• Journal of the Korean Society for Heat Treatment
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• v.9 no.4
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• pp.261-270
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• 1996

Boriding is one of the chemical methods to achieve the case hardening of steel as well as nitriding or carburizing. The surface layer of the borided steel shows higher hardness and exhibits better resistance to corrosion or fatigue than the nitrided or carburized steel. The great majority of previous studies were confined to mild steel or some alloy steel. To enlarge the application, ductile cast iron (DCI) as a material for boriding has been tried in this study. Thus, sliding wear test has conducted using a pin-on-disc machine to compare between borided DCI and mild steel in fluidized bed furnace. The results show that the wear resistance of borided DCI is improved. Especially it is more efficient in the case of occurence of the mechanical wear.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.25-30
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• 1993

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were $SiO_2(68.74\%),\;Al_2O_3(18.40\%),\;CaO(0.42\%),\;MgO(1.04\%)\;and\;K_2O(2.26\%)$ in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.245-253
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• 2004

There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.370-374
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• 2001

The degree of iron recovery from dust agglomerates was investigated experimentally to determine the optimum mixing ratio of coke in cold bonded pellet(CBP) which is fed into electric arc furnace(EAE) in the minimill plant. From the XRD analysis for EAF dust, magnetite(Fe$_3$O$_4$) and franklinite(ZnFe$_2$O$_4$) was identified as major components. Maximum iron recovery was obtained for the solid carbon content of approximately 18 weight percent. From plant trials of CBP composed of this optimal mixing condition, it was observed that electric power consumption and sulfur content increased with increasing the quantity of CBP.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1994.04c
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• pp.7-7
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• 1994

For more than a decade components of low alloy iron powder with nickel and/or molybdenum for general engineering applications have been manufactured from powder metal. In the time to come such PM steel components will gain increasing significance. Because of various manufacturing difficulties they are mostly produced in two separate steps - sintering and hardening - which means high energy and labour requirements. The paper describes how such PM components are produced in just one run through a conveyor belt furnace with automatic atmosphere control and gas quenching zone. Energy and labour costs are low and reproducible quality is exceilent. The mechanical properties obtained with some powder alloys are presented as well.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.489-494
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• 1994

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 1996.04a
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• pp.11-43
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• 1996

• Journal of Korea Foundry Society
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• v.8 no.3
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• pp.243-252
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• 1988

• Journal of Korea Foundry Society
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• v.11 no.1
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• pp.32-43
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• 1991

• Journal of the Korean Ceramic Society
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• v.23 no.2
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• pp.55-63
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• 1986

In variuos physcial and chemical cause of damage of refractories for steel makin the clarification of the wear mechanism of brick is situated on important factor. In the present paper the wear mechanism of high alumina brick for the arc-furnace roof were inves-tigated by means of XRD, EPMA. SEM and microscopy. The results obtained were summerized as follows : (1) The altered layers which exist in high alumina brick used for arc-furnace roof were verified by mineral chemical analysis and EPMA. (2) The diffusion of materials combined with slag dust and iron oxide from furnace atmosphere in high basic process from hot face to interior was verified. (3)Activation energy for the synthesized slag permeated into the unused brick texture was 47-51 kcal per mole.