example of an electrochemical process in Corrosion

Corrosion is material damage caused by the influence of the surrounding environment

Corrosion is material damage caused by the influence of the surrounding environment. The corrosion process that occurs in addition to chemical reactions is also caused by electrochemical processes that involve the transfer of electrons, namely from the reduction of metal ions and metal deposition from the surrounding environment. A metal that undergoes corrosion in an electrolytic environment (water) is an example of an electrochemical process. This process occurs when there is a reaction in the metal part that loses electrons and a reaction in the other metal part that accepts the electron. Both of these reactions will continue until dynamic equilibrium occurs where the number of electrons removed is the same as the number of electrons received.

What is corrosion

1. Corrosion can be referred to as metal damage or degradation due to reaction with a corrosive environment.
2. Corrosion can also be interpreted as an attack that damages metal because the metal reacts chemically or electrochemically with the environment.
3. There is another definition that says that corrosion is the opposite of the process of extracting metals from their mineral ores

Corrosion is an electrochemical process, namely a process (change / chemical reaction) that involves an electric current. Certain parts of the iron act as negative poles (negative electrode, anode), while other parts act as positive poles (positive electrodes, cathode). Electrons flow from the anode to the cathode, resulting in a corrosion event. Corrosion can occur in a dry medium as well as a wet medium. For example, corrosion that takes place in a dry medium is the attack of ferrous metals by oxygen gas (O2) or sulfur dioxide gas (SO2). The anodic reaction in every corrosion reaction is an oxidation reaction of a metal into its ion which is characterized by an increase in valence or the loss of electrons. The cathodic reaction in every corrosion reaction is a reduction reaction characterized by a decrease in valence or the absorption of electrons.

In a wet medium, corrosion can occur uniformly or locally. An example of uniform corrosion in a wet medium is when iron is immersed in a solution of hydrochloric acid (HCl). Corrosion in the wet medium that occurs locally there is giving a macroscopic form and also a microscopic form. Examples of macroscopic forms are galvanic corrosion of the iron-zinc system, erosion corrosion, crack corrosion, pitting corrosion, peeling corrosion, and melt corrosion. While microscopic examples of corrosion that occur are stress corrosion, fracture corrosion, and inter-grain corrosion.

Corrosion rate speed

The rate of corrosion is very dependent on many factors, such as the presence or absence of an oxide layer, because the oxide layer can block the potential difference to other electrodes which will be very different if it is still clean from the oxide. The Volta series and Nernst’s law will help determine the probability of corrosion occurring.

Author Since: May 31, 2021

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