【作者】 张志峰；

【导师】 金俊泽； 李廷举；

【作者基本信息】 大连理工大学 ， 材料加工工程， 2002， 博士

【摘要】 电磁连铸技术由于能生产出无振动痕、裂纹、亚偏析等缺陷的连铸坯，有利于连铸连轧一体化的顺利实现，被认为是继连铸技术之后钢铁业的又一次重大变革，是21世纪金属成形的新方法，正吸引许多学者和技术人员加紧进行这一领域的研究工作。作者参与了国家自然科学基金重大项目“电磁场作用下金属熔体成形及凝固基础研究”和国家科技部重大基础研究课题“电磁力对连铸钢坯细化、均质化和洁净化的影响”两项研究课题，并以此为题完成了博士学位沦文。取得有意义的结果如下： 电磁成形系统是电磁连铸的关键设备，对其结构形状的设计，至今没有系统的理沦。因此，本文首先建立电磁连铸成形系统电磁场计算的数学模型，采用数值模拟和实验研究相结合的方法，研究了电磁成形系统中磁场频率、感应线圈电流和位置、结晶器开缝形式对磁场分布的影响规律，通过优化电磁成形系统结构，获得了最佳成形系统电磁场分布，提出了电磁结晶器的优化结构形式，为开展电磁连铸成形工艺实验捉供了理论依据； 弯月面运动行为与连铸坯质量关系非常人，有效控制弯月面波动是获得优质连铸坯的关键。本文采用电磁特性与钢接近而熔点低的伍德合金作为钢的模拟物，研究了在复合电磁场作用下连铸弯月面的运动变化规律。研究表明，施加复合电磁场能够有效控制山于结晶器内电磁搅拌(M-EMS)引起的弯月面变形；随着施加磁场频率和功率的改变，能够实现对弯月面形状的任意控制。解决了山结晶器内电磁搅拌(M-EMS)引起弯月面变形而产生的铸造技术难题； 低熔点锡铅合金电磁连铸模拟实验表明，施加高频电磁场能够消除表面振动痕等缺陷，但是凝固组织中还存在晶粒粗大的问题；为了获得内外质量高的连铸坯，本文提出了连铸结晶器外施加复合电磁场来改善连铸坯质量的复合电磁连铸新技术，采用该方法不仅能够消除振动痕等表面缺陷，而且能够获得晶粒明显细化、且均田细小等轴晶构成的凝固组织，该项技术已经申请了发明专利； 在模拟实验的基础上，对小型电磁连铸机进行合理放大，设计并制作出实验室规模的钢电磁连铸设备，进行了中碳钢电磁连铸成形实验。在国内首次成功铸造出内外质量较未施加电磁场明显改善的 100X 100连铸钢坯，获得了开展钢电磁连铸技术的工装设备和关键技术参数，添补了该项技术的国内空白。更多还原

【Abstract】 Due to producing cast metals with high quality and benefiting to hot charge rolling and hot direct rolling, Electromagnetic Continuous Casting (ECC) is regarded as a great revolution of material processing, and also a up-to-date casting technique in the 21st century. The writer took part in two great projects: one is "Fundamental Research on Shape and Solidification of Molten Metal by Imposing Electromagnetic Field" supported by the Foundation of National Nature and Science of China, and the other is "the Effect of Electromagnetic Field on Refinement, Homogeneity and Pureness of Continuously Cast Steel Metal" supported by the National Science and Technology Ministry of China. The doctoral dissertation was finished on basis of the above research work. Main research results are as the following:The electromagnetic shaping system is the key apparatus to Electromagnetic Continuous Casting. Till now, there isn’t systematic theory that can be found about the design of its structure and shape. Firstly, mathematical mode! of the system of electromagnetic shaping system was established. Then the effects of input current, current frequency, mold structure, inductor structure, and relative position between the inductor, pouring level and mold on the magnetic field distribution were investigated by means of numerical calculation and experiments. Finally electromagnetic mold with optimum structure and optimum magnetic field distribution was obtained. In a word, the results provided theoretic criterion for shaping technique of electromagnetic continuous casting.Meniscus motion has great effects on quality of continuously cast metals. Behaviors of Meniscus motion were studied under the conditions of multi-electromagnetic field by using Wood Alloy with low melting point. The experimental results showed that multi-electromagnetic field can controlmeniscus disturbance caused by electromagnetic stirring efficiently; as power and frequency of generator are changed, meniscus contour can be controlled optionally.Experiments results show that surface defects such as oscillation mark are eliminated by imposing high electromagnetic field, however, solidification structure of ingot cast is made up of coarse columnar grains. In order to obtain cast metals with high quality, electromagnetic continuous casting with multi-electromagnetic field was developed. Internal and external quality of continuously cast metals can be improved greatly by using the method, and it has been applied for patent.Lab caster for electromagnetic continuous casting was designed and made proportionally on basis of small-scale caster, and casting experiments using middle carbon (0.06%) were carried out. Steel billet with size of 100 x 100 was cast successfully for the first time at home. Both internal quality and external quality of the steel billet are improved more highly compared with qualities of castings produced by conventional continuous casting. Technique equipment and key parameters on electromagnetic continuous casting process are gained.更多还原