With the development of industry, hot-dip galvanizing design has been used in many fields, the advantages of hot-dip galvanizing are the long anti-corrosion life, adapt to a wide range of environments has been a very popular anti-corrosion treatment method. It is widely used in electric power pylons, communication pylons, railroads, highway guardrails, street light poles, marine components, building steel structure components, substation appurtenances, light industry, etc.
Hot-dip galvanizing has a long anti-corrosion life, but the anti-corrosion life varies in different environments: 13 years in heavy industrial areas, 50 years in the ocean, 104 years in the suburbs, and 30 years in cities.
The principle of hot-dip galvanizing: the iron parts are cleaned, then solvent-treated, dried and immersed in a zinc solution, where the iron reacts with the molten zinc to produce an alloyed zinc layer. The process is: degreasing – washing – pickling – assisted plating – drying – hot-dip galvanizing – separation – cooling passivation.
The thickness of the alloyed layer of hot-dip galvanizing depends on the chemical composition of the steel such as silicon content, the size of the cross-sectional area of the steel, the roughness of the steel surface, the temperature of the zinc pot, the time of zinc dipping, the speed of cooling, and the cold rolling deformation.
Advantages of hot-dip galvanizing：
1. Low treatment cost: the cost of hot-dip galvanizing for rust prevention is lower than that of other paint coatings.
2. Durable: In suburban environments, the standard hot-dip galvanized rust protection thickness can be maintained for more than 50 years without repair; in urban or offshore areas, the standard hot-dip galvanized rust protection layer can be maintained for 20 years without repair.
3. Good reliability: the galvanized layer is metallurgically bonded to the steel and becomes part of the steel surface, so the durability of the coating is more reliable.
4. The toughness of the coating: the galvanized layer forms a special metallurgical structure that can withstand mechanical damage during transportation and use.
5. Comprehensive protection: every part of the plated part can be coated with zinc, even in depressions, sharp corners, and hidden places.
6. Saving time and effort: the galvanizing process is faster than other coating methods and avoids the time required to paint on the site after installation.
7. Low initial cost: In general, the cost of hot-dip galvanizing is lower than applying other protective coatings for the simple reason that other protective coatings such as sanding and painting are labor-intensive processes, whereas hot-dip galvanizing is a highly mechanized, closely controlled in-plant process.
8. Simple and convenient inspection: The hot-dip galvanized layer can be tested visually and with a simple, non-destructive coating thickness gauge.
9. Reliability: Hot-dip galvanizing is generally performed in accordance with BS EN ISO 1461, which specifies a minimum zinc layer thickness, so its rust resistance and performance are reliable and predictable.