• Journal of Korea Foundry Society
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• v.10 no.2
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• pp.110-115
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• 1990

• Journal of Korea Foundry Society
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• v.43 no.3
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• pp.107-136
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• 2023

Natural silica sand was commonly used for sand casting of cast steel products, and chromites sand was used to suppress seizure defects due to the lack of thermal properties of silica sand. However there are disadvantages such as deterioration by repeated use, system sand mixing problem, difficulty separating and removing, increased during mold according to high density and to being waste containing chrome. Recently, industrial waste reduction and atmospheric environment improvement have been highlighted as important tasks in the casting industry. In order to solve the problems that occur when using foundry Sand and to improve the environment of casting factories, various artificial sands that can be applied instead of natural silica sand have been developed and introduced. Artificial sands can be classified into artificial sand manufactured by the electric arc atomization or gas flame atomization, artificial sand manufactured by the spray drying & sintering process, artificial sand manufactured by the sintering & crushing process and exhibit different physical properties depending on the type of raw-minerals and manufacturing method. In this study, comparative evaluation tests were conducted on the physical properties of various foundry sands, mold strength, physical durability, thermal durability, and casting test pieces. When comprehensively considering the actual amount of molding sand used according to density, the mold strength according to the shape of sand, the physical and thermal durability of foundry sand, and the heat resistance characteristics of foundry sand, 'Molten artificial sand A1' or 'Molten artificial sand B' is judged to be the most suitable spherical artificial sand for casting of heavy steel castings.

• Journal of Korea Foundry Society
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• v.2 no.2
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• pp.31-39
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• 1982

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1734-1735
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• 2011

In case of inspection on aluminum castings, traditional RT (Radiographic Testing) method have been utilized for its advantages in interpretation, cost and perpetual storage. But it has disadvantages like time consumption in film processing, low efficiency in storage and environmental pollution. In this thesis, a DRS (Digital Radiography System) utilizing X-Ray TDI Camera (Time Delay and Integration Camera) is developed. Inspections on aluminum castings are performed using the developed Digital Radiography System, DRS and reviewed if newly developed system can substitute for the traditional method.

• Journal of Korea Foundry Society
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• v.9 no.1
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• pp.67-72
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• 1989

Solidification analysis was conducted on large steel castings and ingots by a modified finite difference method. Auto-mesh generation system was developed for improving the application of the computer analysis system to casting disign. Combined use of the prediction parameters, solidification time and temperature gradient, and an auxiliary parameter, shrinkage potential, were used to predict the formation of shrinkage defects. Several examples on the prediction of shrinkage cavity by this method were campared with the experimental reslts. It was found that a quantitative design of large steel castings and ingots can be made by the computer aided analysis of solidification process.

• Journal of Korea Foundry Society
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• v.26 no.2
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• pp.57-62
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• 2006

• Tribology and Lubricants
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• v.19 no.4
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• pp.223-229
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• 2003

The sliding wear characteristics of the crane sheave were investigated using a pin-on-disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.11
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• pp.1873-1880
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• 2003

The sliding wear characteristics of the crane sheave were investigated using a pin on disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

• Journal of Korea Foundry Society
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• v.11 no.1
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• pp.54-62
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• 1991

A computer program which consists of pre-processor, main solidification simulator and post-processor has been developed for three dimensional solidification analysis of steel castings. The pre-processor is used for mesh generation in a small personal computing system. The modified finite difference method is adopted for the main solidification simulation algorithm. The post -processor graphically presents the simulation results and shows the formation of shrinkage defects. Several experiments on large steel castings in sand mold were carried out. The temperature variations in casting and mold with time are measured experimentally, and the results are compared with calculation results. Several numerical examples for the prediction of shrinkage cavity in large steel casting of SC42 and SCNCrM2 alloys are compared with experimental results. The effect of sleeve and chills on solidification patterns are also studied. Formation of shrinkage defects for the three cases of experimental castings are relatively well predicted by present model.

• Journal of Korea Foundry Society
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• v.15 no.5
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• pp.494-506
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• 1995

Test castings in plate, disc, and cubic shaped castings for 0.2wt.% carbon and stainless steel have been poured to examine the effects of the riser dimensions including riser neck on the casting soundness. Three empirical methods were chosen in risering of steel castings. A computer program of solidification analysis considering liquid and solidification contraction was developed to apply for riserdesign calculated by using their methods in plate, disc, and cubic shaped castings, and to calculate the position and dimension of shrinkage cavity in complex shaped casting. The potential of present method has been successfully demonstrated by comparing predicted cavity shapes with those obtained in a series of experimental castings. Three empirical methods can be used in a practical way to make a rapid estimation of tie minimum riser diameter, but they can not provide a criterion of casting soundness with shape and material on all occasions. The shape and position of shrinkage cavity can be successfully predicted both using the present method and using risering calculated by their methods regardless of the shape and cast material.