The Difference Between Hot-Dip Galvanized Pipe And Pre-Galvanized Pipe

The process difference between hot dip galvanizing and pre-galvanizing
Hot-dip galvanizing involves immersing steel in a pool of molten zinc, and a layer of zinc alloy coating is coated on the surface of the steel through a chemical reaction. Because the steel is exposed to high temperatures, the coating is firmly connected to the steel surface and therefore more resistant to corrosion. Pre-galvanizing is to galvanize the steel first, apply a thin layer of zinc on the surface of the steel, and then process it. This method is weaker than hot-dip galvanizing in terms of surface protection.
The anti-corrosion effects of hot-dip galvanizing and pre-galvanizing are different
Since hot-dip galvanizing has a thicker coating, it is more effective at protecting than pre-galvanizing. The coating thickness of hot-dip galvanizing is generally 45~85μm, while pre-galvanizing only has a zinc coating of about 5μm. Therefore, under the same conditions, hot-dip galvanizing steel has better anti-corrosion effect.
Hot-dip galvanizing and pre-galvanizing have different appearances
Hot-dip galvanizing usually presents a smoother surface, which looks more crystal clear, and is more suitable for products that require high aesthetics, such as kitchen appliances. On the contrary, the pre-galvanized coating is relatively thin, has a rough surface and looks mottled, and is more suitable for industrial products.
The cost of hot dip galvanizing and pre-galvanizing is different
Due to process differences, the cost of hot-dip galvanizing is higher than that of pre-galvanizing. Since hot-dip galvanizing requires special processes, the impact on production costs is even more significant.
To sum up, hot-dip galvanizing and pre-galvanizing are different in terms of process, anti-corrosion effect, appearance and cost. The specific application needs to be selected according to the actual situation.