Thermal stresses in DC casting of aluminum slabs: application of a finite element model

Thermal shrinkage in direct chill casting of aluminum slabs causes deformations, such as the butt curl in the initial phase. In addition, for some alloys, induced stresses play a major role in the initiation of cracks. These phenomena have been studied using a numerical model based on the finite element program MARC. For different cases, a fully coupled, three dimensional transient analysis was performed, assuming the metal to be elastoplastic with strain-rate dependent behavior. This allows the modeling of butt curl and stress buildup during casting. The calculated deformation of the butt was found to be in correct deformation of the butt was found to be in correct agreement with experimental measurements. The effect of process parameters such as slab dimensions and casting speed on the stresses have been examined.