Erosion tribo performance of HVOF deposited WC-10Co-4Cr and WC-10Co-4Cr + 2%Y₂O₃ micron layers on pump impeller steel

Abstract

SS 410 is widely used as pump impeller material due to its high erosion resistance property. On the other hand, the microhardness of SS 410 is comparatively lower than other steels. So in this paper, WC-10Co-4Cr and WC-10Co-4Cr + 2%Y₂O₃ (yttrium oxide) powders are used to improve the microhardness of SS 410. The erosion due to fly ash slurry mixture has been inspected in a slurry pot analyzer. The erosion wear experiments were performed for equisized slurry of different particle size range, namely <53 µm, 53–106 µm, 106–150 µm, and 150–250 µm. During the experimentation, concentration of fly ash slurry was varied from 35 to 65%. The rotation speed of pot tester was taken as 750, 1000, 1250 and 1500 rpm. Experiments were repeated for different time durations like 75, 120, 165 and 210 min. A high velocity oxygen fuel coating technique was utilized to deposit the coating powders on the pump impeller materials SS 410. WC-10Co-4Cr sprayed SS 410 was found to have better erosion wear resistance as compared to bare SS 410. The addition of 2% Y₂O₃ in WC-10Co-4Cr has enhanced the erosion wear resistance based on change in hardness from 1130 HV to 1190 HV and because of the densification impact of Y₂O₃.

Keywords:

• Erosion wear
• fly ash
• particle size
• pump impeller materials
• HVOF thermal spraying coating