Development of integrated model for batch annealing of cold rolled steels

Abstract

Annealing of flat cold rolled steel sheets is one of the critical operations, which significantly influences the final product quality and overall productivity of cold rolling mills. An integrated process model, with the capability of predicting spatial and temporal evolution of temperature, microstructure and mechanical properties in cold rolled coils during batch annealing, has been developed. The model is based on fundamental principles of heat transfer, microstructural evolution kinetics and microstructure-property correlation. The parameters for heat transfer are based on in plant experimentation, whereas the coefficients for microstructural kinetics and structure-property correlation were obtained from laboratory studies. The prediction capability of the model has been extensively validated through data collected from industrial operations. Details of the model formulation, its validation with the plant data and possible uses of such an integrated model are presented.