Abstract
The model of controlled cooling of rails is presented in the paper. Model predicts temperature field during cooling, kinetics of phase transformations, microstructural parameters and mechanical properties of the product. Identification of the phase transformation model was performed on the basis of dilatometric tests and inverse analysis. Optimization task was formulated with the objective of searching for the cooling process parameters, which give as low as possible interlamellar spacing in pearlite, microstructure free of bainite and uniform hardness distribution in the rail head. The sensitivity analysis was performed and the following parameters were selected as the optimization variables: time of the 1st stage of fast cooling by immersing in the polymer solution, time of the second stage of cooling in air, depth of the immersion in the polymer solution and heat transfer coefficient between the rail head and the polymer solution.