Many industries use steel components and complex assemblies for indoor and outdoor spaces that are susceptible to environmental influences. When exposed to the elements, this metal can corrode rapidly. Steel can corrode when it is buried beneath the ground, immersed in salt water, or embedded in concrete.
To reduce corrosion, hot dip galvanizing steel can be used during the steel fabrication process to ensure a quality coating that will last.
What is Hot Dip Galvanizing of Steel?
Hot-dip galvanized steel (also known as batch or after-fabrication galvanizing) is a corrosion-resistant zinc coating process used to line metal.
Following steel fabrication, the metal is cleaned to remove surface grease, oils, and mill scale. The metal is then immersed in a kettle of molten pure zinc and additives. At a metallurgical level, the zinc bath reacts with the steel and forms a corrosion-protective coating.
The galvanizing process coats every surface of the steel, including edges and crevices. Hot dip galvanizing steel is widely used in a variety of industries, including construction. This metal is also used by electrical utilities for power transmission towers and other applications in the energy sector. Metal sculptors may work on a smaller scale.
Key Considerations When Working with Hot-Dip Galvanized Steel
The American Galvanizers Association recommends design and fabrication considerations when working with hot-dip galvanized steel that every fabricator should be aware of during the fabrication process.
Ignore these critical considerations, and you could be dealing with a slew of problems, such as strain-age embrittlement, excessive friction in working parts, a zinc coating that could be damaged during welding, or welds that may not hold.
When designing with hot-dip galvanized steel, keep in mind that the thickness of the steel can affect the functionality of sub-assemblies and components. There could also be parts with overlapping surfaces, which would cause the coating to wear out faster.
Consider the steel types chosen for the component or finished goods during the design phase. When interacting with molten zinc, each steel type will have different metallurgical properties, which can lead to strain-age embrittlement and cracking of the material. Finally, proper venting and drainage are required for galvanized steel to allow cleaning solutions and molten zinc to pass through for a consistent and even coating.
When fabricating with hot-dip galvanized steel, you must consider how the steel will be joined to other similar and dissimilar materials. When you intend to use fasteners on the metal, this is an important consideration. Fasteners should be made of a material compatible with the zinc coating and have the same or greater corrosion resistance so that other materials do not fail prematurely.
If you are welding metal parts together using spot welding or metal-arc welding, take precautions to prevent zinc from penetrating the weld spot and causing cracking. Also, always ensure that there is adequate ventilation or air filtration around the fabrication operations, as extremely high temperatures on thick zinc coatings can emit toxic fumes that can harm worker health.
If you’re using electric resistance welding, you’ll also need to pay close attention to your welding parameters and make sure the electrodes don’t get too hot, as this can cause a variety of problems with the zinc coating.
Hylite Hot Dip Galvanizing Capabilities
Understanding the properties of hot-dip galvanized steel, as well as how to engage in steel fabrication to produce superior end products and sub-assemblies, is critical to safe and productive operations.
As a result, many of our customers rely on us for our full-service fabrication capabilities, which include an in-house finishing shop where we provide hot dip galvanizing, surface preparation, painting, and other services. We have extensive experience hot dip galvanizing steel after it has been assembled into a structure or sub-assembly. We also offer zinc flake coating and electroplating in Mumbai.