Hot-dip galvanized pipe and galvanized pipe have great differences in galvanizing. The galvanizing amount of hot-dip galvanizing cannot be too small, and the minimum is 50-60 g/m2 on both sides and up to 600 g/m2. The galvanized layer of the electrogalvanized pipe can be very thin, up to 15g/m2, but if the coating is thicker, the production line speed is very slow, and it is not suitable for the process characteristics of the modern unit, and the maximum is about lO0g/m2. Because of this, the production of electrogalvanized pipes is greatly limited.

Hot-dip galvanized pipe and electro-galvanized pipe are fundamentally different in the microstructure of the coating. There is a layer of slightly brittle compound between the pure zinc coating of the hot-dip galvanized pipes and the base of the steel strip. When the pure zinc coating is crystallized, most of the zinc is formed, and the coating is uniform and non-porous. The zinc atom of the electroplated zinc layer is only deposited on the surface of the steel strip, and is attached to the surface of the steel strip by physical action. There are many holes to dry, which is easy to cause pitting due to corrosive medium, so the hot-dip galvanized sheet is more than the electro-galvanized sheet. More resistant to corrosion.

The heat treatment process of hot-dip galvanizing and electro-galvanized pipe is also completely different. The hot-dip galvanized pipe is generally made of chilled board as raw material, and is continuously annealed and hot-dip galvanized on the galvanizing line, and the steel strip is cooled after being heated for a short time. Therefore, the strength and plasticity are affected to some extent, and the punching performance is worse than that of the same cold-hardened plate after the degreasing and annealing of the professional production line. The electrogalvanized pipe is made of cold-rolled sheet, which basically guarantees the same processing performance of the cold-rolled sheet, but its complicated process also increases the production cost. In short, the hot-dip galvanized pipe has a lower production cost and a wider application range, and has become a major variety in the galvanized pipe market.

Hot-dip galvanizing corrosion resistance is much higher than cold galvanizing (also known as electro-galvanizing). Hot-dip galvanizing does not rust in a few years, and cold-galvanizing will rust within three months.

The cold galvanizing process is used to protect the metal from corrosion. For this purpose, a coating of zinc filler is applied, which is applied to the protected surface by any coating method and dried to form a zinc filler coating in the dried coating. Has a content of zinc (up to 95%). Steel is galvanized on the surface under cooling conditions, while hot-dip galvanizing is the galvanization of the surface of the steel pipe under hot dip conditions. Its adhesion is very strong and it is not easy to fall off. Although the hot-dip galvanized pipe is also rusted, However, in a long period of time, technical and sanitary requirements can be met.
 
The difference between galvanized products:
1) Both the inner and outer walls of the hot-dip galvanized steel pipe are galvanized, while the cold-galvanized steel pipe is only galvanized on the outer wall.
2) The cold plating layer is uniform and the thickness is very thin; the hot plating layer is thick and the thickness is not uniform.
3) The appearance of cold plating is bright and the color of hot plating is dark.
4) Because the cold plating layer is thin, the corrosion resistance is poor; the hot plating layer is several times times thicker than the cold galvanizing, and the infiltrated layer is formed with the base metal, and the corrosion resistance is good.
5) The cold-galvanized steel pipe looks brighter and smoother; the hot-dip galvanized steel surface is not cold-plated and bright, and the surface of the hot-dip galvanized steel pipe looks like some uneven bumps, and the surface is not bright, not reflective.