Bearing steel GCr15 production technology capable of preventing plugging of continuous casting water gap

Abstract

The invention relates to a bearing steel GCr15 production technology capable of preventing the plugging of a continuous casting water gap. The technology route comprises the steps of a top and bottom combined blow converter, an LF refining furnace, VD vacuum degassing and six-strand billet continuous casting of a Comcast six machine in sequence, the top and bottom combined blow converter conducts dephosphorization by adopting a double-slag method, the high catch carbon [C] at finishing point is more than or equal to 0.25%, final slag alkalinity before tapping is over 3.5, Als content in the molten steel in refining of the LF refining furnace is controlled to be over 0.05%, and Als / Alt is more than 95%; and argon blowing protection is conducted in the whole process of the continuous casting procedures, and low-pulling rate weak-cooling technology is adopted. Under the conditions of the technology, the cleanness of the molten steel can be improved, the non-metallic inclusion can be reduced, the plugging phenomenon of the continuous casting water gap can be prevented, the quality of the continuous casting blank can be improved, and the cost of the casting blank can be lowered, thereby finally improving the product quality.

Description

technical field [0001] The invention belongs to the technical field of metallurgical technology, and in particular relates to a production process of bearing steel GCr15 for preventing continuous casting nozzle blockage. Background technique [0002] Bearing is the "heart of industry". Bearing steel is one of the steels that are difficult to produce in special steel products. The cleanliness of molten steel is the most important technical index that affects the performance of bearing steel. For high-purity bearing steel, the oxygen content in the steel is generally controlled at 5-8×10 -6 %, it is necessary to use aluminum deoxidation to control the oxygen content in steel. [0003] When continuous casting produces aluminum-containing steel, the phenomenon of nozzle blockage often occurs, especially for the bearing steel GCr15 deoxidized with aluminum, the aluminum content of the finished product is about 0.035%, and the phenomenon of submerged nozzle blockage often occurs ...

AI Technical Summary

Problems solved by technology

When the nozzle is blocked seriously, it will cause the casting speed to decrease and the crystallizer liquid level to fluctuate greatly, so that the nozzle will be blocked, the molten steel temperature will be returned to the furnace at a low temperature, and even the continuous casting machine will be shut down.

Therefore, the blockage of the nozzle not only affects the quality of the continuous casting slab, but also affects the normal production process, and also limits the continuous casting of multiple heats, increasing the cost of the casting slab