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Journal of Aerospace Engineering & Technology

Comparative Study of Oxidation and Hot Corrosion Behavior of Uncoated and Detonation Gun Sprayed Cr3C2-25NiCr Coating on SA516 Boiler Steel at 800°C

  1. Anil Kumar
  2. Vivek Srivastava
  3. N.K. Mishra

Abstract

In the present investigation Cr3C2-25NiCr powder was deposited on boiler steel SA 516 (Grade 70) by detonation gun process. The oxidation and hot corrosion performance of coated as well as bare boiler steel was studying in the air and aggressive environment of Na2SO4–50% NaCl under cyclic conditions at an elevated temperature of 8000C. Oxidation and hot corrosion of metals and alloys has been recognized as a serious problem for elevated-temperature applications such as boilers, gas turbines, fluidized bed combustion and industrial waste incinerators. At the present conditions, problems of component materials reliability in power plant concentrate on assessing the potential behavior of coatings, in order to avoid expensive failure in service. The kinetics of the corrosion were examined by the weight change measurements made after each cycle for a total period of 50 cycles. Each cycle consisted of 60 min heating in a silicon wire tube furnace followed by 20 min cool about ambient air. The thermo-gravimetric technique was used to establish oxidation kinetics and Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS) techniques were used to analyze the corrosion products. Both the uncoated boiler steels suffered intensive spallation in the form of removal of their oxide scales, which may be attributed to the formation of unproductive Fe2O3 dominated oxide scales. Cr3C2-25NiCr coated boiler steel consists of granules structure, which appear to be interconnected with each other at most of the places and forms oxide of chromium, which has found to be good corrosion resistance to both environments. Keywords: Detonation-Gun, Elevated temperature, SA-516 (grade-70), Cr3C2-25NiCr coating, SEM/EDS morphologyCite this ArticleAnil Kumar, Vivek Srivastava, Mishra NK. Comparative Study of Oxidation and Hot Corrosion Behavior of Uncoated and Detonation Gun Sprayed Cr3C2-25NiCr Coating on SA516 Boiler Steel at 800°C. Journal of Aerospace Engineering & Technology. 2018; 8(1): 5–10p.
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