Leakage-proof plating assistant solution for batch hot-dip galvanizing as well as preparation method and use method of leakage-proof plating assistant solution

Abstract

The invention provides a leakproof plating assistant solution for batch hot-dip galvanizing as well as a preparation method and a use method of the leakproof plating assistant solution, and belongs to the technical field of hot-dip galvanizing. The leakage-proof plating assistant solution comprises the following components: 50-180g / L of ammonium chloride, 20-40g / L of sodium chloride, 20-40g / L of sodium 90-100 g / L of zinc chloride; 0.1 to 1.0 g / L of bismuth chloride; 0.2 to 1.0 g / L of an AEO9 active agent; the solvent is water, and the solution pH is controlled to be less than or equal to 3. The using method of the leakage-proof plating assistant solution comprises the steps that S1, a steel workpiece is subjected to oil removal and rust removal, and surface impurities are removed through washing after oil removal and rust removal are completed for standby application; s2, the steel workpiece treated in the step S1 is immersed in a leakage-proof plating assistant solution to be soaked; and S3, the steel workpiece treated in the S2 is subjected to high-aluminum hot-dip galvanizing, cooling and passivation process treatment are conducted after zinc dipping is completed, and hot-dip galvanizing is completed. The leakproof plating assistant solution can be directly used on a batch galvanizing production line, and no plating leakage occurs on the galvanized surface after workpiece plating assistant.

Description

Technical Field

[0001] The invention relates to the technical field of hot-dip galvanizing for surface treatment of steel workpieces, and in particular to a leak-proof plating aid solution for batch hot-dip galvanizing, and a preparation method and a use method thereof. Background Art

[0002] At present, the conventional method for increasing the service life of steel is to perform hot-dip galvanizing on the workpiece so that a certain thickness of galvanized layer is obtained on the surface of the steel to prevent corrosion of the steel matrix. The basic principle of galvanized layer protection is mainly the physical shielding and electrochemical protection of the galvanized layer (sacrificial anode protection method). However, with the development and consumption of zinc resources, the special needs of some steel products (relatively low service life) and the excellent corrosion resistance of the galvanized layer itself, the surface of the steel workpiece does not need a very thick galvanized layer to meet the use requirements, and it can also greatly reduce production costs and save zinc resources. The hanging plating industry usually increases the Al content in the zinc liquid to a higher level. Because the affinity of Al to Fe is greater than the affinity of Zn to Fe, when the workpiece is immersed in the zinc liquid, a very thin Fe2Al5 intermediate alloy layer is first formed on the surface of the workpiece, which ensures the adhesion of the coating, while inhibiting the growth of the iron-zinc alloy phase and reducing the thickness of the coating, thereby achieving the goal of reducing costs.

[0003] According to the density of solid zinc is 7.14g / cm 3 , the density of liquid zinc is about 6.8g / cm 3 The density of the Fe-Zn alloy precipitate is greater than that of the liquid zinc, so it sinks to become bottom slag, while the density of the precipitate Fe2Al5 is only 4.2g / cm 3 , which is lower than the density of liquid zinc, so it will automatically float on the surface of the zinc liquid to become surface slag. In the process of hanging plating, the ratio of surface slag to bottom slag in the zinc pot changes with the change of Al content in the zinc liquid. When the Al content in the zinc liquid is less than 0.135%, all or most of the zinc slag sinks to the bottom of the zinc pot. When the Al content in the zinc liquid reaches 0.135%, it is mainly surface slag, and only a small amount of bottom slag is produced. When the Al content exceeds 0.14%, the bottom slag is completely transformed into surface slag; in the actual hanging plating production process, as the Al content in the zinc liquid gradually increases, the floating slag on the upper layer of the zinc liquid also gradually increases. In order to obtain better coating surface quality, the Al content in the zinc liquid is generally controlled not to exceed 0.10%. Otherwise, when the workpiece is taken out of the zinc liquid after the galvanizing is completed, a large number of zinc particles will appear on the surface of the workpiece, affecting the delivery and use of the product.

[0004] However, based on the current production status of the hanging plating industry, increasing the Al content in the zinc solution faces major technical difficulties. The main problem is that after the workpiece is treated with ammonium chloride zinc auxiliary agent on the existing hanging plating production line, a large area of ​​galvanizing leakage occurs on the surface of the workpiece. The galvanized products obtained are of poor quality and cannot be delivered to customers. Summary of the invention

[0005] In order to overcome the shortcomings of the ammonium chloride zinc additive process used in the existing galvanizing plant production line, and to appropriately increase the Al content in the plating solution to significantly reduce costs and increase efficiency in the hanging plating industry, the present invention provides a batch hot-dip galvanizing leak-proof plating additive solution, which can prevent leaks on the galvanized surface of the workpiece after plating by adding the plating additive of the present invention to the plating pool.

[0006] Specifically:

[0007] A leak-proof plating aid solution for batch hot-dip galvanizing, wherein the solution pH is ≤3, and the components thereof include:

[0008] Ammonium chloride: 50-180g / L;

[0009] Zinc chloride: 90-100g / L;

[0010] Bismuth chloride: 0.1-1.0g / L;

[0011] AEO9 active agent: 0.2-1.0g / L;

[0012] The solvent is water.

[0013] When implementing the above embodiment, preferably, the surface tension of the solution is less than 40 mN / m.

[0014] When implementing the above embodiment, preferably, the pH value of the solution is 1-3.

[0015] When implementing the above embodiment, preferably, the bismuth chloride is pre-treated with hydrochloric acid.

[0016] Before adding and using, it is necessary to control the pH of the leak-proof plating agent solution to ≤3, the ammonium chloride concentration to 50-180g / L, and the zinc chloride concentration to 90-100g / L. It should be noted that if the concentration of ammonium chloride and zinc chloride is too low, the workpiece is prone to leak plating after galvanizing, and if the concentration is too high, the amount of zinc ash will increase.

[0017] In addition, the present invention also provides a method for preparing the above-mentioned leak-proof plating aid solution for batch hot-dip galvanizing, the steps of which include: dissolving ammonium chloride and zinc chloride in water, then adding bismuth chloride and AEO9 activator, controlling the solution pH to ≤3, and mixing evenly to obtain the leak-proof plating aid solution.

[0018] Furthermore, the added bismuth chloride is a hydrochloric acid aqueous solution in which bismuth chloride is dissolved.

[0019] In addition, the present invention also provides a method for using the above-mentioned leak-proof plating aid solution for batch hot-dip galvanizing, the steps of which include:

[0020] S1. Degrease and rust the steel workpiece, wash it with water to remove surface impurities, and set it aside;

[0021] S2, immersing the steel workpiece treated in S1 into a leak-proof plating assistant solution;

[0022] S3, the steel workpiece treated in S2 is subjected to high-aluminum hot-dip galvanizing, and after the galvanizing is completed, it is cooled and passivated, and the hot-dip galvanizing is completed.

[0023] Furthermore, in step S2, the steel workpiece is immersed in a leak-proof plating aid solution, the leak-proof plating aid solution is used at a temperature of 50-70° C., and the immersion time is 30-90 seconds.

[0024] Furthermore, the zinc solution in step S3 contains aluminum.

[0025] Furthermore, the mass percentage of aluminum content in the zinc liquid in step S3 is ≤0.10%.

[0026] The anti-leakage plating aid solution of the present invention can form a uniform bismuth-containing metal salt film on the surface of the workpiece after plating, can prevent the surface of the workpiece from being oxidized and rusted after plating, and at the same time increase the wettability between the workpiece and the zinc bath during galvanizing, reduce the surface tension, and can effectively solve the problem of leakage plating that has occurred in galvanizing under high-aluminum (<0.20% Al) zinc bath conditions, fully meet the needs of batch hot-dip galvanizing, and achieve the goal of reducing costs and increasing efficiency. The anti-leakage plating aid solution of the present invention can be directly used in a batch galvanizing production line to achieve no leakage plating on the galvanized surface of the workpiece after plating. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0028] Figure 1 This is the SEM image of the coating structure morphology of batch hot-dip galvanizing;

[0029] Figure 2 This is the SEM image of the coating structure morphology of high aluminum hot-dip galvanizing;

[0030] Figure 3 This is a schematic diagram of galvanizing a workpiece in Example 1;

[0031] Figure 4 This is a schematic diagram of galvanizing a workpiece in Example 2;

[0032] Figure 5 This is a schematic diagram of galvanizing a workpiece in Example 3;

[0033] Figure 6 This is a schematic diagram of galvanizing a workpiece in Example 4;

[0034] Figure 7 This is a schematic diagram of galvanizing a workpiece in Example 5;

[0035] Figure 8 This is a schematic diagram of galvanizing a workpiece in Example 6;

[0036] Fig. 9 This is a schematic diagram of galvanizing a workpiece in Comparative Example 1;

[0037] Fig.10 Schematic diagram of galvanizing workpiece of comparative example 2

[0038] Fig.11 Schematic diagram of galvanizing workpiece of comparative example 3

[0039] Fig.12 Schematic diagram of galvanizing workpiece of comparative example 4

[0040] Fig.13 This is a schematic diagram of the galvanizing of the workpiece in Comparative Example 5. DETAILED DESCRIPTION

[0041] 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.

[0042] Example 1

[0043] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0044] Ammonium chloride: 120g / L

[0045] Zinc chloride: 90g / L

[0046] Bismuth chloride: 0.3g / L

[0047] AEO9 active agent: 0.2g / L

[0048] The rest is water and the solution pH is 2.5.

[0049] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0050] Directions:

[0051] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0052] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, the temperature is controlled at 50°C, and the immersion time is 90s;

[0053] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.08% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0054] Galvanized steel workpieces such as Figure 3 As shown, there is no missing plating on the surface.

[0055] Example 2

[0056] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0057] Ammonium chloride: 50g / L

[0058] Zinc chloride: 90g / L

[0059] Bismuth chloride: 0.1g / L

[0060] AEO9 active agent: 0.2g / L

[0061] The rest is water, and the solution pH is 3.0.

[0062] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0063] Directions:

[0064] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0065] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, the temperature is controlled at 55°C, and the immersion time is 80s;

[0066] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.06% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0067] Galvanized steel workpieces such as Figure 4 As shown, there is no missing plating on the surface.

[0068] Example 3

[0069] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0070] Ammonium chloride: 100g / L

[0071] Zinc chloride: 90g / L

[0072] Bismuth chloride: 0.3g / L

[0073] AEO9 active agent: 0.2g / L

[0074] The rest is water, and the solution pH is 1.3.

[0075] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0076] Directions:

[0077] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0078] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, with the temperature controlled at 60°C and the immersion time being 70s;

[0079] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.06% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0080] Galvanized steel workpieces such as Figure 5 As shown, there is no missing plating on the surface.

[0081] Example 4

[0082] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0083] Ammonium chloride: 120g / L

[0084] Zinc chloride: 100g / L

[0085] Bismuth chloride: 0.3g / L

[0086] AEO9 active agent: 0.3g / L

[0087] The rest is water, and the solution pH is 2.6.

[0088] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0089] Directions:

[0090] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0091] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, with the temperature controlled at 65°C and the immersion time being 60s;

[0092] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.09% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0093] Galvanized steel workpieces such as Figure 6 As shown, there is no missing plating on the surface.

[0094] Example 5

[0095] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0096] Ammonium chloride: 180g / L

[0097] Zinc chloride: 100g / L

[0098] Bismuth chloride: 0.3g / L

[0099] AEO9 active agent: 0.2g / L

[0100] The rest is water, and the solution pH is 2.2.

[0101] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0102] Directions:

[0103] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0104] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, the temperature is controlled at 70°C, and the immersion time is 50s;

[0105] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.07% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0106] Galvanized steel workpieces such as Figure 7 As shown, there is no missing plating on the surface.

[0107] Example 6

[0108] A leak-proof plating aid solution for batch hot-dip galvanizing, comprising the following components and proportions:

[0109] Ammonium chloride: 150g / L

[0110] Zinc chloride: 100g / L

[0111] Bismuth chloride: 0.1g / L

[0112] AEO9 active agent: 0.2g / L

[0113] The rest is water, and the solution pH is 1.0.

[0114] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0115] Directions:

[0116] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0117] S2, immersing the steel workpiece treated in S1 into a leak-proof plating agent solution, the temperature is controlled at 70°C, and the immersion time is 30s;

[0118] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.06% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0119] Galvanized steel workpieces such as Figure 8 As shown, there is no missing plating on the surface.

[0120] Comparative Example 1

[0121] A plating flux, comprising the following components and proportions:

[0122] Ammonium chloride: 100g / L

[0123] Zinc chloride: 100g / L

[0124] AEO9 active agent: 0.15g / L

[0125] The rest is water and the solution pH is 2.5.

[0126] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add AEO9 surfactant, control the pH of the solution, and mix well.

[0127] Directions:

[0128] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0129] S2, immersing the steel workpiece treated in S1 into the plating agent, the temperature is controlled at 50°C, and the immersion time is 90s;

[0130] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.06% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0131] Galvanized steel workpieces such as Fig. 9 As shown, there is obvious missing plating on the surface.

[0132] Comparative Example 2

[0133] A plating flux, comprising the following components and proportions:

[0134] Ammonium chloride: 100g / L

[0135] Zinc chloride: 100g / L

[0136] AEO9 active agent: 0.3g / L

[0137] The rest is water, and the pH of the plating solution is 1.8.

[0138] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add AEO9 surfactant, control the pH of the solution, and mix well.

[0139] Directions:

[0140] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0141] S2, immersing the steel workpiece treated in S1 into the plating agent, the temperature is controlled at 50°C, and the immersion time is 90s;

[0142] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.10% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0143] Galvanized steel workpieces such as Fig.10 As shown, there is obvious missing plating on the surface.

[0144] Comparative Example 3

[0145] A plating flux, comprising the following components and proportions:

[0146] Ammonium chloride: 150g / L

[0147] Zinc chloride: 100g / L

[0148] AEO9 active agent: 0.3g / L

[0149] The rest is water, and the solution pH is 1.5.

[0150] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add AEO9 surfactant, control the pH of the solution, and mix well.

[0151] Directions:

[0152] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0153] S2, immersing the steel workpiece treated in S1 into the plating agent, the temperature is controlled at 50°C, and the immersion time is 90s;

[0154] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.09% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0155] Galvanized steel workpieces such as Fig.11 As shown, there is obvious missing plating on the surface.

[0156] Comparative Example 4

[0157] A plating flux, comprising the following components and proportions:

[0158] Ammonium chloride: 120g / L

[0159] Zinc chloride: 90g / L

[0160] The rest is water, and the solution pH is 1.3.

[0161] Preparation process: Dissolve ammonium chloride and zinc chloride in water, control the pH of the solution, and mix well.

[0162] Directions:

[0163] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0164] S2, immersing the steel workpiece treated in S1 into the plating agent, the temperature is controlled at 50°C, and the immersion time is 90s;

[0165] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.10% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0166] Galvanized steel workpieces such as Fig.12 As shown, there is obvious missing plating on the surface.

[0167] Comparative Example 5

[0168] A plating flux, comprising the following components and proportions:

[0169] Ammonium chloride: 50g / L

[0170] Zinc chloride: 50g / L

[0171] Bismuth chloride: 0.3g / L

[0172] AEO9 active agent: 0.2g / L

[0173] The rest is water and the solution pH is 2.5.

[0174] Preparation process: Dissolve ammonium chloride and zinc chloride in water, then add bismuth chloride and AEO9 active agent which are completely dissolved in 2% hydrochloric acid aqueous solution, control the pH of the solution, and mix well.

[0175] Directions:

[0176] S1. Degrease and rust round steel, angle steel, steel plate, square tube and other steel workpieces, wash with water to remove surface impurities and set aside;

[0177] S2, immersing the steel workpiece treated in S1 into the plating agent, the temperature is controlled at 70°C, and the immersion time is 30s;

[0178] S3, immersing the steel workpiece treated in S2 into a zinc solution containing 0.09% Al for high-aluminum hot-dip galvanizing, cooling and passivation treatment after the galvanizing is completed, and hot-dip galvanizing is completed.

[0179] Galvanized steel workpieces such as Fig.13 As shown, there is obvious missing plating on the surface.

[0180] 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 leak-proof plating agent solution for batch hot-dip galvanizing, characterized in that: The solution pH is ≤3, and its components include: Ammonium chloride: 50-180g / L; Zinc chloride: 90-100g / L; Bismuth chloride: 0.1-1.0g / L; AEO9 active agent: 0.2-1.0g / L; The solvent is water.

2. The leak-proof plating assistant solution according to claim 1, characterized in that: The surface tension of its solution is less than 40mN / m.

3. The leak-proof plating assistant solution according to claim 1, characterized in that: The solution pH is 1-3.

4. The leak-proof plating assistant solution according to claim 1, characterized in that: The bismuth chloride is pre-treated with hydrochloric acid.

5. A method for preparing a leak-proof plating aid solution for batch hot-dip galvanizing according to any one of claims 1 to 4, characterized in that: The steps include: dissolving ammonium chloride and zinc chloride in water, then adding bismuth chloride and AEO9 activator, controlling the pH value of the solution to be less than or equal to 3, and mixing evenly to obtain a leak-proof plating assistant solution.

6. The method for preparing the leak-proof plating assistant solution according to claim 5, characterized in that: The bismuth chloride to be added is a hydrochloric acid aqueous solution in which bismuth chloride is dissolved.

7. A method for using the leak-proof plating aid solution for batch hot-dip galvanizing according to any one of claims 1 to 4, characterized in that: The steps include: S1. Degrease and rust the steel workpiece, wash it with water to remove surface impurities, and set it aside; S2, immersing the steel workpiece treated in S1 into a leak-proof plating assistant solution; S3, immersing the steel workpiece treated in S2 into zinc liquid for high-aluminum hot-dip galvanizing, cooling and passivation process after galvanizing, and hot-dip galvanizing is completed.

8. The method for using the leak-proof plating aid solution according to claim 7, characterized in that: In step S2, the steel workpiece is immersed in a leak-proof plating aid solution, the leak-proof plating aid solution has a use temperature of 50-70° C., and a soaking time of 30-90 seconds.

9. The method for using the leak-proof plating aid solution according to claim 7, characterized in that: The zinc solution in step S3 contains aluminum.

10. The method for using the leak-proof plating assistant solution according to claim 9, characterized in that: The mass percentage of aluminum content in the zinc liquid in step S3 is ≤0.10%.

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