1.What are the differences in process principles?
Electrogalvanized pipe: Using the principle of electrolysis, the metal product to be plated is used as the cathode and placed in an electrolyte containing zinc ions. Through the action of direct current, the zinc ions are reduced and deposited on the surface of the metal product to form a zinc coating.
Hot-dip galvanized pipe: The metal products that have been pre-treated by degreasing, pickling, etc. are immersed in molten zinc liquid at about 450°C. Under high temperature, zinc reacts chemically with the metal surface to form a zinc-iron alloy layer and a pure zinc layer, thereby attaching a layer of zinc to the metal surface.
2.What is the difference in coating thickness?
Electrogalvanized pipe: The coating is relatively thin, usually between 5-20μm.
Hot-dip galvanized pipe: The coating is thicker, usually between 50-100μm, or even higher.
3.What is the difference in coating adhesion?
Electrogalvanized pipe: The bonding force between the coating and the substrate is relatively weak. When subjected to external impact or friction, the coating is prone to peeling.
Hot-dip galvanized pipe: The coating and the metal substrate form a metallurgical bond with a strong bonding force and are not easy to peel off.
4.What is the difference in productivity?
Electrogalvanized pipe: The process is relatively simple, the production speed is fast, the production efficiency is high, and it can quickly form a uniform coating on the metal surface.
Hot-dip galvanized pipe: The production process is relatively complex, requiring multiple pretreatment steps, and the metal products are immersed in the zinc liquid for a long time, the production speed is slow, and the production efficiency is relatively low.
5.What is the difference in corrosion resistance?
Electrogalvanized pipe: The amount of zinc plating is very small, only 10-50g/m², the zinc layer is thin, the zinc layer is simply attached to the steel pipe substrate and is easy to fall off, so its corrosion resistance is poor.
Hot-dip galvanized pipe: The zinc layer is thick, with the advantages of uniform plating, strong adhesion, long service life, and strong corrosion resistance.