The converter steelmaking manner which uses the dephosphorization molten iron which features

摘要

PROBLEM TO BE SOLVED: To achieve the refining so that the phosphorus content after the dephosphorization refining is the prescribed value taking into consideration the change in the P-content in the molten steel in the decarburization refining in producing steel through decarburization refining in other converter after the molten iron is dephosphorization refined in a refining vessel in advance. ;SOLUTION: The dephosphorized molten iron is obtained through the following processes. (a) The molten iron is dephosphorization-refined so that the phosphorus content ([P] f wt.%) at the terminating point satisfies the inequality of [P] f wt.% ≤[P] k wt.% -Δ1-Δ2 (where, [P] k wt.% is P content required for crude steel (standard composition of steel), Δ1 is increase (wt.%) in phosphorus by the slag left behind in a furnace after the preceding decarburization- refining in a converter to decarburization-refine the molten iron, Δ2 is recovered quantity of phosphorus (wt.%) of the molten steel in a ladle), and (b) the dephosphorization-refined molten iron is charged in other converter, and the decarburization-refining is achieved without substantially charging the slag- forming material.;COPYRIGHT: (C)1999,JPO