Corrosion of PVD TiN coatings under simultaneous erosion in sodium carbonate bicarbonate buffered slurries

The aqueous corrosion resistance of mild steel (BS6323) in the presence and absence of PVD TiN coatings was studied potentiodynamically in a rotating cylinder electrode system, in comparison with that of AISI 304 stainless steel, in an alkaline buffer slurry solution of sodium carbonate and bicarbonate containing 150 mu m alumina particles at a velocity up to 8 m/s. Weight loss of the samples resulted due to the action of both wear and corrosion. This paper summarises the preliminary results for studies of corrosion of the coated and uncoated samples. In addition. the weight loss due to corrosion under conditions of simultaneous erosion-corrosion was obtained from the current response using Faraday's law. The significant resistance to corrosion and the outstanding stability of the corrosion resistance with the increases of particle velocity accounted for the excellent corrosion performance of the TiN coatings over that of AISI 304 stainless steel or the mild steel.