» Processes / Zinc Coat :

THE ROLE OF ZINC IN PREVENTING CORROSION

• Iron begins to rust immediately when exposed to the atmosphere. Rust, a hydrated iron oxide, is porous and does not prevent the penetration of moisture and air. As a result, the corrosion of the metal continues and with given time the metal corrodes completely.
  
  
• The most effective way to prevent rust is to cover the metal surface with an impenetrable barrier between the moisture / air and the metal. A coating of zinc acts as a barrier which gives the metal maximum protection against rust.
  
  
• Zinc is higher than Iron in the Electrochemical series. Therefore Zinc corrodes in  preference to Iron. This ‘Sacrificial’ feature of zinc protects the cut edge of galvanised sheets from rusting.
  
  
• Prior to painting, Cold Rolled Steel and Zincal Coils processed through a series of spray baths and subjected to the following chemical treatment.