Production process for high-purity bearing steel

Abstract

The invention belongs to the technical field of steel preparation, and particularly relates to a production process for high-purity bearing steel. The production process comprises the following steps: firstly, adding blast-furnace molten iron and steel scrap in an electric converter and smelting; secondly, alloying a steel ladle by virtue of an alloy, an aluminium cake and a low-nitrogen carburant; thirdly, discharging molten steel into the steel ladle subjected to the alloying treatment after the smelting is completed, slagging and enabling the slagging result to meet the requirements of while slag in the earlier stage of refining, obtaining the while slag and then carrying out aluminium line feeding operation; fourthly, hoisting molten steel qualified after the refining into a vacuum tank and carrying out vacuum treatment; and finally carrying out continuous casting. Cancel of molten steel modification treatment is realized; and moreover, the molten steel is high in castability and meets the production requirements of high-standard bearing steel.

Description

technical field [0001] The invention belongs to the technical field of steel preparation, in particular to a production process of high-purity bearing steel. Background technique [0002] High-standard bearing steel has particularly strict requirements on purity. The purity of steel refers to the amount of non-metallic inclusions contained in the steel. The higher the purity, the less inclusions in the steel. Harmful inclusions such as oxides, nitrides, and silicates in bearing steel are the main causes of early fatigue spalling of bearings and a significant reduction in bearing fatigue life, especially large particle point-like inclusions (Ds type) have a significant impact on the fatigue life of bearing steel. It has a far-reaching impact. The latest research point of view believes that: large particle point inclusions are the main factor for the generation of fatigue cracks in bearing steel. Although the current national standard GB / T18254-2002 does not specify Ds, some ...

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Problems solved by technology

However, on the one hand, the control of total oxygen, residual elements and inclusions in the steel is unstable; at the same time, if the subsequent denaturation treatment is not carried out due to the deep deoxidation of Al, it will easily cause nodules in continuous casting, and continuous casting in multiple furnaces cannot be realized. It cannot be guaranteed. In this regard, in order to ensure the pourability of molten steel, some steel mills denature the molten steel after vacuum treatment, but instead cause the increase of point-like inclusions and the increase of the level, which cannot meet the production requirements of high-standard bearing steel.

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