Smelting method of low-phosphorus steel

Abstract

The invention provides a smelting method for efficiently producing low-phosphorous liquid steel through one-time slagging in a converter. The method comprises converter smelting and ladle refining. The method is characterized in that the temperature of converter smelting liquid steel is higher than or equal to 1,680 DEG C; the phosphorous content of the liquid steel is less than 0.012 percent; activity oxygen in the liquid steel is controlled to account for 0.1 to 0.13 percent; before converter tapping, deep dephosphorization agents are put into a ladle; in a converter tapping process, slag stopping control is performed so as to ensure that the amount of outflow slag is less than or equal to 3 kilograms per ton of steel, and the liquid steel in the ladle is subjected to weak deoxidation treatment; after the tapping is over, the deep dephosphorization agents are put into the ladle again; then ladle bottom blowing and argon stirring are carried out; and finally, steel slag in the ladle is eliminated by use of a ladle slagging-off device. Compared with other methods, the low-phosphorous liquid steel smelting method reduces slag amount by more than 20 percent and shortens converter smelting period by more than 5 percent. As slagging is carried out only once in a converter, the method is little in the erosion of a converter lining, and rephosphorization phenomena can not occur in a secondary refining process of the liquid steel.

Description

technical field [0001] The invention belongs to the technical field of iron and steel smelting, and in particular relates to a production method of low-phosphorus steel. Background technique [0002] Phosphorus is a common harmful element in steel, which is easy to segregate at grain boundaries, causing low temperature brittleness and temper brittleness of steel. High-grade high-quality steel has increasingly stringent requirements for phosphorus content in steel, especially for low-temperature steel, marine steel, and hydrogen-induced cracking-resistant steel. Therefore, the problem of dephosphorization in steelmaking production has always been highly concerned by the metallurgical industry. In recent years, the smelting of pure steel has been highly valued by countries all over the world. As an important part of pure steel smelting, the production of low phosphorus steel (ω[P]<0.01%) and ultra-low phosphorus steel (ω[P]<0.003%) Production is a content that cannot be...

AI Technical Summary

Problems solved by technology

[0005] Both the single-furnace double-slag method and the double-link method complete the dephosphorization treatment in the converter, and a large amount of slagging is required twice in the converter, and both need to be quickly slagged in the converter. Therefore, low melting point substances are often introduced as fast slagging agents , causing damage to the converter lining and reducing the life of the converter

In addition, the single-furnace double-slag method and the double-link method both make slag twice in the converter, which leads to a long time in the converter during production and affects the productivity of the converter