A method for reducing the amount of phosphorus returned in the tapping process of producing low-phosphorus steel in a dephosphorization furnace

Abstract

The invention belongs to the field of converter steelmaking, and in particular relates to a control method for reducing the phosphorus return amount in the tapping process of producing low-phosphorus steel in a dephosphorization furnace. It includes the following steps: 1) After the carbon pulling at the end of the converter, quickly use the auxiliary gun to measure the temperature and take samples. After the sampling is completed, it is forbidden to use nitrogen gas pressure slag, and directly shake the furnace on the slag surface, and pour out part of the phosphorus-rich slag; 2) Pour the phosphorus-rich slag After the completion, shake the converter to zero position, and add lime and sintered ore into the furnace; 3) After the components at the end of the converter return and meet the tapping requirements, start shaking the furnace to tap; 4) During the tapping process, add graphite carbon into the ladle 5) After the pre-deoxidation is completed, add synthetic slag; 6) After the synthetic slag is added, carry out the final deoxidation and alloying operation of molten steel; 7) The sliding plate blocks the slag at the end, and the slag in the tapping hole is prohibited from being put into the ladle after the steel is placed . The method can stably control phosphorus return within 0.002% in the process of putting steel, and can significantly reduce the blowing rate of edge components and the out-of-standard rate of components caused by returning phosphorus in the process of putting steel.

Description

technical field [0001] The invention belongs to the field of converter steelmaking, and in particular relates to a method for reducing the amount of phosphorus returned in the tapping process of low-phosphorus steel produced by a dephosphorization furnace. Background technique [0002] Phosphorus is a harmful element for most converter smelted steels. At present, the main methods of producing converter low-phosphorus steel at home and abroad include single slag leaving slag method, double slag deep dephosphorization method, and double-combined method. The dephosphorization rate is about 85%-93%. In the process of smelting low-phosphorus steel by the above-mentioned method, especially when the phosphorus content in molten iron is high (≥0.140%), it is inevitable that the composition of the converter smelting end point will deviate from the upper limit, and the phosphorus in the slag at the end point of low-phosphorus steel smelting is at an excessive level. In the saturated ...

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Problems solved by technology

[0005] The invention aims at the problem that molten steel is very easy to return phosphorus in the process of tapping steel, which leads to the problem that the phosphorus composition of the finished product is out of order, and provides a control method for reducing the amount of phosphorus returned in the tapping process of producing low-phosphorus steel in a dephosphorization furnace

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