High quality steel continuous casting argon blowing stopper rod, and argon blowing system and argon blowing method of stopper rod

Abstract

The invention relates to a high quality steel continuous casting argon blowing stopper rod, and an argon blowing system and an argon blowing method of the stopper rod and belongs to the technical field of steelmaking continuous casting. A gas channel in the argon blowing stopper rod comprises a main channel, a diffusion air chamber and a plurality of slit channels, wherein the main channel is arranged on the center axis of a stopper rod body, the head of the stopper rod is provided with the diffusion air chamber and the slit channels, one end of the main channel is connected to an air supply pipeline while the other end of the main channel is connected to the slit channels through the diffusion air chamber, outlets of the slit channels are dispersively formed in the bottom surface of the head of the stopper rod, and a displacement sensor for detecting displacement of the stopper rod in the argon blowing system is connected to a flow control valve which controls the flow of argon through a PLC. The high quality steel continuous casting argon blowing stopper rod has the beneficial effects that dimensions and distribution state of argon bubbles entering molten steel are improved, andthe flow of argon in the stopper rod is dynamically adjusted according to an actual pouring process, so that the nodulation state and the continuous casting pouring state of inclusions at a bowl and on the inner wall of a water gap are improved effectively, and the quality of the molten steel is improved.

Description

technical field [0001] The invention relates to the technical field of steelmaking and continuous casting, in particular to a high-quality steel continuous casting argon blowing stopper, a stopper argon blowing system and an argon blowing method. Background technique [0002] In the process of steelmaking, aluminum deoxidation is mostly used for deoxidation of molten steel, especially aluminum-containing steel. Therefore, there is a certain amount of alumina-like inclusions in molten steel. In order to meet the pourability, calcium treatment is usually used. However, for some high-quality metallurgical products, in order to meet special performance and quality requirements, there are strict requirements on DS inclusions in steel, and calcium treatment measures cannot be used in the smelting process. In the continuous casting process of this type of product, the nozzle of the crystallizer is very easy to nodulate and block, the casting stability of the continuous casting is p...

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Problems solved by technology

The existing treatment methods have a certain effect on preventing nodulation and clogging of the nozzle, but there are also certain problems and limitations: 1. There are certain limitations in the design of the argon channel inside the stopper rod, and the head area of ​​the stopper rod is pre-treated Embedding high-temperature-resistant straight pipes to realize argon gas circulation, the size of argon bubbles entering the molten steel in this way is relatively large, and the degree of dispersion is poor. The effect of improving inclusions on the nozzle bowl and inner wall is limited, and this design is very easy 2. According to the actual situation on site, the diameter of the argon gas outlet at the head of the stopper rod is too large, and it is very easy to form a negative pressure in the main channel cavity inside the stopper rod under the action of steel flow. The connection with the argon blowing pipe is a high-temperature hard connection. When the argon pressure and flow rate are not suitable, it is very easy to inhale air from this connection, resulting in serious secondary oxidation of molten steel; the diameter of the argon outlet at the head of the stopper is too small, and the argon The gas outlet pressure is too high, the gas impact depth is deep, the probability of argon bubbles dispersing to the inner wall of the nozzle is low, the effect of argon blowing to improve the casting state is not good, and even the interface of the steel slag in the crystallizer fluctuates seriously.

3. The change of the rod position during the casting process reflects the degree of nodulation of inclusions on the inner wall of the nozzle or the erosion of the refractory material of the nozzle, while the flow rate of argon blowing in the existing casting process is constant, or only within a set period of time Then start to adjust the flow of argon blowing, so that the flow of argon blowing does not adapt to the actual casting conditions

If the liquid level of molten steel in the crystallizer drops greatly, the stopper rod position needs to be raised upwards, and there is a certain degree of inclusions attached to the inner wall of the nozzle, and the inclusions continue to adhere or fall off on the bowl and inner wall of the nozzle, which seriously affects the Continuous Casting Casting Stability and Liquid Steel Quality

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