Multiscale modelling of microstructure evolution during laminar cooling of hot rolled DP steels

Accelerated cooling of DP steel strips after hot rolling is considered in the paper. The work is focused on the multi scale model based on the Cellular Automata method as well as on conventional models. Dilatometric tests were performed to identify the coefficients in the models for a DP steel. These models are implemented in the computer system, which simulates controlled cooling of products after hot rolling. This system is described briefly in the paper. Results of numerical tests, which show an influence of the cooling parameters on the structure of the DP steels, are presented in the paper, as well. Arbitrary laminar cooling system, composed of n1 boxes in the first section and n2 boxes in the second section, is considered. Such parameters as strip thickness and velocity, the number of active boxes in the first section of the laminar cooling, the time interval between the two sections and water flux in the sections were independent variables in the analysis. The optimal cooling schedule is the main result of the work.