A zirconia nozzle and its manufacturing method

Abstract

The invention discloses a zirconia nozzle, which comprises a zirconia inner core, and a layer of meltable erosion-resistant composite material coating is arranged on the inner surface of the inner core. Also disclosed is a method for manufacturing a zirconia nozzle, comprising: making a zirconia inner core; making an anti-scouring composite material coating; adding the coating to the zirconia inner core, sealing both ends of the inner core and putting it into a high-speed centrifuge, centrifuging Molding; after molding, heat to 300°C and dry. By adding a composite material coating on the inner surface of the inner core of the high-density zirconia nozzle, avoiding direct contact between the molten steel and the inner surface of the zirconia nozzle, the composite coating will slowly disappear within 5 to 10 minutes under the washing of the molten steel, thus Strive for a 5-minute warm-up time for the zirconia upper nozzle to avoid the appearance of micro-cracks. The high-density zirconia upper nozzle without micro-cracks has very good corrosion resistance, and the service life will be greatly increased by 30-50%.

Description

Technical field [0001] The present invention relates to the field of refractory materials, and more particularly to a zirconia water and a method of producing thereof. Background technique [0002] The water port mainly uses a refractory material such as magnesium, high aluminum, zirconia, and is sintered by high temperature. During the continuous casting process, whether it is immersed in the water, the long-range long water port is still in other forms of water, the heat stress produced by the flushing of the steel, the mechanical vibration of the associated facility, and the internal and external surface temperature. These external factors are easy to generate cracks for refractory materials without flexible, brittleness, and poor seismic performance, and even crispy, seriously affecting the safety production of the continuous casting process. With the demand for energy-saving reduction, the demand for energy conservation is getting higher and higher, and it is generally incre...

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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