Thus, both the anodic and the cathodic reactions combined in a corrosion reaction, i.e.
The galvanic cell represents all the corrosion cells in which combination of two electrodes (conductors) are absorbed in an electrolyte.
According to Revie and Uhlig (4), there are 3 main types of galvanic cells which are operational in corrosion reactions.
On short-circuiting the cell with a good conductor, the Zinc cup will perforate by corrosion within a few hours.
The formation of such cells cause pronounced damage at cracks, crevices, hence the true crevice corrosion. In engineering studies crevices are quite common at the border of two pipes that are coupled together and at junctions made y threaded pieces.
This results in the formation of differential aeration cells causing pitting corrosion under rust (Fig.
Fontana  has classified corrosion forms in which they manifest themselves.
Fontana  has mentioned 8 forms of corrosion, more or less all related to each other.
Uhlig  have more or less classified the corrosion types as: (1) General Corrosion or Uniform Attack, (2) Pitting, Fretting, Cavitation-erosion, (3) Dealloying Dezincification and Parting, (4) Intergranular corrosion, (5) Cracking.
We would now briefly discuss the various forms of corrosion mentioned above.
It is general kind of corrosion, usually associated with electrochemical reaction that spreads uniformly over the complete open or expose surface.
Uniform corrosion usually results in the greatest loss of metals.