The synergistic effect of temperature, sulfuric acid concentration and solution flow on the corrosion behavior and passive film properties of austenitic SS 304L and 316L have been investigated in concentrated sulfuric acid. Design of experiment was used and electrochemical techniques were employed. It was found that investigated parameters synergistically affect the corrosion behavior and passive film properties. Surface films formed at high concentrations are less defective and increasing temperature and solution flow introduced more defects; however, the passive film repairs itself. Increasing the temperature and solution flow resulted in higher passive film coverage and cracking of the passive film, respectively.