Superaustenitic stainless steel Alloy 926 was evaluated after different isothermal annealing and thermomechanical heat treatments. The impact of two different quenching and tempering processes on sensitization was determined. Since Alloy 926 contains large amounts of molybdenum and chromium, precipitation of various intermetallic phases is strongly favored. Based on SEM and EF-TEM, it was found that the size as well as the extent of elemental depletion zones is in good agreement with the degree of sensitization (DOS), independently of the applied corrosion test. Elemental depletion zones of two isothermally annealed conditions were obtained quantitatively and related to those of thermo-mechanically rolled samples. Comparison of both annealed conditions revealed the different operating principles of Streicher test and DL-EPR-test. In consequence, morphology, distribution, and chemical composition of precipitates have a considerable impact on corrosion test results. Different microstructural parameters and their relevance on prediction of corrosion properties are pointed out and discussed accurately.