In order to obtain sharper and tougher weapons, craftsmen invented "Hundred Steelmaking". "Hundred Steelmaking" is to repeatedly heat, fold and forge an ironmaking piece to make the steel body more uniform in composition and less in impurities, thus improving the quality of steel utensils. 1974, a steel knife in the sixth year of the Eastern Han Dynasty (A.D. 1 12) was unearthed from the Han Tomb in Cangshan, Linyi, Shandong Province, which is the earliest steel-making unearthed so far.
China's ancient steel explosion technology was invented in the middle and late Western Han Dynasty, and has been used until the Ming and Qing Dynasties. This method is semi-liquid smelting. After pig iron is heated to semi-liquid, it is decarburized into steel and wrought iron by oxygen in blast. Because the metal needs to be continuously fried in this process, it is called "fried steel".
Extended data
China ancient steelmaking technology was first invented in the late Spring and Autumn Period. At present, the earliest discovered steel object is the steel sword unearthed in Yangjiashan, Changsha in the late Spring and Autumn Period, which has proved that the steelmaking history in China is at least 2,500 years!
In ancient China, natural copper was first used. In the early Shang dynasty, bronze of copper-tin alloy could be refined by pyrometallurgy. The process of smelting bronze is more complicated. Probably, the selected ore is first added with flux, and then put into a smelting furnace for smelting with charcoal. When the temperature is ripe, the refined copper liquid is taken out and the smelting slag is discarded to obtain primary copper. Primary copper is still coarse, and it needs refining to get pure copper. Copper forms an alloy with tin and lead, which is bronze.
References:
Baidu Encyclopedia-China Ancient Bronze Smelting and Casting Technology