Experimental and numerical studies to enhance the reproducibility of corrosion testing

 
In the development of new products or new surface treatments it is necessary to use accelerated tests to evaluate the corrosion protection. Many of these tests contain a salt spray phase, in which a water solution with NaCl or CaCl2 is atomized in a chamber with work pieces. A crucial point in these chambers is to achieve a high reproducibility in the results. For that reason the size of the droplets has to be controlled, if the distribution of the salty fog is homogeneous and stable and the brine deposition on the work piece is constant. In this paper methods will be introduced to measure and calculate the properties of the salt-fog-atomizers and of the circulation of the liquid medium in the chamber. Especially the chambers in the corrosion test centre of Daimler AG in Sindelfingen have been investigated.