A Review on Corrosion Protection of Iron and Steel

Ferrous based-metals, e.g., iron metal and metal alloys containing iron (mild steel), and steels are routinely used in the construction of cooling systems and in other fields due to their low cost and availability. Environmental considerations have been of paramount importance. Corrosion resistant stainless steel or “super alloys” have been used in applications where prevention of corrosion of steel structures or pipes was absolutely essential. These materials are expensive and more difficult to produce than conventional steel materials. Iron and steels undergo inhibition, passivation and corrosion protection treatments to make these materials economical and durable for variety of applications. Numerous techniques are available in the literature to provide these treatments. Heavy metals, chromates, phosphates and fluorides are employed as effective materials for inhibition, passivation and corrosion prevention. A lot of research is underway to remove these materials due to their toxicity. In Europe rules have been established to limit the Chromium content (due to its toxicity) for easy and safe recycling of the materials. There still exists a need for finding out economical, efficient processes and materials which will reliably adhere to the surface being treated in chemically adverse or saline environment and can provide protection against corrosion. For these reasons tremendous efforts are being made to develop/invent new processes for inhibition, passivation and corrosion protection.