Hot-dip galvanizing is an effective metal anti-corrosion method and is mainly used in metal structure facilities in various industries. The rust-removed steel member is immersed in a zinc solution melted at about 500°C to adhere the zinc layer to the surface of the steel member, which makes it safer and increases the useful life of the metal.
The hot-dip galvanizing process has the following basic steps:
Surface Treatment - The material is subjected to three cleaning steps to prepare the steel to be galvanized.
Step 1: Degreasing - removes the foul oil and organic residue and then rinses the structure.
Step 2: Pickling - remove scale, iron oxide, and etch steel and then rinse again.
Step 3: Fluxing - remove any residual oxide and coat the steel with a protective layer to prevent any further oxide formation prior to galvanizing.
Step 4: Galvanizing - once the structure is clean and dry, immerse it in a molten zinc bath. When the material is immersed, zinc will flow throughout and around the structure, protecting all surfaces. In the bath, the chemical reaction takes place between zinc and iron and steel, forming a series of zinc-iron intermetallic compounds and outer pure zinc.
Step 5: Inspection - Inspection and quality assurance is the final step in the galvanizing process. Visual inspection of each structure ensures proper coverage and ensures that the project meets project requirements.