• Journal of the Korean Ceramic Society
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• v.34 no.5
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• pp.544-551
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• 1997

We tried to improve the coating capability of the coating material using an additive(hexagonal cystalline graphite) of 2%, 3%, 4% and 6% under various pouring temperature for the easy isolation of sand and coating material from the final product. As a result in case of using a 2% and 3% additive generally no burning state has been occurred under the low pouring temperature, but it has been gradually increased with the pouring temperature. On the other hand in case of using a 4% and 6% additive there has been no burning state through out the whole pouring temperature. From this result we could see that the best state of the final product without sand and coating material could generally be obtained if 4% and/or 6% of the crystalline graphite and the pouring temperature of 140$0^{\circ}C$$\pm$5$^{\circ}C$ would be used.

• Journal of Korea Foundry Society
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• v.21 no.4
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• pp.232-238
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• 2001

Experimental study on the twin roll strip casting of BCuP-5(Cu-15wt%Ag-wt5%P) alloy was carried out using laboratory scale horizontal type twin roll caster. In this study, among the various operating parameters, such as tundish angle, contact angle, pouring temperature, roll speed, presetting gap of the rolls and kinds of roll and tundish materials, effect of pouring temperature for strip casting of BCuP-5 alloy which has long freezing range of about $170^{\circ}C$ was mainly investigated. BCuP-5 alloy strip was successfully produced when pouring molten metal at lower temperature than its liquidus temperature. Microstructure of the cast strip consists of primary Cu and eutectic. Especially the size of primary Cu phase increased with decreasing of pouring temperature.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.151-164
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• 1997

We tried to improve the coating capability of the coating material using an additive(hexagonal crystalline graphite) of 2%, 3%, 4% and 6% under various pouring temperature for the easy isolation of sand and coating material from the final product. As a result in case of using a 2% and 3% additive to the Korean coating material generally no burning state has been occurred under the low pouring temperature, but it has been gradually increased with the pouring temperature, while in case of using a 2% and 3% additive to the Japanese coating material we could observe a strong burning state throughout the whole pouring temperature. On the other hand in case of using a 4% and 6% additive there has been no burning state through out the whole pouring temperature. From this result we could see that the best state of the final product without sand and coating material could generally be obtained if 4% and/or 6% of the crystalline graphite and the pouring temperature of $1400^{\circ}C$$\pm$$5^{\circ}C$ would be used.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.429-436
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• 1988

The influences of some casting conditions on bonding ratio and state at bonding zone of stainless steel-cast iron dual tube produced by centrifugal casting process were investigated to estimate fabrication technics. 1) Bonding ratio is increasing such as increasing of inner surface temperature of outer metal(stainless steel STS 304), if pouring temperature of inner metal (cast iron) is constant. 2) The more pouring temperature of inner metal (cast iron) increase, the more bonding ratio increase when inner surface temperature of outer metal (cast iron) is constant. 3) As the mold rotary speed is increase, the hatching area of bonding map (perfect bonding area) goes down to the low pouring temperature of inner metal. 4) In order to predict bonding state of two different metal, we are able to make and use the bonding map about casting conditions such as inner surface temperature of outer metal, pouring temperature of inner metal and mold rotary speed.

• Journal of Korea Foundry Society
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• v.29 no.2
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• pp.78-85
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• 2009

Functionally graded microstructure of centrifugal cast Al-Si alloy, especially distribution of primary Si particles according to the changes of melt pouring temperature and rotation frequency was investigated by numerical simulation. Moving velocity of Si particles increased as the melt pouring temperature and rotational frequency of mold increased. Therefore, segregation tendency of primary Si particles toward inner side of cylindrical sample increased as the melt pouring temperature and rotational frequency of mold increased. Rich distribution region of particles was located at 0.9, 0.7, 0.4 mm from inner surface of cylindrical sample under the centrifugal cast condition of $750^{\circ}C$ melt pouring temperature and 1500, 2000 and 2500 rpm mold rotational frequencies, respectively, by numerical simulation.

• Journal of Korea Foundry Society
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• v.13 no.2
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• pp.155-162
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• 1993

This study has been focused on the influence of the metallic mold cooling effects on the solidification structures and the mechanical properties for Al-10%Si alloy castings by the variation of pouring temperatures, metallic mold temperatures and Cooling part of metallic mold. The dendrite arm spacing of Al-10%Si alloy was decreased with increasing cooling rate. In case of bottom cooling of metallic mold, DAS was appeared to be $20-22{\mu}m$ and in the middle cooling, it was increased to $36-40{\mu}m$. The DAS decreased proportionally $with(cooling\;rate)^{-3/2}$ at pouring temperatures $680^{\circ}C$ and $(cooling\;rate)^{-1/2}$ at pouring temperature $760^{\circ}C$, but it was proportionally increased to $(local\;solidification\;time)^{1/2-1/3}$ at pouring temperature $680^{\circ}C$ and $760^{\circ}C$. The maximum tensile strength of Al-10%Si alloy casting was obtained in case of bottom cooling of mold at pouring temperature $680^{\circ}C$ and metallic mold temperature $320^{\circ}C$.

• Journal of Korea Foundry Society
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• v.7 no.1
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• pp.45-52
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• 1987

The effects of melting and casting conditions on cast structures of Cu-Sn-Pb alloys were studied. Specimens were prepared at different pouring temperatures of $1100^{\circ}C$ to $1260^{\circ}C$ with use of various kind of molds, green sand mold, $CO_2$ sand mold, shell mold, furan sand mold and metallic mold. (1) The transition of equiaxed to columnar structure greatly influenced by adding elements and mold binders. (2) The change of equiaxed structure according to pouring temperatures were expressed by separation theory. Lower pouring temperature and rapid cooling rate increase hardness and it's further increase was shown in the region of columnar structure. (3) Proper controls of pouring temperature, cooling rate and mold binder were important factors to improve wear properties of Cu-Sn-Pb alloys castings.

• Journal of Korea Foundry Society
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• v.28 no.1
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• pp.25-30
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• 2008

To develop a functionally graded microstructure of cylindrical liner, effect of centrifugal casting parameters such as pouring temperature of hyper-eutectic Al-Si alloy melt, mold pre-heating temperature, and rotational frequency of mold on distribution of primary Si particles across wall thickness were investigated. Segregation tendency of Si particles toward inner side of cylindrical liner increased as the increase of rotational frequency of mold, pouring temperature of melt and mold pre-heating temperature. Especially, distribution density of primary Si particles within 1.5 mm from inner surface of cylindrical liner was above 35% under the centrifugal casting condition of $750^{\circ}C$ melt pouring temperature, $300^{\circ}C$ mold pre-heating temperature, and 2500 rpm mold rotational frequency.

• Journal of Korea Foundry Society
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• v.20 no.2
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• pp.80-88
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• 2000

Continuous casting equipment was designed to cast the metallic uranium rods, and a thermal analysis was carried out to calculate the temperature and solidification profiles. Fluid flow and heat transfer analysis model including the effects of phase change was used to simulate the continuous casting process by finite volume method. In the design of continuous casting equipment, the casting speed, pouring temperature and cooling conditions should be considered as significant factors. In this study, the effects of casting speed, pouring temperature, and air gap between the uranium and mold were investigate. The results represented that the temperature and solidification profiles of continuous casting equipment varied with the casting speed, pouring temperature, and air gap.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.566-575
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• 1994

The effects of varying the pouring temperature and the die preheating temperature in producing centrifugally cast HP alloy modified with Nb was evaluated on the basis of the resultant macrostructure, microstructure and hardness of these castings. Increased die preheating temperatures and pouring temperatures resulted in an increase in the thickness of the columnar dendritic zone, the primary and secondary dendrite arm spacing and the thickness of the zone of porosity at the casting I.D.(inner diameter). Lower die preheating temperature and pouring temperatures result in increased grain fineness and an increased zone of equiaxed grains. A higher hardness was achieved toward the casting O.D.(outer diameter) compared to the casting I.D., attributable to alloy segregation toward the casting I.D. and segregation differences resulting from reduced solidification cooling rates toward the casting I.D. Also, a higher hardness was realized at the cold end of the casting attributed to a more uniform distribution of carbides.