KANPUR, INDIA, October 13, 2007: 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. “This is a significant first step in the possible commercial (large-scale) use of these irons,” Balasubramaniam, better known as Bala, told IANS.
Most steels today contain small amounts of carbon and manganese. Modern steel makers avoid phosphorus because its segregation to grain boundaries makes the steel brittle. But the IIT team successfully produced ductile phosphoric irons by driving the phosphorus away from grain boundaries through clever alloy design and novel heat treatment.
Ironically, Bala’s material is not new. It was being made by Indian ironsmiths centuries ago. Bala says he got the clue for developing this material from the six-ton seven-meter tall Delhi Iron Pillar – a major tourist attraction in the Qutb Minar complex — that has been standing for centuries in the harsh weather of the capital without any corrosion. “As a metallurgist, I was intrigued,” Bala told IANS. And his passionate quest to unravel the mystery that began in 1990s has now culminated in phosphoric irons.
Bala thanks his forefathers for the success. “I am of the firm belief that ancient Indian metallurgists had the empirical knowledge that high phosphorus content ores resulted in corrosion-resistant iron. They did not create this material by accident.”