Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1660407 | Surface and Coatings Technology | 2009 | 10 Pages |
Abstract
In the present investigation, Cr3C2-NiCr cermet coatings were deposited on two Ni-based superalloys, namely superni 75, superni 718 and one Fe-based superalloy superfer 800H by detonation-gun thermal spray process. The cyclic hot-corrosion studies were conducted on uncoated as well as D-gun coated superalloys in the presence of mixture of 75 wt.% Na2SO4 + 25 wt.% K2SO4 film at 900 °C for 100 cycles. Thermogravimetric technique was used to establish the kinetics of hot corrosion of uncoated and coated superalloys. X-ray diffraction, FE-SEM/EDAX and X-ray mapping techniques were used to analyze the corrosion products for rendering an insight into the corrosion mechanisms. It was observed that Cr3C2-NiCr-coated superalloys showed better hot-corrosion resistance than the uncoated superalloys in the presence of 75 wt.% Na2SO4 + 25 wt.% K2SO4 film as a result of the formation of continuous and protective oxides of chromium, nickel and their spinel, as evident from the XRD analysis.
Related Topics
Physical Sciences and Engineering
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Authors
Subhash Kamal, R. Jayaganthan, Satya Prakash,