ZINCALUME® STEEL PIONEER WATER TANKS
ZINCALUME® steel employs a combination of both barrier and sacrificial protection
ZINCALUME® steel is coated in an alloy of approximately 55% aluminum, 43.5% zinc and 1.5% silicon. Although both Galvanized and Zincaclume Steel are produced as continuously hot-dip coated products, they perform very differently, especially in construction industry applications such as roofing and walling. All coatings protect steel sheets from corrosive attack by acting as a barrier to exclude air, water, and other corrosion caused by contact with the steel substrate.
Barrier protected steel is coated with a material that prevents moisture and oxygen from coming into contact with the base metal. The absence of moisture and oxygen prevents steel from corroding. In a metal-coated context, coatings consist of inherently corrosion-resistant metals such as Aluminium, Tin, Gold, and so forth. The advantages of barrier protection are that these coatings are long-lasting and resistant to temperature change, abrasion, erosion, UV and are often electrically conductive. On the downside, if the coating is scratched or cracked localized corrosion will occur.
Sacrificial coatings are based on the principle that all metals have the potential to corrode, this potential is referred to as “activity”. When steel is coated with a more active metal, the active metal will corrode in preference to the steel and protect from the corrosive influence. In other words, the active material will sacrifice itself. Sacrificial coatings are effective even if the steel substrate is exposed, as it is based on electrical conductivity. Sacrificial coatings physically migrate to a corrosion site to provide protection. Galvanized steel relies mainly on sacrificial protection to resist corrosion. Galvanized steel is coated in almost pure zinc.