Back to Search
Start Over
Cyclic Oxidation and Hot-Corrosion Behavior of HVOF-Sprayed NiCrAl Coating on Industrial Boiler Tube Steels.
- Source :
- JOM: The Journal of The Minerals, Metals & Materials Society (TMS); Jun2024, Vol. 76 Issue 6, p3172-3184, 13p
- Publication Year :
- 2024
-
Abstract
- At high temperatures, coatings provide a protective scale development on surfaces to maintain long-term stability. In the current study, ASTM-SA210-Grade A1 (GrA1) and ASTM-SA213-T-11 (T11) boiler tube steels were coated with NiCrAl alloy with high-velocity oxy-fuel (HVOF) to prevent oxidation and hot corrosion. For hot corrosion and oxidation, 50 cycles at 900°C were taken into account. Additionally, tests of hot-corrosion behavior were conducted in an atmosphere containing molten salt (Na<subscript>2</subscript>SO<subscript>4</subscript>-60%V<subscript>2</subscript>O<subscript>5</subscript>), while tests of oxidation behavior were conducted in static air. The kinetics of oxidation were calculated using the thermogravimetric method. Using XRD, EPMA, and SEM/EDAX methods, the produced oxide scales were characterized. The oxidation rate of NiCrAl-coated steels was found to be lower than that of uncoated steels. The coated steels subjected to oxidation in air exhibit slow scale growth kinetics and oxides of α-Al<subscript>2</subscript>O<subscript>3</subscript> and Cr<subscript>2</subscript>O<subscript>3</subscript> on the outermost surface, while accelerated oxidation caused by the molten salt exhibits metastable Al<subscript>2</subscript>O<subscript>3</subscript>. Along the nickel-rich splat boundary, Cr and Al were formed a preferential oxidation, which prevents other oxygen from entering the coating via pores and voids, resulting in steady-state oxidation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10474838
- Volume :
- 76
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- JOM: The Journal of The Minerals, Metals & Materials Society (TMS)
- Publication Type :
- Academic Journal
- Accession number :
- 177311049
- Full Text :
- https://doi.org/10.1007/s11837-024-06526-1