Finite element model of steel oxide failure during tensile testing under hot rolling conditions

A coupled thermomechanical model of oxide scale failure based on the finite element method has been developed and applied to high temperature tensile testing. The model allows for the analysis of elastic deformation, viscous sliding along the oxide/metal interface, cracking, and spallation of the oxide scale from the metal surface. The different modes of oxide scale failure are predicted, taking into account the main physical phenomena, namely, stress directed diffusion, fracture, and adhesion. The model can be used to evaluate the state of secondary oxide scales in the roll gap when deformation in tension takes place on the stock surface just before entering the roll gap. The combination of the modelling approach and the high temperature tensile tests allows accurate determination of the temperature range for the transition from through thickness fracture of the scale to sliding of the non-fractured oxide raft.