Method for controlling vacuum treatment carbon-oxygen reaction of aluminum-free bearing steel

Abstract

The invention relates to the technical field of metallurgy, in particular to an aluminum-free bearing steel vacuum treatment carbon-oxygen reaction control method which comprises the following specific steps: (1) in a primary smelting process, the end point oxygen content and the target carbon content need to be controlled, the tapping operation is strengthened, and a sliding plate is used for stopping slag during tapping; (2) the steel ladle is washed; (3) refining: controlling slag alkalinity in the early stage of refining, and adding quartz sand to reduce the slag alkalinity in the later stage of refining; (4) strengthening LF refining slag surface deoxidation, using high-purity high-density silicon carbide for deoxidation operation, and controlling the oxygen content before vacuum treatment to be less than or equal to 15ppm; (5) an early-stage vacuum tank is adopted, and residual steel residues in a vacuum chamber are cleaned before production; and (6) the vacuum treatment time is prolonged, the vacuum degree is increased to 67 pa or below, high-vacuum pressure maintaining is conducted, the oxygen content in the bearing steel production process can be reduced, carbon-oxygen reaction balance can be maintained, the stability of a vacuum chamber is improved, and accidental production accidents are reduced.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a method for controlling carbon-oxygen reaction in vacuum treatment of aluminum-free bearing steel. Background technique [0002] The production feature of aluminum-free bearing steel is to control the aluminum content of molten steel to ≤15ppm. The aluminum content of the alloy auxiliary materials used and the refractory materials in contact with molten steel are strictly controlled. Therefore, the inclusions are plastic inclusions with low melting point, and the molten steel has strong castability. The impact on the fatigue life of steel is lower than that of high melting point non-deformable inclusions. However, due to the high carbon content of molten steel in the production process, the carbon-oxygen reaction in the vacuum treatment process is severe, the molten steel is splashed to the upper tank and the top gun, the carbon monoxide concentration continues to rise, and t...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is: in order to overcome the severe carbon-oxygen reaction in the vacuum treatment process caused by the high carbon content of the molten steel in the production process in the prior art, the molten steel is splashed to the upper tank and the top lance, the carbon monoxide concentration continues to rise, and the carbon content of the molten steel is low. The content exceeds the process requirements, and it is forced to undergo secondary treatment, which may cause the continuous casting machine to stop production. A method for controlling the carbon-oxygen reaction of aluminum-free bearing steel in vacuum treatment is provided.