Rainbow chromate passivation (c2C) is performed on the basis of electrogalvanizing to form a colored passivation film with a thickness of about 8-15μm. The salt spray test can last for more than 72 hours without white rust.
Surface treatment: Rainbow chromate passivation (c2C) is performed on the basis of electrogalvanizing to form a colored passivation film with a thickness of about 8-15μm. The salt spray test can last for more than 72 hours without white rust.
Features: In addition to anti-corrosion, it has beautiful appearance and decorative properties, and is suitable for scenes with requirements for appearance. Its anti-corrosion performance is better than that of ordinary electrogalvanizing, especially in humid or slightly acidic and alkaline environments.
Application: It is widely used in infrastructure projects such as ports, power, and railways, as well as heavy-duty pendant fixation in home decoration, such as large lamp bases, radiator hanging cards, etc.
Treatment process | Color | Thickness range | Salt spray test | Corrosion resistance | Wear resistance | Main application scenarios |
Electrogalvanizing | Silvery white / blue-white | 5-12μm | 24-48 hours | General | Medium | Indoor dry environment, ordinary mechanical connection |
Colored zinc plating | Rainbow color | 8-15μm | More than 72 hours | Good | Medium | Outdoor, humid or mildly corrosive environment |
Black zinc plating | Black | 10-15μm | More than 96 hours | Excellent | Good | High temperature, high humidity or decorative scenes |
Environmental factors: Colored zinc plating or black zinc plating is preferred in humid or industrial environments; electrogalvanizing can be selected in dry indoor environments.
Load requirements: For high-load scenarios, it is necessary to select expansion bolts of appropriate grades (such as 8.8 or above) according to the specification table, and pay attention to the impact of the galvanizing process on mechanical properties (such as hot-dip galvanizing may cause a decrease in tensile strength of about 5-10%).
Environmental requirements: Colored zinc plating and black zinc plating may contain hexavalent chromium and must comply with environmental directives such as RoHS; cold galvanizing (electrogalvanizing) has better environmental performance and does not contain heavy metals.
Appearance requirements: Colored zinc plating or black zinc plating is preferred for decorative scenes, and electrogalvanizing can be selected for general industrial use.