Mechanical properties prediction for hot rolled products

Abstract

The improvement of the mechanical properties of the hot rolled products is directly related to the rolling process, concerning the reduction schemes and cooling conditions. These operational parameters influence the steel internal microstructure and therefore mechanical properties. In order to link the mechanical properties of the final product with plant operational conditions there are some intermediate variables that must be solved, like thermal field in the steel section and its microstructure evolution. Recrystallization, grain growth, precipitation and phase change models, which are dependent on steel composition and process variables, are able to predict the microstructure evolution along the rolling process. At the same time, the thermal field prediction can be solved by an appropriate mathematical model that takes into account all related effects such as roll contact, volumetric heat generation during the strip reductions or scale effects, apart from the thermal conduction in the strip thickness. Once these models get solved, it is straight forward to obtain another important data like roll power or roll torque, which are the key for considering roll wear and other economical aspects. The global idea is to get operational plant data and steel composition, and to calculate the prediction of the thermal history of the process, the microstructure during the processing time and the final mechanical properties. An overview of the lay out is presented in figure1.