Method for smelting high-phosphorus steel through converter

Abstract

The invention relates to a method for smelting high-phosphorus steel through a converter. The method includes the following steps of firstly, adding all active lime and light-burned dolomite at a timewithin 5 minutes of open blowing of the converter, controlling the alkalinity of final slag to be 2.0-2.5 and the oxygen pressure in the smelting process to be 0.85-1.00 Mpa, controlling the positionof a blowing lance to be 100-200 mm lower than that in normal dephosphorization melt, applying the high-low-low lance position to an oxygen lance in the blowing process, controlling the end point carbon temperature to hit the target, controlling the temperature, measured by a sublance, of a molten pool of a TSC to be 1610-1640 DEG C when oxygen blowing is completed by 80-85%, and forbidding to add a cold material within 100 seconds before oxygen blowing ends; secondly, controlling the end point carbon C in the converter to be 0.04-0.09%, controlling the tapping temperature to be 1645-1685 DEGC, and controlling the end point phosphorus P to be 0.040-0.070%; and thirdly, pouring part of slag after tapping is completed, adding light-burned dolomite for slag-splashing for protection of the converter, determining whether slag needs to be poured or not according to the after-slag-splashing slag amount condition, and controlling the residual slag amount to be 3-5 t for a next round of high-phosphorus steel smelting in the converter. By means of the method, the consumption of slag and alloy can be reduced, and the continuous and stable smelting of the converter can be ensured.

Description

technical field [0001] The invention relates to the technical field of converter steelmaking, in particular to a method for smelting high-phosphorus steel in a converter. Background technique [0002] When smelting 1215CW, 1215YG, 1214Bi and other free-cutting steels, the phosphorus content is required to be controlled between 0.040~0.070%. In the traditional converter smelting operation method, the phosphorus content at the end of the converter is controlled within 0.030%. Phosphorus-iron alloys need to be added during the tapping process, increasing the Steelmaking alloy costs. At present, there are the following four modes for smelting phosphorus-containing steel in converters. [0003] The first one is "A Method for Smelting Phosphorus-Containing Steel" with the patent application number 200410047045.0. The converter adopts the smelting operation of rapidly raising the temperature to remove carbon and retain phosphorus, and create high-phosphorus slag. In the initial st...

AI Technical Summary

Problems solved by technology

This method cannot continuously smelt long-cast phosphorus-containing steel in one converter, which has a great impact on the production rhythm and production organization of the subsequent process, and the slag splashing in the separate furnace is not conducive to the maintenance of the converter condition

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