Oxidation is a chemical reaction in which oxygen mixes with other substances to form oxides. The main difference between corrosion and oxidation is that Corrosion is the deterioration of a material caused by an electrochemical attack on its environment.
What is Oxidation?
Oxidation is known as chemical reactions in which oxygen joins other substances to form oxides. This process is common in metals, but it is not unique to them. In chemical terms, oxidation is understood as the loss of electrons from an atom, which increases its positive charge.
Because oxygen is the element that accepts these excess electrons, this reaction was baptized as oxidation, although the correct term is reduction-oxidation, oxide-reduction, or simply redox.
Because of these reactions, oxygen has the ability to corrode metals.
Two elements participate in an oxidation process:
The oxidizing agent: It is the chemical element that captures the transferred electrons, receives them, and increases their negative charge. This means that its oxidation state is reduced.
The reducing agent: It is the chemical element that gives up or loses its electrons, thus increasing its positive charge.
Types of oxidation:
Slow oxidation: It is produced by the oxygen contained in the air or in the water. It is the type of oxidation that corrodes metals.
Rapid oxidation: Produces violent chemical reactions such as combustion.
What is Corrosion?
It is the deterioration of a material due to an attack from its environment. It is produced by the tendency of a material to seek its most stable or lowest internal energy form. The corrosion process is natural.
It can be caused by an oxide-reduction chemical reaction, although there are other factors that can corrode a part. It is a serious problem and it is estimated that every few seconds five tons of steel in the world corrode.
Corrosion occurs when there is a potential difference between the part and the environment.
Types of corrosion
Chemical corrosion: The material dissolves in a corrosive liquid.
Liquid metal attack: Liquid metals attack solids at their critical energy points, generating cracks.
Selective leaching: The solids of an alloy are separated.
Dissolution and oxidation of ceramic materials: Refractory ceramic materials that contain molten metal during their refinement are dissolved by the slags caused on the metal surface.
A chemical attack on polymers: Polymers are resistant to corrosion, but some solvents can have small molecules that separate the plastic chains, causing cracks in the material.
Microbiological corrosion: It is electrochemical corrosion in which some microorganisms can cause corrosion on submerged metal surfaces. Some of them can be Bacteria, algae, and fungi.
Difference between Oxidation and Corrosion
- In metals, oxidation is an effect that oxygen produces on the metal surface and that is accentuated by increasing temperature. It is weak oxidation in which the oxide film formed prevents the metal from contacting atmospheric oxygen, slowing down the reaction. This can only accelerate due to an increase in temperature.
- Corrosion is a slow and progressive deterioration of a metal by an external agent, it can occur by oxidation, by contact with chemicals, by microorganisms, by the electrical union of two metals (galvanized corrosion)
- Corrosion is the deterioration of a material as a result of an attack from its environment.
- Oxidation is the attack of oxygen, whether present in air or water, on a material. Oxidation causes corrosion in the material.
- Corrosion is a type of oxidation. When oxidation increases due to temperature diluting the material, we will be in the presence of corrosion.