Refining technology for molten medium-high carbon steel

Abstract

A provided refining technology for molten medium-high carbon steel comprises: during the process that molten steel is subjected to tapping from a converter to a steel ladle, adding the first batch of a carburant into the molten steel to enable the carbon content of the molten steel to be 0.20%-0.30%; during cyclic vacuum degassing treatment of the molten steel, adding the second batch of the carburant into the molten steel for deoxidation; and then alloying the molten steel to enable the oxygen content, the carbon content and the alloy content of the molten steel to reach target values. The refining technology is capable of reducing viscosity of steel slag, avoiding or reducing generation of Al2O3 to improve molten steel cleanliness, improving the yielding rate of alloy elements as well as reducing metal oxide inclusions in the molten steel, and / or reducing treatment cost.

Description

technical field [0001] The invention relates to steel smelting, in particular to a refining process for medium-high carbon molten steel. Background technique [0002] Medium and high carbon steel such as rail steel is usually smelted by killed steel treatment process, specifically, carburization, deoxidation, alloying in the process of converter tapping, and then vacuum treatment, degassing, removal of some inclusions, and fine-tuning of the alloy. In the killed steel treatment process, aluminum deoxidizer is used to deoxidize molten steel, and the deoxidized product is Al 2 o 3 . For example, aluminum alloy is added to the molten steel during the tapping process of the converter to partially deoxidize the molten steel. Aluminum shot or aluminum wire may be added at the LF station, and then a certain amount of aluminum shot will be added after the molten steel enters the RH cycle vacuum degassing equipment. Final deoxidation of molten steel. [0003] Deoxidation of molte...

AI Technical Summary

Problems solved by technology

[0003] Deoxidation of molten steel by aluminum deoxidizer leads to Al in steel slag 2 o 3 With the increase of the content, the viscosity of the slag increases, which makes the slag stick to the insertion pipe of the RH cycle vacuum degassing equipment and is difficult to clean, which seriously affects the operation rate of the RH cycle vacuum degassing equipment

[0004] In addition, the deoxidized product Al 2 o 3 Easy to be included in molten steel, reducing the quality of steel

[0005] In addition, the molten steel is deoxidized and alloyed before RH cycle vacuum degassing, alloying and deoxidation may be carried out at the same time, so that part of the alloy is oxidized into oxides, thereby reducing the yield of the alloy

In addition, the amount of oxide inclusions that are excluded in subsequent treatments such as RH cycle vacuum degassing is limited, which reduces the quality of the steel