2020-11-03
Electro-galvanizing, also known as cold galvanizing in the industry, is the process of using electrolysis to form a uniform, dense, and well-bonded metal or alloy deposition layer on the surface of the part. Compared with other metals, zinc is a relatively cheap and easily plated metal. It is a low-value anti-corrosion electroplating layer and is widely used to protect steel parts, especially to prevent atmospheric corrosion, and for decoration. Plating technology includes slot plating (or rack plating), barrel plating (suitable for small parts), blue plating, automatic plating and continuous plating (suitable for wire and strip). Gaoxin Plating provides professional electro-galvanizing (blue-white zinc/black zinc/color zinc) services. According to the classification of electroplating solution, domestic electrogalvanization can be divided into four categories: 1. Cyanide zinc plating Because (CN) is highly toxic, environmental protection has imposed strict restrictions on the use of cyanide in electroplating zinc, and continuously promote the development of electrogalvanizing bath systems for reducing cyanide and replacing cyanide, requiring the use of low-cyanide (microcyanide) electroplating baths . After electroplating with this process, the product quality is good, especially the color plating, the color remains good after passivation. 2. Zincate zinc plating This process is evolved from cyanide zinc plating. Two major factions have formed in China, namely: a) the "DPE" series of Wuhan Material Insurance Institute; b) the "DE" series of the Radio and Television Institute. Both are zincate zinc plating with alkaline additives, with a pH of 12.5~13. Using this process, the coating crystal lattice structure is columnar, with good corrosion resistance, suitable for color galvanizing. Note: After the product comes out of the tank —>; water washing —>; light (nitric acid + hydrochloric acid) —>; water washing —>; passivation —>; water washing —>; water washing —>; hot and dry —>; drying —>; aging Treatment (80~90℃ in the oven. 3. Chloride zinc plating This process is widely used in the electroplating industry, accounting for up to 40%. After passivation (blue and white), zinc can be substituted for chromium (comparable to chromium plating), especially after adding water-soluble varnish, it is difficult for laymen to distinguish whether it is zinc plating or chrome plating. This process is suitable for white passivation (blue white, silver white). 4. Sulfate zinc plating This process is suitable for continuous plating (wire, strip, simple, thick and large parts, parts), with low cost. The purpose of electro-galvanizing is to prevent steel objects from being corroded, to improve the corrosion resistance and service life of steel, and to increase the decorative appearance of the product. Steel will be weathered, corroded by water or soil over time. The steel that is corroded every year in China accounts for almost 10% of the total steel volume. Therefore, in order to protect the service life of steel or its parts, electro-galvanizing is generally used to process steel. Because zinc is not easy to change in dry air, and it can produce a basic zinc carbonate film in a humid environment, this film can protect internal parts from corrosion and damage, even if the zinc layer is damaged by some factor In this case, the combination of zinc and steel over a period of time will form a micro-battery, and the steel matrix will become the cathode and be protected. In summary, electro-galvanizing has the following characteristics: 1. Good corrosion resistance, meticulous and uniform combination, not easy for corrosive gas or liquid to enter the interior. 2. Because the zinc layer is relatively pure, it is not easy to be corroded in an acid or alkali environment. Effectively protect the steel body for a long time. 3. After chromic acid passivation, it can be used in various colors, which can be selected according to the customer's preference. Galvanizing is beautiful and decorative. 4. The zinc coating has good ductility and will not fall easily during various bending, handling and impact. |