Smokeless plating assistant for hot galvanizing and application method of smokeless plating assistant

Abstract

The invention relates to the technical field of hot galvanizing, and particularly discloses a smokeless plating assistant for hot galvanizing and an application method of the smokeless plating assistant. The smokeless plating assistant for hot galvanizing comprises the following components: 100-160g / L of zinc chloride; 30-50 g / L of calcium chloride; 5-8 g / L of potassium chloride; 12-15 g / L of magnesium chloride; 10-16 g / L of sodium fluoride; 5-12 g / L of rare earth chloride; 1-5 g / L of a surfactant; 1-2 g / L of a corrosion inhibitor; the solvent is deionized water; the rare earth chloride is composed of cerium chloride and lanthanum chloride, and the dosage ratio of cerium chloride to lanthanum chloride is 1: (1.8-2.5); the surfactant is composed of hexadecyl trimethyl ammonium bromide and fatty alcohol-polyoxyethylene ether, and the dosage ratio of the hexadecyl trimethyl ammonium bromide to the fatty alcohol-polyoxyethylene ether is (1.6-2.2): 1. The application method of the smokeless plating assistant comprises the following steps: putting a plated part into the smokeless plating assistant, dipping at 40-80 DEG C for 4-8 minutes, then taking out and drying at 80-120 DEG C, thereby completing the process. According to the application, a protective film is formed after the smokeless plating assistant agent assists plating and can uniformly and completely cover a plating piece, so that a plating layer with relatively good binding force is obtained after the plating piece is subjected to hot-dip galvanizing.

Description

Technical Field

[0001] The present application relates to the technical field of hot-dip galvanizing, and more specifically, to a smokeless plating aid for hot-dip galvanizing and an application method thereof. Background Art

[0002] Hot-dip galvanizing, also known as hot-dip galvanizing, is a process in which a cleaned and activated steel product is immersed in molten zinc liquid to form a zinc alloy coating with good adhesion on the steel surface through the reaction and diffusion between iron and zinc. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. It is one of the effective means to delay environmental corrosion of steel materials. The hot-dip galvanizing process generally includes the following steps: pickling, cleaning, plating assistance, hot-dip galvanizing, cooling and passivation.

[0003] Plating aid is an important treatment process in the pretreatment of hot-dip galvanizing. It deposits a layer of salt film on the surface of steel, which can not only remove the surface oxide of the workpiece and protect the surface of the workpiece from oxidation before immersion plating, but also activate the surface of the workpiece, improve the wetting ability of the zinc liquid on the workpiece, and thus improve 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.

[0004] Smokeless plating aid is a chemical reagent used in the hot-dip galvanizing process, which aims to reduce or eliminate the smoke and harmful gases produced by traditional plating aids during the galvanizing process, thereby improving the working environment and reducing environmental pollution. Therefore, smokeless plating aid has become one of the research hotspots in the current hot-dip galvanizing industry. The main principle of smokeless plating aid is to replace ammonium chloride and zinc chloride in traditional plating aids with other chemical components to reduce or eliminate the smoke produced during the hot-dip galvanizing process. These alternative components will not decompose and produce smoke during the hot-dip galvanizing process, thus achieving a smokeless effect.

[0005] With respect to the above-mentioned related technologies, the inventors believe that although smokeless plating aids can solve the smoke pollution problem in the immersion plating process of traditional plating aids, the salt film after plating with smokeless plating aids is often distributed in a strip-shaped diffusion state, which is difficult to distribute evenly, and sometimes there is a situation where the plated parts are not completely covered, and some gaps still leak out, which leads to the coating on the surface of the finished plated parts after hot-dip galvanizing. It is difficult to achieve the expected bonding, which has an adverse effect on the service life of the coating.

[0006] Therefore, it is urgent to propose a solution to solve the above technical problems. Summary of the invention

[0007] In order to enable the protective film formed by the smokeless plating aid after plating to evenly and completely cover the plated parts, and then obtain a coating with better bonding strength after hot-dip galvanizing, the present application provides a smokeless plating aid for hot-dip galvanizing and an application method thereof.

[0008] In the first aspect, the present application provides a smokeless plating aid for hot-dip galvanizing, which adopts the following technical solution: A smokeless plating aid for hot-dip galvanizing, comprising the following components in the following amounts: Zinc chloride 100-160g / L; Calcium chloride 30-50g / L; Potassium chloride 5-8g / L; Magnesium chloride 12-15g / L; Sodium fluoride 10-16g / L; Rare earth chloride 5-12g / L; Surfactant 1-5g / L; Corrosion inhibitor 1-2g / L; The solvent was deionized water; The rare earth chloride is composed of cerium chloride and lanthanum chloride, and the usage ratio of cerium chloride to lanthanum chloride is 1:(1.8-2.5); The surfactant is composed of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether, and the usage ratio of the hexadecyltrimethylammonium bromide and the fatty alcohol polyoxyethylene ether is (1.6-2.2):1.

[0009] By adopting the above technical scheme, zinc chloride, calcium chloride, potassium chloride and magnesium chloride are used as chloride salts, which are the main components of the protective film formed after the smokeless plating agent is used for plating. During the application process, it can play a role in cleaning and activating the surface of the plated substrate, peeling off the residual iron oxide film on the plated part, and improving the surface activity. Furthermore, during the hot-dip galvanizing process, it can reduce the surface tension of the zinc liquid and promote the rapid infiltration and reaction of the plated substrate and the liquid zinc.

[0010] Sodium fluoride can wet the substrate of the plated part and help dissolve the oxides on the surface of the plated part, so that the surface of the plated part produces interface activation, which is conducive to the subsequent acceleration of the growth of the hot-dip alloy layer. Rare earth chloride can undergo a replacement reaction with the iron in the plated part, covering the surface of the plated part with a continuous metal film to ensure that there is no leakage plating on the surface before the iron-aluminum compound is generated; and rare earth chloride is composed of cerium chloride and lanthanum chloride. Cerium chloride can promote the uniform distribution of smokeless plating aids, and lanthanum chloride can further activate the surface of the substrate of the plated part. The mutual combination of the two helps the protective film formed by the smokeless plating aid after plating to evenly and completely cover the plated part, and the cerium and lanthanum in the plating aid layer can refine the organization of the hot-dip galvanized layer, thereby improving the bonding strength between the coating and the substrate of the plated part. The surfactant has an activation wetting effect and a protective reduction effect. It can not only improve the interfacial wettability between the smokeless plating agent and the plated substrate, provide an active and uniform surface for immersion plating, improve the uniformity and integrity of the protective film formed after the smokeless plating agent is assisted, but also prevent the surface oxidation of the plated part, which is conducive to obtaining a protective film that can completely cover the plated part and has good quality. At the same time, when the sodium fluoride, rare earth chloride and surfactant are used in combination, they can have an excellent compounding and synergistic effect with each other, so that the protective film formed after the smokeless plating agent is assisted can evenly and completely cover the plated part, and a coating with good bonding strength can be obtained after hot-dip galvanizing.

[0011] Preferably, the usage ratio of cerium chloride to lanthanum chloride is 1:2.

[0012] By adopting the above technical scheme, when the cerium chloride and lanthanum chloride in the above dosage ratio are used to form rare earth chloride, the effect brought by the mutual matching of the two is better, and the coordination between the two and sodium fluoride and the surfactant is better, thereby being able to exert a relatively excellent corresponding effect.

[0013] Preferably, the usage ratio of cetyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether is 2:1.

[0014] By adopting the above technical scheme, when the hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in the above dosage ratio are used to form a surfactant, the effect brought by the mutual matching of the two is better, so that the spreading and wetting ability of the smokeless plating aid on the plated parts is significantly improved, which is conducive to obtaining a better plating aid effect and ensuring that the plated parts after the plating aid treatment have a coating with excellent bonding performance after hot-dip galvanizing.

[0015] Preferably, the usage ratio of sodium fluoride, rare earth chloride and surfactant is 12:8:3.

[0016] By adopting the above technical scheme, when the sodium fluoride, rare earth chloride and surfactant are mixed in the above weight ratio, the compounding effect between them is better, so that after the smokeless plating aid is used, it can not only evenly and completely cover the plated parts, but also form a relatively dense microstructure of the protective film, so that it can give full play to its own role in the subsequent hot-dip galvanizing, and can obtain a coating with excellent bonding performance, so as to obtain a smokeless plating aid for hot-dip galvanizing with better application quality.

[0017] Preferably, the smokeless plating aid for hot-dip galvanizing comprises the following components in the following amounts: Zinc chloride 130g / L; Calcium chloride 40g / L; Potassium chloride 6g / L; Magnesium chloride 13g / L; Sodium fluoride 12g / L; Rare earth chloride 8g / L; Surfactant 3g / L; Corrosion inhibitor 1.5g / L The solvent is deionized water.

[0018] By adopting the above technical scheme, when the raw materials with the above content are mixed to form the smokeless plating aid for hot-dip galvanizing, the coordination between the components of the raw materials is better, especially for the compound between sodium fluoride, rare earth chloride and rare earth chloride, which can play a more significant corresponding effect, thereby enabling the smokeless plating aid for hot-dip galvanizing to bring a more excellent plating effect after application.

[0019] Preferably, the corrosion inhibitor is one or a combination of nitrite, phosphate and benzoate.

[0020] By adopting the above technical scheme, the corrosion inhibitor can form a protective film on the surface of the plated part to prevent it from being oxidized before immersion plating, thereby ensuring the quality of the plated part during the immersion plating process; and the above types of corrosion inhibitors are all suitable for the preparation of smokeless plating aids for hot-dip galvanizing, and can exert the above-mentioned excellent and stable effects, thereby ensuring that the smokeless plating aids for hot-dip galvanizing have better application quality.

[0021] Preferably, a functional auxiliary agent in an amount of 6-10 g / L is added to the components of the smokeless plating aid for hot-dip galvanizing, and the functional auxiliary agent consists of ferrous chloride and zinc phytate, and the dosage ratio of ferrous chloride to zinc phytate is (6-8):1.

[0022] By adopting the above technical scheme, ferrous chloride can peel off the iron oxide film remaining on the plated substrate, improve the activity of the surface, reduce the surface tension of the hot-dip galvanizing solution, enhance the wettability of the hot-dip galvanizing solution to the plated substrate, prevent the surface of the plated substrate from being oxidized again, and ensure the tightness of the coating; zinc phytate, as a plating aid component, can significantly improve the quality of the coating. By complexing with metal ions, zinc phytate can form a dense monomolecular protective film on the metal surface and improve the adhesion of the coating. When ferrous chloride and zinc phytate are used as functional auxiliary agents, the two are compounded with each other, so that after the smokeless plating aid is applied, the plated part can obtain a coating with better bonding after hot-dip galvanizing; at the same time, the functional auxiliary agent mainly acts on the hot-dip galvanizing solution, and the corresponding effects brought by the compounding with sodium fluoride, rare earth chloride and surfactant can form excellent complementarity, bringing about a significant enhancement of the corresponding effects between each other, thereby greatly improving the overall application quality of the smokeless plating aid.

[0023] Preferably, the usage ratio of ferrous chloride to zinc phytate is 7:1.

[0024] By adopting the above technical scheme, when the ferrous chloride and zinc phytate in the above dosage ratio are used to form a functional auxiliary agent, the composite effect between the two is relatively excellent, and the action system formed with sodium fluoride, rare earth chloride and surfactant has a better complementary effect, thereby making the actual effect brought by the application of the smokeless plating agent better.

[0025] In the second aspect, the present application provides an application method of a smokeless plating aid for hot-dip galvanizing, which adopts the following technical solution: A method for applying a smokeless plating aid for hot-dip galvanizing comprises the following steps: (1) preparing a smokeless plating aid comprising zinc chloride, calcium chloride, potassium chloride, magnesium chloride, sodium fluoride, rare earth chloride, a surfactant and a corrosion inhibitor, wherein the solvent is deionized water; (2) placing the plated part in the smokeless plating aid of step (1), immersing it at 40-80°C for 4-8 minutes, then taking it out and drying it at 80-120°C, thus completing the plating application of the smokeless plating aid.

[0026] By adopting the above technical scheme, the application method of the above smokeless plating aid for hot-dip galvanizing is relatively simple and convenient, and the combination of the above operating parameters is selected during the application process, so that the coordination effect between the components is relatively excellent, so that the protective film formed by the smokeless plating aid after plating can evenly and completely cover the plated parts, and thus a coating with better bonding strength is obtained after hot-dip galvanizing.

[0027] In summary, this application has the following beneficial effects: 1. The present application uses sodium fluoride, rare earth chloride and surfactant in a smokeless plating aid to wet the substrate of the plated part and help dissolve the oxide on the surface of the plated part. The smokeless plating aid forms a protective film that can evenly and completely cover the plated part, and a plating layer with good bonding strength can be obtained after hot-dip galvanizing. 2. The present application uses a functional auxiliary agent composed of ferrous chloride and zinc phytate, so that after the smokeless plating agent is applied, the plated parts can obtain a coating with better bonding strength after hot-dip galvanizing, and the action system formed by the smokeless plating agent and the sodium fluoride, rare earth chloride and surfactant has a better complementary effect, which brings about a significant enhancement of the corresponding action effects between each other, thereby greatly improving the overall application quality of the smokeless plating agent. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with embodiments and comparative examples. Example

[0029] Examples 1-4 A smokeless plating aid for hot-dip galvanizing, the components and corresponding dosages of which are shown in Table 1; wherein the rare earth chloride consists of cerium chloride and lanthanum chloride, and the dosage ratio of cerium chloride to lanthanum chloride is 1:2; the surfactant consists of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether, and the dosage ratio of hexadecyltrimethylammonium bromide to fatty alcohol polyoxyethylene ether is 2:1; the solvent is deionized water; and the corrosion inhibitor is sodium benzoate.

[0030] Table 1 Components and corresponding dosages of smokeless plating aids for hot-dip galvanizing in Examples 1-4 (g / L) Components Example 1 Example 2 Example 3 Example 4 Zinc chloride 130 130 100 160 Calcium chloride 40 40 30 50 Potassium chloride 6 6.5 5 8 Magnesium chloride 13 13.5 12 15 Sodium fluoride 12 13 10 16 Rare earth chlorides 8 8.5 5 12 Surfactants 3 3 1 5 Corrosion Inhibitor 1.5 1.5 1 2 Example 5 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the rare earth chloride consists of cerium chloride and lanthanum chloride in a dosage ratio of 1:1.8.

[0031] Example 6 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the rare earth chloride consists of cerium chloride and lanthanum chloride in a dosage ratio of 1:2.8.

[0032] Example 7 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the rare earth chloride consists of cerium chloride and lanthanum chloride in a dosage ratio of 1:2.15.

[0033] Example 8 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the surfactant is composed of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a dosage ratio of 1.6:1.

[0034] Example 9 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the surfactant is composed of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a dosage ratio of 2.2:1.

[0035] Example 10 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that the surfactant is composed of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a dosage ratio of 1.9:1.

[0036] Embodiment 11 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that a functional auxiliary agent in an amount of 8 g / L is further added to the components of the smokeless plating aid for hot-dip galvanizing, and the functional auxiliary agent is composed of ferrous chloride and zinc phytate in a dosage ratio of 7:1.

[0037] Example 12 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that the amount of the functional auxiliary agent is 6 g / L.

[0038] Example 13 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that the amount of the functional auxiliary agent is 10 g / L.

[0039] Embodiment 14 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that the functional auxiliary agent consists of ferrous chloride and zinc phytate in a dosage ratio of 6:1.

[0040] Embodiment 15 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that the functional auxiliary agent consists of ferrous chloride and zinc phytate in a dosage ratio of 8:1.

[0041] Example 16 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that ferrous chloride is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0042] Embodiment 17 A smokeless plating aid for hot-dip galvanizing, which is different from Example 11 in that zinc phytate is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0043] Embodiment 18 A method for applying a smokeless plating aid for hot-dip galvanizing comprises the following steps: (1) preparing a smokeless plating aid comprising zinc chloride, calcium chloride, potassium chloride, magnesium chloride, sodium fluoride, rare earth chloride, a surfactant and a corrosion inhibitor, wherein the solvent is deionized water; (2) The plated part is placed in the smokeless plating aid of step (1), immersed at 60°C for 6 minutes, and then taken out and dried at 100°C, thereby completing the plating application of the smokeless plating aid.

[0044] Embodiment 19 A method for applying a smokeless plating aid for hot-dip galvanizing comprises the following steps: (1) preparing a smokeless plating aid comprising zinc chloride, calcium chloride, potassium chloride, magnesium chloride, sodium fluoride, rare earth chloride, a surfactant and a corrosion inhibitor, wherein the solvent is deionized water; (2) The plated part is placed in the smokeless plating aid of step (1), immersed at 40°C for 8 minutes, and then taken out and dried at 80°C, thereby completing the plating application of the smokeless plating aid.

[0045] Embodiment 20 A method for applying a smokeless plating aid for hot-dip galvanizing comprises the following steps: (1) preparing a smokeless plating aid comprising zinc chloride, calcium chloride, potassium chloride, magnesium chloride, sodium fluoride, rare earth chloride, a surfactant and a corrosion inhibitor, wherein the solvent is deionized water; (2) The plated part is placed in the smokeless plating aid of step (1), immersed at 80°C for 4 minutes, and then taken out and dried at 120°C, thereby completing the plating application of the smokeless plating aid.

[0046] Comparative Example Comparative Example 1 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that sodium fluoride is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0047] Comparative Example 2 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that no rare earth chloride is used in the components of the smokeless plating aid for hot-dip galvanizing.

[0048] Comparative Example 3 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that no surfactant is used in the components of the smokeless plating aid for hot-dip galvanizing.

[0049] Comparative Example 4 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that cerium chloride is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0050] Comparative Example 5 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that lanthanum chloride is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0051] Comparative Example 6 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that hexadecyltrimethylammonium bromide is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0052] Comparative Example 7 A smokeless plating aid for hot-dip galvanizing, which is different from Example 1 in that fatty alcohol polyoxyethylene ether is not used in the components of the smokeless plating aid for hot-dip galvanizing.

[0053] Performance test test sample: The smokeless plating aid for hot-dip galvanizing obtained in Example 1-17 is used by the application method of the smokeless plating aid for hot-dip galvanizing in Example 18, and is applied to hot-dip galvanizing of plated parts, and the plated parts obtained are test samples 1-17; The smokeless plating aid for hot-dip galvanizing obtained in Example 1 was used by the application method of the smokeless plating aid for hot-dip galvanizing in Examples 19-20, and was applied to hot-dip galvanizing of plated parts, and the plated parts obtained were test samples 18-19; The smokeless plating aid for hot-dip galvanizing obtained in Comparative Examples 1-7 was used by the application method of the smokeless plating aid for hot-dip galvanizing in Example 18, and was applied to hot-dip galvanizing of plated parts, and the plated parts obtained were test samples 1-17; The plated substrate is Q235 industrial steel, which is cut into small square pieces of 10mm×10mm×3mm, and then subjected to surface grinding → alkaline washing and degreasing (15% NaOH, 80°C, 2min) → water washing → acid washing and derusting (15% HCl, 25°C, 1.5min) → water washing → hot-dip galvanizing with smokeless plating aid → drying to obtain a pretreated substrate; then the pretreated substrate is immersed in a molten zinc solution at 480°C, the hot-dip galvanizing time is 1.5min, and a finished plated product is obtained.

[0054] Test method: Select a tape with a bonding strength of 10N, take a hot-dip galvanized product, use a sharp blade to score on its surface, the depth of the score only penetrates the coating, and the distance between two adjacent scores is 0.1mm. After completing the longitudinal and transverse cross-scoring, stick the above tape to the surface of the hot-dip galvanized product so that it fits tightly without generating bubbles, then peel off the tape and calculate the proportion of the adhered coating to the adhesive area of ​​the tape; the higher the proportion, the worse the bonding performance between the coating formed by the hot-dip galvanizing liquid and the substrate.

[0055] After completing the above tests on test samples 1-19 and control samples 1-7 in sequence, the corresponding results are recorded in Table 2.

[0056] Table 2 Test results of test samples 1-19 and control samples 1-8 sample The percentage of the adhered coating to the adhesive tape bonding area (%) Test sample 1 8.13 Test sample 2 8.34 Test sample 3 8.27 Test sample 4 8.31 Test sample 5 8.26 Test sample 6 8.22 Test sample 7 8.19 Test sample 8 8.32 Test sample 9 8.30 Test sample 10 8.23 Test sample 11 6.46 Test sample 12 6.53 Test sample 13 6.51 Test sample 14 6.55 Test sample 15 6.52 Test sample 16 7.57 Test sample 17 7.46 Test sample 18 8.25 Test sample 19 8.28 Control sample 1 15.63 Control sample 2 18.14 Control sample 3 17.21 Control sample 4 14.68 Control sample 5 13.97 Control sample 6 14.23 Control sample 7 14.11 Combining Example 1 and Comparative Examples 1-3 and Table 2, it can be seen that by using sodium fluoride, rare earth chloride and surfactant in the smokeless plating agent for compounding, the plated part can be plated with the smokeless plating agent and hot-dip galvanized to ensure that the coating on the surface of the plated part has better bonding, indicating that the protective film formed after the smokeless plating agent can evenly and completely cover the plated part, and the lack of any one of sodium fluoride, rare earth chloride and surfactant will lead to a significant increase in the ratio obtained in the above test. Combining Comparative Examples 4-5 and Table 2, it can be seen that the rare earth chloride is composed of cerium chloride and lanthanum chloride, which can play a better corresponding effect, while if only any one of cerium chloride and lanthanum chloride is used, the corresponding effect is limited, and the sum of the improvement effects brought by the addition of each of them is far less than the excellent compounding of the two. Combined with Comparative Examples 4-5 and Table 2, it can be seen that when cetyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether are used as surfactants, they can exert better corresponding effects. If only any one of cetyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether is used, the corresponding effects brought are limited, and the sum of the enhancement effects brought by adding each of them separately is far less than the excellent combination of the two.

[0057] It can be seen from Example 1 and Example 2-10 and Table 2 that when the dosage ratio of sodium fluoride, rare earth chloride and surfactant is 12:8:3, the dosage ratio of cerium chloride and lanthanum chloride is 1:2, and the dosage ratio of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether is 2:1, the sodium fluoride, rare earth chloride and surfactant have a better compounding effect with each other, so that the smokeless plating aid can evenly and completely cover the plated parts after application, and obtain a coating with excellent bonding performance.

[0058] Combining Example 1 and Example 11-17 and Table 2, it can be seen that the present application uses a functional auxiliary agent composed of ferrous chloride and zinc phytate, so that after the smokeless plating agent is applied, the plated parts can obtain a coating with better bonding strength after hot-dip galvanizing, and the ratio value obtained by the above test is further reduced. If any one of ferrous chloride and zinc phytate is added and used alone, the improvement of the bonding strength of the coating is limited, and the sum of the improvement effects brought by the addition of each of the two alone is far less than the excellent combination of the two, indicating that the combination of ferrous chloride and zinc phytate can bring a significant improvement effect of 1+1>2.

[0059] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A smokeless plating aid for hot-dip galvanizing, characterized in that: Contains the following ingredients in the following amounts: Zinc chloride 100-160g / L; Calcium chloride 30-50 g / L; Potassium chloride 5-8 g / L; Magnesium chloride 12-15g / L; Sodium fluoride 10-16 g / L; Rare earth chloride 5-12 g / L; Surfactant 1-5 g / L; ‌ Corrosion inhibitor 1-2 g / L; The solvent was deionized water; The rare earth chloride is composed of cerium chloride and lanthanum chloride, and the dosage ratio of cerium chloride to lanthanum chloride is 1:(1.8-2.5); The surfactant is composed of hexadecyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether, and the usage ratio of the hexadecyl trimethyl ammonium bromide and the fatty alcohol polyoxyethylene ether is (1.6-2.2):

1.

2. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The dosage ratio of the cerium chloride to the lanthanum chloride is 1:

2.

3. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The usage ratio of hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether is 2:

1.

4. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The dosage ratio of the sodium fluoride, rare earth chloride and surfactant is 12:8:

3.

5. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The smokeless plating aid for hot-dip galvanizing comprises the following components in the following amounts: Zinc chloride 130g / L; Calcium chloride 40 g / L; Potassium chloride 6 g / L; Magnesium chloride 13g / L; Sodium fluoride 12 g / L; Rare earth chloride 8g / L; Surfactant 3 g / L; Corrosion inhibitor 1.5 g / L The solvent is deionized water.

6. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The corrosion inhibitor is one or a combination of nitrite, phosphate and benzoate.

7. The smokeless plating aid for hot-dip galvanizing according to claim 1, characterized in that: The components of the smokeless plating aid for hot-dip galvanizing are also added with a functional auxiliary agent in an amount of 6-10 g / L, and the functional auxiliary agent is composed of ferrous chloride and zinc phytate, and the dosage ratio of ferrous chloride to zinc phytate is (6-8):

1.

8. The smokeless plating aid for hot-dip galvanizing according to claim 7, characterized in that: The dosage ratio of ferrous chloride to zinc phytate is 7:

1.

9. The method for applying the smokeless plating aid for hot dip galvanizing according to claim 1, characterized in that: The following steps are involved: (1) Prepare a smokeless plating aid comprising zinc chloride, calcium chloride, potassium chloride, magnesium chloride, sodium fluoride, rare earth chloride, surfactant and corrosion inhibitor, and the solvent is deionized water; (2) Place the plated part in the smokeless plating agent of step (1), immerse it at 40-80°C for 4-8 minutes, then take it out and dry it at 80-120°C, thus completing the plating application of the smokeless plating agent.