Degradation behaviour and microstructural characterisation of HVOF-sprayed Cr3C2-NiCr cermet coatings in molten salt environment Online publication date: Thu, 05-May-2016
by V.N. Shukla; R. Jayaganthan; V.K. Tewari
International Journal of Materials and Product Technology (IJMPT), Vol. 53, No. 1, 2016
Abstract: The present work investigated the cyclic high temperature degradation behaviour of high velocity oxy-fuel (HVOF) sprayed Cr3C2-NiCr coating deposited on 310S stainless steel (310S). The coated as well as uncoated specimens were exposed to molten salt (Na2SO4-60%V2O5) environment at 700°C under cyclic conditions. The kinetics of hot corrosion was established using thermogravimetric technique. The corrosion products were characterised using the techniques such as X-ray diffraction, FE-SEM/EDAX and X-ray mapping for elucidating the corrosion mechanisms. The Cr3C2-25%NiCr coating was found to be successful in maintaining its continuous contact with the alloy substrate during cyclic degradation under simulated laboratory condition. HVOF sprayed Cr3C2-25%NiCr coating on 310S alloy substrate is found to be very effective in reducing the corrosion rate in the aggressive environment at 700°C as observed from the present work. The oxide scales for Cr3C2-25%NiCr coated specimen were found to be intact and spallation-free. The parabolic rate constant of the coated specimen was lower than that of the bare specimen. The better hot corrosion resistance imparted by Cr3C2-NiCr coatings may be attributed to the formation of oxides of chromium, nickel and spinel of nickel and chromium.
Online publication date: Thu, 05-May-2016
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Materials and Product Technology (IJMPT):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email firstname.lastname@example.org