| 摘要 |
<p>A high cleanness steel which is produced by adding, as a Li-containing material, a Li-Si alloy having a Li content of 20 to 40 % and/or Li2CO3 into a molten steel, specifically, at a step wherein a series of molten metal treatments of the adjustment of components, temperature adjustments and the slag smelting have been completed, and which has a total Li content of 0.020 to 20 ppm (on the mass basis) and contains oxide based inclusions having a longer diameter of 20 mum or more in an amount of 1.0 piece or less per 50 g of the steel, wherein the oxide based inclusions being present in the steel contain, in mass %, 15 to 55 % of CaO, 20 to 70 % of SiO2, 35 % or less of Al2O3, 20 % or less of MgO, and 5 to 20 % of Li2O; and a method for the high cleanness steel. The above high cleanness steel is further improved in cold workability or in fatigue characteristics.</p> |
