Large size high strength steels parts used in transport and energy applications undergo several heating and cooling cycles during their manufacturing process (casting, forging, quench, tempering). Generally, in the tempering process the parts are heated in industrial furnaces and the impact of non-uniform heating on the subsequent steps is of critical importance. A non-uniform temperature distribution may result in property variation from one end to another of the part, changes in microstructure, or even cracking. On the other hand, optimization of residence time of these products inside the furnace can minimize energy consumption and avoid undesirable property changes. However, due to the large size of the components, empirical approaches based on trial and error are costly and not always reliable. The proposed project, through a combination of 3D numerical CFD simulations, multiscale experimentalmeasurements (industrial scale and laboratory physical simulation), and computer aided artificial neural network optimization, considering all participating parameters during the tempering within the industrial furnace, will develop heat treatment procedures with optimized residence time and uniform temperature distribution.