A converter smelting method for increasing residual manganese in molten steel with high manganese and high silicon

Abstract

The invention discloses a converter smelting method for improving end-point molten steel residual manganese in high-manganese and high-silica molten iron (4.40 to 4.80 weight percent of C, 1.10 to 1.30 weight percent of Mn, 0.75 to 1.00 weight percent of Si, 0.085 to 0.105 weight percent of P and 0.015 to 0.035 weight percent of S). According to the method, by adopting technologies such as low alkalinity slag making technology, constant pressure gun change operation at gun position during smelting process, converter inverting gun pressing operation at minimum gun position, steel tapping whole-process wash heat process and carrying out integrated innovation, kinetic and thermodynamic conditions of smelting reaction are optimized, the distribution concentration of the slag (MnO) in the smelting process is improved and better smelting dephosphorizing effect is obtained under the conditions of less slag and a low basicity slag system; moreover, molten steel rephosphorization at the late smelting period and in the steel tapping process is reduced to the maximum extent, so that the residual Mn content (0.48 to 0.65 weight percent) of end-point molten steel is significantly increased, theadding amount of a manganese alloy during the deoxygenation alloying process is significantly reduced, the consumption of steelmaking alloys and the alloying cost are reduced, the improvement of smelting technical and economic indicators is promoted and further the market competitiveness of a product is improved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy and steelmaking technology, and in particular relates to a converter smelting method for increasing residual manganese in molten steel with high manganese and high silicon. Background technique [0002] Manganese (Mn) element is a beneficial element in steel. Most of Mn in molten iron is oxidized during converter blowing, and a small amount of Mn (residual Mn) remains in molten steel at the end of smelting. The Mn content of molten steel at the end of converter smelting mainly comes from Mn in molten iron. During the blowing process, manganese oxidation and reduction reactions occur between the molten metal pool, slag and oxygen, and the residual Mn content in molten steel at the end of converter is affected by The influence of factors such as the amount of slag, the oxidation of molten steel and slag at the end of the converter, and the temperature at the end of the converter. ...

AI Technical Summary

Problems solved by technology

At present, most domestic steel mills basically use low-Mn and low-P molten iron with the following chemical composition (Mn≤0.60wt%, Si 0.25-0.45wt%, P≤0.085wt%). There are certain research reports on the converter smelting process of the residual Mn content of molten steel at the end point, but the use of high manganese high There is no relevant research report on the converter smelting method of ferrosilicon molten steel to increase residual manganese in molten steel