Measurement and prediction of distortions during casting of a steel bar

An elasto-visco-plastic deformation model predicts stresses and distortions in a low-carbon steel casting. Features of the model include rate and hardening effects, temperature-dependent properties, and pressure-dependent deformation in the mushy zone. A volume-averaging technique considers the multiple phases during solidification and is used to formulate the conservation equations, which (due to a weak link between temperatures and deformations) are decoupled and solved sequentially using commercial software. Temperature fields are calculated first using MAGMAsoft (MAGMAsoft, MAGMA GmbH, Kackerstrasse 11, 52072 Aachen, Germany) and then exported to a finite element software package, ABAQUS (Abaqus/Standard, Abaqus, Inc., Providence, RI, 2006), which predicts stresses and distortions. In order to simulate the conditions encountered in an industrial casting process, predicted temperatures and distortions are matched with experimental data from in situ casting trials. Preliminary simulations do not agree with the experimental distortions, which suggest that stress-strain data from mechanical tests (from which the mechanical properties were estimated) does not accurately characterize the material behavior of a casting during solidification and cooling. The adjustments needed to match measured and predicted distortions provide valuable insight to the effect a solidified microstructure has on its mechanical properties.