基于熔池搅拌动力学的电弧炉炼钢成分预报基础研究

End point prediction and control is the key technology to smelt high quality special steel and to realize intelligent in EAF steelmaking process. Due to uneven regional chemical reactions in bath of electric arc furnace, and the mechanism of steel flow to the reaction in molten bath is not clear, the technical problems of composition accurate prediction in EAF steelmaking have not been able to solve thoroughly. With technology of reasonable power supply, strengthening the oxygen supply and bottom blowing to be adopted, rhythm of smelting has accelerated, so end point composition prediction has become more urgent. In view of the research status at home and abroad, and prophase research work for bath stirring and end point prediction, the applicant put forward the new method “Composition prediction based on bath stirring dynamics in EAF steelmaking”. The molten pool is divided into “violent reaction area” and “flow area”. By using theoretical calculation, numerical simulation, water simulation, and hot state experiment, this topic study selective oxidation thermodynamics mechanism in the violent reaction area by oxygen jet, proven the characteristics of steel flow and the mass transfer cycle number in bath of EAF steelmaking, and study the characteristics in violent reaction area with chemical reaction, to determine the composition of the each element in the molten bath for the establishment of composition prediction model based on bath stirring dynamics in EAF steelmaking. This topic will improve accuracy of molten steel composition prediction in EAF steelmaking, providing theoretical basis and application method for intelligence of EAF steelmaking.

终点预报与控制是电弧炉冶炼高品质特殊钢与实现智能化的关键技术。由于电弧炉炉内各区域化学反应不均衡，钢液流动对熔池内反应作用机理尚不清晰，一直未能彻底解决电弧炉炼钢成分准确预报的技术难题。随着合理供电、强化供氧与底吹等技术的采用，冶炼节奏加快，实现成分的预报更为迫切。针对国内外研究状况和本人在熔池搅拌与终点预报的前期研究工作，申请人提出了“基于熔池搅拌动力学的电弧炉炼钢成分预报”新方法，将熔池划分为“剧烈反应区”与“流动区”，采用理论计算、数值模拟、水模拟、热试实验等方法，研究氧气射流作用的剧烈反应区的选择性氧化热力学机理，探明电弧炉炼钢熔池钢液流动特征规律与传质的循环准数，分析集成化学反应的剧烈反应区熔池特征规律，确定整个熔池内各元素成分变化规律，建立基于熔池搅拌动力学的电弧炉炼钢成分预报模型。本研究将提高电弧炉炼钢钢液成分预报准确性，为电弧炉炼钢实现智能化提供理论基础与应用方法。

电弧炉炼钢熔池扁平，原料结构复杂且初始碳含量不足，钢液流动速度慢，炉内各区域化学反应不均衡，成分、温度差异大，冶炼终点控制困难。究其根源，电弧炉熔池搅拌规律未能掌握，其与化学反应的匹配关系尚不明确，难以预测炉内冶金反应强度与冶炼进程，影响终点的准确预报。近年来，随着合理供电、强化供氧与底吹等技术的采用，冶炼节奏加快，对终点预报提出了更急迫的需求。提出了将熔池划分为“剧烈反应区”与“流动区”，采用理论计算、数值模拟、水模拟、热试实验等方法，研究氧气射流作用的剧烈反应区的选择性氧化热力学机理，定量揭示了剧烈反应区与钢液流动区在搅拌作用条件下的变化规律，建立了熔池动力学条件量化评价的单因素与多因素的量化关系以及拟合分析的量化分析方法，得到了建立电弧炉炼钢熔池搅拌动力学条件量化评价的方法和交互软件，评价方法能为不同电弧炉，不同工况的炼钢过程提供参考，为电弧炉炼钢过程熔池反应与熔池成分变化特征提供量化的动力学理论基础，提高电弧炉炼钢成分的准确预报。构建了基于熔池搅拌动力学的电弧炉炼钢成分预报模型，模型在华菱衡钢100t电弧炉进行应用，能够实时采集冶炼过程的电能、氧气消耗量、碳粉消耗、石灰等过程数据，实现了现场冶炼过程中熔池成分预报，提供更加科学、准确地工艺操作指导。本研究提高了电弧炉炼钢钢液成分预报准确性，为电弧炉炼钢实现智能化提供理论基础与应用方法。