| 摘要 |
<p>Mold flux for continuously casting steel which contains SiO 2 , T.CaO, Al 2 O 3 and MgO as main components, one or two or more of alkali metal oxides, and further the constituent F, while the ratio of the T.CaO content to the SiO 2 content being from 0.7 to 2.0, the Al 2 O 3 content being 35% or less, the MgO content being 20% or less, the total content of alkali metal oxides being 8% or less, the F content being 7% or less, characterized in that each of the contents expressed by formulae (b) to (e) below satisfies the formula (a): 0.63 + 2.51 × Y Al2O3 ‰¤ Y CaO /Y SiO2 ‰¤ 1.23+2.51 × Y Al2O3 ... (a), Y SiO2 = X SiO2 / (X SiO2 + X CaO + X Al2O3 + X MgO ) ... (b) , Y CaO = X CaO / (X SiO2 + X CaO + X Al2O3 + X MgO ) ... (C), Y Al2O3 = X Al2O3 / (X SiO2 + X CaO + X Al2O3 + X MgO ) ... (d) , and Y MgO = X MgO / (X SiO2 + X CaO + X Al2O3 + X MgO ) ... (e). Continuous casting of a round billet using this mold flux can effectively prevent the generation of pin-hole defects and longitudinal cracking.</p> |
