连铸坯宏观偏析与大尺寸液析碳化物是降低轴承疲劳寿命的主要影响因素，目前对其仍缺乏稳定有效的控制。本项目以高碳铬轴承钢为研究对象，以碳化物析出—迁移—回溶为主线，采用实验研究与数值模拟相结合手段开展工作。首先测定高碳铬轴承钢两相区熔体黏性，定量表征熔体黏度与冷却参数、剪切参数的函数关系，阐明合金熔体流变特性；其次基于Thermo-Calc热力学数据库和高温共聚焦显微镜，开展碳化物析出热力学与动力学研究，揭示碳化物液析临界条件；在此基础上结合熔体流动、晶粒生长、碳化物析出行为，建立多相—多尺度—多外场凝固模型，阐明冷却强度—电磁搅拌—机械压下复合作用下铸坯宏观偏析演变与碳化物析出迁移特征，改善铸坯宏观偏析，促进碳化物弥散分布；然后开展热处理过程中电脉冲作用下碳化物回溶实验研究，探究电脉冲参数对C、Cr元素扩散的影响规律，揭示促进碳化物快速回溶的关键因素，为碳化物尺寸控制提供新思路。

The macrosegregation and large-size carbide in the continuous casting strand are the critical factors to deteriorate the fatigue life of bearings. However, the control mechanisms are not very effective. Therefore, the precipitation, migration, and dissolution of carbide in high carbon-chromium bearing steel is investigated in this program, with experimental research and numerical simulation. Firstly, the melt rheological behavior in the mushy zone is measured by the high-temperature physical property analyzer. The melt viscosities with different cooling parameters and shear parameters are quantitatively characterized. Secondly, the thermodynamic and kinetic study of primary carbide precipitation are investigated by the Thermo-Calc database and the high temperature microscope. Then，a multiphase-multiscale-multifield solidification model is built to simulate the solute transport and carbide precipitation in the continuous casting process. The effects of cooling intensity, electromagnetic stirring, and mechanical reduction on strand macrosegregation evolution and carbide migration are investigated. The technical parameters on the macrosegregation improvement and carbide dispersion distribution are obtained. Thirdly, the effect of pulsed electrical current on the diffusion rate of C and Cr elements are explored by the laboratory experiment. The key factors influencing the carbide dissolution will be obtained, which provides new guidance for the control mechanism of carbide size in high carbon-chromium bearing steel.