Method for increasing carbon content of semi-steel steelmaking end point and semi-steel steel-making method

Abstract

The invention provides a method for improving the steelmaking end-point carbon content of semisteel and a semisteel steelmaking method. The method comprises: during tapping of semisteel to a ladle, adding 1.5-6.0kg / (t semisteel) ferrosilicon into the ladle; then adding the semisteel into a steelmaking furnace, putting an oxygen lance into the furnace to perform oxygen blowing smelting, and adding related slag making materials and alloys according to blowing requirements, conducting carbon drawing, then performing reblowing according to the carbon content, controlling the end-point carbon content of molten steel at 0.10%-0.20%, taking out the oxygen lance, and stopping blowing. Specifically, the semisteel is molten steel obtained by subjecting vanadium-containing molten steel to a vanadium recovery converter or dephosphorization converter to undergo blowing, and by weight, has a C content of 3.20%-3.80% and an Si content of 0.001%-0.05%. The method provided by the invention can shorten the initial slag forming time, improve the steelmaking and slagging speed, can enhance the molten steel temperature, can effectively control the steel material consumption in the steelmaking process, and can avoid the low utilization problem of carbon recarburization materials.

Description

Technical field [0001] The invention belongs to the technical field of semi-steel steelmaking. Specifically, it relates to a method for increasing the carbon content of the semi-steel steelmaking endpoint and a semi-steel steelmaking method adopting the method for increasing the carbon content of the semi-steel steelmaking endpoint. Background technique [0002] Generally speaking, the vanadium-containing molten iron obtained from vanadium-containing iron ore (for example, vanadium-titanium magnetite) is smelted in a blast furnace to obtain semi-steel after smelting in a vanadium extraction converter or a dephosphorization converter. The semi-steel is characterized by low carbon (Average around 3.6%), low silicon (below 0.01%), low manganese (below 0.05%), insufficient heat source, low slag-forming element content, higher temperature than molten iron, low early oxidation of slag and difficulty in initial slag formation . When the semi-steel is used for smelting, since the heat-g...