It is well recognized that inappropriate heat treatment deteriorates the intergranular corrosion resistance of duplex stainless steels due to precipitation of deleterious phases such as chromium nitride, chi phase and sigma phase(1) which leads to chromium depletion at grain boundaries(2). It is worth to say that the state of secondary phases depends on previous heat treatment(2). The objective of this work is to study the influence of preliminary solution annealing heat treatment that results in different fraction of ferrite and austenite, on sensitization of 2205 duplex stainless steel at short time ageing. Samples were solution annealed at 1050°C, 1150°C, 1250°C, for 45 min, followed by water quenching. Subsequently, alloy in each annealing condition were submitted to reheating temperature of 850°C for 10 min and 30 min prior to water quenching. It was previously stated that the fastest precipitation rate for sigma phase is at 850°C (1). Degree of sensitization (DOS) was investigated by Double-loop electrochemical potentiokinetic reactivation (DL-EPR) method, using a modified solution for DSS 2205 steel consisted of 0.25 M HCl + 0.002M Na2S2O4.

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