Corrugated iron sheets are galvanised. Image credit

Corrugated iron sheets are galvanised. Image credit

ZIMSEC O Level Combined Science Notes: Galvinasing iron

  • Galvanising is one of the methods used to prevent iron from rusting
  • Iron and steel can be coated with zinc
  • Zinc is a fairly more reactive metal
  • This means it will corrode before the iron does
  • This is also known asĀ sacrificial plating
  • Even when the metal underneath (iron/steel) is exposed the zinc will corrode instead of thus protecting the iron
  • Zinc plating is also calledĀ galvanizing
  • It is usually used for small items such as nuts and bolts
  • It is also used on large items such as iron roofing sheets
  • Steel is used to make the galvanised roofing sheets
  • Steel sheets are cleaned first
  • They are then passed through molten zinc
  • An alloy of zinc and iron then forms on the surface of the steel sheets
  • The zinc in the galvanised iron sheets prevents the sheets from rusting
  • Zinc is more reactive than iron thus it will corrode first
  • Even if the iron is exposed to the atmosphere
  • This method is used to make corrugated roofing sheets which are widely used in Zimbabwe

To access more topics go to the Combined Science Notes page.

Quick NetOne, Telecel, Africom, And Econet Airtime Recharge

If anything goes wrong, chat with us using the chat feature at the bottom right of this screen