Corrosion is a common problem which occurs with the destruction of metal as a result of chemical reactions which harm our surrounding environment. Almost every metal can corrode like stainless steel, pure iron corrode easily but combine with iron and alloys are slower to corrode and used more frequently.
a) The general attack corrosion- it causes a metal to fail and common type of corrosion.
b) The localised corrosion- The localised corrosion is of three kinds such as pitting, filiform and crevice corrosion and it only harms a portion of metal structure
c) The galvanic corrosion- this happens only when two different metals are located together in a liquid electrolyte.
d) The environmental cracking- This is due to environmental condition because when environment condition becomes then some metal begins to weaken and crack.
To prevent corrosion engineers work with a metallurgical expert, so they choose proper metal with awareness of possible chemical interactions of metal surface and fittings.
There are some modifications which help such as proper metal selection and surface condition, coating, cathodic protection and plating.