03

2023

Common surface treatment processes for precision sheet metal parts

Due to the fact that some sheet metal materials themselves do not have the ability to prevent rust and corrosion, they need to undergo surface treatment to achieve their objectives. Common surface treatment processes for steel plates Electrogalvanizing: The process of forming a uniform, dense, and well bonded metal or alloy deposition layer on the surface of a workpiece by electrolysis. Compared with other metals, zinc is a relatively inexpensive and easy to plated metal, belonging to a low value anti-corrosion electrodeposit. It is widely used to protect steel parts, especially against atmospheric corrosion, and for decoration. Plating technology includes bath plating (or hanging plating), barrel plating (suitable for small parts), automatic plating, and continuous plating (suitable for wire and strip). According to the classification of electroplating solutions in China, they can be divided into four categories: Cyanide zinc plating Due to the highly toxic nature of (CN), environmental protection has imposed strict restrictions on the use of cyanide in zinc electroplating, continuously promoting the development of cyanide reduction and replacement electroplating solution systems, requiring the use of low cyanide (micro cyanide) electroplating solutions. After adopting this process for electroplating, the product quality is good, especially for color plating, and the color remains good after passivation. Zincate zinc plating This process is evolved from cyanide zinc plating. Currently, there are two major factions in China, namely: a) the "DPE" series of Wuhan Material Protection Institute; b) "DE" series of radio and television stations. Zincate zinc plating, which belongs to alkaline additives; The PH value is 12.5~13. Using this process, the lattice structure of the plating layer is columnar, with good corrosion resistance, and is suitable for color galvanizing. Chloride zinc plating

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