Obtaining a Smooth and Dense Interface Structure Between Al-C Nozzle Material and the Molten Steel Containing Rare Earth by Pulsed Electric Current

Pulsed electric current is used to control the interface structure between Al-C nozzle material and the molten steel containing rare earth in this work. In the absence of a pulsed electric current, the interface shows a loose, rough structure with nodules, and interconnected holes are observed in the interface layer. Furthermore, inclusions CeAlO3/LaAlO3 adhere to the surface of the nozzle. However, pulsed electric current causes the interface to form amorphously, which results in a smooth and dense interface structure. As a result, the thickness of the interface layer without a pulsed electric current exceeds 1000 μm. However, by applying a pulsed electric current, the average thickness of the interface layer is only about 280 μm. That is, the thickness of the interface layer is reduced by about 70 pct. Besides, by investigating the corrosion of molten steel on Al-C nozzle material and adhesion of inclusions on the surface, the formation mechanism of the interface structure with and without pulsed electric current is discussed. Manuscript submitted August 30, 2020; accepted February 15, 2021.