The best method providing corrosion protection is hot galvanization. This is a particularly effective, durable and known for 160 years method providing corrosion protection. The conventional method of hot galvanization consists of a series of processes. One of the most important is immersion of the charge in a bath of molten zinc of temperature 450°C. The, fast reaction between iron and zinc takes place, which leads to formation of zinc coating on the steel surface. Its composition and properties depend on the chemical composition of the steel substrate as well as on structure thickness.
When specified conditions concerning steel grade are met (this concerns silicon and phosphorous content) as well as with proper design of elements to be galvanized, it is possible to obtain a coating of thickness 70 to 200 micrometres, resistant to mechanical damage, abrasion, erosion, strokes, free from roughness, showing perfect adhesion to substrate, of great ecological and aesthetic values.
Zinc coating protects steel for many years and does not require maintenance. Average durability of zinc coating is 30 – 50 years. Moreover, it is possible to extend its life and provide the product with required aesthetic properties by covering the zinc coating with additional lacquer or paint layer (so called duplex system). Because of long-term protection against corrosion provided by hit galvanized coating, it is a very economic protection. Costs sustained at the moment of providing the coating with reference to its end of life are negligible. The below graph presents comparison of costs concerning two popular methods of providing corrosion protection: painting and galvanizing. As you can see, in case of paint coatings, cost increase step-wise and this is due to low durability of the coating and the necessity of maintenance coating. Hot galvanized coating does not require this thus the costs remain unchanged.
Additional evidence supporting selection of the hot galvanized coating is the time of completing the operation. In case of hot galvanized coating, this is a few hours.
There are two technological lines for hot galvanization in Mostostal Siedlce, equipped with baths of the following dimensions:
Length x width x depth:
- 13000 x 1800 x 3300 mm
- 9000 x 1800 x 3300 mm
- 7000 x 1800 x 3300 mm
- 12500 x 1700 x 2900 mm, unitary weight up to 4 tonnes
- 8500 x 1700 X 2900 mm, unitary weight up to 6 tonnes
- 6500 x 1700 x 2900 mm, unitary weight up to 4 tonnes
