摘要:
The invention provides a process for obtaining low-nitrogen steel by tapping molten steel from a converter without deoxidizing and by then deoxidizing the molten steel in a ladle refining furnace from which slag has been removed, and a process for obtaining low phosphorus steel by tapping molten steel from a converter without deoxidation at a tapping temperature lower than conventional processes, and by performing deoxidation and composition adjustment of the molten steel in a ladle refining furnace from which slag has been removed.
摘要:
Molten steel (6) is tapped from a converter into a refining ladle (2) and ore such as Nb 2 0 3 ore is charged into the molten steel (6). Then. the interior of the refining ladle (2) is held in an inert gas atmosphere. A reducing agent such as an At reducing agent is charged into the molten steel. Electrodes (10) are dipped in slag (8) on the molten steel to form an arc therebetween so as to heat the molten steel with an arc. The ore is reduced by the reducing agent, so that a metallic component of the ore is added to the molten steel. On the other hand, carbon electrodes each having a gas supply port at its lower end can be used to inject an ore powder or particles from the injection ports to the arc between the electrodes and molten steel. The ore is reduced by electrode carbon with arc heat, so that a desired component is added to the molten steel.
摘要:
@ A gap (32) between an insertion hole (24) formed in a covering (22) of a ladle (2) and an electrode (20) inserted through the insertion hole (24) is sealed by sealing means (26, 28). The sealing means (26, 28) have a cap seal (28) longitudinally and slidably fitted over the electrode (20). A base seal (26) is hermetically disposed between the cap seal (28) and the covering (22) in such a manner that the gap (32) is provided between the electrode (20) and the base seal (26). The base seal (26) has a gas injection nozzle (38) intended to discharge a gas towards the electrode (20) and another gas injection nozzle (40) intended to discharge the gas downwardly. The base seal may be cooled by causing cooling water to be circulated therethrough.