Rh vacuum refining system and desulfurization method for molten steel desulfurization

Abstract

The invention discloses an RH (Relative Humidity) vacuum refining system and a desulfuration method for molten steel desulfuration. The RH vacuum refining system for molten steel desulfuration comprises a RH vacuum refining device, at least one jetting tank and an enhancing gas conveying device, wherein the RH vacuum refining device comprises a vacuum chamber, an upper lifting tube and a descending tube; the lifting tube is provided with at least one enhancing gas jetting tube; the at least one jetting tank is internally provided with a desulfuration powder agent; the jetting tank is provided with a feeding hole and a discharge hole; the feeding hole is higher than the discharge hole; the discharge hole is connected with the enhancing gas jetting tube through a pipeline; a discharge valve is arranged at the discharge hole; the enhancing gas conveying device is connected with the pipeline so as to jet the gas into the RH vacuum refining device; the desulfuration powder agent inside the jetting tank is jetted into the RH vacuum refining device through the gas jetted from the enhancing gas conveying device. By adopting the RH vacuum refining system for molten steel desulfuration, the desulfuration efficiency of molten steel can be remarkably improved.

Description

technical field [0001] The invention relates to an RH vacuum refining system for molten steel desulfurization and a desulfurization method using the RH vacuum refining system. Background technique [0002] Generally speaking, except for individual steel grades such as free-cutting steel, sulfur is a harmful element in steel, which forms sulfide inclusions in steel, reducing the ductility, toughness and impact toughness of steel. When the sulfur in the steel exists in the form of iron sulfide, it will cause hot embrittlement of the steel. At the same time, the corrosion resistance of steel with high sulfur content will be greatly reduced, and sulfur also has a certain adverse effect on the welding performance of steel. Sulfide stress corrosion cracking (SSCC) can occur in austenitic stainless steel through pitting corrosion, and the source of pitting corrosion is at the non-metallic inclusions such as manganese sulfide inclusions; hydrogen-induced cracking (HIC) is the most ...

AI Technical Summary

Problems solved by technology

The existing RH vacuum refining desulfurization process has the following deficiencies or constraints, resulting in complex process and difficult to further improve the desulfurization effect:

[0005] (1) The RH powder spraying desulfurization process of the prior art needs to add various auxiliary equipment (specifically, another top blowing spray gun or another submerged spray gun is required). These auxiliary equipment are complex in structure and difficult to maintain, which makes the desulfurization cost high

[0006] (2) The RH desulfurization process of the prior art, especially the VI vacuum method, RH-PTB, and RH-KPB methods, uses a desulfurizer with a large particle size, and it is difficult for the sulfur element in the steel to enter into the desulfurizer (such as calcium oxide, etc.) Diffusion or diffusion is slow, the desulfurization reaction speed is low, and the desulfurization effect is poor

[0007] (3) The side blowing or top blowing of the desulfurizer in the vacuum chamber of the RH refining device will cause serious splashing in the vacuum chamber, and part of the desulfurizer will escape or stay on the surface of the molten steel in the vacuum chamber, and cannot form a circulating flow with the molten steel, making it difficult to Fully react with sulfur in molten steel, reducing the utilization rate of desulfurizer

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