Method for preventing air from entering molten steel through water gap during steel making and casting

Abstract

The invention relates to a method for preventing air from entering molten steel through a water gap during steel making and casting and belongs to the technical field of steel making and casting processes. The method comprises the steps that (1) the surface of the water gap is coated with a first layer of SiO2+H2O sol hole sealing agent, then the inner wall of the water gap is flushed, and curing treatment is conducted on the water gap after flushing is finished; and (2) the surface of the water gap subjected to the curing treatment is coated with a second layer of hole sealing agent, the second layer of hole sealing agent comprises PbO, SiO2, B2O3 and H2O, heat treatment is conducted on the water gap after coating is finished, and a coating is fused into a glass layer. By means of the method, nanoparticles entering holes in the outer wall of the water gap so that the poriferous tissue structures of the water gap can be decorated, and the holes are enabled to become small. The second layer of hole sealing agent has the characteristics of being good in sealing performance, resistant to high temperature and resistant to falling after being fused into the glass layer. By means of the method, the porosity of the water gap can be reduced by over 95% compared with the condition when the holes are not sealed; the process operation is easy, raw materials are easy to obtain, and continuous casting efficiency and product quality are improved.

Description

technical field [0001] The invention relates to a method for preventing air from entering molten steel through a nozzle during the steelmaking and casting process, and belongs to the technical field of steelmaking and casting technology. Background technique [0002] In the continuous casting process of steelmaking production, a certain negative pressure will be generated when molten steel passes through the nozzle, and the negative pressure will accelerate the penetration of external air through the outer wall of the nozzle to contact the molten steel interface and react with Al in molten steel to form Al 2 o 3 , some of which Al 2 o 3 Residing on the inner surface of the nozzle and agglomerating, forming nozzle nodules and causing nozzle blockage; nozzle nodulation or blockage not only reduces the production efficiency of the continuous casting machine, but also is one of the main reasons for the defects of steel products. Therefore, it is of great significance to solve...

AI Technical Summary

Problems solved by technology

[0003] At present, most enterprises use inert gas to protect the nozzle casting method to reduce the diffusion of air to the molten steel in the nozzle. Although this method can play a certain role, because the gas protection only works near the nozzle interface, and the nozzle itself has micropores In addition, the rapid flow of molten steel will generate a certain negative pressure on the inner wall of the nozzle when pouring steel, so that the external air can still enter through the nozzle wall to form nodules and block the nozzle; therefore, methods other than inert gas protection casting are used to prevent The entry of air into the molten steel through the nozzle has become an urgent technical problem to be solved

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