Passive corrosion protection refers to all measures taken to specifically "shield" a metallic component from the influence of corrosive media.
The principle of passive corrosion protection is to prevent a corrosive attack on a metal - for example steel - by physical blocking. In practice, this is achieved by special coatings or the coating of the respective material.
After cleaning, the metal surfaces are chemically clean and extremely reactive. For this reason, the substrate must be converted directly afterwards into an inert material.
There are three possible chemically distinguishable coatings available: