Hot-dip galvanizing process provides long-term corrosion protection and many additional benefits that may sometimes be overlooked, forgotten, or misunderstood.
FREMONT, CA: Galvanized steel is all around us in various industries, including road, rail, water and waste, energy plants, oil and gas, agriculture, and sports and leisure. It can play an important role in buildings, bridges, facades, signal gantries, gates, balconies, and even sculptures. Wherever there is a steel corrosion risk, galvanizing should be used.
1. Galvanizing is Durable
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A galvanized coating is one of the market's most durable forms of corrosion protection.
The coating thickness of An average of 85 microns, the same thickness as a sheet of A4 paper, can defend a steel structure for 100 years.
One of the inherent benefits of hot-dip galvanizing is that when clean steel greater than 6mm thick is immersed into molten zinc, it will develop a least mean coating of 85 microns. This coating thickness will encounter the corrosion performance necessary in many applications.
2. Galvanizing is Sustainable
The long-term durability of galvanizing is achieved at a relatively low environmental burden in energy and other globally appropriate impacts.
Various studies have shown the high economic and environmental costs associated with the repeated maintenance painting of steel structures. An initial investment can significantly reduce these burdens in long-term protection. However, a lack of concern for optimal corrosion protection can damage the economic legacy of repeated maintenance costs.
In social housing projects, the local authorities will bear future maintenance costs. In public infrastructure projects, using galvanized steel leads to lower maintenance budgets, releasing public funds for other purposes.
3. Galvanizing is Cost-effective
The cost of protecting steelwork from corrosion has to consider two important elements, the initial cost of protection and the lifetime cost.
Hot-dip galvanizing is often perceived to be more expensive than it is. There are two reasons for this: Firstly, such a high-performance coating is assumed to be expensive. Additionally, the initial cost of galvanizing relative to paint has changed considerably over recent years. As a result, painting costs have steadily increased while galvanizing costs have remained firm.
Galvanizers Association licensed independent consultants, The Steel Protection Consultancy Ltd (SPC), to investigate galvanizing prices and the cost competitiveness of galvanizing. With consulting engineers WS Atkins, SPC designed a typical 240-tonne, steel-framed building and sent it to tender.
Two corrosion protection systems were specified; (i) hot-dip galvanizing and (ii) a good quality grit blast and three-layer paint system of 250µm dry film thickness. Quotations from eight fabricators in various parts of the UK were obtained and averaged. The paint system was 35% more expensive than hot-dip galvanizing.
4. Galvanizing is Reliable
Galvanizing is a comparatively straightforward and closely controlled process. As a result, the coating created is consistent, predictable and simply specified.
Hot-dip galvanizing is defined by a single standard – EN ISO 1461.
For several reasons, galvanizing steel is the most dependable form of corrosion protection. Foremost, as a natural metallurgical reaction – a function of inserting clean steel into molten zinc at a particular temperature – galvanizing is a duplicate process.
Unlike a paint coating, the metallurgical bond formed through galvanizing turns part of the steel itself and is not just a chemical or mechanical bond.
As a natural reaction, galvanizing happens automatically and does not rely on the manual application or require cooling and reapplication of additional layers. The resultant galvanized coating protects the steel from day one and can be depended upon for generations.
We have started creating an archive of case histories. This will attribute a broad range of projects and locations and encompass details from coating thickness measurements to coating aesthetics.
5. Galvanizing is Honest
Corrosion protection operates from day one. If your galvanized coating is present, you can be certain it is working. With hot-dip, galvanizing seeing is indeed believing.
Due to the metallurgical bond formed when steel is dipped into molten zinc, a galvanized coating offers straightforward, secure protection from the get-go.
Hot-dip galvanizing requires rust-free, uncontaminated steel for the process to occur. Once the coating is present, it can't fail from underneath. Other coatings can stick to residual contaminants; this can undermine performance, lead to flaking and cause premature failure.
You can be confident of long-term protection if you can see a constant galvanized coating on day one.
Over a question of months or years, the initial bright, silvery finish will modify to form a dimmer patina as the surface reacts with water, oxygen, and carbon dioxide. A complicated but tough, stable, protective layer is formed, closely adherent to the zinc.
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