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High temperature alloys are being investigated for use in cathode air pre-heater for solid oxide fuel cell systems because of their high thermal conductivity, formability, manufacturability, and superior mechanical properties. However, it is well-known that high temperature alloys often contain a high concentration of Cr which presents a risk of evaporation and contaminating the cathode of the solid oxide fuel cell (SOFC). The oxidation and Cr₂O₃ evaporation mechanisms of the alloys including alloy 625, SS309, and alloy 318 have been investigated by varying temperatures and water content of the exposure atmosphere. For the influence of water content, the alloys were isothermally exposed at 850 °C in dry air and air containing 1%, 3% and 9% of H2O at a high flow rate for 168 h. For the influence of temperature, the alloys were isothermally exposed at 650 °C, 750 °C and 850 °C in a 6.0 L/min air stream containing …