Electro-galvanizing is the electro-chemical deposition of a zinc layer on a metal surface, due to its relatively thin coating, the salt spray test time is relatively short. Electro-galvanized layers without additional treatment can withstand a salt spray test of 24-36 hours;
Author: Anna
The salt spray resistance time of galvanizing varies depending on the galvanizing process and post-treatment method.
Salt spray resistance time of different galvanizing processes
Electro-galvanizing: Electro-galvanizing is the electro-chemical deposition of a zinc layer on a metal surface, due to its relatively thin coating, the salt spray test time is relatively short. Electro-galvanized layers without additional treatment can withstand a salt spray test of 24-36 hours; if post-treatment such as blue-white passivation is carried out, the salt spray time can be increased to not less than 72 hours.
Hot-dip galvanizing: Hot-dip galvanizing involves dipping metal parts into molten zinc to form a thicker layer of zinc on the surface. Under standard salt spray test conditions, hot dip galvanized layers can withstand hundreds to thousands of hours of salt spray testing. This time may be longer if additional corrosion protection treatments are applied, such as passivation, sealing or painting.
Factors affecting salt spray test time
In addition to the galvanizing process and post-treatment method, salt spray test time is affected by the following factors:
Thickness of the plating: the thicker the plating, the longer the salt spray resistance time.
The quality of the galvanizing process: a good quality galvanizing process can improve the denseness and adhesion of the plating layer, thus prolonging the salt spray resistance time.
Salt spray test conditions: The temperature and humidity of the test environment will also affect the results of the salt spray test.
Methods to improve the salt spray resistance of galvanized layers
In order to extend the salt spray resistance time of the galvanized layer, the following measures can be taken:
Optimize galvanizing process parameters: Improve the quality and denseness of the coating by adjusting the process parameters.
Enhance post-plating treatments: Treatments such as blue-white passivation, sealing or painting can significantly improve the corrosion resistance of the galvanized layer.
Selection of high-quality galvanizing additives: The use of high-quality additives can improve the performance of the coating, thereby extending its salt spray resistance time.