Introduction to electrolytic galvanized sheets (electrolytic sheets)

Electrolytic plate, also known as electrolytic galvanized plate, is a process that uses electrolysis to form a uniform, dense, and well-bonded metal or alloy deposition layer on the surface of the workpiece.

Introduction
Compared with other metals, zinc is a metal that is relatively cheap and easy to coat. It is a low-value anti-corrosion plating layer. It is widely used to protect steel parts, especially against atmospheric corrosion, and for decoration. Plating technologies include tank plating (or rack plating), barrel plating (suitable for small parts), automatic plating and continuous plating (suitable for wires and strips). The electrolytic plate is rolled by the cold tandem rolling unit and then annealed by the CAPL unit before entering the electrolytic galvanizing unit. After surface cleaning and electroplating, it can be phosphated, passivated, oiled, fingerprint-resistant, alloyed, etc. according to different uses. The mechanical properties of the resulting product refer to the corresponding substrate.

Classification
At present, domestic electroplating solutions can be divided into four major categories:
1. Cyanide galvanizing Since (CN) is highly toxic, environmental protection has put forward strict restrictions on the use of cyanide in electroplating zinc. The development of electroplating zinc plating solutions that reduce cyanide and replace cyanide is continuously promoted, requiring the use of low cyanide (micro cyanide) electroplating solutions. .

After electroplating using this process, the product quality is good, especially the color plating, and the color remains good after passivation.

2. Zincate zinc plating

This process evolved from cyanide galvanizing. At present, two major factions have formed in China, namely: a) the "DPE" series of the Wuhan Materials Protection Institute; b) the "DE" series of the Institute of Radio, Film and Television. They all belong to zincate zinc plating with alkaline additives; the pH value is 12.5~13.

Using this process, the coating lattice structure is columnar, has good corrosion resistance, and is suitable for color galvanizing.

Note: After the product comes out of the tank → wash → light (nitric acid + hydrochloric acid) → wash → passivate → wash → wash → iron and dry → dry → aging treatment (80~90℃ in the oven).

3. Chloride galvanizing

This process is widely used in the electroplating industry, accounting for up to 40%.

After passivation (blue and white), zinc can replace chromium (comparable to chrome plating). Especially after adding water-soluble varnish, it is difficult for laymen to identify whether it is zinc plating or chromium plating.

This process is suitable for white passivation (blue-white, silver-white).

4. Sulfate galvanizing

This process is suitable for continuous plating (wires, strips, simple, thick and large parts and components). low cost .