Modeling the thermal and thermoelastic responses of work rolls used for hot rolling steel strip

The thermal and thermoelastic responses of the work rolls used for hot rolling of steel strip are described by means of an hybrid, analytic-numerical, model. The model assumes that the work roll is heated-up by conduction from the steel slab, and cools-down by the use of cooling headers and to the surrounding media. Fatigue of the work roll is assumed to be due to thermal and mechanical phenomena, as the heat transfer conditions at the surface of the roll are cyclic due to the intermittent contact with slab and water coming from cooling headers. In this way, the strain-life of the work roll was computed from the stress and strain gradients caused by the superposition of thermal and mechanical effects. The model is flexible enough to allow for changes in the thermophysical properties of the work rolls, or for changes in operational parameters, such as rolling pace, or the temperature profile or length of slabs. This approach provides for a novel insight in computer modeling and simulation of working processes.