The History & More of Galvanising

Ever since the Industrial Revolution, the demand for steel and other metallic products has only increased manifold for a variety of reasons such as cost, durability and structural strength. However, one of the banes of using metal is the danger of corrosion, which is the deterioration of metal due to a reaction with its environment. Galvanising as a process helps prevent these risks of corrosion, hence minimising wastage, and making your product durable and sustainable.

What is Galvanised Steel?

Patented and invented as a process by Stanislas Sorel in 1836, galvanising refers to the cutting of steel, and then coating it by dipping it in molten zinc. Also known as hot-dipped galvanising, this is an efficient method that is used by all industries to safeguard their metallic products or parts and components.

Just like all other metals, zinc is not immune to corrosion, however, it does not rust like most metals. When zinc reacts with atmospheric oxygen, it forms an oxide layer, which in turn reacts with the moisture to form zinc hydroxide. This then reacts with carbon dioxide to form zinc carbonate, which is resilient and chemically stable. It acts as a protective barrier by attaching itself to the substrate, hence protecting it from corrosion and deterioration. Zinc also has a faster rate of corrosion, hence making it a good choice for protecting other metals, like iron, and alloys, such as steel.

What Is Hot Dipped Galvanised Steel? Hot Dip vs Cold Galvanising

Two of the primary methods for galvanising a metal are hot-dip galvanising and cold galvanising. Both methods serve to provide a similar result, in the sense that they both protect the substrate from corrosion and deterioration. In hot dipping, the metallic object is immersed into a zinc bath at temperatures of about 449°C (840°F), then allowed to cool down and chemically bond with the substrate. Cold galvanising, on the other hand, is somewhat of a misnomer, and is simply the application of zinc-rich paint to a surface by using a brush, roller or spray gun. In this case, the zinc mechanically bonds with the surface through the presence of a binding compound.

The main difference between the two methods is the level of protection offered to the substrate, with hot-dipped metals much better equipped to deal with corrosion than cold galvanised ones. As such, the costs for hot-dipping is much higher as well and is therefore used for heavy-duty industrial uses and larger structures. What method of galvanising you choose largely boils down to this cost-benefit analysis.

How is Galvanised Sheet Metal Made?

One of the most basic forms of metalworking, sheet metal is a metal that is shaped into thin, flat pieces that is thicker than foil, but thinner than 6mm. Sheet metal is made by running hot slabs of metal through rollers that make it thinner and longer, and then cooled and rolled into coils. Based on its usage, sheet metal can be treated with other finishing procedures, and galvanising is one of them. Sheet metal undergoes one of the galvanising methods to increase its resistance to corrosion, hence making it more durable and increasing its utility and making it suitable for a variety of applications.

Can Galvanised Steel Be Laser Cut?

When it comes to laser cutting galvanised steel, safety is paramount. The high temperatures that laser cutters produce can release zinc fumes from galvanised surfaces, which in high doses can cause metal fume fever. This can result in flu-like symptoms, such as nausea, chills, aches, dizziness and fever. Using a computer-controlled laser avoids human error and distances said person from the whole process. Having a well-ventilated room with a filtration extractor also helps in the easy passage of these potentially harmful fumes.

Why More People Are Choosing to Laser Cut Their Steel?

Computerised laser cutters provide a seamless finish with a virtually negligible margin of error, are quick and cost-effective. Laser cutting also helps produce all kinds of objects or products, from decorative to technical ones, and is used across industries. At Lightning Laser, our team of experts has decades of experience in laser cutting and other related services, such as anodising, powder coating and engraving. If you have any questions about our services, send us an email at [email protected] or give us a call at (03) 9587 7999.

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