Hot-dip galvanized – what is it?
Hot-dip galvanized (zinc galvanizing in melt) is a simple and effective way to protect steel structures. It protects metal working under the influence of atmospheric, soil, water corrosion, and ensures long life without periodic resurfacing. Zinc film deposited hot method provides a high quality, durable and environmentally friendly corrosion protection at a reasonable price. We propose to consider more principle and main advantages of hot dip galvanizing.
How does this happen?
The film structure is formed by immersion in molten zinc as a result of a diffusion process between zinc and iron. To ensure the smooth interaction of the molten zinc and iron is necessary to perform a pre-cleaning metal surfaces, for example, chemical preparation, consisting of the following steps: degreasing; etching; flushing; fluxing. For the formation of fine-grained plastic coating that retains a metallic luster, galvanized steel is cooled in water. If necessary, obtain coarse matt coating (e.g., a further coloring) metal is cooled in air.
What is different from the hot-dip galvanizing other methods?
During the hot dip galvanizing interact zinc melt with steel. As a result of the diffusion process of zinc atoms penetrate the surface of the steel, and iron atoms in the zinc melt – to form a coating consisting of various iron-containing alloy of the two metals. During the metal removal from the galvanizing bath surface of the iron-zinc alloy on a so-called pure zinc coating layer, the composition of the melt in the corresponding bath.
The presence of chemically bonded iron-alloy leads to the formation of the film are inseparably linked with zinc to the steel substrate (the surface). This is a very important feature, when one considers that the surface of steel parts subjected to heavy loads during transport, installation and so on. Thus, it can be argued that parts of the hot-dip galvanized, is resistant to abrasion and mechanical damage.
coating Thickness
To provide corrosion protection for tens of years, the protective film must have an appropriate thickness. The resulting hot-dip galvanized coating thickness, depending on the chemical composition of the steel and the steel member mass, ranges from 70 to 150 microns.
Anti-corrosion properties of zinc coating provides zinc property to create extremely resistant and sparingly soluble compounds. They are formed during contact with the galvanized surface of air or water. Even after the coating on the impact of aggressive environment Zinc allows you to save all the anti-corrosion properties.
Cathodic protection
What if the transport or installation of corrosion protection components will be damaged? For the majority of anti-corrosion systems is fraught with consequences: microscopic lesions remain generally unnoticed, and soon begin to increase. Larger lesions should be removed, and this requires additional costs.
Zinc coatings provide so-called “cathodic protection” due to the fact that zinc is more active metal less active protection, which is iron. This is a particularly valuable feature of zinc coatings.
Hot-dip galvanizing provides long-term protection of steel against corrosion without the need for the restoration of that, along with the resistance is a key indicator, affecting its efficiency. The cost of hot-dip galvanizing is the end result is low when you consider all the benefits that this method guarantees. With all these advantages it is environmentally friendly protection that meets all 6normam as the national standards, in particular, GOST 9307-89, and the international EN ISO 1461.
Resistance zinc coating depends primarily on the thickness and the degree of environmental aggression. Conducted in the US study the durability of coating hot galvanizing bridge structures show that effective protection can be 70 or more years.
According to the magazine “Professional Painting”
Supports for grapes of our company held a special hot-dip galvanizing. More information can be found in the section “Grape bollards and support.”