| 摘要 |
PURPOSE:To reduce erosion of tundish refractory and to produce a cast slab having little defect in a product by covering molten steel surface in the tundish with the specific composition of molten steel surface coating powder and surrounding the outer circumference of the molten steel surface coating powder with the specific composition of tundish protecting powder. CONSTITUTION:At the time of continuously casting the steel, the molten steel surface in the tundish is coasted with the molten steel surface coating powder 5 containing 40-60wt.% CaO, 20-40% Al2O3, 0.5-5.0% MgO, 0.5-2.0% C, 0.1-5.0% Na2O, 1-10% CaF2 and regulating <=7.0% SiO2. Then, the powder 5 is surrounded with the tundish protecting powder 6 containing 30-40% CaO, 30-40% SiO2, <=20% Al2O3, <=10% MgO, and by preventing contact of the molten steel covering powder 5 with the tundish 8, the tundish 8 is protected. |
