1. Thickness Differences: The hot-dip galvanized zinc layer itself is relatively thick, generally over 10µm thick, which provides excellent corrosion resistance. While the surface is bright, it is slightly rough and may show zinc spangles.
Electro-galvanized steel, on the other hand, has a thinner zinc layer, approximately 3-5µm thick. While smooth, it can appear dull and smudged. While workability is good, corrosion resistance is limited.

2. The surface of hot-dip galvanized steel is a pure zinc coating, which is uniform and has no pores. However, there is a layer of relatively brittle compound between the coating and the substrate.
The electro-galvanized coating is composed of only zinc atoms, which are deposited on the surface of the steel strip. It is a physical adhesion effect and has many pores on the surface, so it is more susceptible to corrosion.

3. Hot-dip galvanizing uses the alloying reaction of metallic zinc and iron at high temperature to form a zinc-iron alloy layer on the surface of steel. The process is relatively complex and has certain requirements for steel, but the coating is stronger, more corrosion-resistant, and has a wider range of applications.
Electrogalvanizing is the process of forming a zinc layer on the surface of steel using electrochemical principles. The process is simple, environmentally friendly and low-cost, but the coating is thin, the adhesion between the zinc layer and the steel substrate is poor, and its scope of application is narrow.

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