Converter smelting method for improving end molten steel remainder Mn with medium-high-Mn, high-P and low-Si molten iron

Abstract

The invention discloses a converter smelting method for improving end molten steel remainder Mn with medium-high-Mn, high-P and low-Si molten iron (C4.20-4.60wt, Mn 0.90wt%-1.15wt%, Si 0.05-0.15wt%, P0.100-0.130wt% and S smaller than or equal to 0.040wt%). Integrated innovation is conducted on processes such as slag retention operation, continuous casting residual slag application, low-alkalinityslagging process, constant-pressure low lance position operation in the smelting process and tapping slag washing in the whole process, smelting reaction dynamics and thermodynamic conditions are optimized, the distribution concentration of MnO in slag in the smelting process is increased, better smelting slagging and dephosphorization effects are obtained under the conditions of little slag andlow-alkalinity slag systems, rephosphorization of molten steel in the later period of smelting and the tapping process is reduced to the greatest extent, the content (0.43wt%-0.55wt%) of end point molten steel residual Mn is significantly increased, the addition amount of Mn alloys in the deoxidation alloying process is reduced, the steelmaking alloy consumption and alloying cost are significantlyreduced, the economic indexes of the smelting technology is improved, and the market competitiveness of products 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 end-point molten steel with medium-high-manganese, high-phosphorus, and low-silicon molten iron. 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 ...