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pISSN : 1598-706X / eISSN : 2288-8381


한국주조공학회지 (24권1호 52-59)

Microstructure and Mechanical Properties of Continuous Cast Ductile Iron

연속주조한 구상흑연주철의 미세조직과 기계적 성질

Kyeong-Hwan Choel, Gue-Serb Cho, Kyong-Whoan Lee, Ki-Young Kim*

Korea Institute of Industrial Technology, *Korea University of Technology and Education


Microstructure and mechanical properties of ductile cast iron were investigated in terms of diameter change of samples that gives rise to modify the microstructure due to different cooling rate in the continuous casting process. The chemical composition used in this study was GCD 400 grade. From the microstructural observation, we have found a large number of graphite with small size in diameter which is comparable to the microstructure of the sample produced by conventional sand casting. The major reason of this would he due to high cooling rate. In the sample with 26 mm in diameter, the microstructure was composed of pearlite, iron carbide, and graphite. In the samples with 60 and 100 mm in diameter, however, we have observed a dissimilar microstructure that consisting of ferrite and graphite. Concerning the mechanical property, the sample with 26 mm in diameter showed higher hardness and strength compared to those samples with 60 and 100 mm in diameter. The result obtained for ductility appeared a reversal. Much more works such as inoculation, process design and chemical composition would be required in order to have a sound product even in a small diameter of samples.


continuous casting, ductile cast iron, graphite, cooling rate