High-temperature sealing coating for stopper rod for continuous casting

Abstract

The invention relates to a high-temperature sealing coating for a stopper rod for continuous casting. The high-temperature sealing coating comprises the following raw materials in percentage by weight: 60-76% of kyanite and 24-40% of corundum micro powder, and 6.0-7.5% of alumina sol is added. The linear change rate of the coating is + 0.22-+ 0.31%, and the detection environment is 1450 DEG C, and the temperature is kept for 3 hours. The thermal expansion coefficient of the stopper rod under the high-temperature condition is approximately consistent with that of a metal connecting rod after the stopper rod is coated with the thermal expansion coating, and the expansion difference of a non-metal material and a metal material under the high-temperature condition is eliminated.

Description

technical field [0001] The invention relates to the technical field of continuous steel casting, in particular to a high-temperature sealing coating suitable for stopper rods. Background technique [0002] Stopper rods belong to the three major functional refractory materials for continuous casting, and play a very important role in continuous casting production. The stopper rod is used in the tundish, usually including the rod head and the rod body, wherein: the rod head controls the flow of molten steel through the matching gap with the integral submerged nozzle or the bowl of the upper nozzle of the tundish to obtain a suitable casting speed and Qualified slab; the inside of the rod body is provided with an argon gas channel, and the upper end of the rod body is generally connected with a connecting rod, which is made of metal, and the connecting rod is driven by a lifting device to drive the stopper rod to move up and down. [0003] In the production process of large si...

AI Technical Summary

Problems solved by technology

And because the non-metallic material of the stopper rod body and the metal material of the connecting rod have different thermal expansion coefficients at high temperatures, the connection position between the rod body and the connecting rod has different degrees of expansion joints after the argon gas is blown in at a high temperature. The upper argon blowing has a certain initial rate, and a downward negative pressure zone is formed at the connection position, causing the stopper rod to suck air from the expansion gap in the later stage

Since metal aluminum is the product of deoxidation of molten steel, it is easy to form alumina when it encounters oxygen in the air, so inhaling air will increase the amount of alumina formed, which will easily cause the stopper rod to be plugged due to the adsorption of excessive alumina after it is cast into the third furnace. The rod opening increases, the flow control accuracy decreases and the final pouring is abnormal, which increases the aluminum loss of the variety steel, deteriorates the purity of the variety steel, and leads to a decrease in the number of continuous casting furnaces in the tundish

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