Abstract: Non-metallic inclusion is a important factor affecting the fatigue property of high-temperature bearing steel. The effect of electroslag remelting （ESR） using 37 slag on inclusions of M50 high-temperature bearing steel was investigated in order to improve the level of inclusion control. Inclusions were characterized by field emission scanning electron microscope equipped with energy dispersive spectrometer. The ingredients of slags before and after ESR was analyzed by X-ray fluorescence method. In the consumable electrode， inclusions were finer Al₂O₃-SiO₂ with high SiO₂ content （about 29.3% in average value）. No inclusions clusters were observed.After ESR， inclusions changed to Al₂O₃， the clusters inclusions with large size were observed. The content of SiO₂ in the slag increased from 1.73% to 3.42%， and the Al₂O₃ content decreased； The content of Al in the steel increased significantly from <0.000 5% to 0.020 7%， and the content of Si in the steel decreased from 0.356% to 0.296%. The metallurgical reaction during ESR was explained based on slag-steel reaction theory. The dissolved Si in the steel reacted with Al₂O₃ of the molten slag at the interface between molten steel and slag， and the products were dissolved Al and SiO₂. Subsequently， dissolved Al diffused into the molten steel and reacted with SiO₂ of the inclusions， and the products were dissolved Si and Al₂O₃. In the end， inclusions in the steel were transformed into Al₂O₃.The methods to control inclusions of M50 bearing steel during ESR using 37 slag were proposed.

Key words: Electroslag Remelting, High-temperature Bearing Steel, M50, Inclusions, Slag-steel Reaction, 37 Slag

摘要： 非金属夹杂物是影响高温轴承钢疲劳性能的重要因素。为了提高M50高温轴承钢的夹杂物控制水平，分析了三七渣电渣重熔精炼技术对夹杂物的影响。采用场发射扫描电子显微镜和能谱仪对夹杂物进行了表征，采用X射线荧光光谱仪分析了电渣重熔前后渣料成分的变化。在自耗电极中，夹杂物为尺寸较小的Al₂O₃-SiO₂，其中，w［SiO₂］较高（平均值为29.3%），不存在聚集状夹杂物。经过电渣重熔，夹杂物转变为Al₂O₃，而且存在大尺寸的簇状夹杂物；渣料中w［SiO₂］从1.73%增加到3.42%，同时Al₂O₃含量发生降低；钢中w［Al］从＜0.000 5%显著增加到0.020 7%，w［Si］从0.356%降低至0.296%。基于渣-钢反应理论对电渣重熔过程的冶金反应进行了解释。钢液中的溶解Si和熔渣中的Al₂O₃在钢液和熔渣的界面发生反应，产物为溶解Al和SiO₂。随后溶解Al扩散进入钢液并与夹杂物中SiO₂发生反应，产物为溶解Si和Al₂O₃。最终使得钢中夹杂物转变为Al₂O₃。提出了控制三七渣电渣重熔M50轴承钢中夹杂物的方法。

关键词: 电渣重熔, 高温轴承钢, M50, 夹杂物, 渣-钢反应, 三七渣