In the countryside of western India, there is an iron pillar cast in the 5th century AD. 7m high pillar, about 1.37m in diameter, using steel I cast into, solid, on the top decorated with ancient patterns.
Legend has it that this iron pillar was cast to commemorate King Chamdaro.
But what surprised us was that the iron pillar had been exposed for more than 1,600 years, without experiencing so many winds and rain until today, there is still no visible rust.
Meanwhile, iron is a very easy metal to rust after a few dozen years, not to mention more than a thousand years.
So far, earth people have not found an effective way to combat the rust of iron-based objects. Although in theory, pure iron is not rusty but pure iron is difficult to train, the price is extremely high. Moreover, some scientists have analyzed the composition of the iron column, discovering that there are many impurities rather than pure iron. And in theory, iron columns are easier to rust than conventional iron types.
If you think that the ancient Indians were soon able to grasp the stainless steel smelting technique and this technique was lost, why didn’t they train other stainless iron? Moreover, there is no record in this book of iron making by ancient Indians to address this issue.
That iron pillar stood alone, seemingly challenging with the intelligent intelligence of mankind, the sky also symbolized the ancient Indian civilization.
Outdated technology creates extraordinary miracles
But in the end, the experts of the Indian Institute of Technology have also solved the mystery of the longevity of the Delhi iron pillar . Observing through microscopic microscopes, they discovered a very thin layer of “coats” covering the entire surface of the pillar.
Sampling on the study, the composition of the shell is defined as a compound of iron, oxygen and hydrogen . It is this compound that prevents the iron metal of the column from reaching the air. As a result, corrosion reactions due to their reaction can not happen, causing the iron column to become immortal.
The radioisotope analysis also showed that this protective layer began to form around three years after the iron column was made, which is equivalent to the lifespan of the pillar. Throughout that millennium, they continued to thicken year by year at a very slow pace. After 1,600 years, this shell has only reached a thickness of about 1/20 millimeter.
The ancient text is as sharp as it has been engraved, though thousands of years have passed.
But why does this iron pole have such a valuable protective cover? The announcement of a research group has surprised the scientific community all over the world: It is the fourth-century backward metallurgical technology that inadvertently created this compound. Dr. Balasubramanian, who led the study, said his team found an unusually high concentration of phosphorus in the iron sample collected from the pillar.
The ratio of analytical phosphorus was more than 1%, much higher than the rate of phosphorus in modern iron today, which is less than 0.05%. It is this high phosphorus content that acts as a catalyst , accelerating the reactions that make up the above protective agent.
This is an accidental accomplishment, derived from a very crude metallurgy technique of the time. Ancient Indians mixed coal with iron ore to shorten the firing time. In this way, the phosphorus in the iron ore will not be able to be separated and left in the finished iron.
Meanwhile, with modern blast furnace iron technology, phosphorus content can be reduced very low. It is the purity created by modern technology that makes today’s iron impossible to survive as Delhi steel pillars.
The discovery of these scientists is further strengthened when people find some weapons such as swords, arrows, knives and swords . in India with the same year as Delhi steel columns and almost no Rusty. This confirms that it is the backward early metallurgical technique that made the precious masterpiece of surprise for posterity later, making them remain forever with time. The mysterious veil has been lifted up by scientists.