High-carbon dephosphorization method for high-carbon steel in converter smelting

Abstract

The invention discloses a high-carbon dephosphorization method for high-carbon steel in converter smelting, and belongs to the technical field of converter steelmaking. The technological thought of high gun position soft blowing and improving slag alkalinity is adopted, and the high-alkalinity slag is prepared with variable flow and variable gun position. Compared with the traditional process, thebiggest different is that the oxygen supply system with high gun position and low oxygen flow is adopted in the early and middle stages of smelting, the adding amount of the lime is increased to 40-45 kg/t, in contrast to an adding mode of adding materials in batches and small amounts of the traditional process, the steelmaking auxiliary materials are added to be more than 80% before 9 minutes. The purpose of adopting the high gun position and the low oxygen flow is to rapidly generate a large amount of FeO in the furnace slag, so that slagging is facilitated; the purpose of adding as early as possible is to combine with a soft blowing oxygen supply system, so that the FeO has the effect of promoting the melting of the lime, the utilization rate of the lime is increased to 85%, the high-alkalinity slag is generated so as to facilitate early-stage dephosphorization. The alkalinity of the terminal slag can be controlled to be larger than 3.2, the FeO in the slag is controlled to be 16-20%, and over-oxidation of the molten steel is avoided. The method has the advantages that the practical guidance is provided for producing low-cost and high-quality molten steel by the converter.

Description

technical field [0001] The invention belongs to the technical field of converter steelmaking, and in particular provides a high-carbon dephosphorization method for medium-high carbon steel in converter smelting, which is suitable for achieving the smelting effect of high-carbon dephosphorization in converter smelting medium-high carbon steel. Background technique [0002] At present, when domestic iron and steel enterprises require steel grades with high carbon content and low phosphorus content (finished product [C]≥0.5%, [P]≤0.025%, such as GCr15, 65Mn, etc.), the converter station tapping requirements [P ]<0.015%. In order to meet the requirements of low-phosphorus tapping, on-site operators have to control the content of [C] at the end point of converter smelting to a low level, generally below 0.15% or even below 0.10%, which leads to the following problems: 1. The medium FeO is high, and a large amount of recarburizer and deoxidizing alloy need to be added when tap...

AI Technical Summary

Problems solved by technology

[0005] The present invention adopts a new type of high-drawing carbon process, aiming to solve the technical problem of high-carbon dephosphorizatio

Images