• Transactions of Materials Processing
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• v.22 no.3
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• pp.165-170
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• 2013

High temperature deformation behavior of a heat-resistant duplex stainless steel, used as a retort in the Pidgeon process for Mg production, was investigated in this study. 25Cr-8Ni based duplex stainless steels were cast into rectangular ingots, with dimensions of $350mm{\times}350mm{\times}100mm$. Nitrogen and yttrium were added at 0.3wt.% each to enhance the heat-resistance of the steel. Phase equilibrium was calculated using the thermodynamic software FactSage$^{(R)}$ and the database of FSStel. For comparison, cast 310S steel, a widely used heat-resistant austenitic stainless steel, was also examined in this study. Dilatometry was conducted on the as-cast ingots for the temperature range from RT to $1200^{\circ}C$ and the thermal expansion coefficients were evaluated. The nitrogen addition was found to have an effect on the thermal expansion behavior for temperatures between 800 and $1000^{\circ}C$. High temperature tensile and compression tests were conducted on the ingots for temperatures ranging from 900 to $1230^{\circ}C$, which is the operation temperature employed in Mg production by the Silico-thermic reduction process. The steel containing both N and Y showed much higher strength as compared to 310S.

• Journal of Korea Foundry Society
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• v.15 no.3
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• pp.272-282
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• 1995

Iron-based metal matrix composites have been recently investigated for the use of inexpensive abrasion resistance material. This paper carried out to investigate the in-situ reaction effects on the microstructural characteristics and the formation mechanism of tungsten carbides in a white cast iron matrix. The specimens of Fe-3.2%C-2.8%Si alloy cast-bonded with tungsten wire were cast in the metal mold and isothermally heat treated at $950^{\circ}C$ up to 48 hours. The typical microstructure of heat treated specimens showed the reaction layer of WC at the interface of tungsten wire and the carbon depletion zone between the WC layer and the matrix. During the formation of WC layer, if the carbon supply is insufficient due to the decarburization of matrix or the isolation of matrix by cast-bonded W wires, the reaction layer develops coarse hexagonal crystalline WC. From the microstructural investigation, it was found that the volume of WC layer and the carbon depletion zone increased linearly with the isothermal heat treating time. This results supported that the formation rate of WC in the white cast iron matrix is controlled by the interfacial reaction with a constant reaction rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6019-6026
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• 2015

In this study, we have tried to use 3D-printing technology, which is very useful for small amount production and individual personalization manufacturing to produce a cast customized by individual. To do this, we have made casts by the 3D printer in the method of fused deposition modeling technique using ABS(acrylonitrile butadiene styrene) resin which is thermoplastic plastics. The computed tomography of human hand part was used as the modeling of the cast and it was designed to circulate air well. As a result, an individual personalized cast that fitted well with the model part was produced. In addition, we could get more excellent radiography from the cast than the existing cast. In conclusion, this study of 3D-printing could be used as basic data when a similar designed structure in fused deposition modeling technique by ABS resin is printed out.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.1-5
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• 2014

This study was carried out to investigate the effect of feeding fermented earthworm cast additives (FEC) on egg production, egg yolk fatty acids, blood lipid, cecal microorganism and fecal odor. The completely randomized experiment was applied, and the treatments were designed as 2 feeding regimens (control vs. FEC feeding), and FEC contained 3.5% top dressing to common diet. Egg production and egg weight of FEC group were significantly higher than that of control (p<0.05). Ratios of n-6/n-3 fatty acids in the egg yolk of FEC group were significantly higher than those in control group (p<0.05). Concentrations of HDL-C in FEC group was significantly higher than control group (p<0.05), but not triglyceride and total cholesterol. The caecal Lactobacillus of FEC group was significantly higher in FEC group than control group (p<0.05). $NH_3$ concentrations from poultry house were significantly lower in FEC group than control (p<0.05). In conclusion, these study results showed that the addition of FEC at 3.5% to the diet has reduced odor of poultry house and improved the n-6/n-3 fatty acid of egg yolk and egg production in laying hens.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.91-97
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• 2015

BACKGROUND: Earthworms are essential detritus feeders that play a vital role in the process of decomposition of organic matter and soil metabolism. The complex process of partial breakdown of organic matter and mixing with mucous and gut microbial flora in the form of earthworm cast results in the reduction of the toxicity. This study focused on the change of cast amount and pollutant contents before and after the eating of the organic waste and upland soil with the two species of earthworm. METHODS AND RESULTS: The two species of earthworms were compared to the cast production. In the upland soil material, the daily amount of worm's cast was 1.42 g in E. andrei and 0.40 g in A. agrestis. In the organic waste material, the cast of E. andrei was 0.78~0.83 g and the cast of A. agrestis. have not been collected because all earthworms died after the treatment. The heavy metals treated in the upland soil were evaluated the impact of the worm excretion. With the E. andrei, the cast production was decreased 0.1~0.8 times in zinc, 0.2~0.5 times in copper, and 0.1~0.7 times in cadmium compared to the control treatment according to the levels of concentration. With A. agrestis, the cast amount was decreased 0.3~1.1 times in zinc, 0.2~0.3 times in copper, and 0.1~2.1 times in cadmium, respectively. The changes of pollutant contents before and after the eating of the organic wastes with E. andrei were studied. In the treatment of the Alcohol Fermentation Processing Sludge and the Fruit Juice Processing Sludge, heavy metal content of the cast was increased 0.7~53.3% compared to the sludge materials. PAHs contents were decreased 50.1% in the cast of the Alcohol Fermentation Processing Sludge and 36.6% in the cast of the Fruit Juice Processing Sludge, respectively. CONCLUSION: In conclusion, although the A. agrestis was bigger than E. andrei in size and weight, the cast amount of A. agrestis was small. The two species of earthworm was less excretion with high concentration of heavy metals. While the heavy metals such as zinc, copper, and cadmium were considerably accumulated in the cast, the total compounds, PAHs were fairly decomposed. There results would provide us for restoring contaminated soil and cleaning organic wastes.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2235-2240
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• 2011

Recently, government agencies such as MKE Ministry of the small and midsize businesses and technology development requirements, technical difficulties to solve the Institute of Cast cooperation by establishing a network hub system Institute of Cast diffusion and commercialization of the R & D and are encouraged to promote. SME supporting with the experting technologies required to small and medium-sized businesses through "A comprehensive support program production site" of ISTK(Korea Research council Industrial Science & Technology) having been performed from 2010 to 2012, a pilot project in 2009. In this paper, customized technology services program in the past two years run will be discussed with the performance and improvement. Comprehensive support program that ends the production site in 2012 onwards the needs of maintenance difficulties of the railroad companies to build a support system and its ongoing research about the future plans to do.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.8-12
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• 2012

Recently, a wide range of industrial production area has a competitive advantage through cost reduction. Moreover with the development of industrial technology, base material and cutting tool help the machining technology. But most of the machining enterprises have not hold the R&D facilities and human resources. This mainly disturbs the industrial development and th increase of production efficiency. Especially in the interrupted machining process, it showed different behavior with continuous machining process. So it needs to research and develop the tool life and tool wear mechanism analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.188-191
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• 2005

Lower arm for automobile has been made in steel traditionally. Nowadays steel is being substituted fur aluminum to reduce weight of automobile. Widely applied production method of aluminum component has been casting processes or cast/forging processes. But casting or cast/forging processes have limits of application to parts which is required high strength durability like automotive component. In this research, hot forging process has been adopted to produce aluminum lower arm to ensure required mechanical properties. To reduce production cost, 2 pieces with 1 blow process was developed. Optimization and verification of hot forging process for aluminum lower arm was performed by computer aided engineering using finite volume methods.

• Computers and Concrete
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• v.20 no.3
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• pp.311-318
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• 2017

This paper investigates the utilization of waste tyre crumb rubber as the fine aggregate in precast concrete Paving block (PCPB). PCPB's are generally preferred for city roads, pedestrian crosswalk, parking lots and bus terminals. The main aim of this paper is to evaluate the mechanical properties of wet cast PCPB containing waste tyre crumb rubber. The mechanical properties were investigated using a density, compressive strength, split tensile strength and flexural strength tests at 7, 28 56 days according to the IS 15688:2006 and EN1338. The wet cast method was followed for producing PCPB samples. The fine aggregate (river sand) was replaced with waste tyre crumb in percentage of 5%, 10%, 15%, 20% and 25% by volume. All the test results were compared with the conventional PCPB (Without rubber). The test results indicate its feasibility for incorporating waste tyre crumb rubber in the production of PCPB by the wet cast method.

• Journal of Korea Foundry Society
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• v.3 no.4
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• pp.248-255
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• 1983

The effect of chromium, aluminium and copper contents on the structures and mechanical properties of cast iron was investigated. 1) Mechanical properties were improved with the formation of ledeburite by chromium addition. The primary carbides dispersed in martensitic matrix contributed to high strength and wear resistance. 2) Small addition of aluminium decreased hardness of the cast iron. 3) The impact values were decreased by the formation of the double carbides but improved by the heat treatment. 4) Small addition of copper up to a certain level increased the hardness. Also impact values were considerably increased.