Longitudinal face crack prediction with thermo-mechanical models of thin slabs in funnel moulds

This paper investigates longitudinal depressions and cracks in steel continuous-cast in funnel moulds using a finite-element model to simulate thermo-mechanical behavior of the solidifying shell in the thin-slab caster mould at the Corus Direct Sheet Plant (DSP) in IJmuiden, The Netherlands. The commercial code ABAQUS [1] is used to study the effect of the funnel shape on the stresses developed within a two-dimensional section through the shell while it moves through the mould. The model first simulates heat transfer, based on heat flux profiles found from extensive plant measurements of mould heat removal and thermocouples embedded in the mould wall. It incorporates the drop in heat flux due to local gap formation. The temperature solution is input to the mechanical model which incorporates grade-dependent elastic-viscoplastic constitutive behavior, ferrostatic pressure, taper, mould-wall oscillations, and contact with the profiled mould wall. The results are validated with plant measurements, including a breakout shell, and crack statistics. The model is applied to study the effects of increasing casting speed and funnel design in order to avoid longitudinal cracks.