Commotion with Corrosion
This is not another boring science topic that will put you off
to sleep. Trust me, I'll make this as simple and as interesting
read as possible.
Corrosion's dictionary meaning is synonymous to a list of words
like rusting, corroding, erosion, a chemical process, a chemical
change, a chemical action a natural activity, deterioration of
metals through the process of oxidation or chemical action.
Whew!
To explain it further, corrosion is defined as the wearing away
of materials in a slow blow by blow process. It does not
literally pertain to the destruction of metals and other related
materials.
Corrosion is then followed by reversion to a more subtle and
balanced pairs or combination where metals are known as the most
popular examples. Corrosion, in short, is the opposite of
metallurgy.
Because while metallurgy is the molding and making of metals,
corrosion on the other hand, is the rusting, corroding and
unmaking of metals caused by a chemical reaction between the
metal and its external faculties which makes up its environment.
Corrosion, in its broadest studies are subdivided into a number
of categories with each type processing a different
characteristic from the other.
But for a more comprehensive study and understanding of
corrosion, scientist have specifically classified corrosion into
2 general and most known types and methods in which the process
of unmaking the metals can take place.
The first of which is "typified corrosion" whereby metal iron is
exposed to its external agencies during which the temperature is
high or eleveated. During typified corrosion, the corroding and
rusting of the metal begins as soon as the oxygen in the
atmosphere to produce 'mill scale', a common product formed
whenever oxygen reacts with its surroundings.
Mill scale and magnetite, which plays a vital role in the method
of typified corrosion, contains the same chemical composition
called iron ores.
Other forms of metals behave in the same way when associated to
its external environment, they also produce varieties of oxides
and may have the tendency to behave in the similar manner to
come up with other compounds.
All of these chemical reaction and activity points to summarize
that the result of direct combination between the given reacting
elements results to products of corrosion, and does not plainly
embody the end product formed through the substitution of or
displacement of an element for or by another element.
However, the second type and method of corrosion is referred to
as "galvanic" corrosion or "electrochemical corrosion".
This method is characterized by the process of displacement of
one given element in one phase (usually in the form of alloy or
metal). And since electric current is the focal point of the
variable displacement of one given element by the other given
element, literally defining the very meaning of galvanic or
electrochemical corrosion.
Furthermore, electrochemical corrosion generally refers to cases
of corrosion in which metal or alloy being rusted is
continuously associated and linked with the corrosion-causing
solution, or another given element that is a dissimilar metal or
may also be some different conducting or solid material.
The term electrochemical corrosion may also be used in cases
when either pure metal, impure metals, or other forms of metal
or alloys are exposed to pure water, aqueous solution of water
soluble materials, or different mixtures of water with other
elements which is both not soluble nor a solvent of water.
Corrosion will not take place in the absence of corrosion cells.
In a more simplified situation, it's like a cheeseburger without
cheese. Before such corrosion cells do their function, some
pre-requisites must be met.
First requirement is for cells to have doors to connect two
points, the metal and the solution, to allow the flow of
electric current to and from each other in the metal surface.
Second, the cell must be capable of electric conductivity. And
lastly, there must be a motivating force or 'push' that will
enable the initiation (first step), and maintenance (second
step) of flow of current all throughout the system.