Iron decarburisation techniques in the eastern Guanzhong Plain, China, during Late Warring States period: an investigation based on slag inclusion analyses

Iron production in the Central Plains area of China has been largely based on cast iron smelting since ca. fifth century BC, with different techniques developed in the following Warring States period and Han dynasty to convert this material into malleable soft iron. Whilst there is a broad consensus about the evolution of technological traditions in the Early Iron Age, the methodologies employed for differentiating artefacts derived from different iron smelting and decarburisation methods have been variable and not sufficiently conclusive. Taking advantage of renewed analytical approaches and archaeological evidence recovered in recent years, this paper summarises our current understanding of the decarburisation techniques employed in Early Iron Age China and sheds new light on this subject through the analysis of archaeological artefacts from two civilian cemeteries in the eastern part of the Guanzhong Plain (Shaanxi), dated to the third century BC. The analytical results indicate that both solid-state and liquid-state decarburisation were employed for soft iron production in this area during the Late Warring States period. The methodology employed in this paper, based on slag inclusion analysis, also provides a more systematic approach to differentiating soft iron production techniques in future archaeometallurgical research in China.