MetModel: microstructural evolution model for hot rolling and prediction of final product properties

Abstract

Corus is actively working to develop metallurgical modelling tools (collectively known as MetModel) for describing the hot processing of steel in the austenitic temperature range and applying these both to offline ‘what if’development studies and to the online control of hot rolling mills. These models may be used to describe the evolution of structure during processing and to predict hot flow behaviour. They can additionally be coupled with analytical hot rolling models to allow rolling loads and torques to be predicted. Although previously used to develop flow stress predictions and rolling force calculations for the online setup control of a coil plate mill, MetModel is primarily a microstructural prediction system, tracking the evolution of austenite during repeated deformation and recrystallisation (dynamic, metadynamic, and static) events. The prediction of microstructure during rolling and subsequent cooling and the calculation of as rolled product mechanical properties are described. These developments are moving towards a position where online setup and dynamic control strategies can be based not only on the achievement of shape and gauge, but also on the use of the hot rolling mill as a metallurgical tool to engineer microstructures. Hence, despite any variability in input stock and conditions, the processing route can be tailored to maintain consistency in final mechanical properties.