METHOD FOR CONTINUOUSLY CASTING LOW CARBON SULFUR AND SULFUR COMPLEX TYPE FREE CUTTING STEEL

摘要

PURPOSE: To execute the stable operation and to enable the secureness of a good cast slab by suitably adjusting basicity of powder and beforehand adding MnO, at the time of casting a low carbon and high oxygen steel. ;CONSTITUTION: A sulfur fry cutting steel or a sulfur complex free cutting steel containing ≤0.15wt.% C, ≤0.03wt.% Si, 0.003wt.% Al, 0.015-0.025wt.% Total O is continuously cast. Then, the powder having ≥1.0 basicity (CaO/SiO₂ wt.% ratio) is added on the molten steel in a mold. Further, by adding the powder having ≥1.0 basicity (CaO/SiO₂ wt.% ratio) and ≤6wt.% MnO in the molten steel in the mold, the absorption of (MnO) and (FeO) from the molten steel is restrained. By this method, i.e., by suitably adjusting the basicity of the powder and beforehand adding MnO, the execution of the stable operation and the secureness of the good cast slab can be obtd..;COPYRIGHT: (C)1994,JPO