Delhi column

Delhi column, located in the courtyard of the minaret Kutub-Minar, always surprises travelers who visited the old part of Delhi. According to Indian scientists, it is almost one thousand six hundred years old, since it was erected in 415 AD. The weight of the column is 6500 kg, the height is 7,3 m, the diameter of the base is 41,6 cm. But the Delhi column is not famous for its dimensions. Its main feature is that it does not undergo corrosion. The most interesting thing is that the Delhi column is not made of stainless steel - it is iron. Researchers have shown that carbon in the column is 0,08%, silicon is 0,046%, sulfur is 0,006%, phosphorus is 0,114%, nitrogen is 0,032%, and the rest is iron. According to modern concepts, this composition corresponds to low-carbon steel.

Delhi column, located in the courtyard of the minaret Kutub-Minar, always surprises travelers who visited the old part of Delhi

According to metallurgists, corrosion causes great damage to the economy, "eating" 10-15% of the produced ferrous metals. According to the estimates of economists, only in the US, corrosion losses amount to 75 billion dollars. While the Deli column is on the globe, more than 200 million tons of iron have been lost from corrosion.

So why is the Delhi column not afraid of rye? There is no answer, there are many hypotheses. First, the climate is dry and warm, the air without corrosive gases. Secondly - a sufficiently high purity of iron. And, of course, that this is the work of aliens. However, if you look carefully at the Delhi column, it has a brilliant chocolate shade in places inaccessible to tourists. Therefore, there is another version - from rusting the Delhi column is protected by a patina. True, it is unknown - artificial, or natural. Another scientific version is the high content of phosphorus, since in the industry phosphating is one of the methods of protecting the metal from atmospheric influences.

Be that as it may, the Delhi column is still one of the symbols of the lost technology of antiquity.

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