Hot-dip galvanisation is the process whereby steel is given corrosion protection. It entails the dipping of steel in a bath of hot molten zinc to create an even coating over the steel. Through this method, the zinc bonds with the underlying steel to create a strong, durable, and corrosion-resistant surface.
Galvanised steel is used in building and construction, roadworks, agriculture, sport structures, and more. Wherever there is a risk that steel will be exposed to water and environmental factors, it is imperative to protect it, possible with galvanisation. With the high-corrosion activity in coastal areas, it is imperative to use only hot-dipped galvanised steel in any type of road or construction project to ensure the steel can be protected for at least 25 years.
Armco Galvanisers Isando and Armco Galvanisers Randfontein provide high-quality galvanisation services. Clients benefit from the quality control systems in place, adherence to strict international and local standards for galvanisation, and the expertise of the firm. To understand why it is crucial to purchase galvanised steel products for culverts and other outdoor applications from trusted galvanisers such as Armco Galvanisers in Isando and Randfontein, we briefly look at the top reasons to galvanise steel below.
Improves Durability Through Long-Term Protection of the Steel Surface
Even a galvanised coat at the micron thickness of A4 Bond paper provides for protection against corrosion for more than 25 years. It has been reported that a sheet of clean steel of more than 6-mm thick, galvanised through the hot-dip method has a corrosion protection layer of at least 85 microns, which is about the thickness of a sheet of typing paper. Every micron in thickness provides a protective coating. The zinc offers itself where the surface is scratched, ensuring that the integrity of the coated steel is not compromised.
Corrosion Protection with a Low Environmental Impact
Hot-dip galvanisation provides long-term corrosion protection whereas having to paint steel to provide protection entails applications of the protective paint every few years. Companies thus focussed on the reduction of their environmental footprint benefit from making use of our processes and galvanised steel products. The repeated labour, chemical applications, and costs associated with non-galvanised steel products have long-term economic, social, and environmental effects. Using galvanised steel, such as W-beam guardrails in road infrastructure projects and for housing projects, helps local authorities and roadworks maintenance authorities to save money over the long term as the products are durable and don’t require regular protection maintenance. These savings can be used towards other projects to the benefit of communities in South Africa.
Cost-Effective Means to Prolong the Lifespan of Steel Products
The misconception exists that the process is expensive and that this makes steel products expensive. The truth is that unprotected steel cannot be used outdoors. The steel must receive a type of protection such as paint, but the cost of paint has gone up over the years while galvanisation prices have stabilised. With paint prices going up with inflation, maintenance coats every few years also go up with inflation. Considering that the steel is protected for at least 15 to 25 years through hot-dip galvanisation, and it becomes clear that the initial investment is worth the many years of not having to apply protective paints. Also, consider the cost of appropriate paint and the two to three layers needed for the initial protection. Galvanisation is thus the best option for durability, environmental impact reduction, reduced maintenance costs, and initial protection.
Proven Track Record
Galvanisation has been used for more than one hundred years and many of the steel products that were galvanised decades ago are still in working order. This is testimony to the strength given and durability features possible. The industry is well regulated and strict standards apply. Plants with the likes of Armco Isando and Armco Randfontein adhere to the strict standards and are members of professional associations in the industry, ensuring ethical conduct and adherence to strict quality standards and processes. Clients benefit from the consistency in performance and knowing that they can trust the warranties given on products.
Reliability and Consistency in Performance
As mentioned earlier, the galvanisation industry is well regulated. Armco’s hot-dip galvanising plants are listed according to the ISO 9001:2015 scheme for quality management systems. The company’s plants are also SANS 121 / ISO 1461 accredited. This means that the company complies with international standards for hot-dip galvanising. With a regulated process in place, predictable end results are possible, making galvanisation as applied by Armco Superlite a reliable process.
The steel is cleaned and then dipped in the molten zinc. This is done at a set temperature. The outcome can thus be controlled, and the process repeated with the exact outcome possible because the metallurgical bonding of zinc with the steel takes place at the set temperature. Instead of the zinc being an overlay on the steel, it bonds with it. The zinc becomes part of the steel through the bonding process. This is unlike paint, which just serves as a protective coat. If the paint is scratched and the steel exposed, the steel corrodes. With galvanisation, the zinc becomes a part of the steel. If the surface is scratched, the zinc offers itself and the steel stays protected. Paint is only a chemical bond whereas, with the galvanisation process, the zinc forms a metallurgical bond with the steel, making it a superior bond and thus protection.
The bonding of the zinc with the steel is a natural metallurgical process. It happens automatically at the set temperature. It is a strong bond from the moment it happens. The steel is immediately protected, and this protection lasts for years.
Hot-dip galvanisation only works if the steel is corrosion free and clean. If not, the failed results are immediate. If the steel is clean and corrosion-free, the zinc bonds with it at the right temperature. The bonding is immediate. Corrosion thus does not occur from underneath the zinc surface. With other types of protective coats, it is possible for the coats to adhere to contaminants on the surface of the steel, giving the impression of protection at first, but flaking can occur later and the steel integrity can thus be compromised. This may only become visible later on.
Where to Find Trusted Galvanisation Plants in South Africa
Armco Galvanisers Isando has a track record of excellence dating back to 1989. The plant in Isando has been designed for hot-dip galvanisation of heavy structural steel of up to 13 metres in length. With a production output of up to 2 000 tons per month, the Isando plant can handle large projects with ease. The Armco Galvanisers Randfontein plant has been designed for light and medium structural steel galvanisation for steel of up to 6 metres in length. The production output is on average 800 tons per month, also ensuring optimal project handling capacity.