Manipulating the motion and size of typical inclusions in titanium containing steel melt by pulsed electric current

During the continuous casting process of titanium containing steel, titanium containing inclusions in the molten steel tend to aggregate on the inner wall of the nozzle, forming grid–like and cluster–like deposits, which ultimately lead to nozzle blockage through nodulation. These inclusions within the crystallizer may also induce floater formation and increase the risk of steel leakage incidents. Addressing these challenges requires precise control over the migration behavior and dimensional characteristics of inclusions in molten steel. This study employs electropulsing treatment as a physical intervention method to systematically investigate the effects of current intensity, frequency, and duration on the number density, size distribution, and spatial distribution of inclusions. Results indicated that the pulsed electric current successfully drove the migration of inclusions from the top and middle regions to the bottom of the molten steel. Under the optimal parameters (150 A, 5000 Hz, 10 min), the number density of inclusions in the top region was reduced by over 80%. Furthermore, the pulsed electric current effectively refined the inclusions, leading to a decrease in their average size and a significant reduction in the proportion of large inclusions (>10 μm) — from 17% in the untreated sample to less than 1%. Enhanced current parameters were found to effectively reduce the interfacial tension between the inclusions and the molten steel, thereby suppressing the collision and aggregation of inclusions. This study establishes a theoretical foundation for manipulating inclusions in molten steel via pulsed electric current and proposes an innovative solution to industrial challenges, including nozzle clogging and crystallizer floater formation in titanium containing steel continuous casting processes.