What is the Difference Between Cathodic Protection and Sacrificial Protection?

Cathodic protection and sacrificial protection are two related electrochemical processes used to prevent corrosion in metallic structures. The main difference between the two methods lies in the source of the protection:

• Cathodic Protection: This method involves the protection of a metal surface by making it a cathode. It can be achieved using sacrificial anodes or impressed current systems. In the case of impressed current systems, an external power source is used with inert anodes, while sacrificial anode systems rely on the naturally occurring electrochemical potential difference between different metallic elements to provide protection.
• Sacrificial Protection: This process involves the use of a sacrificial anode that makes the desired metal surface a cathode. The sacrificial anode corrodes in place of the base metal, providing protection. The anode is supplied by an unlimited power source, and it can often provide much longer protection than a sacrificial anode.

In summary, the key difference between cathodic protection and sacrificial protection is the source of the protection: cathodic protection uses an external power source or sacrificial anodes, while sacrificial protection relies solely on the use of a sacrificial metal to prevent corrosion.

Comparative Table: Cathodic Protection vs Sacrificial Protection

Cathodic protection and sacrificial protection are two related electrochemical processes used to prevent corrosion in metal structures. Here is a table highlighting the differences between the two methods:

In summary, cathodic protection involves making a metal surface a cathode to prevent corrosion, while sacrificial protection relies on the use of a sacrificial anode that corrodes in place of the protected metal.