Theory:

Methods of preventing corrosion:
 
(i). Alloying:
 
Metals can be alloyed to prevent the corrosion process.
Example:
Stainless Steel
(ii). Surface coating:
  
shutterstock_768849040.jpg
Surface coating process
  
Surface coating involves the application of a protective layer over the metal. It is classified as follows.
  
(a). Galvanization:
  
Galvanization is a method of coating zinc on iron sheets by using an electric current.
 
shutterstock_1517600279.jpg
Industrial galvanization process
 
(b). Electroplating:
  
Electroplating is a technique of coating one metal over another metal by passing an electric current.
 
shutterstock_1504853519.png
Copper electroplating technique
 
(c). Anodizing:
  
Anodizing is an electrochemical method that turns the metal surface into decorative, durable and corrosion-resistant. Aluminium is widely used for the anodizing process.
 
shutterstock_1159956469.jpg
Aluminium anodizing process
 
(d). Cathodic protection:
  
Cathodic protection is a process of controlling corrosion of a protected metal surface coated with easily corrodible metal. The easily corrodible metal is called sacrificial metal, which acts as an anode, ensuring cathodic protection.
 
1_1.png
Steel cathodic protection process