Galvanized Steel

What is galvanized steel？

Galvanized steel is standard steel coated with zinc to provide enhanced corrosion resistance. Galvanized protective coatings protect iron and steel substrates from corrosion due to moisture, saturated environmental conditions or ambient humidity. The galvanizing process creates a sacrificial layer between the protective layer of zinc and the steel, thus maximizing protection from the rusty elements.

Galvanized steel manufacturing process

Typically, manufacturers will dip the steel into molten zinc, which will bond itself to the steel like any other alloy. This makes the zinc more than just a protective coating as it becomes part of the steel's chemical composition. The inside might be steel, the outside might be zinc, but in between is a gradient mixture of steel and zinc that combines the properties of both metals.

• Hot dip galvanizing is the most common form of galvanizing.
• You can also spray zinc onto steel, but this method creates a weaker zinc layer.

Galvanized steel applications

Galvanized steel is ideal for outdoor use and is coated with zinc oxide to prevent rust. Zinc oxide provides a protective coating to prevent rust. Zinc oxide coating compounds take longer to corrode than non-galvanized steel. As a cost-effective process, galvanized steel provides you with a maintenance-free material option that is used in a wide range of industries.

Advantages of galvanized steel
Because its sacrificial zinc layer protects from many different types of environmental conditions, galvanized steel offers many unique advantages, including:

• Rust Resistance: The iron in steel is very susceptible to rust, but zinc acts as a protective buffer between moisture, oxygen, and the steel.
• Easy to check: You can judge the strength of the galvanized coating just by looking at it. A quick pressure test can tell you how thick your zinc is.
• Sacrificial Anode: This ensures that any damaged steel is protected by the surrounding zinc coating. It doesn't matter if the steel profile is fully exposed; the zinc will still corrode first.
• Longer Life: With galvanization, a piece of industrial steel can be expected to last over 50 years in average environments and over 20 years with severe exposure to water. No maintenance required.

Disadvantages of galvanized steel

Galvanized steel is not suitable for every application. Certain industrial applications will not warrant the use of galvanized steel due to the following disadvantages:

• Dipping Certain Items Impractical: Some steel pieces are too small or too large to be hot dipped, and there is no point in galvanizing them using other methods.
• Zinc can be temperamental: it's important to give the galvanized steel enough time to cool and settle so the zinc doesn't flake. Galvanizing is not as effective if the zinc does not bond with the steel. The correct coating thickness must be applied.

Will galvanized steel rust?

While galvanized steel provides a protective barrier of zinc oxide, eventually even galvanized steel will rust. The question remains how quickly galvanized steel rusts, with some galvanizing lasting 50 years or more. Some factors that increase corrosion include:

Outdoor environmental issues such as salt water or humidity.
Atmospheric factors such as natural gas or acid rain.
Temperature fluctuations.
Air pollution.

Galvanized steel parts such as nuts or fasteners can withstand exposure to water, but exposure to salt water or immersion underwater will accelerate the degradation of the galvanized coating.