Tag #Iron Pillar

What accounts for the Delhi Iron Pillar's exceptional resistance to corrosion despite 1600 years of exposure to the elements?

The 7.2-meter, six-ton iron pillar in Delhi's Qutb Minar complex, dating back to the 5th century, shows almost no corrosion despite centuries of exposure. Scientists attribute this to its high phosphorus content (around 1%), lack of sulfur and magnesium, and the ancient forge-welding technique used in its creation. A protective layer of misawite further enhances its durability.