Indian metallurgists have developed a type of corrosion-resistant iron that construction engineers would love. And vital clues for it came for Delhi's famous Iron Pillar that has been standing tall for over 1,600 years. Developed by Ramamurthy Balasubramaniam and his former student Gadadhar Sahoo of the Indian Institute of Technology (IIT) in Kanpur, the iron contains phosphorus and shows remarkable resistance to corrosion, especially in concrete.
The iron pillar next to the Qutab Minar in Delhi has been the centre of attraction for metallurgists from all over the world. For nearly 1600 years, it has been standing undaunted under the open skies, during all type of weather conditions. In so many years, it has not rusted; this has been a matter of surprise for the world. As far as the question of it history is concerned, it was made in the 4th century. According to the Sanskrit inscription on it, it was set up as a flag post in front of the temple of Lord Vishnu on the Vishnu mountain in Mathura by Chandra Raj. It may have been made to place Garuda on top of it. That is why it is also called the Garuda pillar. It was brought to Delhi in 1050 by Anang Pal, the founder of Delhi.