【摘要】 对不锈钢侧顶复吹AOD精炼过程的数学模拟作了进一步研究,提出了一个新的数学模型.该模型大体仍基于预研究中对该过程所作的分析和假设,但按二维复合壁的瞬态导热分析了炉体的传热,对体系作了更全面和精确的热量衡算;按实际工艺更贴切地考虑了整个精炼过程中各操作因素的影响.应用该模型于120 t AOD炉内28炉304型不锈钢的精炼,结果表明,该模型可精确估计整个吹炼过程中钢液成分和温度随时间的变化.氧化精炼期各元素间的竞争性氧化和氧的分配比,氩气搅拌和还原精炼期各氧化物的竞争性还原及其供氧率,均可用各反应的Gibbs自由能来表征和确定.对本工作条件下304型不锈钢的精炼,顶吹、侧吹和复吹脱碳过程的临界碳的质量分数(在该质量分数后,脱碳变为主要由钢液内碳的传质控制)分别在0.895%～0.942%,0.078%～0.224%,0.144%～0.255%范围内.由该模型的估计考察了一些因素对精炼效果的影响和吹炼工艺的优化.该模型可为不锈钢侧顶复吹AOD精炼过程工艺的制定和优化及实时在线控制提供有用的信息和可靠的依据.更多还原

【Abstract】 Mathematical modeling of the combined side and top blowing AOD refining process has further been studied.A new mathematical model proposed is generally based on the analysis and assumptions made for the process in our preliminary investigation.However,the heat transfer of the vessel is analyzed in terms of the two-dimensional transient heat-conduction problems of composite walls.The heat and mass balances of the system are more comprehensively and accurately carried out.The influence of the operating factors in the whole process has more appropriately been considered according to the practice.The model was applied to 28 heats of 304-grade stainless steel refining in a 120 t AOD converter,and the results show that the changes in the composition and temperature of the liquid steel with the time during the whole process can be precisely predicted using it.The competitive oxidation among the elements in the steel during the oxidative refining with the relevant oxygen distribution ratios,and the competitive reduction of the oxides in the slag during the Ar agitating and reductive refining with the appropriate oxygen supply ratios can be well characterized and reasonably determined using the Gibbs free energies of the reactions.The critical carbon concentrations(after which the decarburization alters to be controlled by the mass transfer of carbon in liquid steel) for the top,side and combined blowing of 304-grade steel in this work are in the ranges of 0.895 to 0.942,0.078 to 0.224,0.144 to 0.255 mass%,respectively.The effects of some factors on the refining result and the optimization of blowing technology have been considered from the model predictions.The model can provide a reliable basis and useful information for determining and optimizing the technology of this AOD process of stainless steel,and controlling the process in real time and on-line.更多还原