To understand the role of annealing conditions on the segregation and selective oxidation phenomena, Fe 2Mn 2Si 0.8Cr (all in wt.%) model alloy was investigated. The samples were annealed at 820°C in N2-5%H2 forming gas atmospheres over a wide range of dew pints (-80 to 0°C) with dwelling time of 1 to 5 minutes. At all dew points, the strong chemical interaction between Mn and Si causes the formation of manganese silicates. External oxidation of Mn, Si and Cr were decreased at the higher dew points. Increasing the dwelling time shows an extended oxidation front i.e. pronounced external/internal oxidation of Mn, Si and Cr. Basically, the present work addresses the two stages of oxidation front.