抽锭式电渣重熔过程中渣/金界面液-固转变行为及漏钢漏渣机理研究

Electroslag remelting withdrawing (ESRW) technology is more efficient and lower-cost than traditional Electroslag Remelting(ESR) technology. ESRW is a new method for mass production of high quality large ingot and hollow ingot. Slag and steel leakage control is the key technology of ESRW. This task will study on the interaction behavior between electromagnetic field, flow field and temperature field, then establish the mathematical model of electrode-slag pool-metal molten pool-temperature field of the ingot. By using the method of combination of theoretical and experimental,we will study on formation process and high temperature mechanical properties of slag shell in the slag/metal interface in order to elucidate the relationship between components and crystalline state of slag shell and high temperature mechanical properties, then find the essential reason of slag shell cracked and confirm the theoretical basis for the selection of slag system. The mathematical model of temperature field in the system is used to study the volume variation of ingot due to the solidification shrinkage and air gap formation process, we will obtain design basis of mold taper. Analysis of the results of the study, we can find the occurrence mechanism of steel and slag leakage during ESRW process and the main influencing factors. The results of this study can enrich ESRW technology theory and provide a new theoretical guidance for the production process.

抽锭式电渣重熔技术解决了固定式电渣重熔生产效率低、成材率低的问题，也是生产优质大型钢锭和空心电渣锭的一种新方法。漏渣漏钢问题是阻碍该技术发展的瓶颈，本项目旨在解析漏钢漏渣机理。构建多场（电磁场、流场和温度场）耦合抽锭式电渣重熔体系（电极-渣池-金属熔池-钢锭）温度场数学模型作为研究渣壳高温力学性能和钢锭凝固收缩规律的前提。采用理论分析和实验结合的方法对渣系成分、渣壳结晶状态与渣壳高温力学性能之间的关系进行研究，提出抽锭式电渣重熔用渣系的物理化学性质和渣壳高温力学性能评价指标，奠定抽锭式电渣重熔用渣系选配的理论依据。研究钢锭凝固收缩过程中体积变化规律，阐明钢锭凝固收缩行为和气隙形成过程，建立抽锭结晶器锥度的优化设计方法。将上述研究结果归纳总结，解析漏钢漏渣发生机理，建立其与主要影响因素之间的关系。项目的研究成果将完善抽锭式电渣重熔工艺理论，将为生产工艺提供新的理论指导。

抽锭式电渣重熔技术生产效率高、成材率高，是生产优质大型钢锭和空心电渣锭的一种新方法。漏渣漏钢问题是阻碍该技术发展的瓶颈，本项目以抽锭式电渣重熔体系（电极-渣池-金属熔池-钢锭）温度场数学模型研究为基础，对渣壳高温力学性能和钢锭凝固收缩规律进行研究，解析漏钢漏渣机理。研究结果表明，钢锭凝固收缩及其体积变化是气隙产生的主要原因，采用ANSYS和CFX软件计算得到的钢锭的收缩曲线，建立了抽锭结晶器锥度的优化设计方法。采用理论分析和DSC实验结合的方法对渣系成分、渣壳结晶状态与渣壳高温力学性能之间的关系进行研究渣系组成以及物相组织对渣壳状态和高温力学性能的影响，研究结果表明四元渣系中含有3%的SiO2时，熔渣的结晶物相组成对改善渣皮的高温力学性能更有利，CaF2-Al2O3-CaO-SiO2四元渣系拥有良好的结晶性能，它有利于改善渣膜的润滑并且在结晶物相性质上可以提高渣膜的高温力学性能。本项目研究成果在工业生产中取得了很好的效果，为抽锭电渣重熔生产工艺提供新的理论指导。