Modeling of the surface marks formation in an immovable mold during continuous casting of steel

Continuous casting is the main process used today for manufacturing of billets. During continuous casting the surface marks (SM) are forming on the surface of continuous casting billets. The surface marks can cause cracking and can decrease the yield of the casting process because the billet surface containing marks has to be grinded away to avoid crack growth. Using a mathematical model, it is possible to understand how to decrease the negative impact of the SM formation process.; Most of previously developed models of surface mark formation had a phenomenological, qualitative character and the major factor determining process of mark formation in these models was the mold oscillation. The basic mathematical model of SM formation in which the surface of the liquid metal in the mold is free from additional factors such as reciprocating mold movement does not exist. The objective of this work is to create the mathematical model of the SM formation during continuous casting in an immovable mold.; In order to numerically describe the complex process of SM formation the two stage approach for the description of the cycle of SM formation was developed. For the thermal analysis the equation of transient heat transfer with the source function has been derived. An initial condition and boundary conditions were formulated based upon a physical conception of SM formation process. The temperature distribution on meniscus during first stage was calculated. Adequacy testing of the mechanical part of model (using mathematical statistics) demonstrates excellent correspondence between the model and experimental data.; The developed model can be considered as a basic model for the simulation of the initial solidification process under different conditions during continuous casting.