With the development of industry, hot-dip galvanized products have been applied in numerous fields. The advantages of hot-dip galvanizing, such as its long-term corrosion resistance and wide environmental adaptability, have made it a popular corrosion treatment method. It is extensively used in power transmission towers, communication towers, railway and highway protection, streetlight poles, ship components, building steel structures, substation facilities, and light industry, among others.
Hot-dip galvanized coatings offer long-lasting corrosion protection, but the lifespan varies depending on the environment: 13 years in heavy industrial areas, 50 years in marine environments, 104 years in suburban areas, and 30 years in urban settings.
Hot-Dip Galvanizing Principle: The iron parts are first cleaned, then solvent treated, dried, and immersed in a zinc bath. The iron reacts with molten zinc to form an alloyed zinc layer. The process includes: degreasing -- water washing -- acid pickling -- pre-galvanizing -- drying -- hot-dip galvanizing -- separation -- cooling passivation.
The thickness of the galvanized alloy layer primarily depends on the chemical composition of the steel, such as its silicon content, the cross-sectional area of the steel, the roughness of the steel surface, the temperature of the zinc pot, the immersion time, the rate of cooling, and cold rolling deformation.
Advantages of Hot-Dip Galvanizing
Low Processing Costs: The cost of hot-dip galvanized rust prevention is lower than that of other paint coatings.
2. Longevity: In suburban environments, the standard hot-dipped galvanized corrosion protection can last over 50 years without maintenance; in urban or coastal areas, the standard hot-dipped galvanized layer can maintain its integrity for up to 20 years without repair.
3. Excellent Reliability: The galvanized layer forms a metallurgical bond with the steel, becoming an integral part of the steel surface, thus ensuring the durability of the coating is highly reliable.
The coating exhibits high tensile strength: the galvanized layer forms a unique metallurgical structure that can withstand mechanical damage during transportation and use.
5. Protection: Every part of the plated piece can be zinc-coated, even in concave areas, sharp corners, and hidden spots, ensuring comprehensive protection.
6. Time and Effort-Saving: The galvanizing process is faster than other coating methods, and it eliminates the need for painting on-site after installation.
7. Low Initial Costs: Generally, the cost of hot-dip galvanizing is lower than applying other protective coatings. The reason is simple: other protective coatings, such as sandblasting and painting, are labor-intensive processes, whereas the hot-dip galvanizing process is highly mechanized and tightly controlled in-house.
8. Easy and Convenient Inspection: The hot-dip galvanized layer can be visually inspected and tested with a simple non-destructive coating thickness gauge.
9. Reliability: The specifications for hot-dip galvanizing are generally in compliance with BS EN ISO 1461, which limits the minimum thickness of the zinc layer, ensuring reliable and predictable corrosion protection life and performance.
