Corrosion classes and what is corrosion?

Corrosion is the process by which metallic materials break down as a result of electrochemical reactions. This usually occurs when the metal comes into contact with environmental factors such as water, oxygen and other chemical substances, leading to the gradual dissolution of the metal. A common example of corrosion is rust, which occurs when iron or steel reacts with oxygen and moisture in the air. Rust forms a reddish-brown layer of iron oxide on the surface, which both weakens the metal and reduces its lifespan.

Corrosion is a major problem in many industries, as it can lead to structural damage, leaks and economic losses. To combat corrosion, various protection techniques are often used, such as painting, galvanizing, the use of stainless alloys or cathodic protection.

Corrosion is a natural process that damages materials, so it is important to know the corrosion classes so that you can choose the right material and surface treatment against corrosion.

In many corrosive environments, corrosion of metals, steels and aluminum to major problems. The problems are both aesthetic and safety-related, and manifest themselves as rust on steel surfaces, running rust water, spots of silver or green coating.

Hidden corrosion processes may also be taking place, for example on concrete reinforcement and ceiling fasteners.

Therefore, it is important to choose the right surface treatment based on the environment to which the steel will be exposed.

There are a number of different corrosion classifications, the most common corrosion classes being: C1-C5 based on the ISO 12944-2 standard.

Explanation of corrosion classes/types: