This paper describes an investigation of the influence of impingement angle of a solid/liquid jet upon the erosion corrosion behaviour of a tungsten carbide-cobalt-chromium thermal sprayed coating. The coating type investigated was a nominal WC-10%Co-4%Cr material, HVOF-sprayed onto a stainless steel substrate. This coating was subjected to a submerged impinging jet at 12 m/s of 3.5% NaCl solution containing various concentrations of suspended sand particles at 18°C. The angles of impingement employed were 30, 45, 60, 75 and 90 degrees and the measured total weight losses exhibited a significant influence of impingement angle with reduced material losses at more oblique angles of jet impact. The implementation of cathodic protection to the specimens enabled the pure mechanical component of the overall erosion-corrosion damage to be determined and this was also found to be dependent upon the angle of impingement of the liquid/solid stream. In contrast, the pure corrosion component (determined from in-situ electrochemical monitoring) exhibited no systematic trends with impingement angle. The findings are discussed in terms of the detailed erosion-corrosion mechanisms and implications for operational durability of cermet coatings

This paper describes and discusses aspects of the erosion-corrosion behaviour of a WC-Co-Cr, HVOF sprayed coating when subjected to an impinging jet of an aqueous solution of 3.5% NaCl containing solid particles at 18°C. Although pure mechanical erosion has been found to contribute to a large part of material degradation, a considerable amount of material loss can be attributed to the direct and indirect (synergy) effect of corrosion. Aspects of the influence of time, solids loading and impingement angle have been investigated and the mechanisms of erosion-corrosion are discussed.