Prevent Rusting & Corrosion With Galvanized Coils
Certainly, you have noticed the silver shining color on road signs while driving your car, actually this silver is the zinc that coating the steel and making it corrosion-resistance.
The steel that is coated with zinc is called Galvanized steel, and it comes in two forms: galvanized coils and galvanized sheets and has important applications in many industries.
What is Galvanization?
Galvanization is the process of applying a thin zinc coat on steel to prevent rusting and corrosion.
Galvanization helps in shielding steel from surrounding environmental effects.
Galvanization offers a cost-effective solution as an alternative to using expensive materials like austenitic stainless steel or aluminum to prevent rusting.
There are more than one method for galvanizing, but in general all galvanizing methods include four basic steps:
- Surface preparation
- Pre fluxing
This is the most common method of galvanizing, and as its name indicates it involves immersion steel in a pool of molten zinc.
- First, the steel is cleaned mechanically and chemically to ensure forming a strong bond between steel and zinc.
- Then steel is fluxed to get rid of any residual oxides that might remain after cleaning.
- Finally, the steel is dipped into a liquid bath of heated zinc and a metallurgical bond is formed between zinc and steel.
Hot-dip galvanizing is an economical process, and can be applied quickly and on complex shapes of steel, but it doesn’t give high-quality finishing like other methods.
This method is very similar to hot-dip galvanizing but is usually performed on materials that already have a specific shape.
- First, the steel sheet is rolled through a cleaning process.
- Then, the steel is passed through a pool of hot, liquid zinc.
- Finally, the metal sheet is winded to form a galvanized coil.
With Pre-galvanizing, a uniform zinc coating can be applied to large steel coils rapidly. but, while fabrication of this steel, the uncoated areas start to appear like cut edges.
This method is different to previous methods. Electro-galvanizing doesn’t use a bath of molten zinc, instead it uses an electrical current to apply zinc on the steel.
- First, the steel is cleaned and prepared for galvanizing.
- Then, an electrical current in an electrolyte solution is used to reduce the positively charged ions in zinc metal which is then deposited on the positively charged steel.
- After that, grain refiners are added to ensure a smooth zinc coating.
- Finally, galvanized steel is rolled into coils.
Electro-galvanizing gives a uniform coating and precise coating thickness.but, the zinc layer is typically thinner than the zinc layer in hot-dip galvanizing which reduces the corrosion protection.
How galvanizing protects steel?
Iron and other metals generally corrode when exposed to oxygen and water or moisture.
The oxidation of the steel forms the undesired rusting.
The zinc coating that applied by galvanizing protects steel in three ways:
1. Barrier protection for rust prevention:
The galvanized coating forms a protective envelope around the steel that prevents corrosive substances from reaching to it.
Also, the zinc protects its base steel by corroding before it.
2. Protective patina:
The zinc reacts with the environment and develops a protective patina on its surface that is insoluble in rainwater.
The protective patina reduces the exposure of galvanize coating to the environment and thus greatly slowing the corrosion process.
This patina regenerates itself after damage by slowly consuming the zinc coating.
3. Small damaged areas protection:
When galvanized steel is cut, drilled or scratched, the exposed small areas of steel are still protected by surrounding or remaining zinc coating.
for example: the uncoated internal threads of galvanized nuts are protected from corrosion by the zinc coating on studs and bolts.
- Galvanizing is lower in first cost than other coatings that are used in steel protection.
- Galvanizing is cheaper in the long term since it lasts longer and needs less maintenance.
- The average life of galvanized coating exceeds 50 years in inner areas and more than 25 years in coastal areas.
- Galvanizing is applied according to global standards, thus the coating life and performance are reliable.
- The galvanized coating offers significant resistance to mechanical damages while transporting and erection.
- Small damaged areas don’t need any repair because they are automatically protected by surrounding zinc coating.
- Every part of galvanized steel is protected, even the unreachable parts like holes and sharp corners.
- Galvanized coating can be easily checked by eye, if it appears continuous and sound then it is.
- Galvanized steel is ready for use, there is no need for surface preparation.
- Galvanizing is a fast process and can be applied in minutes, it is not related to weather conditions.
Galvanized Coils Applications:
Galvanized coils have basic application in many industries:
They are mainly used for roofing in industrial and residential buildings to prevent corrosion and weather elements.
Galvanized steel coils are ideal options for constructing strong roofing systems over bridges and valleys, the coil is rolled out flat on the roof, and bent either over a bridge or a valley.
Also, they are used in inner construction like doors, shelves, electrical light fittings and dry wall partitioning systems
In light industries:
They are used in outer covers for electrical appliances, Kitchen tools,water heaters, solar panels and furniture.
They are used in manufacturing automobile parts that are exposed to corrosion and for wheels, truck bodies and railcar components.
They are used in farming, animal husbandry, and fishery area for transport and storage and also in manufacturing agricultural equipment.
Galvanized coils from our company:
With the aim to provide you the excellent service and best quality and durability of steel coils, Exanvil Gmbh keeps dealing directly with largest steel manufacturers in Europe, Ukraine and Russia and bringing you the best qualities and prices.
Galvanized coils are available in standard or specific sizes and dimensions.
Other types of galvanized steel like wires or structural steel are also available upon your request.
Exanvil Gmbh company has extensive experience in trading steel products, you will be satisfied and glad dealing with us.
Galvanized coils are really very important steel products that serve efficiently in corrosive environments and also distinguished by cost and durability benefits.