Ladle slag carryover is one of the main sources of large-sized inclusions in steel. In continuous casting production,the control of the residual molten steel in the ladle is commonly used to avoid vortex slag entrainment during ladle pouring. This paper conducts industrial trials of casting with different amounts of residual steel in the actual steel production process, analyzes the characteristic evolution of large particle inclusions in steel, and investigates the ladle slag carryover under different residual steel conditions, providing references for the rational control of ladle residual steel during the casting process of target steel grades. For test steel grade xx, the production route is “converter→LF refining→RH vacuum treatment→Continuous casting→Rolling”. The main type of inclusions in the tested steel is Al₂O₃ inclusions, and their Al₂O₃ content shows an overall upward trend during the smelting process and stabilizes in the tundish stage. As the residual steel amount decreases, the T.O and T.N content in steel will increase, and the changes in the area fraction and number density of inclusions are consistent with this change regulation.The larger the area fraction and number density of inclusions in the cast slab and rolled products, the more likely slag entrainment occurs with reduced residual steel. The difference in inclusion distribution is small when the residual steel is 7.4 t and 9.8 t. It is recommended to leave about 7.4 t of steel during the casting process. Inclusions in the surface layer of the cast slab are mainly distributed at 2 mm-5 mm, with relatively high area fraction and number density.
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