• Journal of Conservation Science
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• v.26 no.3
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• pp.269-276
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• 2010

This study aims to extract manufacturing techniques by analysing metallurgical characteristics of the cast-iron pot from Bubjusa, examining corrosion status and microstructure with a optical microscope, SEM-EDS, micro vickers hardness tester and XRD. The microstructure analysis has presented that ferrite and partial portion of pearlite exist within the corroded outer layer. The analysis of the inner layer revealed that there is pearlite and graphite of feather shape. The one of the middle layer, which is placed between outer and inner layer, showed that corrosion has been heavily developed. Micro vickers hardness values range from 217Hv to 698Hv in constituent layers and such values lie within the ranges of the ancient iron relics. The result of EDS analysis for each microstructure presented that the outer layer has been more decarbonized than the inner layer. XRD analysis of iron corrosion compound revealed that Goethite and Hematite had been produced from the corrosive process of iron. The study concludes that the large iron pot was made by casting technique, and microstructure of inner layer had a gray cast iron. Outer layer has been decarbonized through repetitive process of heating and cooling. This results can be used as fundamental data for comparative study to reveal manufacturing techniques of large cast-iron pot.

• Korean Journal of Metals and Materials
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• v.50 no.4
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• pp.324-330
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• 2012

The microstructural changes of three pieces from an ancient iron pot were studied in order to identify present the material degradation due to repeated heating for one-thousand years. The microstructures of the pieces were divided into the areas of ferrite/graphite, ferrite/pearlite, and corroded oxidation. The area of ferrite/graphite was undergone by severe Galvanic corrosion, but that of ferrite/pearlite was not even during a thousand years' using. The shape of the graphites was coexisted with types of A, B, and C of as modern graphite classification. In the ferrite/pearlite area, abnormal acicula precipitates with a high aspect ratio of $0.2{\mu}m$ thickness and several hundreds ${\mu}m$ length were presented. They might be a kind of carbide in the ferrite matrix with its special precipitate plane.