Modeling and optimization of industrial-scale horizontal direct chill casting

Horizontal direct chill (HDC) casting is one of the important manufacturing processes for producing aluminum billets. Because of its horizontal nature and gravity effects, controlling HDC casting still remains a challenge. In this study, we tried to simulate and optimize HDC casting to overcome these challenges. This process was investigated with a three-dimensional finite element model (FE) including energy, turbulent Navier–Stokes, and phase change equations applied to industrial HDC casting. The melt flow, sump profile, and mushy zone width were clearly identified under various conditions. The mushy zone width was strongly found to be a function of casting speed, and it was observed that increasing the casting speed increases the sump depth. The asymmetric sump shape has been found to be independent of the casting speed. The effect of water-cooling temperature on the sump depth and shape was not pronounced. The shape of the sump was strongly dependent on the melt inlet’s vertical position. The results revealed that gravity’s effect on the cooling water causes an asymmetrical sump shape that may affect the billet quality. It was found that the asymmetric sump profile problem can be solved by shifting the melt inlet’s vertical position downward. The findings from the simulation were correlated to actual industrial HCD casting, and a symmetric and uniform sump profile was successfully obtained.