The chemical composition was investigated by means of X-ray
photoelectron spectroscopy (XPS), (Quantum 2000 by Physical Electronics,
using an Al Kα1 source). For investigation of the chemical bonds
Fourier transforminfrared reflection absorption spectroscopy (FT-IRRAS)
was carried out (Excalibur FTS 3000) by BioRad Digilab in p-polarisation
at an incident angle of 80°). The spectrometer was equipped with a
deuterated triglycine sulfate (DTGS) detector. For displaying the assembly
of the complete coating system cross-sectional views were made with a
field emission scanning electron microscope (FE-SEM) “LEO 1530”. The
corrosion resistance of the coating systems was tested by applying the
cycling corrosion test according to VDA 621-415 with flange geometry
samplesmade of the coated material. For the flange geometry two pieces
of the coated steel sheets were bonded in a way, that an overlap with a
defined gap was formed. The remaining area was coatedwith an electrocataphoretic
coating (BASF Cathogard 310). In this way only the defined
area in the overlapwas exposed to the corrosivemedia and was evaluated
after the test.