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

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