Fabrication processes may affect the corrosion behavior of nominally corrosion-resistant alloys due to the precipitation of metal carbides at grain boundaries and the subsequent development of chromium- and molybdenum-depleted grain boundary layers. Other factors that affect the corrosion resistance of Fe-Ni-Cr-Mo-W alloys include segregation of alloying elements and precipitation of intermetallic phases. To rationalize and predict the effects of such phenomena on localized corrosion, a computational model has been established. In the first stage of calculations, the model predicts the chromium and molybdenum depletion profiles as a function of temperature and time of thermal exposure and carbon content of the alloy. In the second stage, the repassivation potential of the heat-treated sample is calculated to evaluate the thershold conditions for localized corrosion. The model relates the repassivation potential to the microchemistry of the depleted zone. At the same time, it predicts the repassivation potential as a function of environmental conditions, including temperature and the concentrations of aggressive and inhibitive ions. The model has been verified using experimental data for heat-treated samples of alloys 600 and 825. Also, it has been shown to predict the repassivation potential of welded and heat-treated samples of alloy 22.