Electro-galvanizing: It is the use of electrolysis to form a uniform and dense surface on the workpiece. The process of incorporating a well-deposited layer of metal or alloy.
Compared with other metals, zinc is a relatively inexpensive and easily plated metal. And is a low-value corrosion-resistant plating. It is widely used to protect steel parts, especially against atmospheric corrosion, and for decoration.
Plating techniques include:
1. Tank plating (or rack plating),
2. Barrel plating (suitable for small parts),
3. Automatic plating and continuous plating (suitable for wire, strip).
Second, the classification of electro-galvanized
At present, it has four the domestic classification of electroplating solutions:
1. Cyanide galvanized.
Since (CN) is highly toxic, environmental protection has put forward strict restrictions on the use of cyanide in electro-galvanizing. And constantly promotes the development of cyanide-reducing and replacing cyanide electro-galvanizing bath systems, requiring the use of low-cyanide (micro-cyanide) electroplating baths .
After electroplating by this process, the product quality is good. Especially the color plating, the color remains well after passivation.
This process is evolved from cyanide zinc plating. At present, two major factions have been formed in China, namely: a) “DPE” series of Wuhan Material Insurance Institute; b) “DE” series of Radio and Television Institute. Both belong to zincate zinc plating with alkaline additives, and the pH value is 12.5~13.
Using this process, the lattice structure of the coating is columnar. And the corrosion resistance is good, which is suitable for color galvanizing.
Note: After the product is out of the tank -> washing -> light (nitric acid + hydrochloric acid) -> washing -> passivation -> washing -> washing -> scalding -> drying -> aging treatment (80~90℃ in the oven.
3. Chloride Zinc
This process is widely used in the electroplating industry, accounting for up to 40%.
After passivation (blue white), zinc can replace chromium (comparable to chrome plating). Especially after adding water-soluble varnish. It is difficult for a layman to distinguish whether it is galvanized or chrome plated.
This process is suitable for white passivation (blue white, silver white).
4. Sulfate Zinc
This process is suitable for continuous plating (wires, strips, simple, thick and large parts and components), and the cost is low.
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Post time: Feb-24-2022