Study on High Temperature Performances of NiCr-Cr3C2 Coatings by Supersonic Plasma Spraying

NiCr-Cr3C2 coatings were fabricated by supersonic plasma spraying. The coating surface was painted by Na2SO4: K2SO4=7:3, and then the thermal corrosion test and high temperature frictional wear test were adopted to study high temperature performances of NiCr-Cr3C2. SEM, EDAX, XRD and micro-profilometer were adopted to comprehensively analyze the coatings' microstructure and the surface morphology of wear trace. The results show that the coatings are very dense, which is typical "hard phase + soft matrix" of wear-resisting organization. The excellent corrosion resistance performance is 15 times higher than that of 20G steel. At 800 degrees C, the wear behavior between NiCr-Cr3C2 and Si3N4 are particle attrition and fatigue wear.