What is galvanising?
Galvanising is the process of protecting steel or iron from corrosion. It involves the coating of a thin layer of zinc on the metal surface to offer protection and prevent rusting. Galvanised steel is widely used in construction because it can offer the high strength and durability properties of steel plus the long-lasting protection of zinc coating.
What is involved in the process of galvanising?
There are different methods of galvanising with the most common being hot-dipped galvanising. The steps involved in galvanising steel can be summarised as below:
- Degreasing: This is a preliminary treatment in which a hot alkali solution, mild acidic bath or biological cleaning bath removes the contaminants on the metal surface such as dirt, oil, paint etc.
- Pickling: After degreasing, the steel undergoes pickling in which an acid is used to clean any mill scale or rust from its surface. Usually sulfuric acid or hydrochloric acid is used for this purpose.
- Fluxing: This is the final surface preparation step. Steel is immersed in a zinc ammonium chloride solution which removes any remaining oxides and forms a protective layer on the surface which prevents further oxidation prior to galvanising.
- Galvanising: Steel is immersed in molten zinc where the bath is at least 98% pure zinc and maintained at a temperature of approximately 449 degree celsius. The period of immersion can be from a few minutes for relatively light structures, or longer for heavy structures. This process results in the formation of an outer protective layer of zinc.
Zinc will not react with unclean steel. Therefore, the quality of zinc coating can be easily determined by a visual inspection.
Advantages of galvanised steel
Less maintenance cost:
The protective layer of zinc prevents it from rusting and damage. So no on-going maintenance or extra coats of paints will be required.
The galvanising of steel at Melsteel is carried out according to the Australian standards. Coating life is reliable and predictable for all the galvanised steel products we sell.
Steel which is galvanised is ready for use immediately at the site. No time is lost preparing the surface or painting.
Every part of the steel including all the sharp corners and inaccessible areas are protected through galvanising.
Uses of galvanised steel
Galvanised steel is used almost everywhere!
You will see galvanised steel in the construction of modern steel-frame buildings, verandas, balconies, fences, roofs, walkways and more. It is also widely used in the wind & solar industry and in the agriculture industry where the equipment needs high- protection from harsh environmental damages. Automotive industry commonly utilises galvanised steel in the construction of cars. It is also popularly used in marine environments.Telecommunication industry uses galvanised steel in phone lines to reduce the risk of damage.
With over 30 years of industry knowledge and experience, Melsteel continues to build decade long relationships within the building and construction industry, providing a reliable source for steel in Melbourne.
At Melsteel, we offer a range of galvanised steel products. Our stock includes Galvanised steel channels, Galvanised T bar cut to size, Galvanised steel angles, Galvanised SHS Steel, Galvabond and much more! You can buy steel online at Melsteel or give us a call on 03 8794 3100 and our sales team can help you get your steel project started today.
You can also send us your drawings at email@example.com or just tell us your requirements and we can draw it for you. We can fabricate, cut the steel to your requirements, deliver and install it for you at your site.
Download the latest copy of our steel prices here.