In this study, the effect of alloying elements, cerium (Ce) and tungsten (W), on the oxidation behavior of medium chromium ferritic stainless steel in simulated automotive exhaust gases containing 5 vol.% H2O was studied in the temperature range of 950-1100 degrees C for 5 h. The oxidation kinetics and oxide film characteristics were analyzed by means of thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and elemental probe micro-analyzer (EPMA). The growth rate of oxidation and oxidation mass gain were significantly decreased on the addition of Ce. A dense, uniform, and thin oxide scale formed on Ce-containing steels. The steel containing Ce and similar to 0.5 wt% W displayed similar oxidation behavior compared to the steel containing only Ce. A large number of cracks and pores existed in the oxide film and oxide/metal interface leading to the spallation of oxide film, when the addition of W reached similar to 1.0 wt%. (C) 2017 Elsevier B.V. All rights reserved.