금속학적 분석을 통한 판상철부의 제작기술 연구 - 울산 하대고분 출토 유물을 중심으로 -

Abstract

This study examined the manufacturing technology used for the flat iron axes excavated from Ulsan Hadae. Theirmicrostructures were analyzed using metallurgical methods. In addition, a variety of manufacturing technologieswere examined and compared using existing research materials on flat iron axes. As a result of analyzing ten flat ironaxes, which were excavated in the order that they were laid out in a row in one of the wooden coffin tombs at UlsanHadae, Tomb No. 44, it was possible to classify the flat iron axe manufacturing technology and system into threetypes: ‘pure iron – shape processing’, ‘pure iron – shape processing – carburizing’, and ‘pure iron – shape processing– carburizing – decarburizing.’ All of the flat iron axes were produced by forging, and most of them were madeby beating the pure iron into their shapes. In particular, a number of the flat iron axes were reinforced through acarburizing process after shaping the iron. This appears as steel products forming the basis of the steel industry atthe time were commonly used as an intermediary material or currency. On the other hand, it was commonly foundin all samples that the hardening was not performed after shaping or carburizing. Since the microstructure of theflat iron axes made of pure iron contained a large number of impure inclusions and the result of analyzing thecomponents of the non-metal inclusions showed characteristics of slag which contains a mixture of glass phase andwustite, it is possible that low-temperature reduction was used in the refining process.