An iron production and exchange system at the center of the Western Han Empire: Scientific study of iron products and manufacturing remains from the Taicheng site complex

摘要

The discovery of a small-scale ironworks and ironware from burials at the Taicheng site complex in the Wei River Valley, Shaanxi, provides a valuable chance to systematically examine not only manufacturing technology but also the distribution system of iron objects within the region surrounding the Western Han Empires capital city. According to metallurgical and SEM-EDS analyses, the ironworks primarily employed melting/casting techniques to manufacture agricultural tools via recycled scrap iron and imported iron semi-products from other manufacturing centers. In addition, forging and, possibly fined iron manufacturing, were identified through the discovery of hammer scale and slag. The artefactual evidence from a nearby cemetery shows that solid-state decarburization of cast iron and fined iron were employed intensively in the manufacturing of iron tools buried as grave goods, but these were unlikely to be manufactured entirely and directly by the local ironworks. By integrating other lines of evidence (e.g., ceramic casting molds), we suggest that, since local, small ironworks like Taicheng only focused on agricultural tools, the supply of most daily iron objects was met via commodity exchange. The study proposes that the local iron industry employed a strategy of "diversification" in order to maximize both the sources of raw materials and supply of final objects, and the exchange or transportation of ironware played an essential role in the development of the iron industry during the Han period.