Contents lists available at ScienceDirect Wear journal homepage: www.elsevier.com/locate/wear An erosion and corrosion study on thermally sprayed WC-Co-Cr powder synergized with Mo 2 C/Y 2 O 3 /ZrO 2 feedstock powders ☆ Jashanpreet Singh a,⁎ , Satish Kumar b , S.K. Mohapatra a a Mechanical Engineering Department, Thapar Institute of Engineering and Technology, Patiala, Punjab 147004, India b Department of Mechanical Engineering, National Institute of Technology, Jamshedpur, Jharkhand, India ARTICLEINFO Keywords: Slurry erosion Corrosion Super-duplex stainless steel (SDSS) 2507 Cermet coatings WC-Co-Cr powder HVOF thermal spraying ABSTRACT 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 Mo 2 C, Y 2 O 3 and ZrO 2 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 90–180min. 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. Resultsshowthatthe3%additionoffeedstockpowderswasbenefcialtoimprovetheerosionwearresistanceof SDSS-2507. The addition of Y 2 O 3 and Mo 2 C had improved the erosion wear performance of WC-Co-Cr coating. The addition of Y 2 O 3 provided high erosion wear as compared to Mo 2 C addition. The addition of ZrO 2 was helpful to signifcantly improve the corrosion resistance of WC-Co-Cr coating whereas it decreases the erosion wear resistance of coating. 1. Introduction Hydraulicmachinery(suchasturbines,pumps,valves,fttings,etc.) and their components undergo erosion and corrosion while they come into contact with liquids or solid-liquids [1]. The erosion and corrosion on components of slurry pump is illustrated in Fig. 1. Generally, the slurry erosion caused by silt/sand slurry predominantly afects the ef- fciencyandlifeofhydraulicmachinery [2].Insuchcases,itisessential to prevent or reduce material deterioration and to increase the life of components. The present investigation was aimed to study the slurry erosion of pump material used in slurry transportation systems of mining industry as well as thermal power plants. The solids processed through slurry pumps in these industries are entirely diferent in nature from each other. Super duplex stainless steel (SDSS) 2507 is widely used to fab- ricate the diferent components of slurry pump [3].Themainreasonof selectingthismaterialwasitsversatilityinmanyapplicationsexcepting slurry pumps such as turbine blades [3,4]. The applications of SDSS 2507 in centrifugal slurry pumps, mining and marine pumps are fab- rication of pump impeller, seals, valve seats, heavy duty pump im- pellers, etc. [5]. Prior to experimentation, a literature survey was carried out, ana- lyzing earlier studies performed by diferent researchers. Various coating processes have been used at the industrial level. The high ve- locity oxy-fuel (HVOF) spraying process is widely used to coat the components of hydraulic machinery for the application of solid-liquid fow. The HVOF spraying process is widely-used to provide resistance against erosion, abrasion, and corrosion to hydraulic machinery [6]. Many researchers have used WC-Co and WC-Co-Cr coatings to improve the erosion wear resistance of stainless steels use in diferent hydraulic machineries. WC-10Co-4Cr is very widely-used in many industrial ap- plications and commercially successful [7,8]. A good deal of literature is available on WC-Co-Cr coatings deposited by diferent spraying processes. However, these cermet coatings can be still improved in termsoferosionandcorrosionperformance.Choetal. [9] have studied the microstructure of HVOF sprayed nano and micron WC–Co coating powders. The nano and micron coating powders were taken in pro- portion of 12% and 88% (by weight) respectively. They found that hardness of nano WC–Co was lower than that of micro WC–Co because of hard WC decomposition. Thakur et al. [10] reported the slurry ero- sion behavior of coated surface with the help of slurry pot erosion tester.Theyusedmultiwalledcarbonnanotubestoimprovethebinding https://doi.org/10.1016/j.wear.2019.01.082 Received 3 September 2018; Received in revised form 13 January 2019; Accepted 19 January 2019 ☆ This paper was originally accepted for the International Conference on Wear of Materials 2019. ⁎ Corresponding Author. E-mail address: jashanpreet.singh@thapar.edu (J. Singh). Wear 438-439 (2019) 102751 0043-1648/ © 2019 Elsevier B.V. All rights reserved. T