Why use copper mold tube protection slag for continuous casting in steel mills?Continuous casting mold powder(copper mold tube protection slag) has five main

Why use copper mold tube protection slag for continuous casting in steel mills?

Continuous casting mold powder(copper mold tube protection slag) has five main functions in the continuous casting process

1. Barrier function (mainly completed by the liquid slag layer) It isolates the contact between air and molten steel, blocks the secondary oxidation of molten steel, blocks the contact between the carbon-rich layer and molten steel, avoids the increase of carbon on the surface of the billet, and improves the surface quality of the billet. , reducing the loss of steel. Note: Carburizing on the surface of mild steel and ultra-low carbon steel will result in brittle blanks.

2. Thermal insulation (mainly completed by solid slag) greatly improves the factory operating environment (heat radiation) and facilitates the smooth continuous casting. A sufficiently thick solid slag layer can better exert the thermal insulation performance of the mold slag and prevent the condensation of cold steel and floating steel on the molten steel surface of the mold. An increase in the temperature of the meniscus region of the mold will avoid many problems and accidents. Such as cracks, billet surface pores, etc.

3. Absorption and melting of impurities (mainly completed by the liquid slag layer) assimilation can effectively absorb and dissolve inclusions (system refractory materials, metal inclusions such as deoxidation products), and protect its own performance from changing, purify molten steel, and improve the casting billet. surface purity. The low viscosity of the mold powder and the proper control of some components of the mold powder are beneficial to the suction of the powder.

4. Lubrication function The excellent lubricating function of the mold flux can greatly reduce the friction between the billet and the copper wall, thereby ensuring the smoothness of the billet and providing a guarantee for the continuous improvement of speed control. Improving the speed control is related to the process. Furthermore, it is directly related to the excellent mold powder.

5. Control and uniform heat transfer Uniform heat transfer: The slag film cannot flow uniformly between the copper wall and the billet shell, which will cause uneven heat transfer, and all cracks are caused by uneven heat transfer. Control of heat transfer: For gold peritectic steel, the heat transfer rate should be controlled to reduce the degree of peritectic reaction, otherwise serious cracks may occur on the surface of the slab.

The good effect of mold slag is related to other chemical composition, physical properties of raw materials and the combination format of various raw materials. One of the three must be strictly matched with the relevant process (steel grade, mold size, casting temperature, speed control), in order to maximize its role