Steel Fabrication: The Hot-Dip Galvanizing Process

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Steel can corrode especially when it’s entirely to sea water or moist air. So all equipment hardware has very high requirement for corrosion protection. There are ways to protect steel from getting corroded: zinc plating and hot-dip galvanizing. These methods involve using zinc for anti-corrosion purpose. The primary behind these two processes is the same: using the oxidation reaction of zinc.

But why zinc? Zinc is a strong reducing agent and a fairly reactive metal. The surface of pure metal could quickly tarnish, eventually forming a protective layer of zinc carbonate, due to the reaction with carbon dioxide in the atmosphere. Such protective layer adheres to the metal’s surface, helps hamper further reaction with air and moisture, and extends the metal’s life expectancy.

There are different benefits of using zinc as the primary material for corrosion resistance. One of the many benefits of zinc is that the length of time for the oxidation reaction to transpire takes just a couple of minutes, and it’s easy for manufacturers to operate. It is also cheap and readily available. These are the main reasons why such metal is popularly utilized for protecting steel.

So what’s hot dip galvanizing? It is the immersion of iron or steel in molten zinc creating a protective finish. The galvanizing reaction transpires only on a surface that is chemically clean. Just like other coating processes, the key to achieving a quality coating will depend on how well the surface of the steel is prepared. It is very important that the steel surface is free from any dirt or grease before before the coating process starts.


When the steel or iron component is submerged in molten zinc (at 450 degrees Celsius) a series of zinc-iron alloy coatings are created by a metallurgical reaction between the zinc and steel or iron. Once the iron or steel piece is withdrawn from the zinc bath, a molten zinc layer is taken out on the top of the alloy layer. It should cool down to display the shiny appearance of zinc finish. When the chemical reaction between the steel and the zinc stops and the steel is taken out of the molten zinc bath with its external zinc finish, the process is finished.


Complete Coverage: Because piece of iron is submerged into molten zinc, all parts of the article are coated — both inside and out — including all gaps and corners.

Toughness: The zinc coat metallurgically bonds with steel component, providing further protection against damage compared to other kinds of coatings.

Three-way Protection: Hot-dip galvanizing protects the iron in 3 ways. It doesn’t wear out quickly, providing a long life. The coating sacrifices itself to small areas exposed due to accidental drilling, damage, or cutting. If big areas get damaged, the finish hampers the sideways creep of corrosion.

To get good quality steel products that have undergone hot-dip galvanizing, visit TCG industries in Mandurah by clicking on the given link.

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