Scientific analysis of han dynasty iron artifacts excavated from the Luojiaba Site in Southwest China

Seventeen Han Dynasty iron artifacts from the Luojiaba site, including materials from unit H235 and a burial area, were analyzed using metallography and SEM–EDS. The results indicate the concurrent use of cast iron and wrought iron/steel technologies. Cast iron artifacts—comprising white iron, mottled iron, and malleable cast iron—were mainly employed for containers and plates, whereas wrought iron and steel objects, such as knives and awls, were produced through forging, carburization, and possibly ‘CHAO’-fining processes. The constitution of inclusion demonstrates the coexistence of bloomery iron and fining steel, with bloomery iron predominating. Comparisons between slag from H235 and artifact inclusions reveal close compositional correlations, suggesting local production of many bloomery iron artifacts, while some items, including a fining steel bar and an iron sword, likely originated elsewhere. These results provide the scientific evidence for a complex, regionally adaptive metallurgical system at that region during the Han Dynasty.