Black passivation has certain anti-corrosion properties, but its use conditions need to be carefully considered.
Author: Marisa
Black passivation has certain anti-corrosion properties, but its use conditions need to be carefully considered.
I. Principle and characteristics of black passivation
Black passivation is a metal treatment process that forms a black passivation layer on the metal surface through chemical reaction, thereby achieving a certain anti-corrosion and beautification effect. This passivation layer is generally an oxide film, mainly Fe3O4 and FeO, so it is also called a black oxide layer.
Compared with traditional surface treatment technologies such as chrome plating and anodizing, the advantages of black passivation are: chromium-free, low cost, environmental protection, no electrolyte, not easy to fall off, high corrosion resistance, fast film formation, and low requirements for raw materials. These advantages make black passivation widely used in industries such as automobiles, home appliances, building materials, and electronics.
II. Analysis of the anti-corrosion performance of black passivation
Since the main component of black passivation is oxide, it has certain anti-corrosion performance to a certain extent, but compared with other surface treatment technologies, its anti-corrosion performance still has certain advantages and disadvantages. It is mainly manifested in the following aspects:
1. Short anti-corrosion time: The salt spray test time that black passivated iron parts can withstand is relatively short, about 48 hours, and it is not suitable for key equipment and parts that are exposed to marine and chloride environments for a long time.
2. Thin film thickness: The thickness of the black passivation film is much smaller than that of electroplating, hot-dip iron plating and anodizing, and its anti-corrosion performance is difficult to compare with these technologies.
3. Harsh conditions of use: The anti-corrosion performance of black passivation is greatly affected by the conditions of use, including the composition, temperature, humidity and other factors of the material, and is not suitable for harsh environments such as high temperature, strong acid and strong alkali.
III. Conclusion
In summary, black passivation has its unique advantages as a surface treatment technology, but its anti-corrosion performance is subject to certain limitations, and its effect is different in different use environments. Therefore, when choosing a surface treatment technology, it is necessary to comprehensively consider various factors and choose a technology that suits you.
Hebei Ruisite (RST) produces kinds of electroplating machines and electroless plating machines. They can be zinc(galvanizing) plating, nickel plating, chrome plating, copper plating, phosphating, gold plating, tin plating, cadium plating etc. Welcome to contact sales manager Ms.Marisa whatsapp 0086-18132654670 for details.