The Study on Technology of Manufacturing Ironware of Goguryeo Shown in Steel Weapons and Socketed Iron Spear

Abstract

Background/Objectives: The study is aimed at estimating a technology of manufacturing weapons in the times of Goguryeo through metallurgical analysis on 2 socketed iron spears excavated.

Methods/Statistical analysis: The collected specimen is fixed by epoxy resin and made to be a specimen for observation by a microscope after going through fine grinding up to 1 μm and etching. The nital (HNO3 + Ethyl alcohol) 3% solution was used for etching, and microstructure was observed by a metallograph and nonmetallic inclusion existing inside the microstructure were investigated by using an integrated scanning electron microscope-energy dispersion type spectrometer.

Findings: There was no trace of repeating to fold and hit around the blade all in the socketed iron spear (No.1) and two axes, one big sword. It is judged that a technology of manufacturing ironware that can increase content of carbon without omitting any desired part through the cementation process aiming at the blade part directly through the manufacturing process based on the sequence of molding→manufacturing steel→thermal treatment.It was observed that ferrite and pearlite coexisted at the sharp part of the socketed iron spear (No.2), and it is estimated that low-carbon steel materials with the content of carbon of around 0.2 to 0.3% were used. It is judged that the socketed iron spear (No.2) was made by using low-carbon steel materials and there would be no special thermal treatment to increase its strength except for the fact that carbon was contained to some degree, and that relics made by using low-carbon steel like this are similar with the manufacturing technology of one iron pointed tip excavated from the bastion #4 at Mt.

Improvements/Applications: It is judged that they would be equipped with workforce, facilities and technical skills enough to produce iron weapons by themselves even in a military bastion which was far away from the capital. 

Keywords: Socketed Iron Spear, Goguryeo, Ironware, Manufacturing Technology, Microstructure