What is corrosion anyway?


Corrosion is mostly known from metals, in many cases it is simply used as a nicer word for rust. Both are not correct. Corrosion can occur with all materials, and corrosion is not just the reddish-needed rust we know. What corrosion actually is, and where you can find it everywhere, you can learn in this post.

Corrosion as a chemical change of surfaces

According to the correct definition, corrosion is any reaction that a component or workpiece makes to certain substances. As a result, the workpiece is measurably changed and may no longer function or change its external shape.

Corrosion also occurs in Betonk and glass. In addition, other materials such as plastic may be affected by corrosion.

Chemical corrosion

Chemical corrosion only occurs in the high temperature range. Here no longer electrochemical processes provide aqueous solutions for the development of corrosion, but gases.

Corrosion of metals

All metallic materials are affected by electrochemical corrosion. Either one of the causes is oxygen or hydrogen leading to chemical reactions. These reactions always take place to form a so-called galvanic cell, ie a closed circuit. The flowing current is generated by the current reaction and simultaneously drives it on.

The explanation of why individual metals react so differently to corrosion media is due to their chemical structure. Most non-ferrous metals form an oxide layer on their surface that prevents the progression of corrosion.

On the other hand, ferrous metals do not form such a layer and are therefore very susceptible to corrosion. When iron corrodes, it creates rust. These are FeOOH - iron oxide hydroxide. This is the rust that we all know and wrongly always equate with corrosion.

Types of corrosion

Not every corrosion looks the same. Some species are visible on the surface and form weathering, others remain invisible from the outside and only occur along the grain boundaries of the material inside.

You can read more about the different types of corrosion here.

Tips & Tricks

Corrosion is a complex event. To remedy this, you often have to understand the processes and the causes.


Video Board: Oppressor - Corrosion - Elements Of Corrosion