The difference between HDGI steel and EGI steel
The surface of electro-galvanized steel is smooth, dense, beautiful and shiny without zinc flower.
The surface of the hot-dip galvanized steel is uneven, rough and uneven, shiny and white. Some products have zinc flowers and knocking may cause the zinc-iron alloy layer to fall off in small pieces.
2.Application range difference
Electro-galvanized is suitable for small parts.
Hot dip galvanizing is more suitable for large parts.
3.Zinc coating thickness and weight difference
The thickness of the electroplated zinc layer is about 10um, the zinc layer is thin, and the adhesion is weak; the minimum galvanized amount is 15g / m2 and the maximum is 100g / m2.
The thickness of the hot-dip galvanized zinc layer is about 60um, the zinc layer is thick, the adhesion is strong, and the zinc layer is not easy to fall off; the minimum amount of galvanizing is 40-60g / m2 on both sides and the maximum is 600g g / m2.
4.Corrosion resistance and zinc coating structure difference
Galvanized zinc has poor corrosion resistance compared to hot-dip galvanized and is suitable for indoor use. The zinc atoms of the electroplated zinc layer are only deposited on the surface of the metal parts and adhere to the surface of the steel strip by physical action. There are many pores, which are easy to cause pitting corrosion due to corrosive media.
Hot-dip galvanizing is more corrosion resistant than electro-galvanizing and suitable for outdoor use. There is a slightly brittle compound layer between the pure zinc coating of the hot-dip galvanized sheet and the steel strip substrate. When the pure zinc coating crystallizes, zinc flower is formed, and the coating is uniform and non-porous.
The price of small parts of electrogalvanized zinc is low, and the price of large parts is high. The process of zinc coating for large parts of electro-galvanized zinc is complicated, the speed of zinc coating is slow, the cost increases more, and it is not economical.
The price of hot-dip galvanized small parts is high and the price of large parts is low. Hot-dip galvanizing has a fast galvanizing speed and a large amount of hot-dip galvanizing.
6.Different degrees of environmental pollution
Galvanized zinc has great environmental pollution, while hot-dip galvanizing has little environmental pollution
7.Processing performance difference
The processing performance of electro-galvanized parts is good: electro-galvanized sheet uses cold-rolled sheet as raw material, which basically guarantees the same processing performance of cold-rolled sheet.
The processing performance of hot-dip galvanized parts is not as good as that of electro-galvanized parts: the heat treatment process of hot-dip galvanized and electro-galvanized sheets is also completely different. The steel strip is heated and cooled in a short time, so the strength and plasticity are affected to a certain extent.