There are a number of reasons why galvanising steel is the most reliable form of corrosion protection. Firstly, as a natural metallurgical reaction – a function of introducing clean steel into molten zinc at a specified temperature – galvanizing is a replicable process.

• As a natural metallurgical reaction – a function of introducing clean steel into molten zinc at a specified temperature – galvanizing is a replicable process.
• Unlike a paint coating, the metallurgical bond that is formed through galvanizing becomes part of the steel itself and is not merely a chemical or mechanical bond.
• As a natural reaction, galvanizing occurs automatically and does not rely on manual application, or require cooling and reapplication of additional layers. The resultant galvanized coating protects steel from day one and can be depended upon for generations.

• After an initial cleaning cycle, clean iron or steel components are immersed into molten zinc, commonly at around 450°C. The rate of reaction is rapid and a typical time for immersion is only a few minutes. Heavier articles with a high thermal inertia may take longer.
• A further benefit of hot dip galvanizing is that hollow components are coated on internal surfaces too, meaning that a structure will not corrode from the inside out. In addition, the coating will also build up at vital corners and edges, unlike brushed or sprayed coatings, which traditionally thin out in these areas.
• Hot dip galvanizing is used equally for small components, making sure they are given the same level of corrosion protection as larger articles. Complete structures receive complete corrosion protection.

Due to its unique metallurgical bond, a galvanized coating is incredibly tough, offering exceptional performance across multiple layers. An initial outer layer provides reliability as a buffer zone, helping to absorb any initial shock to the coating.

Underlying zinc-iron alloys can be harder than mild steel itself, and will further reduce any potential penetration of the coating or the exposure of bare steel.

This means that a galvanized coating is highly chip resistant and particularly suited to areas of high frequency industrial wear. 

Microsection of a hot dip galvanized steel coating. The zinc-iron alloys can be harder than the base steel.

Hardness, HV values >

A galvanized coating can also help prevent damage during construction, where its toughness can protect components during transport, erection and the other mechanical activities.

Overall a galvanized coating has a high corrosion prevention value. It is extremely hardwearing, long-lived and suited to applications where both mechanical and corrosive protection are paramount. 

It is the most durable corrosion protection on the market, and provides optimum performance without the expense or disruption of maintenance procedures. There are three ways a galvanized coating will protect your steel.

Galvanizing is not a time-consuming process and in reality, it takes just a few minutes to dip prepared steelwork into molten zinc to form a durable, reliable coating.

The metallurgical reaction occurs in a matter of minutes, with the whole galvanizing procedure taking only a few hours. In practice of course, there are many orders being processed at a galvanizing plant at any one time, so the typical turnaround for hot dip galvanizing is about three days.

Today’s galvanizing plants have highly efficient logistics in place, meaning that your steelwork can be galvanized in as little as 24 hours if arranged in advance. 

• It pays to communicate with your galvanizer and a quick phone call a few days ahead is all it requires to plan work into a busy galvanizing schedule.
• Sending in ‘clean’ steelwork will save preparation time. Work that is contaminated with material which will not be removed by the normal galvanizing pre-treatment, will need special steps to remove it.
• The same applies for venting and drainage. As a dip process, galvanizing will protect the inside of steel sections as well as the outside, these holes are in the right places. Ensuring that there are correct vent and drain holes in hollow steelwork, saves the galvanizer valuable time, as they would have to complete that work for you.
• Finally, it pays to liaise on transport. If the galvanizer is providing transport, liaise about the regular runs and plan around them. Galvanized steelwork may even be able to go directly to site.

The coating thickness depends upon the gauge of the steel that is galvanized and is produced consistently across the component, both inside and out. This can be measured easily throughout its lifetime, using non-destructive methods.

Galvanized steel coating minimum masses/ thickness on articles that are not centrifuged.

Galvanized steel coating minimum masses/ thickness on articles that are centrifuged

Galvanizing weathers in a predictable, linear fashion. This guarantees that if climactic conditions are stable, the lifespan of a galvanized coating can be correctly forecast, and there will be no unexpected surprises.

The lifespan of the coating is also exceptionally long compared with other forms of corrosion protection and will weather at less than one micron per year in certain climates. The local rate of weathering of any given galvanized coating can be reliably calculated.