Zirconia nozzle and manufacturing method thereof

Abstract

The invention discloses a zirconia nozzle. The zirconia nozzle comprises a zirconia inner core, wherein the inner surface of the zirconia inner core is provided with a layer of meltable anti-scouringcomposite material coating. The invention also discloses a manufacturing method of the zirconia nozzle. The manufacturing method comprises the following steps of manufacturing the zirconia inner core;manufacturing an anti-scouring composite material coating material; adding the anti-scouring composite material coating material into the zirconia inner core; sealing two ends of the zirconia inner core, putting into a high-speed centrifugal machine, centrifuging and forming; after forming, heating to the temperature of 300 DEG C, and drying. The zirconia nozzle has the advantages that by additionally arranging the composite material coating on the inner surface of the inner core of a high-density zirconia feeding nozzle, the direct contact between liquid steel and the inner surface of the zirconia nozzle is avoided, and the composite coating slowly disappears within 5 to 10 minutes under the condition of scouring by the liquid steel, so as to win 5-minute preheating time for the zirconiafeeding nozzle, thereby avoiding the occurrence of microcracks; the anti-erosion property of the high-density zirconia feeding nozzle without the microcracks is good, and the service life is greatlyprolonged by 30 to 50%.

Description

technical field [0001] The invention relates to the technical field of refractory materials, in particular to a zirconia nozzle and a manufacturing method thereof. Background technique [0002] The nozzle is mainly made of magnesia, high alumina, zirconia and other refractory materials, which are sintered at high temperature. In the continuous casting process, whether it is a submerged nozzle, ladle long nozzle or other forms of nozzle, it will be scoured by molten steel, mechanical vibration of related facilities and thermal stress caused by temperature difference between inner and outer surfaces. These external factors are prone to cracks and even brittle fractures for refractory materials that are not flexible, brittle, and have poor seismic performance, which seriously affect the safe production of the continuous casting process. With the demand for energy saving and consumption reduction in steel mills, the requirements for the life of the tundish are getting higher an...

AI Technical Summary

Problems solved by technology

These external factors are prone to cracks and even brittle fractures for refractory materials with no flexibility, high brittleness, and poor seismic performance, which seriously affect the safe production of the continuous casting process.

With the demand for energy saving and consumption reduction in steel mills, the requirements for the life of the tundish are getting higher and higher, and the life of the nozzle is generally increased to 40-60 hours. The existing production method of zirconia nozzle is more and more difficult to meet the requirements of 60 hours and above. Require

In order to increase the service life of the zirconia upper nozzle and improve the resistance to molten steel erosion, it is necessary to increase the density and uniformity of the zirconia upper nozzle, but the density of the zirconia upper nozzle is increased to 5.4g / cm 3 When the thermal shock stability becomes very poor, microcracks will appear after being subjected to thermal shock. After the surface of the zirconia nozzle with microcracks is washed by molten steel, the corrosion resistance will decrease instead, and the service life will be reduced.

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