Galvannealed steel (standard galvanized) is coated with a Zinc-Iron Alloy by a process known in the metallurgical technology, as the Hot-Dip Process. This process consists of passing cold reduced sheet steel in coil form continuously through a pot of molten zinc. As the steel leaves the pot, the amount of coating allowed to remain on the sheet is controlled by coating rolls, which are used to establish minimum coating weights in accordance to ASTM Designation A525/A525M. The zinc coating is what protects the steel against corrosion.
This protection acts in two ways. The zinc acts as a shield between the base steel and the atmosphere and when the base steel is exposed, such as at sheared or blanked edges, the zinc acts as a galvanic protector, sacrificing itself in the presence of corrosive elements. The coating structure consists of a layer of zinc superimposed on a thin alloy layer consisting of both iron and zinc. The solidification of the zinc layer results from crystallization of the bath metal.
Protection – With hot dip galvanising, every millimetre of the steel it touches is galvanised, which means the hot dip galvanising process reaches areas inaccessible to other similar processes for preventing rusting and corrosion.
Less Maintenance – The galvanised coating of cold rolled steel, using the hot dip galvanising process ensures it will never shrink or crack because it is metallurgically bonded to the steel it protects. It also offers superior resistance to abrasion and water.
Lowest First Cost – Hot dip galvanising is lower in first cost than many other commonly specified protective coatings for steel.
Lowest Long Term Cost – Even in cases where the initial cost of hot dip galvanising is higher than alternative coatings, hot dip galvanising is almost invariably more cost effective in the long term because it lasts longer and needs less maintenance.
Reliability – Galvanising products from Wybone Ltd is carried out to the appropriate International Standards as well as buyers specification for hot dip galvanising (if required). Coating life and performance are reliable and predictable.
