August 22, 2008

India past shows way for corrosion resistant phosphoric iron re bars

The Gupta period Delhi Iron Pillar near Kutub Minar at New Delhi in India is testimony to the high level of skill achieved by the ancient Indian iron smiths in the extraction and processing of iron. This Pillar has attracted the attention of corrosion technologists because it has withstood corrosion for the last 1600 years.

The presence of relatively high phosphorus with 0.25% in the forge welded Delhi Iron Pillar plays a major role in its excellent corrosion resistance. The presence of phosphorus leads to the formation of a protective passive film on the surface, which provides the Pillar its exceptional corrosion resistance properties.

In the normal steel making process, the phosphorus content is controlled to be less than 0.05% because phosphorus segregation to grain boundaries reduces ductility of steel.

A detailed study has been done by Professor Dr R Balasubramaniam of the Materials and Metallurgical Engineering Department of Institute of Technology of Kanpur India to understand possible industrial applications of phosphoric irons aiming to render the phosphoric irons ductile and locate a modern application wherein the corrosion resistance of phosphoric irons could be put to good use.

The findings indicate excellent properties for highly corrosion resistant rebars for use in reinforcement of concrete especially in chlorides atmospheric conditions, prevailing on the coastal areas.

If you are interested to know more about it, please send a mail at research@steelguru.com to receive a free pdf file.