Narrow-range production control method of rare earth elements La and Ce in rare earth bearing steel

Abstract

The invention discloses a narrow-range production control method of rare earth elements La and Ce in rare earth bearing steel. The control method comprises the steps of converter smelting, LF ladle refining, VD vacuum refining, and continuous casting. At the step of LF ladle refining, a high-alkalinity refining slag system is adopted; during the early and middle period, deoxidation and desulfuration are facilitated through bottom-blowing gas forced mixing, and inclusions in molten steel are adsorbed; and during the later period of LF ladle refining, a reducing atmosphere can be maintained through bottom-blowing gas weak mixing to prevent secondary oxidation of the molten steel; and before VD refining vacuum treatment, a steel rare earth containing barrel is used for conducting rare earth alloying, then the inclusions in the steel are promoted to be modified and float up through VD high-vacuum treatment, soft blowing and still standing, and the purity of the molten steel is improved. Through the narrow-range production control method of the rare earth elements La and Ce in the rare earth bearing steel, the problems that rare earth elements are active and easy to oxidize and cannot be added to the steel accurately and narrow-range control cannot be achieved are avoided; and the production efficiency of the bearing steel containing rare earth can be substantially improved, and theproduction cost can be greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a narrow-range production control method of rare earth elements La and Ce in rare earth bearing steel. Background technique [0002] As an important special steel product, bearing steel is mainly used for rolling elements and inner and outer rings of bearings. Bearing steel is used in mechanical equipment that needs to rotate bearings. Among them, high-carbon chromium bearing steel is the most widely used. To achieve high and uniform hardness, sufficient wear resistance and high elastic limit of bearing steel, the key is to control the metallurgical quality of bearing steel, and non-metallic inclusions in bearing steel are one of the signs of metallurgical quality. Its type, distribution, size and shape have an important influence on the performance of bearing steel. In Al-deoxidized killed steel, Al 2 o 3 Quasi-composite inclusions are the main non-metallic inc...

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Problems solved by technology

The chemical properties of rare earth elements are lively, and their deoxidation ability is stronger than Mg, Al, Ti, and their desulfurization ability is stronger than Mg, second only to Ca. When high-purity rare earth is added to molten steel, if O and S in molten steel are high and When the purity is poor, the rare earth elements will first produce rare earth oxides, followed by rare earth aluminates, rare earth sulfur oxides and rare earth sulfides; the generation of rare earth inclusions will not only easily lead to the failure of on-site batch production of water plugging in the continuous casting process, but also The difference between furnaces of impurities in steel also causes instability in the yield of rare earth elements, and it is impossible to accurately control the content of rare earth elements in steel

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