Effect of Impingement Angle on Erosion Resistance of HVOF Sprayed WC-10Co-4Cr Coating on CA6NM Steel
In the present investigation, WC–10Co–4Cr coating was deposited by high velocity oxy-fuel (HVOF) process on CA6NM hydro turbine steel to improve its erosion resistance. The coating was characterized in term of crossectional microstructure, phase, microhardness and fracture toughness using a field emission scanning electron microscope (FESEM), X-ray diffractometer and microhardness tester respectively. Solid particle erosion resistance of the substrate and coating were evaluated by air jet erosion tester at two different impingement angles (30° and 90°). Coating microstructure has shown a homogeneous and well-bonded laminar morphology. The microhardness of the coating was observed more than three times higher than CA6NM substrate. This resulted in significant improvement in erosion resistance of coated CA6NM steel at both impingement angles.