Casting powder play a major role in the continuous casting of steel due to its multi-functional assignment, as it determines the stability of the continuous casting process. Here we will introduce it by illustrating its five main functions as below:
1. Prevention of re-oxidation (liquid slag)
It can cut off the contact between atmosphere and molten steel, in which way the molten steel is avoid of being re-oxidation. By blocking the contact between carbon-enriched layer and molten steel, it improves the surface quality of steel billet and reduces the tonnage consumption accordingly.
2. Thermal Insulation (Solid Slag)
It could significantly improve the operational environment (thermal radiation) of factory , which would facilitate smooth casting process. Sufficient thick solid slag layer enable casting powder to exert its best thermal insulation performance that prevent the premature solidification of liquid steel on the top of the crystallizer. With the preservation of regional temperature around crystallizer, lots of problems and accidents wouldn???t be occurred, such as crack, billet surface pinhole, etc.
3. Inclusion entrapment
It can effectively absorb or entrap inclusions in the interface of liquid slag metal (such as Al2O3 and TIO2), and keep its own stable chemical character at the same time. In this way, the molten steel get purification and the billet surface get due cleanliness.
It has excellent lubrication ability, which could greatly reduce the fraction between billet and mold, guarantee a continuous casting and control the casting speed as well.
5. Heat transfer control
Heat transfer can be divided into horizontal and vertical transfer. The horizontal has more significant effect on the surface quality, while, the control of vertical heat permits to overcome problems such as pinholes and deep oscillation marks.