Hot corrosion behaviour of Fe–Al based intermetallic in molten NaVO3 salt

Espinosa-Medina, M. A.; Torre, G. Carbajal-De la; Liu, Hong Bo; Martínez‐Villafañe, A.

doi:10.1016/j.corsci.2009.03.028

Cited by 41 publications

(20 citation statements)

References 34 publications

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“…The polarization curves (applied potential vs measured current density) are then used to find the cathodic and anodic Tafel slopes. These slopes are usually found between 730-120 mV relative to the sample-OCP [14]. The intersection of the Tafel slopes provides the corrosion potential (E corr ) and corrosion current density (j corr ), which is the corrosion current (i corr ) divided by the exposed area (A).…”

Section: Introductionmentioning

confidence: 99%

Corrosion of alloys in a chloride molten salt (NaCl-LiCl) for solar thermal technologies

Vidal

Tirawat

2016

Solar Energy Materials and Solar Cells

168

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a b s t r a c tNext-generation solar power conversion systems in concentrating solar power (CSP) applications require high-temperature advanced fluids in the range of 600-800°C. Current commercial CSP plants use molten nitrate salt mixtures as the heat transfer fluid and the thermal energy storage (TES) media while operating with multiple hours of energy capacity and at temperatures lower than 565°C. At higher temperatures, the nitrates cannot be used because they decompose. Molten chloride salts are candidates for CSP applications because of their high decomposition temperatures and good thermal properties; but they can be corrosive to common alloys used in vessels, heat exchangers, and piping at these elevated temperatures. In this article, we present the results of the corrosion evaluations of several alloys in eutectic 34.42 wt% NaCl -65.58 wt% LiCl at 650-700°C in nitrogen atmosphere. Electrochemical evaluations were performed using open-circuit potential followed by a potentiodynamic polarization sweep. Corrosion rates were determined using Tafel slopes and Faraday's law. A temperature increase of as little as 50°C more than doubled the corrosion rate of AISI stainless steel 310 and Incoloy 800H compared to the initial 650°C test. These alloys exhibited localized corrosion. Inconel 625 was the most corrosionresistant alloy with a corrosion rate of 2.80 7 0.38 mm/year. For TES applications, corrosion rates with magnitudes of a few millimeters per year are not acceptable because of economic considerations. Additionally, localized corrosion (intergranular or pitting) can be catastrophic. Thus, corrosion-mitigation approaches are required for advanced CSP plants to be commercially viable.

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Section: Introductionmentioning

confidence: 99%

Corrosion of alloys in a chloride molten salt (NaCl-LiCl) for solar thermal technologies

Vidal

Tirawat

2016

Solar Energy Materials and Solar Cells

168

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“…Therefore, it is of prime importance to develop effective diffusion barrier coatings on the alloys so that the life of the components can be extended. Aluminides are found to be very effective in functioning as diffusion barrier coatings as they form a protective layer of Al 2 O 3 when exposed to high temperature [13][14][15][16][17]. At temperatures above 1273 K and in many aggressive environments with low oxygen partial pressures, a-Al 2 O 3 is reported to be more protective than Cr 2 O 3 scale [18].…”

Section: Introductionmentioning

confidence: 97%

Formation of diffusion barrier coating on superalloy 690 substrate and its stability in borosilicate melt at elevated temperature

Dutta

Yusufali

Paul

et al. 2013

Journal of Nuclear Materials

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“…FeAl alloys have demonstrated particularly improved resistance to various molten salts leading to hot corrosion in heat exchanging systems, incinerators and burners. This pertains to such chemicals as potassium sulfate (K 2 SO 4 ), vanadium pentoxide (V 2 O 5 ), mixtures of sodium sulfate and vanadium pentoxide (Na 2 SO 4 -V 2 O 5 ), chlorates and carbonates, all of which can inflict severe damage in the energy sector (Ref [18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Hot Treatment on Composition and Microstructure of HVOF Iron Aluminide Coatings in Na2SO4 Molten Salts

et al. 2019

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The paper deals with the hot corrosion performance of FeAl base intermetallic HVOF coatings in molten Na 2 SO 4 at 850°C in an isothermal process over the span of 45 h under static conditions. The test was validated with electron microscopy and compositional analyses in the cross-section area, as well as x-ray diffraction techniques. All the coatings were characterized by Al-depleted regions, intersplat oxidation and different stoichiometric ratios of iron aluminides. The results were discussed in relation to the formation of oxide scales on the surface after exposition to corrosive media, as well as heterogeneity and defects of the sprayed coatings. The Fe40Al (at.%) powder showed quite uniform phase distribution after spraying and preserved its integrity after corrosion test; the FeCr-25% ? FeAl-TiAl-Al 2 O 3 (wt.%) and Fe46Al-6.55Si (at.%) powders exhibited interface oxidation, with localized corrosion attacks proceeding through particle boundaries and microcrack networks with no evidence of Na and S penetration. Fe x Al y alloys are susceptible to accelerated damage and decohesion of the coating, whereas the formation of sulfides is observed at certain points.

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Hot corrosion behaviour of Fe–Al based intermetallic in molten NaVO3 salt

Cited by 41 publications

References 34 publications

Corrosion of alloys in a chloride molten salt (NaCl-LiCl) for solar thermal technologies

Corrosion of alloys in a chloride molten salt (NaCl-LiCl) for solar thermal technologies

Formation of diffusion barrier coating on superalloy 690 substrate and its stability in borosilicate melt at elevated temperature

The Effect of Hot Treatment on Composition and Microstructure of HVOF Iron Aluminide Coatings in Na2SO4 Molten Salts

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