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用热力学方法计算并分析了铁水增碳过程中碳溶解反应自由能变化以及碳氧化反应自由能变化的关系,认为碳的氧化是阻碍铁液增碳的不利因素,增碳反应必须在氧气较少的气氛中进行.在此基础之上,进行增碳试验.首先利用过量石墨增碳,分别得到含钒铁水在1450、1500、1550℃时的碳饱和溶解度,并拟合得到碳溶解度与温度的关系式,即w(Cs)=2.7×10-3T+0.38.然后将不同的增碳剂加入到由铁屑熔化而得到的含钒铁液中,并保温一定时间进行增碳试验.由试验结果可知,5种增碳剂的增碳效果优先顺序为:低氮增碳剂、石墨、无烟煤、碳粒、焦炭.由动力学计算可知,在本次试验条件下增碳反应速率常数的数量级为10-4 s-1.通过分析认为,提高温度可以促进增碳反应的进行,而增碳剂中的硫和灰分抑制增碳反应的进行.

The thermodynamic analysis of Gibbs free energy for the carbon dissolution and the oxidation reactions dur-ing the carburization process in vanadium-containing hot metal was conducted. It is concluded that the oxidation of car-bon was bad for the dissolution of hot metal,and the carburization reaction was possible under low oxygen atmosphere. On this basis,the carburization experiment of laboratory level was conducted. Firstly,graphite was used in carburiza-tion experiment and the solubility formula of carbon in vanadium-containing hot metal was obtained through regression of carbon solubility in the hot metal at temperature of 1450,1500℃and 1550℃,respectively. The relationship be-tween carbon solubility and temperature is w(Cs)=2.7 × 10-3T+0.38. Subsequently five carburants were added into the vanadium hot metal which was obtained from the melting of scrap iron and kept for certain holding time. In this way the rank of carburization efficiency for the five carburants was obtained as follows:low nitrogen carburant,graphite,an-thracite,carbon granule,coke. It is also observed that the increase of reaction temperature contributes to higher carburi-zation amount and carburization rate. The order of magnitude of rate constant for carburization reaction in the experi-ments was found to be 10-4 s-1. In the end,it is reached by analysis that higher temperature facilities carburization pro-cess and that the carburization process is suppressed by both sulfur and ash in carburant.