Stahlproben in 3- oder 5prozentiger NaCl-Lösung unter einem Potential von 525, 550 oder 575 mV. Einzelheiten der Lochbildung, Vorgänge im Lochgrund, kanalartiges Wachstum dicht unter der Metalloberfläche. Lupen- und Mikroaufnahmen. Zeitraffung.

The film shows the kinetics of pitting on the surface of chrome-nickel steel plates. A test cell was designed for the investigation, specially suited for microcinematographic filming, with which the processes in the lens area and microscopic magnifications were shot. The steel samples were in a 3% or 5,8% NaCl solution, under a potential of 525, 550, or 575 mV_H. Initial overall views showing the development and distribution of the pits on the steel surface are followed by shots with greater magnification revealing details of pit form and actions on the pit bottom. The, often, channelled growth of this type of corrosion, immediately under the metal surface, is demonstrated particularly clearly at one point. Finally, the shape of resultant pits is shown on steel samples that have been cleaned of corrosive elements.