Numerical Simulations of Aircraft Engine Ring Gear Quenching by Using Mean Field Model of Phase Transformations in Pyroware Steel 53

Development of the fast model of phase transformations in the Pyrowear 53 steel was the objective of the paper. An upgrade of the JMAK (Johnson-Mehl-Avrami-Kolmogorov) was proposed. Coefficients in the model were introduced as modified Gauss functions of the temperature. Changes in the carbon and molybdenum concentrations due to precipitation were accounted for. Dilatometric tests were carried out across a wide range of cooling rates. Identification of the model was performed using inverse analysis for the results of these tests. Three austenitization cycles prior to transformations were applied and an influence of the grain size on the nucleation and kinetics of phase transformations was accounted for in the model. All the tests were carried out on the core samples with the nominal chemical composition and on the carburized samples. Numerical tests confirmed the good accuracy of the model for both compositions in the whole investigated range of the grain size.