China's iron smelting technology from Xia, Shang and Zhou Dynasties to the present.

Around the 6th century BC, China invented pig iron smelting technology. Especially in the Spring and Autumn Period and the Warring States Period, two processes of block ironmaking and pig iron smelting came into being almost simultaneously. These two methods have developed in parallel for a long time in the history of our country and played their respective roles in different situations.

In the early Warring States period, China created white iron Softening. That is, by heating for a long time, the iron carbide in white iron is decomposed into iron and graphite, and large cementite is eliminated, which plays a good role in improving the toughness of iron. After the mid-Warring States period, iron has replaced bronze as the main production tool.

On the basis of massive carburization, the "Hundred Steelmaking" technology rose in the Western Han Dynasty. It is characterized by increasing the number of repeated heating and forging, which can not only be processed and formed, but also reduce, refine and even inclusions, greatly improving the quality of steel. Idioms like "A hundred tempering makes steel ..." come from this. In the middle of the Western Han Dynasty, steel frying appeared again, that is, pig iron was fried into semi-liquid and semi-solid, stirred, decarburized by iron minerals or oxygen in the air to achieve the required carbon content, and then repeatedly hot forged to make steel products. The invention of fried steel also broke the previous boundary that pig iron could not be converted into wrought iron, which enabled the original two technological systems to communicate and become a unified iron and steel smelting technical system. This is another important event in the history of ancient iron and steel technology in China after pig iron smelting and casting.

In the Han Dynasty, the development of iron and steel industry was manifested in many aspects. If the furnace type is expanded and limestone is used as the flux, the tuyere is also developed from one to multiple, and the blowing equipment is changed from manual blowing and animal blowing to the creation of "water exhaust" of hydraulic blowing.

From the Tang Dynasty to the Ming Dynasty, the ancient steel technology was fully developed and finalized. During the Tang and Song Dynasties, the historic transformation of farm tools from casting to forging was realized. From the middle of Ming Dynasty to the end of Qing Dynasty, the annual output of pig iron reached several hundred thousand tons.

/kloc-Before the industrial revolution in the middle of the 8th century, the production scale and technical level of China's iron smelting industry were not inferior to those of Britain, France and other countries at that time.

See: www.tushucheng.com/book/1546941.html.