Question

Q1- Make a table showing all the similarities and differences for the following type of corrosion.
1- Galvanic or two metal corrosion.
2- Crevice corrosion.
3- Pitting.
4- Intergranular corrosion.​​

Answer 1

Type of corrosion	Characteristics
Galvanic corrosion	It is an electrochemical process in which one electrode corrodes another electrode when in contact with an electrolyte. This attack makes the metal of one of the electrode dissolve into the electrolyte.
Crevice corrosion	It refers to the corrosion of a metal close to the crevice or gap between two metals. This maybe because of the moisture content, oxygen levels close to the metal causing some electrochemical reactions
Pitting	This is type of galvanic corrosion which causes holes on the metal surface. This is a very localised form of galvanic corrosion which follows the mechanism of crevice corrosion.
Intergranular corrosion	In this type of corrosion, cracking occurs on the boundaries of the metal than the inside when exposed to stress. The cracking usually takes place along the grain boundaries. Unlike the other type of corrosions described above, intergranular corrosion cannot be seen with naked eyes and requires microscopic images to identify it.