Authors: Harpreet Singh Manpreet Kaur Satya Prakash
Publish Date: 2016/06/06
Volume: 25, Issue: 6, Pages: 1192-1207
Abstract
In this research development of Cr3C225NiCr + 25WCCo composite coating was done and investigated Cr3C225NiCr + 25WCCo composite powder designated as HP2 powder was prepared by mechanical mixing of 75Cr3C225NiCr and 88WC12Co powders in the ratio of 7525 by weight The blended powders were used as feedstock to deposit composite coating on ASTM SA213T22 substrate using High Velocity OxyFuel HVOF spray process Hightemperature oxidation/corrosion behavior of the bare and coated boiler steels was investigated at 700 °C for 50 cycles in air as well as in Na2SO482Fe2SO43 molten salt environment in the laboratory Erosioncorrosion behavior was investigated in the actual boiler environment at 700 ± 10 °C under cyclic conditions for 1500 h The weightchange technique was used to establish the kinetics of oxidation/corrosion/erosioncorrosion Xray diffraction field emissionscanning electron microscopy/energydispersive spectroscopy FESEM/EDS and EDS elemental mapping techniques were used to analyze the exposed samples The uncoated boiler steel suffered from a catastrophic degradation in the form of intense spalling of the scale in all the environments The oxidation/corrosion/erosioncorrosion resistance of the HVOFsprayed HP2 coating was found to be better in comparison with standalone Cr3C225NiCr coating A simultaneous formation of protective phases might have contributed the best properties to the coatingThis article is an invited paper selected from presentations at the 6th Asian Thermal Spray Conference ATSC 2014 and has been expanded from the original presentation ATSC 2014 was held in Hyderabad India November 2426 2014 and was organized by the International Advanced Research Centre for Powder Metallurgy and New Materials ARCI and the Asian Thermal Spray SocietyHarpreet Singh et al thankfully acknowledge the research grant from Department of Science and Technology New Delhi India under SERC FAST Scheme File No SR/FTP/ETA06/06 Dated March 16 2006 to carry out this R D work titled “Development of ErosionCorrosion Resistant Thermal Spray Coatings for Power Plant Boilers”
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