The hot dip galvanizing process consists of 3 distinct phases

• Pre-Treatment
• Galvanizing
• Inspection

Pre-Treatment

Pre Treatment for galvanizing consists of 4 separate stages

• Inspection - Items are inspected to ensure they are safe & suitable to galvanize. This involves checking whether they are adequately vented. Surfaces are checked for signs of contamination with paint, grease, etc. as these will not be removed in the process and would cause the process to fail.
• Degreasing - Steel is immersed in a degreasing solution which removes light oil contamination.
• Pickling - Acid strips the steel surface back to clean base steel.
• Fluxing - A flux solution is applied to the steel to assist with the galvanizing reaction.

Galvanizing

Material is immersed in molten zinc at a temperature of around 450 degrees until the temperature of the work is the same as the Zinc. During this process the molten zinc reacts with the surface of the steel to form a series of zinc/iron alloys. These alloy layers protect steel from corrosion for 30-40 years and more.

As work is removed from the zinc, the zinc on its surface will begin to solidify, as this happens excess zinc is removed to ensure a smooth finish. Work is then usually transferred to a quench tank where it is cooled to allow handling.

Inspection

The galvanized steel is first visually inspected for its appearance and conformity to standard. Batches may then be non-destructively tested for coating thickness and uniformity.