SIMULATION OF THERMAL MECHANICAL BEHAVIOR DURING INITIAL SOLIDIFICATION

Mathematical models have been developed to predict temperature, stress, and shape development during initial solidification. The heat transfer model was run for typical casting conditions in the mold for typical thin slab and conventional continuous slab casters. The calculated temperatures were input to an elastic-viscoplastic fin ite-element stress model of the solidifying steel shell. This model features an efficient algorithm to integrate the highly nonlinear constitutive behavior of steel at high temperature. The stress model includes the temperature and composition-dependent effects of phase tran sformation on both the thermal linear expansion / contraction be havior, creep behavior, and pseudo-strain due to flow in the liquid. Stress and strain distri butions are calculated along a line through the shell thickness, assuming no shell bending or sticking to the mold. Results are compared for 0.044%C and 0.1%C steels and for both cooling conditions. The re sults provide insight into the formation of longitudinal surface cracks in continuous-cast steel.

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