| Abstract: | Under the ambient temperature (25°C) and pressure (one Standard Atmospheric Pressure) conditions, surface Volta potential of an austenitic stainless steel was measured using the Scanning Kelvin Probe Force Microscopy (SKPFM) to study its stressed-related corrosion behavior in a 0.5 M chloride solution. In an oxygen and water regulated environment (using a glovebox), the steel shows a map of Volta potentials with high contrasts among the different grains and grain boundaries, which was then linked to the actual corrosion potential (w.r.t. a saturated calomel electrode) based on a rigorous calibration procedure. Corrosion behavior of the steel under tensile stress was then compared to that of the same sample under no tensile stress in light of the measured Volta potential, which was found to be sensitive to the level of applied tensile stress, although the tested stainless steel in general is known for its high corrosion-resident capability. According to this study, surface Volta potential measured by SKPFM can be used as a high-accuracy indicator for localized corrosion of steels. |
