In the third grade of primary school, I learned such a text, called "Fishing for Iron Cattle", about the Song Dynasty, when the Yellow River was flooded, breaking a pontoon bridge outside the city of Hezhongfu. On both sides of the Yellow River, there were eight large iron cattle tied to the pontoon bridge, which were also washed away by the water, and finally the flood receded, and the eight large iron cattle also sank in the silt of the Yellow River embankment.
Later, the pontoon bridge was to be rebuilt, but the iron bull was trapped in the river, causing Ben to be too high, and he had to ask Hercules to come and salvage it. However, there are Hercules who are familiar with water and have great strength. The last monk, Huai Bing, used two large boats filled with sediment to drive to the bottom of the iron bull, and had the sediment shoveled from the boat into the water, and the hull of the ship was tied to the iron bull in the water. Finally, through the buoyancy of the water, the iron bull was pulled up from the silt of the riverbed little by little.
This text sounds legendary, but it provides a clue for future generations that there are iron bulls in the Yellow River. This kind of iron cow is generally called Zhenhe iron cow, ancient people superstitious river gods, in order to prevent the flooding of the Yellow River, specially built Zhenhe iron cattle thrown into the Yellow River, in order to suppress the Yellow River flood.
The history books record that during the Tang Dynasty, four 60-ton Zhenhe iron cattle were thrown into the river, which ensured that the Tang Dynasty was not plagued by the flooding of the Yellow River for hundreds of years. After thousands of years, due to the lowering of the water level of the modern Yellow River, the riverbed of the iron bull sinking to the bottom of the year was gradually raised. In 1989, finally at the site of Pujindu on the Yellow River, through the efforts of archaeologists, these 4 iron cows reappeared.
Experts have found that the four 60-ton iron cows are made of one-time pouring. What is a one-time pour? It is made by directly flowing molten iron into the mold without any grinding and polishing, and the method is more primitive.
However, this 60-ton iron cow belongs to the behemoth in the iron sculpture, although the workmanship is not very surprising, but after all, it is large, or it needs a lot of manpower and material resources. At that time, there must have been countless craftsmen carrying a large boiler of molten iron into the mold, and it was more than 1,000 years ago, and there was no cooling protection measures, which could easily cause burns or heat stroke.
In the end, the destination of these 4 iron cows was not stored in the museum, because it was too large and too heavy, the museum did not have a place for them, and archaeologists still placed them on the edge of the Yellow River according to the original intention of the ancients. It's been 30 years since it's been today.
There is a very interesting phenomenon, that is, these four iron cows have been sleeping under the water for more than 1200 years, and have been on the shore for another 30 years, but there is no rust at all. Logically, iron is the most susceptible to rusting metal, and it has been soaked in water for such a long time, how come it has not been rusted at all?
Originally, the craftsmen of the Tang Dynasty did not use high purity iron when making Zhenhe iron cattle, you know, the refining technology of iron requires extremely high temperatures, and the Tang Dynasty will have a furnace that can rise to a high temperature of more than 1,000 degrees. The refining technology of iron is still slowly popularized in modern times, so the purity of the iron that creates these iron cows is not high.
Therefore, compared to iron, it should be called ferroalloy, as we all know, pure iron is quite easy to rust, but as long as it is mixed with other elements, it will quickly react with the air to form a layer of oxidation protection, thus eliminating the occurrence of subsequent oxidation and rust reactions. This is also the reason why the Yellow River Town River Iron Bull has not been rusty for thousands of years.
Or perhaps, there is really a river god in the dark to protect the Yellow River, so this group of Yellow River iron cattle will always be as bright as new, but one thing is certain, these 4 60-ton non-rusting iron cattle do reflect the superb iron smelting technology of the ancients. It should be known that at that time, the western iron smelting technology matured around 1300, and the Tang Dynasty was hundreds of years earlier than it, which shows the wisdom of the ancients in China.