Publication | Closed Access
Corrosion Behaviour of HVOF Sprayed Coatings on ASME SA213 T22 Boiler Steel in an Actual Boiler Environment
19
Citations
0
References
2017
Year
EngineeringMechanical EngineeringActual Boiler EnvironmentHvof Sprayed CoatingsCorrosion InhibitionChemical EngineeringCorrosionCorrosion ResistanceWc-cr 3Materials ScienceThermal Spray CoatingThermal Barrier CoatingBetter Corrosion ResistanceMicrostructureCorrosion TechnologyCorrosion ProtectionHigh Temperature MaterialsCorrosion BehaviourMaterials CharacterizationX-ray Diffraction
In present study HVOF spraying process had been employed for depositing 93(WC-Cr 3 C 2 )-7Ni, 75Cr 3 C 2 -25NiCr, 83WC-17CO and 86WC-10CO-4Cr coatings on ASME SA213 T22. All the coatings were found dense and uniform having thickness between 200-250µm. All the coatings on ASME SA213 T22 used in present studies have provided resistance to corrosion in coal fired boiler environment in superheater zone when exposed for 10 cycles at 900°C. Each cycle consists of 100 hours heating followed by 1 hour cooling at ambient conditions. X-ray diffraction (XRD), Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) techniques were used to analyse corrosion products. The results showed that among coated specimens 93(WC-Cr 3 C 2 )-7Ni and 75Cr 3 C 2 -25NiCr coatings has shown maximum and minimum resistance to corrosion respectively. The better corrosion resistance of 93(WC-Cr3C2)-7Ni coated steel alloys may be attributed to the formation of thin band of oxides of nickel, chromium; and carbides of tungsten.