MELTING BEHA VIOR OF IRON CARBIDES INJECTED INTO MOLTEN STEEL

碳化铁有望作为一种新的铁源替代废钢用于炼钢，特别是使用电弧炉。本研究的目的是检查注入钢水的碳化铁的熔化行为，以明确其在不久的将来可用于炼钢的可行性。以下是1996和1997财政年度的结果。（1）以铁矿石为原料，采用流化床反应器，采用新的工艺概念，以天然气为原料，制备了Fe_3C（6.7mass%，粒径0.1 ~ 1 nm）高品位的碳化铁。（2）在50 kg感应炉上用喷枪向钢液表面喷吹碳化铁和氩气进行熔炼试验。通过测量熔体和出口气体中的温度和组分含量的变化来评估质量和热量平衡。（3）碳化物完全溶解于熔体中。随着碳化物化程度的提高，合金的熔化热有降低的趋势。此外，确认熔体中的氮去除如预期。

Iron carbide is expected to be utilized as a new iron source alternative to iron scrap for steelmaking, especially using an electric arc furnace. Objectives of this research are to examine a melting behavior of iron carbide injected into molten steel in order to make clear a feasibility for it to be available for steelmaking in the near future. The following results were derived in the fiscal years 1996 and 1997.(1)High grade iron carbides (Fe_3C, 6.7mass%, diameter : 0.1-1 nun) were produced by reacting iron ores with our specified gas in a fluidized bed based on a new process concept.(2)Their melting tests were performed by blowing the iron carbide with Ar gas to the surface of molten steel through a lance in a 50kg induction furnace. Mass and heat balances were evaluated by measuring the variation of temperature and contents of species in melt and exit gas.(3)The carbides were proved to be dissolved into melt without any problems. Their melting heats tended to decrease with higher carbidization. Also, nitrogen removal in melt was confirmed as expected.