Characterisation of 80% Cr3c2 – 20 % (Ni-20cr) Coating and Erosion Behaviour

Abstract

80 % Cr3C2 – 20 % (Ni-20Cr) powder composition was used to generate coating on T-91 boiler tube steel using high velocity oxy fuel (HVOF) process. This paper focuses on characterization of the coating and will also investigate the mechanism of erosion at different operating temperatures. Microstructure, porosity, surface roughness, coating thickness and microhardness properties of the coating were characterized using the optical microscopy, X-ray diffraction, scanning electron microscopy/energy-dispersive x-ray analysis and electron probe micro analysis techniques. The 80% Cr3C2 -20% (Ni-20Cr) coating possesses thickness 325 μm, surface roughness value 5.206 (Ra), average microhardness value 862 Hv and 1.8% porosity. The uncoated and coated samples were tested in air jet erosion test rig for enhancing the life of boiler tubes and improving the performance of the power plants.