PROTECTIVE AGENT FOR MOLTEN METAL SURFACE FOR CONTINUOUS CASTING OF STEEL WITH DECREASED SURFACE DEFECT

摘要

PURPOSE:To obtain a protective agent for a molten metal surface for continuous casting of steel with decreased surface defects by compounding MgO, TiO2 and MnO as a property adjusting agent for said protective agent in place of alkali metallic ions. CONSTITUTION:A protective agent for a molten metal surface for continuous casting of steel with decreased surface defects has 0.6-1.1 basically (CaO/SiO2) and consists of 25-40wt% CaO, 25-40wt% SiO2, 1-10wt% Al2O3, 5-15wt% F<->, 5-16wt% MgO and >=1 kind of 1-10wt% TiO2 and 1-10wt% MnO. Moisture absorptivity and generation of pinholes are thus decreased and the index for generation of surface flaws of the product is considerably decreased.