What does elemental iron mean

Tinning and galvanizing?

a) Galvanizing: A zinc layer is applied to the iron. Since zinc is less noble than iron (zinc is more easily oxidized than iron), it corrodes (= oxidizes) before iron. The corrosion products form an inert layer that slows down the progress of corrosion. Only when the zinc layer is used up does the now exposed iron corrode.

When galvanizing, one speaks of active corrosion protection.

 

b) Tinning: The tin is more noble than iron, but also more noble than many other materials, so that it cannot be attacked even like the iron underneath. Only when the tin layer is mechanically damaged can the now exposed iron corrode. When tinning, one speaks of passive corrosion protection.

Tinning cans (= tinplate cans) is cheaper than a steel coating, which would also protect against corrosion. In addition, tin is non-toxic and suitable for food areas.