The process consists of three distinct phases:-
Pre-Treatment consists of four separate stages:-
Material is loaded on to jigs before being 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.
As work is removed, the zinc on its surface will begin to solidify and, 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.
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.
This follows the same process as general galvanizing except that the work is placed in baskets to be galvanized and rapidly removed from the bath before the zinc on the work solidifies.
The basket is placed in a centrifuge and spun for several seconds to remove excess zinc from the surface and prevent items from sticking together, ensuring a smooth finish.
Work is then transferred to a quench tank where it is cooled to allow handling.