• 보존과학연구
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• s.16
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• pp.59-111
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• 1995

Chemical composion and crystal form of Corrosion products found on archaeological iron objects were analyzed using X-ray fluorescence analysis, micro-X-ray powder diffraction analysis and ion chromatographic technique. The nature and behavior of the corrosion products were studied in order to aid in the conservation and restoration of burial iron objects. Twenty-two samples analyzed in this study were collected from iron object found in Korea and Japan. The corrosion products of iron objects from burial mounds contain $\alpha$-FeOOH, $\beta$-FeOOH, $\gamma$-FeOOH, $Fe_3O_4$and amorphous iron hydroxides. The content of $\alpha$-HeOOH is the greatest. Because, Ageing for long period should change the amorphous iron hydroxides is considerably less than that in usual atmospheric corrosion products. The concentration of chlorine and sulfine is remarkably variable ($Cl^-$ : 100- 30,000ppm, $SO_4^-2$ : 20-10,000ppm),but the reasons are unclear. The presence of generally high concentrations of chlorine and sulfine the corrosion products of iron objects seem to be influenced by the marine climatic condition. The presence of high chlorine and sulfine concentrations in the corrosion products of iron objects seem to be influenced by the marine burial environments.

• Journal of Conservation Science
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• v.29 no.2
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• pp.187-196
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• 2013

This study is on the corrosion of iron objects caused by sulfides in undersea environment. The corrosion state of objects in seawater and their damage state after underwater and left in highly humid air were studied. The samples of this study were four iron objects which had been taken out from undersea mud layer located in Taean Mado, Chungcheongnamdo. SEM-EDS and XRD analyse on the objects to check whether they have sulfides or not. The result of analysis suggested that the major component of corrosion product generated in undersea deposit soil is sulfur(S) and iron sulfide(FeS) is formed as sulfide. However, there was no clear corrosion on the surface of objects which was exposed to sea water because of the impact of concretion which covered the surface. In order to check the damage status of iron objects after they had been taken out of sea water, exposure tests in high humidity environment and dehumidified environment were done on the corrosion products. The result of the test suggested that the oxidization of iron sulfide corrosion product makes iron sulfate ($FeSO_4$) and sulfuric acid ($H_2SO_4$) and they can cause secondary corrosion of iron objects. Therefore, it is believed that the iron sulfide corrosion product of iron objects taken out from underwater environment should be removed by all means and the keeping environment of the iron objects should also maintain dehumidified state.

• Conservation Science in Museum
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• v.1
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• pp.15-26
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• 1999

More than 200 objects selected for the newly-opened Kimhae National Museum were treated for conservation. The objects which represent ancient Kaya culture, were mainly composed of metallic such as gilt bronze, silver, copper alloy and iron. The corrosion products on gilt bronze and copper alloy objects were preserved or removed according to their stability. Minimum treatment was done for preserving the original state of the objects. For silver objects and iron objects with silver-plate decorations, silver surfaces were revealed after treatment of corrosion products and treatments to prevent corrosion of silver and iron were done emphatically. For iron objects, which were stabilized, the original shape of objects was restored and acrylic coating was applied to prevent further corrosion. For the objects which were being corroded, 2-step de-chloride treatments were undertaken. The first step was immersing the objects in a solution of 0.3M sodium hydroxide and the second was the pressure de-chloride treatment using borax-distilled water. The main purpose of those treatments was to get rid of the causes of corrosion. Besides, conservation treatments for potteries, making of special mounting board for exhibition and amendment of various modeling were done too.

• Journal of the Korean institute of surface engineering
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• v.8 no.1
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• pp.1-9
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• 1975

The crorosion film of gilt bronz, silver and iron objects, which were excaved from Ancient Tomb of Silla Dynasty, was removed by the electrolytic reduction process. These metallic objects were mainly investigated for microstructure, designs and gilting film etc. Most iron objects might be made by hot forging process. The cold extrusion technique might be used for gold and silver objects, in addition to an amalgam method might be applied for the gilting Au film on Cu-alloy surface. For the gilting on glass surface, first, a Cu alloy was cladded on glass , next, Au-film was obtained on the Cu-ally by the amagum method.

• Journal of Conservation Science
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• v.38 no.3
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• pp.217-233
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• 2022

The remains found in Geumcheok-ri, Gyeongju are located in close proximity to the Ancient Tombs in Geumcheok-ri, Gyeongju (Historic Site) which were built between the late 5th and early 6th centuries, and these tombs are known to belong to the powerful rulers of that area. Using metallurgical techniques, this study was conducted on the iron objects obtained from the excavated remains in Geumcheok-ri, Gyeongju which are presumed to have a close relation to the nearby ruins that played an important role in the growth of Silla. To identify differences in manufacturing techniques based on the purpose of the iron objects, eight objects were selected after classifying them by use and the microstructure and non-metallic inclusions were investigated. The analyses results confirmed that the manufacturing process involved forging iron with a high or low carbon content to produce a particular shape, and that the carburization process was applied to iron post forging a shape to increase its strength when necessary. The mechanical properties were improved by selectively applying the steelmaking method and the heat treatment technique considering the functions of the parts, and the low temperature reduction was applied to the smelting process. Furthermore, in comparison with the iron objects excavated from the remains located in the center of Gyeongju and its outskirts, it is confirmed that there is similarity in the smelting and manufacturing techniques between these objects.

• Korean Journal of Metals and Materials
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• v.50 no.5
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• pp.353-360
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• 2012

The corrosion product of archaeological iron objects is supposed to be removed because it causes re-corrosion. So far it is removed by scapel and sand blaster but they depend on the skill and experience of a conservator and the glass-dust of the sand blaster is harmful to humans. Therefore this study applies a laser cleaning system which is used in various industrial cleaning processes, to remove corrosion product from archaeological iron objects. In addition, this work studies the alternation of corrosion product after laser irradiation, which evaluates the reliability of the laser cleaning system. Optical microscopy, SEM-EDS, XRD, Raman have been used to observe and analyse the surface of the objects. The results show the capacity of laser cleaning some corrosion product, but blackening appears with increasing pulses and laser energy, and some corrosion products, goethite and hematite, are partially altered to magnetite. These problems, blackening and alternation of corrosion product, should be solved by further studies which find the optimal laser irradiation condition and use a wetting agent.

• Journal of Conservation Science
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• v.28 no.4
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• pp.343-351
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• 2012

Excavated archaeological iron objects are prevented from being corroded going through desalination which slow down being corroded. However archaeological iron objects are liable to be corroded due to the high ionization tendency even though they are stored in environment restricted from corrosion factors. Iron objects could be deteriorated more than just excavated. Therefore this study investigated about the characteristic of re-corrosion and the effect on objects. In study, archaeological iron nails in storage for 4 years after conservation treatments were tested. Optical microscopy and X-ray photography for appearance, XRD, SEM-EDS, Raman spectroscopy for chemical composition, IC for chloride ions concentration inside iron nails were used. As results, iron nails carried out conservation treatments measured a high concentration of chloride ions after the long storage period. The form of objects were not in good condition such as broken or destroyed when the high chloride ions concentration was detected. In addition, the yellow and red powdery corrosion product were detected on the boundary between corrosion products and substrates and they were identified as akaganeite which is symptom of active corrosion.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.78.2-78.2
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• 2012

We have studied how the intergalactic magnetic field (IGMF) affects the propagation of super-GZK iron nuclei that originate from extragalactic sources within the local GZK sphere. Toward this end, we set up hypothetical sources of ultra-high-energy cosmic-rays (UHECRs), virtual observers, and the magnetized cosmic web in a model universe constructed from cosmological structure formation simulations. We then arranged a set of reference objects at high density region to represent astronomical objects formed in the large scale structure (LSS). With our model IGMF, the paths of UHE iron nuclei are deflected on average by about 70 degrees, which might indicate a nearly isotropic distribution of arrival directions. However, the separation angle between the arrival directions and the nearest reference object on the LSS is only ~6 degrees, which is twice the mean distance to the nearest neighbors among the reference objects. This means that the positional correlation of observed UHE iron events with their true sources would be erased by the IGMF, but the correlation with the LSS itself is to be sustained. We discuss implications of our findings for correlations studies of real UHECR events.