ABSTRACTThis paper presents the results of the analytical study of the microstructural evolution of forged and rolled rings with a diameter greater than 2 meters, since the raw material, set-up forgings, ring rolling and heat treatments, including normalizing, quenching and tempering. Also, great care will be taken on the chemical micro-segregation. Four rings, were instrumented with 20 thermocouples each one in order to follow the thermal profile during heating and quenching. Cooling rates will be used to predict the microstructure developed under the different heat treatments and it will be compared at different positions inside the rings. It can be seen that the cooling curves obtained show no presence of soft phases, as shown in the microstructures in the figure shown below. With the results of microstructure obtained, which show martensitic structure to a greater extent, it meets the desirable mechanical properties, which are shown below.