Effect of?-alumina formation on the growth kinetics of alumina-forming superalloys

Prasanna, Kmn; Khanna, A. S.; Chandra, Ramesh; Quadakkers, Willem J.

doi:10.1007/bf01048641

Cited by 88 publications

(33 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Titanium was cited by Pint et al [6] as promoting alpha formation and Prasanna and al. [7] showed that Ti from the bulk alloy is incorporated in the oxide scale, possibly acting as an accelerator of the h-a transformation. Very recently, and in the course of the present work, Fei and col. [8] clearly demonstrated that a thin TiO 2 [9].…”

Section: Application Of a Titania Slurry Coatingmentioning

confidence: 99%

Metastable alumina formation during oxidation of FeCrAl and its suppression by surface treatments

N’Dah

Galerie²,

Wouters

et al. 2005

Materials and Corrosion

View full text Add to dashboard Cite

The influence of various surface treatments of industrial FeCrAl grades was investigated in order to reduce the formation of transition aluminas during thermal oxidation in the 800 -950 8C temperature range. High temperature gas phase annealing in H 2 -H 2 O mixtures promoted the initial formation of an alpha thin film and no transition alumina formed during subsequent oxidation at lower temperatures, showing very low weight gains compared to nontreated grades. Such a treatment was shown to be efficient for isothermal oxidation in oxygen of laboratory foil specimens but also for cyclic air exposure of fiber mats in near-real operating conditions. Surface modification by application of a slurry TiO 2 coating before oxidation was also shown to greatly reduce the amount of transition alumina, observed by X-Ray Diffraction and Laser Induced Optical Spectroscopy. For both treatments, the optimal conditions were determined and the influence on oxidation rate was assessed.

show abstract

Section: Application Of a Titania Slurry Coatingmentioning

confidence: 99%

Metastable alumina formation during oxidation of FeCrAl and its suppression by surface treatments

N’Dah

Galerie²,

Wouters

et al. 2005

Materials and Corrosion

View full text Add to dashboard Cite

show abstract

“…This change in alloy and environmental composition would increase both the activity of iron and the partial pressure of sulfur, making it more thermodynamically stable for iron sulfide to form. This hypothesis was cited by Kai 26 in a study of the sulfidization of binary iron aluminum alloys. In that work, similar two stage corrosion kinetics were observed, with formation of iron sulfide occurring after an incubation time during which Al 2 O 3 whiskers formed on the alloy surface.…”

Section: Discussionmentioning

confidence: 99%

“…Using the data of Akuezue and Whittle 23 has a relatively slow growth rate at high temperatures, it is likely that at 500°C, transitional aluminas (θ, γ, δ) will form on the alloys studied here, rather than the α-phase; these metastable phases have been shown to exhibit faster growth rates than the slower α-phase 25,26 . Thus in the present work, it is reasonable to assume that the diffusion of aluminum and chromium may be too slow at 500°C to prevent a sub-surface depletion layer from forming in the initial stages of exposure.…”

Section: Scanning Transmission Electron Microscopymentioning

confidence: 99%

Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

Marder¹

2007

View full text Add to dashboard Cite

“…Previous studies extensively described this oxide [37,38]. Y 3 Al 5 O 12 is also identified by ceramists in massive alumina and is located at the Al 2 O 3 grain boundaries [39,40].…”

Section: Discussionmentioning

confidence: 99%

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Chevalier¹,

Issartel²,

Cueff³

et al. 2006

Materials and Corrosion

View full text Add to dashboard Cite

International audienceThe aim of this work was to investigate several different yttrium introduction routes to improve the high temperature oxidation resistance of a Fe-20Cr-5Al model alloy. Y2O3 sol-gel coatings, Y2O3 metal-organic chemical vapor deposition (MOCVD) coatings, yttrium. ion implantation and yttrium as alloying element (0.1 wt.%) were the different methods of introduction of the reactive element. Both isothermal and cyclic oxidation tests showed that the surface introduction of yttrium or yttrium oxide did not drastically improve the oxidation behavior of the steel. Complementary experiments were performed to understand the lack of major beneficial effects of the so-treated samples. Two stage oxidation experiments under 200 mbar O-16(2) and O-18(2) followed by secondary neutral mass spectrometry (SNMS) were performed to understand the alumina scale growth mechanisms, according to the introduction route of the reactive element. The results exhibited that the yttrium induced an increase of the inward transport of oxygen through the alumina scale compared to the untreated specimen. Nevertheless, the outward transport of aluminum was generally observed, except for the specimen containing Y as alloying element, which exhibited only a single O-18 peak close to the metal/oxide interface. Phase transformations during the oxidation at 1100 degrees C were registered by in-situ X-ray diffraction (XRD). The untreated alloy was only covered by a thin layer of alpha-Al2O3. For implanted specimens, yttrium was incorporated in Y3Al5O12 and YAlO3 phases. All the YAlO3 is transformed into Y3Al5O12 after less than 10 h. For the MOCVD or the sol-gel coated samples, the primary formed YAlO3 phase was progressively transformed into Y3Al5O12. For the Fe-20Cr-5Al-0.1Y alloy, no yttrium containing phases could be detected, even after 40 h of oxidation test at 1100 degrees C

show abstract

Effect of?-alumina formation on the growth kinetics of alumina-forming superalloys

Cited by 88 publications

References 18 publications

Metastable alumina formation during oxidation of FeCrAl and its suppression by surface treatments

Metastable alumina formation during oxidation of FeCrAl and its suppression by surface treatments

Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

Influence of the mode of introduction of a reactive element on the high temperature oxidation behavior of an alumina-forming alloy. Part III: The use of two stage oxidation experiments and in situ X-ray diffraction to understand the oxidation mechanisms

Contact Info

Product

Resources

About