Within these two basic classifications there are five
types of corrosion: (1) general or uniform corrosion;
(2) intergranular corrosion; (3) galvanic corrosion,
including pitting and crevice corrosion; (4) stress
corrosion cracking; and, (5) microbiologically
induced corrosion (MIC). Many times, a metal starts
to corrode by one mechanism, for example pitting
corrosion, and then fails by a second mechanism,
stress corrosion cracking.