Umwelteinflüsse auf Werkstoffe

Abstract

The corrosion behavior of different metals commonly used in civil engineering and construction was investigated under outdoor exposure conditions. The exposure sites were chosen at locations of the Swiss National Air Pollution Monitoring Network (NABEL) in different regions of Switzerland, where the concentrations of different air pollutants and climate data are registered continuously. After different exposure times, a set of test specimens is taken back for gravimetric evaluation of material loss and chemical characterization of corrosion products and deposits. Transmission and scanning electron microscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF) were used to characterize corrosion products. Water soluble compounds on the metal surfaces have also been analyzed quantitatively. First results for the exposure period of six months are presented. They show large differences in corrosion rate and in the amount of corrosive species on the metal surfaces for the different test sites. In some cases a very good correlation to the specific pollution and climate conditions at the particular locations is possible.