| 摘要 |
PURPOSE:To manufacture the titled ingot of uniform quality having less inclusion while the inclusion is in form control, by immersing a gas blowing nozzle in the unsolidified part of steel from the upper part of the mold and then by blowing inert gas into the molten steel. CONSTITUTION:As inert gas is injected from gas blowing nozzle 6, molten steel 5 has a stirring flow as shown by arrow 7 and this stirring flow is allowed to collide against molten steel flow 8 discharged from tundish nozzle 1 to return. As a result, large-sized nonmetallic inclusion falls on unsolidified molten steel end 9 naturally and then floats up to the upper of mold 2 without being acquired and solidified and then separated. Further, cooling molten steel 5 near solidifying shell 4 is facilitated over a wide area in the drawing direction of the ingot and then the growth of columnar crystal is suppressed to form isomatric crystal, obtaining homogenized structure. Further, powder such as rare earth elements, Zr and Ca-Si is injected together with inert gas as carrier gas, so that the shape of the remaining nonmagnetic inclusion is made sperical by chemical coupling. |
