钢锭凝固过程中的电磁补缩机理研究

With the rapid development of national defence, electrical construction, petroleum and chemicals, ship-building, machinery equipment and other important industrial field, higher requirements of solidification quality, piece weight and yield for ingot which is primary original material above the fields. The inevitable feeding disorders is a key problem during the freezing of ingot，which seriously affect degree of defect，such as shrinkage holes, composition segregation and low yield. Scientific and reasonable feeding mechanism is important for pushing the limit of ingot quality control. Therefore, the project“Study on electromagnetic-feeding mechanism during solidification of steel ingot”is proposed. The electromagnetic field is introduced into solidification theory of steel ingot. According to the rules of combining theoretic analysis with practical application, and comparing numerical simulation and experiment, the effects of electromagnetic field on structure of solidification constriction-feeding,characteristics of solidification microstructure and composition segregation will be systematically studied. The mechanism of solidification constriction and electromagnetic-feeding will be revealed, and a mathematical model of solidification constriction and electromagnetic-feeding will be constructed. The research results will not only provide reliable science data for industrial implication of electromagnetic-feeding mechanism, but also beneficial for improving solidification quality and yield of steel ingot.

随着我国国防军工、电力、石油化工、造船、机械装备等重要领域的迅速发展，对其主要原材料——钢锭的质量、单重和成材率的要求更加苛刻。凝固过程中不可避免的补缩障碍严重影响着钢锭内部疏松、缩孔、元素偏析、成材率低等缺陷程度。因此，科学合理的补缩机制对于突破钢锭质量控制极限极为重要。为此，提出了“钢锭凝固过程中电磁补缩机理研究”的项目，将电磁场的热、力效应引入到钢锭凝固理论中。本项目拟采用理论分析结合实际应用，数学模型结合实验验证，系统研究电磁补缩机制对于钢锭凝固收缩-补缩结构、凝固组织结构和成分偏析的影响规律，揭示钢锭凝固收缩-电磁补缩机理，建立钢锭凝固收缩-电磁补缩模型。研究结果不仅为电磁补缩机理的工业应用提供科学可靠依据，同时还可以促进钢锭产品质量、成材率和单重的优化升级。

钢锭凝固过程中不可避免的补缩障碍严重影响着钢锭内部疏松、缩孔、元素偏析、成材率低等缺陷程度。因此，科学合理的补缩机制对于突破钢锭质量控制极限极为重要。为此，提出了“钢锭凝固过程中电磁补缩机理研究”的项目，将电磁场的热、力效应引入到钢锭凝固理论中。项目采用了理论分析、数学模型结合实验验证，系统研究了电磁补缩机制对于钢锭凝固收缩-补缩结构、凝固组织结构和成分偏析的影响规律，揭示了钢锭凝固收缩-电磁补缩机理。结果证明：电磁补缩可以在钢锭冒口钢液内建立稳定的热中心，有利于提高钢锭冒口补缩效果、减少缩孔和疏松、促使重偏析区上移；电磁补缩有助于易偏析元素在钢锭凝固过程中的分散、改变钢锭凝固组织形态与分布，提高等轴晶率。研究结果不仅为电磁补缩机理的工业应用提供科学可靠依据，同时还可以促进钢锭产品质量、成材率和单重的优化升级，同时也为电磁补缩技术的下一步研究工作奠定了理论和实践基础。