阅读说明：本技术 一种镀锌液 (Zinc plating solution ) 是由 赵欣泰 赵�权 孙长志 于 2019-12-31 设计创作，主要内容包括：本发明公开了一种电沉积镀锌液及其配套使用的钝化液。所述镀锌液包括硫酸锌,硼酸和聚丁烯酸甲酯；钝化液包括硫酸、磷酸、硝酸、双氧水、硅酸钠、聚马来酸酐、聚乙烯醇、环己六醇六磷酸脂。本发明在含有聚丁烯酸甲酯的硫酸盐镀锌液中采用双脉冲电沉积制备了平均晶粒尺寸在30-50nm,具有镜面光亮效果且与基体结合牢固的纳米晶锌镀层,锌镀层的硬度达到2.11GPa,弹性模量达到94.53GPa,其耐蚀性疏水性、致密性、稳定性方面皆有所提高,后续对镀件进行钝化处理,相比电沉积和钝化处理技术单独作用于传统粗晶锌镀层,二者的结合作用进一步提高了镀层的装饰性能、机械性能、抗划伤能力及耐蚀性能。(The invention discloses an electrodeposition galvanizing solution and a passivation solution matched with the electrodeposition galvanizing solution. The galvanizing solution comprises zinc sulfate, boric acid and methyl polybutene; the passivation solution comprises sulfuric acid, phosphoric acid, nitric acid, hydrogen peroxide, sodium silicate, polymaleic anhydride, polyvinyl alcohol and inositol hexaphosphate. The invention adopts double-pulse electrodeposition to prepare the nanocrystalline zinc coating which has the average grain size of 30-50nm, has mirror surface brightness effect and is firmly combined with a matrix in sulfate zinc plating solution containing the methyl polybutene acid, the hardness of the zinc coating reaches 2.11GPa, the elastic modulus reaches 94.53GPa, the corrosion resistance, the hydrophobicity, the compactness and the stability are improved, and the subsequent passivation treatment is carried out on a plated piece.)

1. The zinc plating solution is characterized by comprising zinc sulfate, boric acid and methyl polybutene.

2. The method for preparing a zinc plating solution according to claim 1, which comprises the steps of:

(1) taking 90-120 parts of zinc sulfate and 15-25 parts of boric acid according to parts by weight, pouring into a container, adding 600-800 parts of deionized water, and stirring under magnetic force until the zinc sulfate and the boric acid are completely dissolved to prepare a basic zinc plating solution;

(2) slowly pouring concentrated sulfuric acid into the basic zinc plating solution under continuous stirring, and adjusting the pH value of the plating solution to 1.2-2.6;

(3) adding 0.8-1.6g of methyl polybutene acid, and stirring until the methyl polybutene acid is completely dissolved, wherein the solution is clear and transparent.

3. The passivation solution matched with the zinc plating solution of the claims 1 to 2 for use is characterized by comprising sulfuric acid, phosphoric acid, nitric acid, hydrogen peroxide, sodium silicate, polymaleic anhydride, polyvinyl alcohol and inositol hexaphosphate.

4. A method for preparing a passivation solution according to claim 3, characterized by comprising the steps of:

(1) according to the weight portion, 15 to 20 portions of sodium silicate, 0.5 to 1.5 portions of polymaleic anhydride, 0.5 to 1.5 portions of polyvinyl alcohol and 0.5 to 1.2 portions of hexachlorocyclohexane are dissolved in 600 portions of 400 portions of water and stirred evenly;

(2) adding 1.5-3.5 parts of sulfuric acid, 1.5-3.5 parts of phosphoric acid and 3-6 parts of nitric acid, and uniformly stirring to prepare a basic passivation solution;

(3) when in use, 40-50 parts of hydrogen peroxide is added.

5. A method for electrodeposition galvanization, characterized by comprising the following steps:

(1) pretreatment of a part to be plated: polishing a piece to be plated with sand paper, then washing with water, then carrying out acid washing activation, and finally washing with water;

(2) and (3) electrodeposition of a part to be plated: the method is finished in a double-electrode electrolytic cell under continuous magnetic stirring, and the water washing and the cold air blow drying are carried out after the deposition is finished;

(3) passivating a plated part: soaking the plated part dried by cold air into the basic passivation solution, adding hydrogen peroxide, continuously stirring for 15-25min, washing with water, and drying by hot air.

6. The method of claim 5, wherein the electrodeposition parameters are: the on time is 0.3ms, the off time is 0.7ms, and the cathode forward average current density is 3A/dm²Reverse average current density of 0.3A/dm²Electroplating time is 30-60min, and temperature is 22-28 ℃.

7. The method of claim 5-6, wherein the anodes of the two electrodes are zinc plates and the cathodes are mild steel.

8. The method of claim 5, wherein the acid in the acid washing is hydrochloric acid, sulfuric acid or nitric acid.

Technical Field

The invention belongs to the technical field of metal corrosion prevention, and particularly relates to an electrodeposition galvanizing solution and a passivation solution matched with the electrodeposition galvanizing solution.

Background

The standard electrode potential of zinc is-0.76V, which is more negative than that of iron (-0.44V), and belongs to an anode coating, and zinc is relatively stable in air, low in cost, rich in reserves, non-toxic and recyclable, so that the electro-deposited zinc becomes an important surface protection means for preventing steel corrosion, and the electro-deposited zinc has wide application in the fields of machinery, aviation, automobiles and buildings.

The electrodeposition technology is an important method for improving the performance of galvanized steel sheets developed in recent years, and numerous researches have been made on the preparation of nanocrystalline zinc coatings in different galvanizing bath systems, such as an alkaline bath system, a sulfate bath system, an acetate bath system, a citrate bath system, and the like. Considering the nature of the sacrificial coating of zinc and its own low corrosion resistance during the steel corrosion protection process, the method of passivating the zinc post-treatment is widely used in industry to prolong its lifetime. The zinc coating passivation solution systems developed at present can be roughly divided into three types according to the compositions: inorganic matter passivation solution, organic matter passivation solution and inorganic/organic matter composite passivation solution.

At present, the plating solution systems for electrodepositing the nanocrystalline zinc coating reported in the literatures all adopt multi-component additives, the composition of the plating solution is complex, the maintenance is difficult, and the passivation effect of the passivation solution is poor.

Disclosure of Invention

The invention aims to provide a zinc plating solution and a passivation solution matched with the zinc plating solution.

A zinc plating solution comprises zinc sulfate, boric acid and methyl polybutene.

The preparation method of the galvanizing solution comprises the following steps:

(1) taking 90-120 parts of zinc sulfate and 15-25 parts of boric acid according to parts by weight, pouring into a container, adding 600-800 parts of deionized water, and stirring under magnetic force until the zinc sulfate and the boric acid are completely dissolved to prepare a basic zinc plating solution;

(2) slowly pouring concentrated sulfuric acid into the basic zinc plating solution under continuous stirring, and adjusting the pH value of the plating solution to 1.2-2.6;

(3) adding 0.8-1.6g of methyl polybutene acid, and stirring until the methyl polybutene acid is completely dissolved, wherein the solution is clear and transparent.

The passivation solution matched with the galvanizing solution comprises sulfuric acid, phosphoric acid, nitric acid, hydrogen peroxide, sodium silicate, polymaleic anhydride, polyvinyl alcohol and inositol hexaphosphate.

The preparation method of the passivation solution comprises the following steps:

(1) according to the weight portion, 15 to 20 portions of sodium silicate, 0.5 to 1.5 portions of polymaleic anhydride, 0.5 to 1.5 portions of polyvinyl alcohol and 0.5 to 1.2 portions of hexachlorocyclohexane are dissolved in 600 portions of 400 portions of water and stirred evenly;

(2) adding 1.5-3.5 parts of sulfuric acid, 1.5-3.5 parts of phosphoric acid and 3-6 parts of nitric acid, and uniformly stirring to prepare a basic passivation solution;

(3) when in use, 40-50 parts of hydrogen peroxide is added.

A method for electroplating zinc by electrodeposition is carried out according to the following steps:

(1) pretreatment of a part to be plated: polishing a piece to be plated with sand paper, then washing with water, then carrying out acid washing activation, and finally washing with water;

(2) and (3) electrodeposition of a part to be plated: the method is finished in a double-electrode electrolytic cell under continuous magnetic stirring, and the water washing and the cold air blow drying are carried out after the deposition is finished;

(3) passivating a plated part: soaking the plated part dried by cold air into the basic passivation solution, adding hydrogen peroxide, continuously stirring for 15-25min, washing with water, and drying by hot air.

The electrodeposition parameters are: the on time is 0.3ms, the off time is 0.7ms, and the cathode forward average current density is 3A/dm²Reverse average current density of 0.3A/dm²Electroplating time is 30-60min, and temperature is 22-28 ℃.

The anode of the double electrode is a zinc plate, and the cathode of the double electrode is low-carbon steel.

The acid in the acid washing is hydrochloric acid, sulfuric acid or nitric acid.

The invention has the beneficial effects that: the invention relates to a sulfate zinc plating solution (ZnSO) containing polymethyl methacrylate₄·7H₂O、H₃BO₃) The nanocrystalline zinc coating which has the average grain size of 30-50nm, has a mirror surface bright effect and is firmly combined with a substrate is prepared by adopting double-pulse electrodeposition, the hardness of the zinc coating reaches 2.11GPa, the elastic modulus reaches 94.53GPa, the corrosion resistance, hydrophobicity, compactness and stability of the zinc coating are improved, and a plated part is passivated subsequently.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the following description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.