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The present study is based on erosion wear analysis of WC-Co-Cr powder thermally sprayed on super-duplex stainless steel (SDSS) 2507. A high-velocity oxy-fuel (HVOF) process was used to deposit the WC-Co-Cr thermal spraying powder. A small weight proportion of Mo2C, Y2O3 and ZrO2 feedstock powders was mechanically blended to WC-Co-Cr thermal spraying powder for analyze the improvement in erosion wear. Erosion wear experiments were conducted using a slurry pot tester at a rotational speed of 600–1500 rev/min for time duration of 90–180 min. Sand was used as the erodent medium; the concentration of solid particles was varied from 30% to 60% (by weight). Present study was extended to analyze the mechanical properties of coatings. Results show that the 3% addition of feedstock powders was beneficial to improve the erosion wear resistance of SDSS-2507. The addition of Y2O3 and Mo2C had improved the erosion wear performance of WC-Co-Cr coating. The addition of Y2O3 provided high erosion wear as compared to Mo2C addition. The addition of ZrO2 was helpful to significantly improve the corrosion resistance of WC-Co-Cr coating whereas it decreases the erosion wear resistance of coating.

Wear tests were conducted in a simulated face seal apparatus of Hastelloy B mated against a resin-bonded graphite. The alloy was tested in the solution-annealed (soft) and the aged (hard) conditions in a light wear and a heavy wear regime. The product of the mating pressure and rotational speed was 0.19 × 10 6 N m −1 s −1 for the light wear regime and 1.15 × 10 6 N m −1 s −1 for the heavy wear regime. The coefficient of friction was 0.07 in the light and about 0.12 in the heavy wear regime; the results were the same for the two conditions of the alloy. The wear rate in the light wear regime was immeasurable. In the heavy wear regime, the wear rate of the graphite was the same against either alloy condition and was about 100 times greater than the wear rate of the alloy. The annealed alloy had a wear rate about twice that of the aged alloy. In the light wear regime, graphite smeared and formed a very adherent coating on the alloy. In the heavy wear regime, the graphite wear surface contained holes and deep grooves; the collected wear debris was mainly graphite flakes and the alloy wear tracks were covered with a rather nonadherent graphite coating. The alloy contained numerous abrasive grooves. The graphite has silicon carbide particles embedded in it which probably improve its wear resistance; these hard particles were responsible for the wear damage to the alloy.