Modeling Macro-Segregation in Castings
Buoyant flow pattern in
0.42% C steel casting
Macro-segregation can occur in castings where significant species transport due to diffusion and convection takes place during solidification, e.g., large steel castings.
The FLOW-3D Cast segregation model has been developed for binary systems and includes solutal buoyancy effects. The image on the left shows buoyant flow patterns in a simple 0.42% C steel casting with an insulated top boundary (carbon segregation is shown in false color: carbon enriched areas are red). The liquid metal is enriched with carbon due to the separation of carbon at the solid/liquid interface (the partition coefficient is 0.19). The flow is driven by thermal and solutal convection resulting in an area of relatively high carbon concentration at the top of the casting.