1. Corrosion and degradation of traditional materials

Metal corrosion

It can take several forms:

• external corrosion (of buildings, engineering structures, ship hulls, underbody of automobiles, etc.), due to the action of water, humid air, the environment, seawater, etc.

• internal corrosion of pipes, sewers and tanks due to the action of liquid or gaseous chemicals transported or stored.

All common metals oxidize in air, especially humid air, but the most serious problems are encountered with steels and iron, since rust is porous and will continue to corrode unless these metals are protected by a suitable coating or paint.

Metals are also attacked by acids, especially ordinary steels, and in chemical engineering we are obliged to use stainless steel, which...