Methods of Surface Passivation Treatment

The primary passivation treatment methods used in the production of galvanized steel pipes worldwide are chromate passivation and phosphating treatment. The former is mainly applied when no additional coatings are required on the surface of the galvanized steel pipe after passivation. The latter is mainly used when galvanized steel parts still need to be painted. Chromate passivation treatment is relatively inexpensive and effective, thus it is widely used in the passivation of galvanized steel sheets and galvanized steel pipes.