Corrosions and oxidations of metals are the most frequent problems in coastal areas, the industrial and nautical sectors, as they generate damage to articles made of metal, reducing their resistance and durability, which can put safety at risk. from the workers.. Oxidation is a chemical reaction in which oxygen mixes with other substances to form oxides. Corrosion is the deterioration of a material caused by an electrochemical attack on its environment. The main difference between corrosion and oxidation is that corrosion generally occurs on metal surfaces, while oxidation occurs everywhere.
However, because oxidation and corrosion of metals are similar phenomena, as they damage metal surfaces, they should not be confused because they are problems with different factors. Next, you will know the types of corrosion, the characteristics that make the difference between these situations, how to solve the damage, as well as an example of corrosion and an example of oxidation so that you can identify them correctly.
The oxidation and corrosion of materials is one of the main material maintenance problems in coastal areas and in sectors such as industrial and nautical. This is because steel sheets have endless uses, as we explained in the article ” The different uses of steel sheets .” Also, if we look around us, many utensils and materials are made of steel or gutters with steel parts.
But speaking of oxidation and corrosion, both are two processes that generate damages in the elements that are constituted by meta and, therefore, reduce their resistance and durability; but, in addition, and what is more serious, deficiencies in the maintenance of certain elements can put people’s lives at risk.
- The destruction of a material when it is exposed to the external environment due to different reactions that take place on its surface is known as corrosion, while the process of loss of electrons by an atom, molecule, ion, etc. it is known as oxidation.
- In metals, oxidation is an effect that oxygen produces on the metal surface and that is accentuated by increasing temperature. It is a 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 occurs mainly on metal surfaces. On the contrary, oxidation takes place everywhere.
- Corrosion is a type of irreversible process. On the other hand, oxidation is half of complete redox reactions.
- Corrosion occurs in the presence of oxygen. On the other hand, oxygen is not essential for oxidation. It can also occur in the absence of oxygen.
- Corrosion occurs when the surface of a metal or metal atoms rusts in the presence of water and oxygen. On the other hand, oxidation is the process of loss of electrons by an atom, molecule or ion, etc. during a reaction.
- Corrosion is a harmful process that causes the destruction of material that is in direct contact with the external environment. For example, oxidation of iron, etc. On the other hand, the oxidation process is beneficial. Provides help in different laboratory processes.
- 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.
- Corrosion is a type of oxidation. When oxidation increases due to temperature diluting the material, we will be in the presence of corrosion.
Difference between corrosion and oxidation in Tabular Form
|Definition||The destruction of a material, when it is exposed to the external environment due to different reactions that take place on its surface, is known as corrosion.||The process of loss of electrons by an atom, molecule or ion, etc. it is known as oxidation.|
|Idea||It takes place mainly on metal surfaces.||Rust happens everywhere.|
|Presence of Oxygen||It takes place in the presence of oxygen.||Oxygen is not essential; it can also occur in the absence of oxygen.|
|Process type||Corrosion is a type of irreversible process.||Oxidation is half of the complete redox reactions.|
|Procedure||It occurs when the surface of metal or metal atoms rust in the presence of water and oxygen.||It is the process of loss of electrons by an atom, molecule or ion, etc. during a reaction.|
|Impact||It is a harmful process that causes the destruction of material that is in direct contact with the external environment. For example, oxidation of iron, etc.||This process is advantageous. Provides help in different laboratory processes.|
Corrosion vs. oxidation – Overview
When an object is exposed to the external environment, it is destroyed due to different processes that take place on its surface, which is known as corrosion. On the other hand, oxidation is the process of loss of electrons by an atom, molecule or ion, etc. during a reaction.
So corrosion is a kind of oxidation. It takes place mainly on metal surfaces. On the other hand, oxidation occurs everywhere. Corrosion occurs in the presence of oxygen. On the other hand, oxygen is not essential for oxidation. It can also occur in the absence of oxygen.
Corrosion is a type of irreversible process. It cannot be restored once it has occurred. On the other hand, oxidation is half of the complete redox reactions. Corrosion is a harmful process.
It causes the destruction of material that is in direct contact with the external environment, for example, oxidation of iron, etc. On the other hand, the oxidation process is beneficial. Provides help in different laboratory processes.
What is corrosion?
Corrosion is known as a natural process that causes the degradation of the properties of an object or material, that is, appearance, structure, resistance, and permeability, etc. It is a type of oxidation. It occurs when the surface of metal or metal atoms rust in the presence of water and oxygen. It takes place due to different chemical reactions that occur between the components of the air and the surface of the material.
Corrosion occurs mainly on metallic surfaces, but can also occur on non-metallic surfaces. Its most common example is oxidation. Change the color and quality of the steel. Therefore, there are different varieties of steel that are used to save the metal from corrosion by changing its chemical composition.
On the other hand, the board and the skin are two examples of non-metallic surfaces that face corrosion. If some corrosive chemicals are added to these surfaces, they will destroy the surface. Examples of such chemicals are strong acids and strong bases.
Corrosion of metal is also called metallic rust. This is because, in this process, the atoms on the metal surface are oxidized by the oxygen present in the air in the presence of water, for example, during the corrosion of iron, the Fe + 2 in the steel is oxidized to Faith + 3 . There are different factors that control the rate of corrosion such as the metal surface that is open to the air and the humidity in the air, etc.
Corrosion can be prevented in different ways, for example, by environmental modification, the use of paints, the use of corrosion inhibitors, that is, chemicals that are used to inhibit corrosion by preventing oxidation, galvanization, that is, zinc coating to prevent rust and by electroplating, etc.
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.
- Selective leaching: The solids of an alloy separate.
- Liquid metal attack: liquid metals attack solids at their critical energy points, generating cracks.
- 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.
- 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 an electrochemical corrosion in which some microorganisms can cause corrosion on submerged metal surfaces. Some of them can be: Bacteria, algae and fungi.
- Electrochemical reaction: when there is a physical or electrical union between different metals. In this case, the larger the contact area the faster the corrosion will act.
- Pitting: An example of pitting corrosion is usually seen in cars with crashes that were not fixed because, as rust accumulates in the pit and an increase in the pH of the environment, the damaged surface corrodes.
Main causes of corrosion in metal
The contact of the metallic material with oxygen and humidity produces a complex electrochemical phenomenon. The presence of water in the environment causes corrosion, while the reaction of metals with air is the cause of oxidation. In metallic materials, the most common corrosion is that generated by a chemical reaction in which electrons are transferred from one material to another. We can say that oxidation is the attack of oxygen (in the form of air or water) and corrosion is the deterioration that it causes.
But, in addition to humidity, there are other corrosive agents : this is the case of high temperatures, the environmental salinity typical of being close to the sea and industrial pollution with concentrated sulfur dioxide.
Depending on the type of metal and environmental conditions, the form and speed at which corrosion occurs will vary . Almost all metals can suffer it, although that of ferric metals is the best known as it is the most frequent and quick to produce. For their part, precious metals, having very little reactivity, are difficult to corrode, although their scarcity and high price do not make them a material widely used in industry.
The factors that most influence the triggering of a corrosion process are the following:
- The acidity of the solution: the most acidic are the most corrosive, above neutral and alkaline, since they allow a greater reaction in the anode zone.
- Dissolved salts: the presence of acid salts accelerates the corrosion process. For their part, alkaline ones can inhibit the process.
- Protective layers: their existence can limit the appearance of corrosion, whether they are coatings applied on the material or layers resulting from passivation .
- The oxygen concentration: depending on the material, the amount of oxygen present can affect the corrosive process. In ferrous metals, the higher the amount of oxygen, the faster the corrosion. However, in passivated materials it serves to enhance the protective layer.
- Temperature: the rate of deterioration tends to increase at higher temperatures, being the factor that most influences oxidation corrosion.
What is oxidation?
Oxidation is the process that involves the loss of electrons by an atom, molecule or ion, etc. during a reaction. Oxygen is not vital for oxidation. It can also occur in the absence of oxygen. Since a neutral atom is made up of an equal number of protons and electrons, the loss of electrons will give the atom a positive charge.
The oxidation state is known as the oxidation state. When oxidation occurs in an atom, its oxidation state increases positively. The opposite of oxidation is known as reduction.
The oxidation and reduction reaction takes place at the same time and is collectively known as the redox reaction. So oxidation is half of the complete redox reactions. It releases the electrons that are then used by the reduction reaction. Compounds that oxidize the other compounds are called oxidizing agents. On the other hand, compounds that oxidize are called reducing agents.
Oxidation is a beneficial process. Provides help in different laboratory processes. In addition, it helps living tissues in many ways, such as weight loss, stimulates metabolism, and reduces the risk of cancer, etc. But it is dangerous for metals where it causes oxidation.
It is known as oxidation to 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.
Oxidation is generated by weather conditions , and this process does not usually deteriorate the resistance of the metal itself, nor its safety or functionality. Also, in certain cases, when rust adheres to steel, it could even improve adhesion.
Therefore, the three corrosive factors are:
- The manufactured part itself
- The environment
Due to this, if maintenance is not carried out, or metals are not well protected, it can lead to serious safety problems in buildings or facilities, for example.
How to avoid rust and corrosion?
To prevent metal from rusting or deteriorating, it must go through several processes to coat it and protect its surface . The most unstable or sensitive materials are iron, zinc and copper. They are the ones that are more easily oxidized, as they are more cohesive and allow oxygen to break the union in the metal.
Due to this, in these three metals it is necessary to always avoid contact with water and humidity , or to keep their surface dry whenever possible . Thus, we prevent the water from stagnating and starting to rust.
Because of this, we recommend that the home, business or industry always protect all metal items from moisture. Above all, remember to check those metal objects that you do not usually use or use little. For this, you can use dehumidifiers or other products that absorb moisture.
If there is no possibility of keeping the metal safe from exposure to water or moisture, it is recommended to use other types of materials more resistant to oxidation and corrosion, such as stainless steel .
In the same way, it is essential to carry out a correct cleaning and maintenance on the surface of the material , always following the manufacturer’s recommendations and making sure that the properties are maintained in the right conditions.
Another very useful resource is to paint the material with zinc-based paints , as they protect against oxidation. These types of paints act as a sacrificial anode, preventing the metal from rusting.
What material is resistant to corrosion and oxidation?
To prevent and avoid damage by corrosion or oxidation, metals have to go through certain processes that coat and protect their surface. A Mexican company and expert in the area has created a solution to this problem: XTREME galvanizing.
XTREME galvanizing , formulated by DEACERO, is a reinforced coating, superior to traditional galvanizing, which is up to 7.5 times more resistant to oxidation. Through galvanized protection and defensive protection, XTREME eliminates the risk of rust appearing and therefore corrosion on metals.
DEACERO applies this type of coating to protect its products against factors such as weather, humidity or corrosive agents and to deliver first-rate quality in the construction industry.
If you want to avoid wear and tear and maintenance in construction, it is important to select an expert supplier like DEACERO and materials that guarantee the best and longest lasting job.
Do all metals corrode with the same ease?
The unstable metals are those that corrode the most easily, these are those that oxidize more easily , since their atoms are less cohesive in a way that allows the oxygen atoms to break the bonds between them with some ease, for example : iron (steel is an alloy of iron, carbon and other metals that achieve other properties), zinc and copper .
For steel to corrode (that is, for rust to form) it must be exposed to oxygen or air. Furthermore, steel corrodes much faster in the presence of other atmospheric agents such as water (rain or humid air) and salt ( salt water splashes).
The above discussion summarizes that corrosion is a process that destroys a material when exposed to an external environment due to different reactions that take place on its surface. On the other hand, oxidation is the process of loss of electrons by an atom, molecule or ion, etc. which can be both harmful and beneficial.
In conclusion, check and protect all metallic materials, especially iron, zinc and copper. In addition, make sure to use professional products in its maintenance, never homemade tricks, since they may not work and spoil the material.