高铁轴承钢冶金缺陷形成机理及其控制原理研究

通过实验、理论分析和数值模拟研究高铁轴承钢GCr19Mo冶金中夹杂物等缺陷形成机理和施加电磁场等手段控制的原理。研究轴承钢液在真空下脱氧热力学和动力学，考察Al, Ca, Mg，Si等元素与O结合生成夹杂物的基本规律，建立在真空及气氛-耐火材料-钢液体系中氧的转移和夹杂物生成的规律以及施加电磁场的影响机制的模型，解析真空中电磁场下吹气时钢液中流动状态和夹杂物运动、聚合长大及上浮被精炼渣吸附过程，探明中间包中施加电磁场和吹气对流动和夹杂物行为的影响规律，研究钢液凝固中夹杂物形成、分布、形态变化规律，重点研究夹杂物与凝固组织间相互作用的关系及其电磁场的影响机制，阐明高铁轴承钢连铸凝固中电磁场作用下碳化物的形成规律及其与凝固组织间的关系，建立高铁轴承钢的疲劳失效与夹杂物等缺陷间的定量关系，为高铁轴承的制造和应用提供基础。

The formation mechanism and the fundamental for electromagnetic control of inclusion in the metallurgy of bearing steel for high speed railway trains will be investigated by experiments, theoretical analysis and numerical simulation. The thermodynamics and kinetics of deoxidation of the steel in a vacuum will be investigated, along with research on the formation of inclusions produced from the combination of O with Al, Ca, Si, and Mg. In the complex system of vacuum and atmosphere-refractory-molten steel, the transfer of the oxygen ,formation of inclusion and the effect of electromagnetic field will be modelled. The migration, coagulation, floatation behavior of the inclusion in the molten steel and absorption by the slag in a vacuum with an electromagnetic field will be studied. The influence of electromagnetic field and blowing bubbles in the melt in a tundish will be discovered. Also, the generation mechanism of the inclusion in the steel, and its distribution and morphology during solidification with electromagnetic field will be explored, as well as the mutual effect between the inclusion and the solidification structures. The formation of the carbide during solidification of the steel in continuous casting under a magnetic field will be illustrated. The quantity relationship between the fatigue life and the inclusion of the bearing steel will be examined to set a sound basis for manufacture and application of the bearing steel for high speed railway trains.