Prediction of temperature distribution, flow stress and microstructure during the multipass hot rolling of steel plate and strip.

Abstract

The hot rolling of steel was simulated using data from laboratory experiments and mill trials. Particular attention was paid to prediction of the temperature distribution through the thickness of the rolled plate or strip. The effects taken into account are radiation and convection from the surface when the material is between stands, and conduction to the rolls and the temperature increase due to mechanical work when the material is in the roll gap. An explicit finite difference method is used to calculate the temperature distribution through the thickness of the workpiece during processing.On the basis of the present temperature model and of the constitutive and recrystallization kinetics equations developed earlier for the steels under investigation, a computer model was developed for the prediction of rolling force and microstructural evolution. The predictions of these models are in good agreement with measurements on both experimental and commercial steels. They can accordingly be used for off-line applications, such as mill construction and rolling schedule design and optimization. They also constitute a step towards the on-line control of plate and hot strip mills.