Corrosion is a term that is used, mostly in chemistry, to talk about the wear of a metal by external agents.
Origin
The etymology is going to help us to know more about this word and to define it we have to go back to Latin since it is a compound word:
-Prefix: “with” which means “together” or “in totality or all”.
-Verb: “rodo” which can be translated as “worn out” or “gnawed”.
-Suffix: “-ion” which translates as “act of”.
Therefore, corrosion can be defined as: act of gnawing or wearing down.
According to the Royal Spanish Academy, corrosion is the “gradual wear of metallic bodies by the action of external agents, whether or not their shape persists”.
Metals
During corrosion, metals suffer a deterioration of all their physical and chemical properties. For example, a metal that is in contact with the outside or under water corrodes.
One of these corrosion actions, in the case of steel, is what is commonly known as oxidation, which is when a brown layer is generated that degrades the material until it fractures or breaks.
The corrosion of metals entails a series of problems since it modifies their properties and can be weakened. In the case of a structure such as a building, a corroded metal structure can cause it to fall. In the same way that it can happen with a bridge.
Types of corrosion
To know how we can act against this phenomenon, we must first know the types of corrosion that exist:
-Atmospheric: is the one that does the greatest amount of damage to the material. Cars, bridges, buildings… are the elements that are most exposed to the atmosphere and, consequently, to oxygen and water.
The severity of this type of corrosion is accentuated when salt, sulfuric compounds and other atmospheric contaminants are present.
-Galvanic: it is a form of accelerated corrosion that can occur when different metals are electrically joined in the presence of a conductive solution.
This type of corrosion can be particularly severe when corrosion films do not form or are removed by erosion.
The biggest problem with this type of corrosion is that it is quite common and comes in many forms.
-Liquid metals: corresponds to a degradation of metals in the presence of metals such as Zinc, Mercury, Cadmium… which are liquid.
-High temperatures: some metals exposed to oxidizing gases in high temperature conditions, can produce direct reactions without the need for an electrolyte, as in the case of galvanic.
In this type of corrosion, all you need is a metal and an oxidizing gas exposed to high temperatures, which will cause a layer or “tarnish” to form on the aforementioned metal.
-Localized: form of corrosion in which the loss of metal occurs in specific areas through small fissures or “pits”.
Prevent corrosion
– Acquire products made of materials such as aluminum or stainless steel when we know that our metals will be exposed to external agents.
– Keep surfaces dry to prevent water, as an external agent, from creating a favorable environment for corrosion. In this sense we have to avoid having dents or undulations on our surface so that the water does not stagnate.
– Use of elements that eliminate humidity. Many times, humid interior environments encourage the metallic element to corrode.
– Use lubricants or greases for elements such as tools, chains or gears or machinery in general to keep them away from favorable environmental effects for corrosion.
– Oil-based paint is another protective element that will help keep the metal structure isolated from external agents.
Remove corrosion
Once the metal is already corroded, it is possible to remove that layer of corrosion. Before starting, we recommend not using homemade methods as these can damage or deteriorate the structure or the tool. It is best to contact experts in the field who can advise and advise us on different deoxidizing products that are made from acids.
On other occasions it is possible to remove that layer of corrosion by brushing or “sanding” the surface with different machinery and provide a subsequent treatment to beautify the surface.
At this point it is very important to remember that many of the liquids or products that can be used to remove corrosion and rust on metals can be highly corrosive and harmful to the skin. For this reason, we remind you once again that the help and advice of experts in the field is essential to help us in our process of eliminating corrosion.
Finally, corrosion, as we mentioned at the beginning, can deteriorate the metal, so the removal of that brown layer on the metal is not always the final solution, but rather another series of treatments must be applied to the surface for it to recover. all its properties.