Galvanisation: Protecting Steel with Zinc Coating

The method specifically involving coating steel and iron with a layer of zinc to prevent rusting is known as Galvanisation.

This process provides a protective barrier against corrosion. Zinc acts as both a physical barrier and a sacrificial anode, meaning it corrodes preferentially to protect the underlying steel or iron.

Understanding Other Methods:

• Passivation: This method forms a protective oxide layer on the surface of metals like stainless steel or aluminum, but it doesn't typically involve coating with zinc.
• Cathodic protection: This technique protects a metal by making it the cathode of an electrochemical cell. It often uses a more reactive metal (like magnesium or zinc) as a sacrificial anode, but it's a broader principle than just zinc coating.
• Electroplating: This involves depositing a layer of one metal onto another using electrolysis. While electroplating can use zinc (forming galvanized coatings), the term itself is more general and doesn't specifically imply the standard galvanization process for rust prevention.

Therefore, Galvanisation is the precise term for coating steel/iron with zinc to prevent rust.