Low carbon production manner and that cast piece null low carbon

摘要

PROBLEM TO BE SOLVED: To provide a process for manufacturing a low-carbon molten steel as a material for thin steel sheet, which may reliably inhibit surface defects by performing deoxidation using mainly Ti to inhibit generation of alumina inclusions, and a strand slab obtained through this process.;SOLUTION: In the process for manufacturing the low-carbon thin steel sheet, ≥0.005 mass% Ti is added for deoxidation to molten steel whose carbon concentration is adjusted to ≤0.01 mass%, and Nd is further added before casting the molten steel. Here, the amount of Nd added is no less than an amount required for reductive decomposition of small amounts of dissolved oxygen and TiO_n inclusion left after Ti deoxidation but no more than an amount contaminating the molten steel by reacting with refractories or mold powders. An appropriate range of Nd concentration in the molten steel is 0.0001-0.01 mass%.;COPYRIGHT: (C)2003,JPO