Iron Pillar of New Delhi

The Iron-Pillar situated in New Delhi, India is indeed a metallurgical marvel. Erected somewhere around 400 A.D, this hisorical monument has resisted something, which is still the biggest problem in industries. Corrosion. Yes, this iron-pillar has smoothly resisted corrosion for last 1600 years. No doubt that it has been the center of attraction for metallurgists and engineers, for it has achieved what modern alloy development techniques are not able to. However, after in-depth studies and analysis at IIT-Kanpur, the technical reason behind this ancient marvel has been explained. This remarkable property has been attributed to the presence of high amount of Phosphorous in the iron which results in the formation of an ultra-thin layer of "misawite", a compound of iron, oxygen and hydrogen.

Hats off to ancient Indian iron-making skills. For more information, click here.