Differences Between Hot-dip and Electro-Galvanized Coils
1. Zinc Layer Thickness
Generally, the thickness of the electro-galvanizing layer is 5-30 g/㎡, and the hot-dip galvanizing layer is often more than 30 g/㎡, or even as high as 600 g/㎡ . At , the max zinc layer of hot-dipped galvanized (HDG) steel can reach up to 275 g/㎡ (Z275/G90, about 38.5154 μm for both sides).
2. Corrosion Resistance
The corrosion resistance of HDG coil is much better than that of an electro-galvanized one. It is because the zinc layer thickness directly matters to the corrosion resistance of GI steel. As for HDG steel, there is a compound layer between the zinc coating and substrate. When the zinc coating is crystallized, spangles are formed. Its zinc coating is uniform and free of pores. While the zinc atoms of the electro-galvanized layer are only precipitated and attached to the surface of the steel. There are many holes in the zinc coating, which causes corrosion easily. So HDG steel can last for decades in outdoor environments.
3. Appearance
The color of the galvanized steel coil is silver-white. The appearance of cold galvanized steel is smooth but not very shiny, while the hot-dip galvanized steel coil looks rough but bright.
4. Production Cost
HDG process consumes more zinc. Compared with hot-dip galvanized steel, the production cost of electro-galvanized steel is lower. But hot-dip galvanizing is suitable for massive production and the yield is high. So the HDG steel price is not much higher than cold galvanized steel.
5. Applications
The hot-dipped galvanized steel coil is widely used in transportation, building, communication, electric power, energy, automobile, petrochemical, home appliances, and other industries. It is ideal for large parts and equipment. While the electro-galvanized coil is more suitable for small parts, indoor environments, etc.
1. Cost-effective Solution
Compared to GL or color coated steel coils, the galvanized coil is the most cost-effective solution but with similar features, such as great corrosion resistance, good appearance, etc.
2. Wide Applications
GI sheet roll is easy to process for different purposes. It is widely used in construction, home appliances, automobile containers, transportation, etc. Besides, it has good coating adhesion and weldability. That's why it is also an ideal base metal for PPGI products.
3. Easy to Transport
Compared to GI steel sheets, coils are easier to transport. In this way, it will save your shipping cost.
