Corrosion fatigue behavior of the duplex stainless steel AISI 2205 was studied by the scanning Kelvin probe force microscopy (SKPFM) in the ambient temperature and pressure condition (25 A degrees C, one standard atmospheric pressure). Surface-polished AISI 2205 samples were subject to a cyclic tensile stress while immersed in a 0.5 M NaCl solution. At specified time intervals, surface Volta potential of the samples was measured using the SKPFM in an oxygen and water regulated environment. The steel samples demonstrated a map of potentials with high contrasts between ferritic and austenitic grain domains, which was then linked to the actual corrosion potential (w.r.t. a saturated calomel electrode-SCE) based on a rigorous calibration procedure. The corrosion fatigue behavior of AISI 2205 was studied by comparing the SKPFM-measured Volta potentials of the same sample under applied cyclic strain and under no applied cyclic strain. It was found that AISI 2205 became more prone to corrosion when the applied tensile strain exceeds one percent (1 %).