• Journal of Conservation Science
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• v.31 no.2
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• pp.95-104
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• 2015

Excavated archaeological cast iron objects in improper storage are quickly corroded and disintegrated into block and powder finally. Hence desalination treatment which is a way of removing internal corrosive factors, especially chloride ion, is an important process. But desalination is often omitted or objects are dehydrated by alcohol because the destruction of objects could occur during desalting. Although current desalting methods mostly use an aqueous alkali solution, $OH^-$ ions of water could accelerate corrosion and broaden internal cracks cause of high surface tension. Therefore this study experimented desalting using ethyl alcohol, which is low surface tension, to investigate an effect of desalination. As a result, desalting using ethyl alcohol showed the similar or more effective results of desalting using water. In addition, as aspects of desalting safety, ethyl alcohol desalting method was smaller destruction of objects and extraction of Fe from the objects than the aqueous alkali solution. However, this study explored the possibility of desalting methods using organic solvent in fieldwork, so the results would provide basic date for making the safe and effective desalting method for archaeological cast iron objects through further experiments.

• Journal of Conservation Science
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• v.29 no.4
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• pp.297-309
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• 2013

Iron objects become corroded at fast speed from the moment when they are excavated, so it is needed to control corrosion through processes of conservation treatment. However, re-corrosion mostly takes place in excavate iron objects, although they have already gone through the process of conservation treatment, and it is more difficult to carry out the second conservation treatment of re-corroded excavated iron objects than the first conservation treatment, and it requires a longer period of time to treat them as well. In this study, aims to discover factors of re-corrosion by scientifically analyzing corrosion products generated during the process of storage after the process of conservation treatment. The finished on conservation treatment of the iron artifacts, which were unearthed from three ancient site in Gyeongju by using the same conservation method between 2002 and 2009, re-corrosion condition observed on the packaging-iron artifacts. Focused on 9 target forged iron artifacts among them, this study analyzed the physical changes by mass measurement, naked-eye and microscopic observations and the chemical changes by SEM-EDS, XRD, IC and ICP analysis. The results show that the yellowish brown corrosion products formed on the facing surface of part dropped from the artifacts had different associated forms but acicular shape. In addition, the acicular shape became clearer as the color changed from red to yellowish brown. According to the process when the conservation treatment was completed, the mass of the artifacts increased in proportion to the corrosion products and the chloride ion ($Cl^-$) concentration had a tendency to increase relatively. ${\beta}$-FeOOH (akaganeite) was confirmed in the XRD analysis for the corrosion products of all the collected samples. As a result of ICP analysis, $Na^+$ and $Ca^{2+}$ components were confirmed.

• Journal of Conservation Science
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• v.25 no.1
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• pp.49-60
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• 2009

Outdoor iron artefacts are easily corroded by salts, especially $Cl^-$ion, from environmental pollutants and acid rain because of their location, so that they need conservational treatments such as stabilization. However the conservation of outdoor iron artefacts are limited to be consolidated for the present and there are a few the studies for the desalinization. The general desalinization method is that objects are immersed in reagent such as alkaline corrosion inhibiting solutions targeting on buried iron artefacts, thus they are not available for outdoor iron artefacts. In this study, concerning those difficulties, the different desalting method is experimented that materials soaked in alkaline solutions attach to objects and they are packed by waterproof to avoid evaporation. This paper experiment burial iron artefacts at first in order to fine out an adaptable method for outdoor iron artefacts. The soaking materials are Korean traditional paper, gauze, cotton wipers, spill pads and the desalting regent is NaOH 0.1M. Additionally the exiting desalinization method which is to immerse objects in solution is performed to compare. The analyses are microscopes, SEM-EDS, X-ray diffraction, pH meter and Ion chromatography. The result is that spill pads show the best desalting effect out of other materials similar to immersing desalting method.

• Conservation Science in Museum
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• v.27
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• pp.91-102
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• 2022

Silica-based inorganic fillers for restoration of iron objects have been used for the reduction of thermal expansivity and the improvement of melt flow index. However, the higher the amount of filler is applied, the more degradation of mechanical properties and the yellowing occur, which could cause retreatment of the objects with adding stress to them. Thus, research on not only the quantification of a mixture of resin and filler but also the yellowing should be emphasized. Experiments on mechanical properties were carried out with a silica-based light filler, Micro Shell as a comparison group. The results of the experiment showed Micro Shell reduced the number of occurrences of the yellowing by 34% compared to existing fillers. The value of adhesion and specific gravity was also improved depending on the filler amount. The results of this research indicate the possibility of using Micro Shell as a new filler.

• Journal of Conservation Science
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• v.5 no.2 s.6
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• pp.35-44
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• 1996

We propose a new method to remove salts that have permeated into excavated metal objects. This method cleans the excavated metal objects by using high temperature, high pressure deoxvgenated water containing inhibitors for corrosion of metals. The method greatly reduces the washing time compared with previous methods. Waste water from the method does not need treatment, nor do chemicals need to be removed from the metal objects. Furthermore, this method is applicable to some kind of metals(for example iron objects, bronze objects). We measured quantitatively the soluble salts dissolved from actual metal objects and found that there was a large difference between soluble chloride ions and sulfate ions.

• 보존과학연구
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• s.19
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• pp.179-191
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• 1998

The Dumu of casted iron objects which is the big vessel for the prevention of fire to wood building is conserved in Kyongpok Palace(Dumu sizes：diameter 97cm, height 42cm, thickness 2cm, weight 250kg). The treated objects which some parts were lost, were not corroded, but cracted and broken by an external power, and strongly attached an cement layer on inside surface. First of all cement layer was mechanically removed by pneumatic needle scaler, welded to electric method for broken and cracked pieces, and then the lost sections were restored to use a epoxy resin and glass fiber. In order to prevent a damage during the handling, the restoration section of the inside surface was treated different colour in comparison with original part.

• Acta Via Serica
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• v.8 no.2
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• pp.95-124
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• 2023

Over the past 30 years, intense archaeological research has revealed a great increase in regional and transregional object mobility across the South China Sea during its Iron Age (500 BCE to 500 CE). Some objects had moved from a long distance: intaglios, seals, fine ceramic, glass containers, and gold coins of Mediterranean origin; and large bronzes, mirrors, and lacquerware connected to central East Asia. This evidence has given rise to larger-scale explanations, among which the most prominent has been the growth of (maritime) Silk Road trade. Scholars are divided as to whether the Silk Road is a suitable concept, with some emphasizing its orientalist overtones and colonial baggage and others finding it useful for the investigation of interregional networks trading in silk and other commodities. This paper explores how productive the Silk Road concept or metaphor really is for understanding transregional connectivity and social change in Iron Age Southeast Asia.

• 보존과학연구
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• s.17
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• pp.1-19
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• 1996

Desalting methods for chloride ions from the excavated iron objects were studied. These methods were compared with room temperature and heating condition of treating solution. During the Desalting treatments the $Cl^-$concentration of the solution were measured regularly and the plotted for $Cl^-$concentrations the square root of time, heating methods showed that the $Cl^-$ ions are more extracted. For the desalting treatments these plots were found to be flattening line, it was showed the changing second solution. Also, the changing solution in the room temperation detected less $Cl^-$ ions of heating treatment solution. As the examination for the relative humidity has compared for desalting objects during 8 days, it was showed a re-corroded appearance of R.H90%. As it did not detected a $Cl^-$ ions of re-corroded section, these phenomena were showed the naturally occuring corrosion of the objects in the high relative humidity.

• Journal of Conservation Science
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• v.27 no.3
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• pp.301-312
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• 2011

Epoxy resin has superior durability and adhesive strength and proper physical strength so that it is used to diversity materials for multi-purposes. However epoxy resin is hardly removed after hardening specially once it is applied to artefacts, it is difficult to remove them under re-conservation. This paper is an experimental study on removing epoxy resin applied to iron objects using Nd:YAG laser cleaning system. Tests conducted in this study investigated how increasing laser energy and pulses would give effect on samples. The samples were prepared in a way that epoxy resin, itself pure and one which was mixed with pigment and they were applied to iron coupons and corroded iron coupons respectively. As a result of experiment, pure epoxy resin applied to corroded iron coupons was ablated at high laser energy but epoxy resin applied to iron coupons and mixing with pigment were not ablated but discolored and bubbled due to laser-induced heat generation. Results of FT-IR showed no component alteration of shifted resins and no residues on the surfaces ablated by laser irradiation. From SEM-EDS for removed surfaces, the debris from epoxy resin and melting iron was observed. Therefore, this study demonstrated the possibilities and limitations for laser cleaning to remove epoxy resin from iron objects.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.3
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• pp.71-77
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• 1996

This paper is described on the eddy current for a peripheral magnetic objects of under ground power cable. The materials of cable rack is used FRP and SUS in the place of iron. Each specimen were measureed for eddy current loss and Hysteresis loss by Epstein's method. The results is compared each other. Hysteresis loss is inversely proportional to $\textrm{f}^{0.6}$ of frequence as supply voltage is constant. Also, iron loss is increased to 0.86 times for varinace of frequency from 60[Hz] to 50[Hz] as a maxium flux density is constant. In the case of Fe, Hysteresis loss is above 70[% ] of total iron loss. In the other hand, SUS is decreased to go[%] of Fe. by the simulation results using Loss Program Package. The iron loss of materials SUS, FRP is near zeor by Epstein's method.