Mold Flux for reducing bleeding and sliver on the cast slab of low carbon grade

摘要

PURPOSE: A continuous casting mold flux for preventing bleeding of molten steel is provided which suppresses sliver surface defects generated due to mixing of slag by having a high viscosity and reduces heat flux flown off to casting wall of mold from molten steel by maintaining a high crystallizing initiation temperature. CONSTITUTION: The mold flux for continuously casting low carbon steel comprises 0.25 to 2 wt.% of MgO, 5 to 10 wt.% of F, 30 to 45 wt.% of CaO, 30 to 45 wt.% of SiO2 and 5 to 15 wt.% of Al2O3, wherein a weight ratio of Al2O3/MgO is 5.0 to 20.0, and a basicity of CaO/SiO2 is 0.8 to 1.2, and wherein the mold flux for continuously casting low carbon steel further comprises less than 6 wt.% of Na2O.