The mystery of the 1,600-year-old stainless steel exposed iron pillar

Delhi Iron Pillar is one of the famous ancient monuments of India. Delhi is an iron pillar cast in the 5th century, erected by King Kumara Gupta I of the Gupta dynasty, who ruled north India in the period 320-540.

This column was originally part of the Muttra temple, with the Garuda idol on top. However, after this Hindu temple was destroyed by Qutb-ud-din Aybak to build the Qutub Minar and the Quwwat-ul-Islam mosque, it was the only remaining part.

The strange thing is that despite being exposed to the sun and rain outdoors for thousands of years, Delhi's iron columns show almost no signs of rust. For decades, metal scientists and engineers from around the world have proposed a series of theories about the properties of this unusual wonder.

Decoding the mystery of the thousand-year-old stainless iron pillar

It has a height of 7.2 m from the ground and a total weight of about 10 tons. Several hundred years ago it was moved to its current location. It has gone through more than 1,600 years of exposure to rain and sun but has not rusted at all. The inscriptions left on its body show that people built it to praise the Hindu god and King Chandra - a mysterious king who is still a puzzle to historians.

Legend has it that this iron pillar was cast to commemorate the kingmdaro.

These What surprises people is the standing iron pillar opencast For more than 1,600 years, through countless rains and winds until today, there is still not a single trace of rust.

Meanwhile, iron is a metal that easily rusts after a few decades, not to mention more than a thousand years.

Until now, Earth people have not found an effective method to fight itrust of iron objects. Although in theory, pure iron does not rust, pure iron is difficult to refine and the price is extremely high. Furthermore, some scientists have analyzed the composition of the iron column, discovering that it contains many impurities rather than pure iron. And in theory, iron columns rust more easily than regular iron.

If for thatancient Indians Since they soon mastered the technique of making stainless iron and this technique was lost, why didn't they make other stainless iron items? Further in the book iron manufacturing There is no record of ancient Indians mentioning this issue.

That iron pillar stands alone, seemingly challenging humanity's intelligence and discovery. The sky also symbolizes the foundation of humanity.ancient Indian civilization.

Outdated technology creates extraordinary miracles

But in the end, the experts of Indian Institute of Technology IIT also decryption mysteriously increases the tree's longevityDelhi iron pillars. Observing through a microscopic microscope, they discovered a layer"jacket" Extremely thin covering the entire surface of this pillar.

Taking samples for research, the composition of that shell was determined to be onecompound of iron, oxygen and hydrogen. It is this compound that prevents the iron metal of the column from coming into contact with the air. Thanks to that, the corrosion reaction due toreact to themc cannot happen, making the iron pillar immortal.

Radioactive isotope analysis also showed that this protective layer began to form about three years after the iron pillars were made, meaning their lifespan is equivalent to the lifespan of the pillar. During more than a millennium, they continued to thicken year by year at a very slow rate. After 1,600 years, this crust has only reached a thickness of about 1/20 of a millimeter.

But how does this iron pillar have such a precious protective covering? The announcement of a research group has surprised scientists around the world: Yes outdated metallurgical technology The 4th century accidentally created this compound. Dr. Balasubramanian - the leader of the research team said that his team found a concentration phosphorus unusually high in the iron sample collected from this pillar.

The phosphorus ratio analyzed was more than 1%, much higher than the phosphorus ratio in today's modern irons, which is less than 0.05%. It is this high phosphorus content that plays such a rolecatalysts, promoting the reactions that create the above protective substances.

This was an accidental achievement, stemming from the very rudimentary metallurgical techniques of that time. The ancient Indians weremix coal with iron ore to shorten the smelting time. With this method, the phosphorus contained in iron ore cannot be completely separated and remains in the finished iron.

Meanwhile, with modern iron smelting technology using blast furnaces, the phosphorus content can be reduced to very low levels. It's puritydo Modern technology has made iron impossible to obtain today permanence like Delhi steel columns.

These scientists' findings were further reinforced when some were found weapons like swords, arrows, knives... in India are of the same age as Delhi steel columns and they are almost rust-free. This confirms that it was the outdated metallurgical techniques of early times that created surprisingly precious masterpieces for future generations, making them last forever. The veil of mystery has been lifted for a long time by scientists.