Electro Corrosion: Prerequisites & Procedures

Electrochemical processes often lead to material removal, weathering and rusting. Electrical corrosion is such an important part of the corrosion process. This can be recognized by some types of corrosion. What is going on in the field of electrocorrosion & what is necessary for it can be found here.

Process of electrocorrosion

There are a few basic requirements for electrocorrosion, so that it can run at all:

  • There must be a cathode
  • there must be an anode
  • There must be an electrolytic conductor
  • There must be a sufficiently large potential difference between the cathode and the anode

Cathode and anode

Two different poles, between which a voltage exists, cause a current flow. This can be clearly seen from the example of contact corrosion. Here, the metal pairs have different levels of electrical potential. If you lie next to each other, this creates an electrical voltage. One metal forms the cathode, the other the anode, depending on the charge.

However, a pole can also be, for example, surrounding soil. The cathode and anode must both be connected directly conducting, as well as an electrolytic conductor.

Electrolytic conductor

Electrolytic conductors can either be liquids with sufficient conductivity, but also humid ambient air. The level of conductivity determines the degree of corrosion. Also water is suitable as a conductor. Depending on the type of water, the conductivity is different.

Galvanic cell

Due to the connection between anode, cathode and electrolyte, a sufficiently large conductivity and sufficient electrical potential difference creates a galvanic cell that alters the metal surfaces.

Prevention of electrocorrosion

One can interrupt the process by either minimizing the potential difference, isolating the anode and cathode, or removing the electrolytic conductor.

Tips & Tricks

The reversal of electrocorrosion can also be used to de-rust objects.

Video Board: Corrosion of Metals: Class 6-10