Verlauf der Korrosion auf einer polierten Fläche bei 75 % relativer Luftfeuchtigkeit und einem geringen Zusatz von HCl in der Atmosphäre: Bildung kleiner Korrosionspunkte, die zu Fäden auswachsen. Mikroaufnahmen. Zeitraffung.

The film shows the initial stages of rust formation on a polished surface of pure iron at microscopic magnifications. The experiments were made in an atmosphere of 75 per cent relative humidity with small additions of hydrochlorid acid acting to accelerate corrosion. Using the fast motion technique it is possible to observe the individual stages of rust formation: First, corrosion points occur which, as corrosion proceeds further, grow into filament-type shapes spreading all over the iron surface. In some instances, the dependence of the direction of filament growth on the polishing direction can be observed. Also, scratches on the metal surface display a greater affinity to corrosion in some places.