Investigation on the Behavior of Detonation Gun Sprayed Stellite-6 Coating on T-22 Boiler Steel in Actual Boiler Environment

2019 ◽  
pp. 196-210
Author(s):  
Yogesh Kumar Sharma ◽  
Anuranjan Sharda ◽  
Rahul Joshi ◽  
Ketan Kakkar
Keyword(s):  
Boiler Steel ◽  
Stellite 6 ◽  
Boiler Environment ◽  
Detonation Gun

scholarly journals Hot Corrosion Behaviour of Detonation Gun Sprayed Stellite-6 and Stellite-21 Coating on Boiler Steel SAE 431 at 900°C

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
N. K. Mishra ◽  
A. K. Rai ◽  
S. B. Mishra ◽  
R. Kumar
Keyword(s):  
Hot Corrosion ◽  
Gas Turbines ◽  
Elevated Temperatures ◽  
Protective Coatings ◽  
Total Duration ◽  
Boiler Steel ◽  
Stellite 6 ◽  
Stellite 21 ◽  
Wide Range ◽  
Detonation Gun

Hot corrosion is the serious problem in gas turbines, superheaters, and economizers of coal-fired boilers. It occurs due to the usage of wide range of fuels such as coal, oil, and so on at the elevated temperatures. Protective coatings on boiler steels are used under such environments. In the present investigation, Stellite-6 and Stellite-21 coatings have been deposited on boiler steel SAE 431 by detonation gun method. The hot corrosion performance of Stellite-6 and Stellite-21 coated as well as uncoated SAE 431 steel has been evaluated in aggressive environment of Na2SO4-82%Fe2(SO4)3under cyclic conditions at an elevated temperature of 900°C for total duration of 50 cycles. Thermogravimetric technique was used to approximate the kinetics of hot corrosion. Stellite-6 coating imparted better hot corrosion resistance than Stellite-21 coating in the given environment. Scanning electron microscopy was used to characterize the surface of hot corrosion products.

Improving the hot corrosion resistance of boiler tube steels by detonation gun sprayed coatings in actual boiler of thermal power plant

2019 ◽  
Vol 66 (4) ◽  
pp. 394-402
Author(s):  
Vikramjit Singh ◽  
Khushdeep Goyal ◽  
Rakesh Goyal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Power Plants ◽  
Thermal Power ◽  
Boiler Steel ◽  
Content Type ◽  
Boiler Environment ◽  
Detonation Gun ◽  
Sprayed Coatings

Purpose This paper aims to investigate the hot corrosion behavior of Ni-Cr and Cr3C2-NiCr coatings, deposited on T11, P91 boiler steels by detonation gun spray coating (D-Gun) process to enhance high temperature corrosion resistance. Design/methodology/approach Hot corrosion studies were conducted in secondary super heater zone of boiler at 900 °C for 10 cycles on bare and D-Gun coated steel specimens. The microhardness and porosity values of as-sprayed coatings were measured before exposing the specimens in the boiler environment. Each cycle consisted 100 h of heating in the boiler environment followed by 20 min of cooling in air. The weight change measurements were performed after each cycle to establish the kinetics of corrosion using thermogravimetric technique. X-ray diffraction, SEM techniques were used to analyze the corroded specimens. Findings Uncoated boiler steel experienced higher weight loss. The Cr3C2-NiCr coating was found to be more protective than Ni-Cr coating. The phases revealed the formation of oxide scale on coated specimens, mainly consist of nickel and chromium, which are reported to be protective against the hot corrosion. Originality/value There is very limited reported literature on hot corrosion behavior of Ni-Cr and Cr3C2-NiCr coatings deposited on the T11 and P91 substrates by detonation gun (D-gun) spray technique. T11 and P91 alloy steels have been chosen for this study because these two alloys are used to manufacture boiler tubes used in Indian thermal power plants.

Investigations on the Behavior of HVOF and Cold Sprayed Ni-20Cr Coating on T22 Boiler Steel in Actual Boiler Environment

2011 ◽  
Vol 21 (1) ◽  
pp. 144-158 ◽  
Author(s):  
Niraj Bala ◽  
Harpreet Singh ◽  
Satya Prakash ◽  
J. Karthikeyan
Keyword(s):  
Boiler Steel ◽  
Boiler Environment

Some Observations Regarding Erosion-Corrosion Performance of HVOF-Sprayed Cr3C2- NiCr and Cr3C2- NiCr-(25) WC-Co Coatings in Actual Boiler Environment

2007 ◽  
Vol 26-28 ◽  
pp. 1345-1348 ◽  
Author(s):  
Manpreet Kaur ◽  
Harpreet Singh ◽  
Satya Prakash
Keyword(s):  
Weight Change ◽  
Thermal Power ◽  
Coated Steel ◽  
Oxide Scales ◽  
Corrosion Performance ◽  
Boiler Steel ◽  
X Ray ◽  
Uncoated Steel ◽  
Erosion Corrosion ◽  
Boiler Environment

Cr3C2- NiCr and Cr3C2- NiCr-(25) WC-Co coatings were deposited on T22 boiler steel by High Velocity Oxy-Fuel (HVOF) Technology. The coated as well as the uncoated steel samples were exposed to the actual boiler environments in a thermal power plant for 1500 hrs under cyclic conditions to evaluate their erosion-corrosion performance. Weight change measurements were taken for each sample after every 100 hrs. It has been observed that the weight change trends for coated steel with Cr3C2- NiCr and Cr3C2- NiCr-(25) WC-Co coatings followed a parabolic trend. The exposed samples were physically investigated for any macroscopic changes after each cycle of 100 hours. The uncoated steel showed blisters and spallation of its oxide scale, whereas the coated samples exhibited intact oxide scales, in general. Scanning Electron Microscopy/Energy Dispersive X-Ray Analysis (SEM/EDAX) was done to characterize morphology of the oxide scales. The protective nature of coatings has been explained based on the results of the study.

An investigation of corrosion resistance of HVOF coated ASME SA213 T91 boiler steel in an actual boiler environment

2017 ◽  
Vol 64 (5) ◽  
pp. 499-507 ◽  
Author(s):  
Varinder Pal Singh Sidhu ◽  
Khushdeep Goyal ◽  
Rakesh Goyal
Keyword(s):  
Corrosion Resistance ◽  
Original Research ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Hvof Spraying ◽  
Boiler Steel ◽  
Content Type ◽  
Boiler Environment ◽  
Spraying Process ◽  
Minimum Resistance

Purpose This paper aims to use the high-velocity oxy fuel (HVOF) spraying process for depositing 93(WC–Cr3C2)–7Ni, 75Cr3C2–25NiCr, 83WC–17CO and 86WC–10CO–4Cr coatings on ASME SA213 T91 to study the corrosion resistance of these coatings in an actual boiler environment. Design/methodology/approach The HVOF spraying process was used for depositing 93(WC–Cr3C2)–7Ni, 75Cr3C2–25NiCr, 83WC–17CO and 86WC–10CO–4Cr coatings on ASME SA213 T91. All the coatings obtained are found to be uniform, dense and having thickness between 200 and 250 μm. All the coatings were exposed in an actual boiler environment at 900°C temperature for 10 cycles. Each cycle consisted of 100 h heating followed by 1 h cooling at ambient conditions. X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy techniques were used to analyse corrosion products. Findings All the coated samples were found to be having higher corrosion resistance than the uncoated samples. Among coated specimens, 93(WC–Cr3C2)–7Ni coating has shown maximum and 75Cr3C2–25NiCr coating has shown minimum resistance to corrosion. Originality/value This paper is original research.

Sign in / Sign up

Export Citation Format

Share Document