Corrosion is an electro-chemical process by which a metal such as mild steel ,returns to its natural state ,state ,such as iron oxide or rust.

This paper studies corrosion and electro-chemical behaviour of steel in the two-phase system of petroleum hydro Caron and oil field Water.

Whereas corrosion of steel occurs due to a drop in activation potential caused by sodium chloride and to the effect of anode polarization produced by electro-chemical factors.