that: The double-chain quaternary ammonium salt type cationic surfactant is selected from one of didecyl dimethyl ammonium bromide and dodecyl bis(hydroxyethyl)methyl ammonium chloride or a mixture of the two.

3. The multi-effect explosion-proof additive solution according to claim 1, characterized in that: The nonionic surfactant is selected from alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether or a mixture of the two.

4. The multi-effect explosion-proof additive solution according to claim 1, characterized in that: The solution pH is 5-7, and the solid content is 25%-35%.

5. A method for preparing a multi-effect explosion-proof additive solution for hot-dip galvanizing according to any one of claims 1 to 4, characterized in that: The steps include: Step 1, weighing a double-chain quaternary ammonium salt cationic surfactant, a nonionic surfactant and deionized water; Step 2: Add a nonionic surfactant to 2 / 3 of deionized water and stir thoroughly; Step 3, continue to add double-chain quaternary ammonium salt cationic surfactant and stir thoroughly; Step 4: Add the remaining amount of deionized water and stir evenly to obtain a multi-effect explosion-proof additive solution.

6. The multi-effect explosion-proof additive solution according to claim 1, characterized in that: In step 2, stir until the liquid becomes transparent and clear.

7. The multi-effect explosion-proof additive solution according to claim 1, characterized in that: In step 3, stir until the liquid becomes transparent and clear.

8. A method for using the multi-effect explosion-proof additive solution for hot-dip galvanizing according to any one of claims 1 to 4, characterized in that: The steps include: directly adding the multi-effect explosion-proof additive solution into the workshop additive tank, and stirring it evenly through the explosion equipment provided in the tank.

9. The method for using the multi-effect explosion-proof additive solution according to claim 8, characterized in that: The multi-effect explosion-proof additive solution is initially added in an amount of 0.1% to 0.5% by volume of the plating aid.

10. The method for using the multi-effect explosion-proof additive solution according to claim 8, characterized in that: The daily addition amount of the multi-effect explosion-proof additive solution is 25 kg of the multi-effect explosion-proof additive solution for every 250-350 tons of output.

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