Center for Archaeological Science, Sichuan University publishes latest research in Archaeometry: 'New discovery of wrought steel in Han Dynasty city sites in Southwest China: A study of wrought steel remains in Xindu City Site.'

Recently, the archaeometallurgy team of the Center for Archaeological Science, Sichuan University, in collaboration with the Chengdu Institute of Cultural Relics and Archaeology, published its latest research findings online in Archaeometry, a flagship journal of archaeometry, titled "A New Discovery of Stir-frying Steel within a Han Dynasty City Site in Southwestern China: A Study of Stir-frying Steel Remains at the Xindu City Site." This research was jointly completed by Professor Li Yingfu of the Center for Archaeological Science, Sichuan University, graduate student Qiu Tian, Associate Researcher Yang Yang, and Researcher Yang Zhanfeng of the Chengdu Institute of Cultural Relics and Archaeology.

The Chengdu Plain was the most important iron industry production center in southwestern China during the Qin and Han periods. So far, the iron production remains of the Western and Eastern Han Dynasties found in the Chengdu Plain are distributed in areas far from towns. The iron production mode and technology type inside the city are not clear. The discovery of metallurgical handicraft remains in the Xindu City site provides new evidence for discussing this issue.

The Xindu City site is located in Qingbaijiang District, Chengdu. The Chengdu Municipal Institute of Cultural Relics and Archeology has cleaned up a large number of metallurgical remains such as slag and tuyeres, and 2 severely damaged "bowl-shaped" furnaces inside the west city wall of the Xindu City site. Based on the carbon-14 dating results of charcoal attached to the surface of the slag and the typological analysis of pottery shards, it is speculated that the age of metallurgical activities was in the middle and late Western Han Dynasty. In order to further determine the technical links corresponding to the slag, the research team carried out slag phase observation and composition analysis of the slag, and found that the microstructure of the slag samples was mainly composed of fayalite and glassy phase, and there were also hypoeutectoid steel particles with different carbon content. In addition, the contents of CaO and P2O5 in the slag were both high, which reflected the characteristics of stir-frying steel slag in terms of microstructure and composition.

Unearthed relics and metallurgical remains at the Xindu City site

Slag and tuyeres unearthed from the Xindu City site

Microstructure of slag unearthed from the Xindu City site

Stir-frying steel is a method of making steel or wrought iron by stirring pig iron in a semi-molten state to achieve oxidation and decarburization. It is a very important invention and creation in the history of ancient Chinese iron and steel technology. At present, the discovered Han Dynasty stir-frying steel slag and stir-frying steel products are mainly concentrated in the Central Plains, especially in the Guanzhong area. The stir-frying steel remains and relics at the Xindu City site are the earliest iron and steel stir-frying and processing remains discovered in southwestern China so far. They not only reveal the iron production mode and technology type laid out in the Han Dynasty cities in the Chengdu Plain, but also provide a new perspective for understanding how the Han Dynasty promoted the Central Plains process in the Chengdu Plain with advanced iron industry.

Article link: http://doi.org/10.1111/arcm.13004