Chinese archaeologists have discovered a decarbonization furnace, whose age dates back to the Warring States period (475-221 BC), at the site of an ancient iron foundry site during archaeological work at the Houduanwan ruins site in Henan Province (Central China), Xinhua reported. https://russian.news.cn/

The site, in the city of Xinzheng, was an official workshop for casting tools and weapons for the State of Han, which was active during that period.

Experts also found the presence of iron with spherical graphite in the iron artifacts found, which appeared to have been treated by decarbonizing the iron and other methods, the Henan Provincial Institute for Cultural Relics and Archaeology said.

According to the researchers, a large number of ceramic products and relics related to cast iron were found during the excavations. Among them are more than 20 important artifacts related to the iron craft, including a firing furnace and an iron decarbonization furnace, first discovered at a Warring States-era iron casting-related site.

"This discovery shows that China mastered ductile iron technology early in the Warring States Period, and pushes forward the history of ductile iron in China at least 200 years," said Fan Wenquan, a researcher with the institute.

He said it is accepted that the modern ductile iron casting technology was developed by British scientists in 1947, and the discovery of the above craft workshop at the site of the ruins of Houduanwan is strong evidence that Chinese iron casting technology entered its golden age during the Warring States period, when iron founders already possessed ductile iron casting technology.