The relation between corrosion and surface potential measured with the scanning Maxwell stress microscope

The topographies and the surface potentials on various corroded metal surfaces have been simultaneously measured with the scanning Maxwell stress microscope to investigate the microscopic relation between the topography of corroded surface and the surface potential in atmosphere. In the early stage of corrosion the potential was low at the corroded region. In the next stage, however, the region where the potential was low at the non-corroded area appeared since anodic region transferred from corroded area to non-corroded area. The microscope is very useful to study the time dependence of the relation between a corroding region and the surface potential.