Duplex stainless steels (DSSs) are steels that have good mechanical properties and corrosion resistance due to the microstructure comprised of about equal parts of austenite and ferrite. Exposure of DSSs to high temperatures, during a welding process for example, result in formation of intermetallics in the temperature range of 1000 to 600 C, including a microstructural change between 1200 to 800 C. These can reduce the properties of the welded joint, especially the heat affected zone (HAZ), such as corrosion in chloride environment. However, during manufacturing or maintenance processes, either by heat treatment or welding processes, the properties of the material can be together with the pitting resistance corrosion. The present study aims to correlate the microstructures obtained by different cooling rates, being these microstructures obtained by simulation, equivalent to that obtained in welding, which is equivalent to a non-equilibrium regime, with the microstructure obtained in an equilibrium regime and to determine how these transformations affect the corrosion resistance. The study was conducted for two DSSs: UNS S32304 and UNS S32750. HAZ equivalent microstructures were obtained by the Gleeble simulator for two heat inputs 1.0 and 3.0 KJ/mm, and the heat treatments were performed at 1000, 1100 and 1250 C for 24, 72 and 240 hours followed by quenching in water. Microstructural analysis was performed by optical microscopy and scanning electron microscopy (SEM) to characterize the phase morphology, quantification and chemical composition. The microhardness of the phases, the hardness and corrosion test (ASTM G48) were determined. The volumetric fraction of the austenite phase of the samples that were heat treated decreased with increasing time and temperature treatment, while for the thermally simulated samples it decreased with the decrease of the heat input for both DSSs. The evaluation of the pitting corrosion resistance it was observed that the increase of the heat treatment temperature equaled the phases (austenite and ferrite) Pitting Resistance Equivalent Number (PREN) values due to the thermodynamic balance of the elements in the phases, thus the heat-treated sample at 1250 C for 24 hours showed better pitting corrosion resistance for both AIDs. For the thermally simulated samples, the heat input of 3 KJ/mm obtained better result of pitting corrosion resistance in both AIDs.