The plug brick is the core component of the plug rod system, located at the bottom of the plug rod and matched with the water outlet brick. It belongs to the refractory material for smelting in the field of metallurgical engineering. Its body is made of raw materials such as pyrophyllite, graphite, high-purity carbon powder, etc., which are pressed and formed by molds, and impregnated with 811 resin binder with a solid content of>70% for dry distillation. It is equipped with a steel argon blowing rod core. This component is divided into plug type and threaded type according to the connection method: the former is prone to contamination of molten steel due to erosion by refractory mud, while the latter poses a risk of detachment of the plug body.
The improved integral plug brick adopts a pre embedded joint mold pressing integrated molding process, which combines the advantages of pin type and threaded structure to avoid excessive erosion and "turning" accidents at the end of the ball crown. This product has the characteristics of high temperature resistance, erosion resistance, and good thermal shock stability, and is widely used in continuous casting equipment such as ladles and intermediate ladles. Precise control of the pouring process is achieved by adjusting the flow rate of molten steel through lifting and lowering. The main materials include clay, high alumina, and tar impregnated non fired high alumina bricks.
At present, there are mainly two types of casting systems for molded steel ingots: one is the plug system; One is the skateboard mechanism system. The stopper system is reliable in opening and closing, and is generally widely used when repeated opening and closing is required during the pouring process. In addition, the intermediate ladle for vacuum casting generally adopts a plug rod system.
The plug brick is the core component of the plug rod system, consisting of a refractory plug brick body and a steel argon blowing rod core embedded in the plug. The types of original plug bricks and their practical problems in use are divided into two types according to their connection with the plug rod: one is the plug-in plug brick; One type is threaded connection plug brick.
Function of plug brick
The plug brick is made of pyrophyllite, graphite, and high-purity carbon powder as raw materials, with 811 resin with a solid content of>70% as the binder, and St powder as the antioxidant. After molding, it is impregnated and dry distilled. Can be used to produce refractory materials for blast furnaces. When not pouring, it blocks the water outlet to ensure no steel leakage. Raise the stopper during pouring to create a gap between the stopper brick and the nozzle brick, allowing the molten steel to flow out from the nozzle. Controlling the height of the plug can adjust the outflow of molten steel. The plug brick and rod core can be fixed with threads or pins. Plug bricks can be clay, non fired high alumina, and tar impregnated non fired high alumina bricks.
Pin connected plug brick
1 Basic Structure
The plug connected plug brick consists of a plug body and a plug type joint. When assembling, first insert the plug type joint into the through-hole at the ball crown end of the plug body, and then fill the gap with refractory mortar.
2 Problems in use
After use observation, it was found that the filled refractory mud material is prone to erosion, and sometimes the nozzle and plug body ball crown tips are also partially eroded. After the refractory mud, nozzle, and plug body ball crown tips are eroded away, foreign inclusions enter the molten steel, seriously affecting the internal quality of the steel.
Threaded connection plug brick
1 Basic Structure
The threaded connection plug brick consists of a plug body and a threaded joint. During assembly, the threaded joint is screwed into the through-hole at the top of the plug body, and the gap between them is filled and compacted with refractory mud from the top.
2 Problems in use
After use, it was observed that the erosion at the end of the threaded plug brick ball crown was good, and the relatively intact tip of the ball crown was retained.
However, during the use of threaded connection plug bricks, there have been accidents where the plug body and threaded joint have come loose, known as "U-turns". The detachment of the plug body prevents the pouring process from continuing, which is a serious quality accident.
Improvement of plug brick and its practical production effect
1 Basic Structure
The improved new type of plug brick is also composed of a plug body and a joint, but it combines the advantages of plug-in plug brick and threaded plug brick in assembly. When designing the mold, full consideration is given to the problems of non perpendicularity between the plug and the plug during the production process, and the hollow plug cannot withstand the pressure deformation of the press. A special mold is used to first place the joint in the mold, and then the refractory material is placed in the mold and pressed into the whole through appropriate pressure. This ensures the strength requirements during use and prevents the hollow plug from deforming.
2. Actual usage effect
After using the integral plug brick, it was observed that the erosion at the end of the plug brick ball crown was good, and there were no "turning around" accidents during use.
summary
The improved new type of integral plug brick does not use filled refractory materials at the end, and effectively reduces the erosion of the plug ball crown end, ensuring the internal quality of the steel ingot.
The improved new type of integral plug brick effectively eliminates quality accidents caused by "U-turns".
The improved new type of integral plug brick combines the advantages of plug-in plug brick and threaded plug brick, avoids the shortcomings of the original plug brick, and can better meet practical production needs.
