Vol.42, No.11, 942 ~ 947, 2004
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Title |
Characteristics of Iron Carbide Synthesized by CO-H2 Gas Mixture Using Hematite Fines |
정성실 Sung Sil Jung , 정우창 Uoo Chang Chung , 강흥원 Heung Won Kang , 박응열 Eung Yeul Park , 정원섭 Won Sub Chung , 박익민 Ik Min Park |
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Abstract |
The synthesis process of iron carbide was proceeded in two stages of reduction of hematite fines by H₂ gas, and carburization of the reduced metal by CO-H₂ gas mixture at 600℃. The surface of reduced iron was pre-treated with an addition of 0.05 vol% NH₃-Ar before carburization. The synthesized iron carbides were comprehensively explored by C/S analyzer (Low C/S determinator), Mossbauer spectroscopy, X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy at various reaction times of 5, 10, 15, 20, 25, 30, and 35 min. By addition of a small amount of NH3 gas, the super iron carbides contained 10 wt% carbon were made, and such addition stabilized iron carbides. It was found that addition of NH3 gas played a major role in the formation of iron carbide without decomposition (Fe₃C→ 3Fe+C) of iron carbides and precipitation of free carbon. From these results, we succeed in synthesis of super iron carbide, Fe_(5)C₂, with a stable single phase without Fe and Fe₃C phases. (Received August 2, 2004) |
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Key Words |
Super iron carbide(Fe5C2), Free carbon, NH3 gas, Synthesis |
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