Slurry and dry particle erosion wear properties of WC-10Co4Cr and Cr3C2-25NiCr hardmetal coatings deposited by HVOF and HVAF spray processes

Abstract

Thermally sprayed hardmetal coatings were produced to provide improved erosion wear compared to conventional cast GX4CrNi13-4 martensitic steel (CA6NM) used in hydro turbine components. Sprayed coatings and reference materials were tested with high-speed slurry pot tester using either fine or coarse quartz as the erosive media. Additional erosion tests were carried out with centrifugal dry erosion tester. Tungsten carbide based coatings provided the highest wear resistance due to the high hardness and even distribution of the fine carbide particles. The cast 13-4 steel samples experienced up to 180 times higher wear rates in fine quartz slurry and up to 36 times higher wear rates in coarse slurry compared to the sprayed coatings.

Surface and bulk modification techniques to mitigate silt erosion in hydro turbines: a review of techniques and parameters

“…Matikainen and associates applied WC–10Cr4Cr and Cr 3 C 2 -25NiCr by HVOF and HVAF with several variations of particle size [64]. They used 13-4 MSS as substrate material and studied the effects on slurry erosive wear.…”