A model for prediction of cracks in a solidifying shell

A model coupling temperature and stress calculations with cracking criteria has been developed in order to predict crack positions in a solidifying shell. The model is based on a one-dimensional FDM approach suitable for continuous casting of slabs. The strain/stress model is based on a purely elastic analysis of a solidifying shell giving a straightforward comparison between stresses and crack criteria. This approach makes the model easy to use. The model is numerically evaluated using available material data for Fe-2%Ni with primary ferrite solidification and Fe-10%Ni with primary austenitic solidification. The results of the calculations are discussed and the impact of material behavior as well as process parameters is evaluated. Evaluation of the influence of changes in the heat transfer coefficient shows that the rapid changes introduce stresses large enough to induce crack formation in the solidifying shell.