Der VerschleiB an den Modellwerkzeugstahlen 9 S 20 K und 165 X CrMoV 12 bei der Thermoplastverarbeitung wurde mit den Schmelzen von glasfaserverstarkten und unverstarkten Styrol-Acrylnitril-Copolymeren (SAN), Polypropylen, Acrylnitril-Butadien-Styrol-Pfropfpolymeren (ABS) und Polycarbonat untersucht. Die beim SpritzgieBen freigesetzten fliichtigen Substanzen wurden isoliert und rnit Gaschromatographie (GC), Gaschromatographie-Massenspektrometrie (GC-MS) und Kernresonanzspektroskopie (NMR)
Contributions to the Study of the Corrosion on Models of the Alloy Steels for Plastic Processing MachinesThe corrosion on the alloy steels 9 S 20 K and 165 X CrMoV 12 during processing of glassfiber reinforced and non-reinforced plastic melts of styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-butadienecopolymer and polycarbonate were tested. The volatile compounds evolved during injection molding were condensed and anafysed by means of gas-chromatography (GC), gas-chromatography-mass-spectroscopy (GC-MS) and nuclear-magnetic-resonance (NMR). They mainly consisted of hydrocarbons and monomers from the degraded plastics. Because of the absence of water, electrochemical corrosion need not be considered. A mechanism on the basis of chemical reactions between the polymer melt and the steel surface was considered to cause corrosion. By means of scanning electron microscopy differences in the surfaces of the steels corroded with different polymer melts could be observed. Analysis of the surfaces by secundary-ionmass-spectroscopy (SIMS) resulted in changes being specific for the polymers. On all the corroded steel surfaces high spectral carbon intensities were detected compared with non corroded ones, as well as higher intensities for the steel compounds like chromium, manganese and vanadium. Chemical reactions of these compounds with the polymer melt were considered to cause changes in the lattices of the steel resulting in a change of the properties. erscheinungen und der Korrosivitat der isolierten, mit Gaschromatographie (GC), Gaschromatographie-Massenspektrometrie (GC-MS)