Corrosion behaviour of TiN hard layer systems on a low alloyed steel

Hard coated components are characterized by a high wear resistance, but oft en a limited corrosion resistance. The corrosion medium may penetrate the l ayer through the layer defects and yield to a corrosion attack on the subst rate's surface, especially if low alloyed steels are used as substrate mate rial. Duplex and multilayers on the basis of TiN deposited on the steel 20M nCr5 are offered in this paper. The duplexlayers were produced through a co mbination of nitriding and notrocarburizing nsp., and a HCD-TiN-deposition. The multilayer systems consisting of titanium and amorphous carbon were de posited by magnetronsputtering. The variation of the layer parameters resul ts in a large number of layersystems. Electrochemical methods were used to characterize the corrosion behaviour in a 0.9 m NaCl solution. The results were discussed with respect to the layer structure.