Initial Oxidation of Fe–Al and Fe–Cr–Al Alloys: Cr as an Alumina Booster

Heinonen, Maarit; Kokko, K.; Punkkinen, M.; Nurmi, E.; Kollár, János; Vitos, Levente

doi:10.1007/s11085-011-9258-2

Cited by 34 publications

(14 citation statements)

References 39 publications

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“…Many alloys or alloy coatings for high-temperature applications are based on iron, nickel and/or cobalt and rely on the establishment of Cr 2 O 3 , A1 2 O 3 or SiO 2 healing layers for protection against oxidation. These oxides are thermodynamically very stable with respect to the metal and have high melting points; transport processes through the scales are generally slow [54][55][56][57]. Actually, in the various methods for CVD diamond films on steel substrates, the Al, Si, Cr elements have already been used by some researchers.…”

Section: Methods Similar To Hot Corrosion Resistance Such As Aluminimentioning

confidence: 99%

Diamond Deposition on Iron and Steel Substrates: A Review

et al. 2020

Micromachines

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This article presents an overview of the research in chemical vapor deposition (CVD) diamond films on steel substrates. Since the steels are the most commonly used and cost-effective structural materials in modern industry, CVD coating diamond films on steel substrates are extremely important, combining the unique surface properties of diamond with the superior toughness and strength of the core steel substrates, and will open up many new applications in the industry. However, CVD diamond deposition on steel substrates continues to be a persistent problem. We go through the most relevant results of the last two and a half decades, including recent advances in our group. This review discusses the essential reason of the thick catalytic graphite interlayer formed on steel substrates before diamond deposition. The high carbon diffusion in iron would induce severe internal carburization, and then voluminous graphite precipitated from the substrate. In order to hinder the catalytic graphite formation, various methods have been applied for the adherent diamond film deposition, such as pre-imposed various interlayers or multi-interlayers, special controls of the deposition process, the approaches of substrate alloying and so on. We found that adherent diamond films can be directly deposited on Al alloying steel substrates, and then the role of Al alloying element was examined. That is a thin dense amorphous alumina sublayer in situ formed on the alloying substrate, which played a critical role in preventing the formation of graphite phase and consequently enhancing diamond growth and adhesion. The mechanism of Al alloying suggests that the way used to improve hot corrosion resistance is also applicable. Then, some of the hot corrosion resistance methods, such as aluminizing, siliconizing, and so on, which have been used by some researchers examining CVD diamond films on steel substrates, are reviewed. Another way is to prepare diamond-like carbon (DLC) films on steel substrates at low temperature, and then the precipitated graphite from the internal carburization can be effectively avoided. In addition, based on some new findings, the understanding of the diamond nucleation and metastable growth is discussed.

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Section: Methods Similar To Hot Corrosion Resistance Such As Aluminimentioning

confidence: 99%

Diamond Deposition on Iron and Steel Substrates: A Review

et al. 2020

Micromachines

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“…Moreover, it seems that, in many cases, several transition phases can be simultaneously present [3]. In previous studies, transmission electron microscopy (TEM) was used to probe the oxidation of either an intermetallic alloy, Fe 3 Al, or an ODS (oxide dispersion strengthening) FeCrAl alloy strengthened by very small Y 2 O 3 particles, PM2000 [4][5][6][7]. The formation of transition Al 2 O 3 for various heat treatment conditions was evidenced and the transition to the -Al 2 O 3 was studied.…”

Section: Introductionmentioning

confidence: 99%

XPS, FTIR, EDX, and XRD Analysis of Al₂O₃Scales Grown on PM2000 Alloy

Djebaili

Mekhalif

Boumaza

et al. 2015

Journal of Spectroscopy

199

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This work is an original example to compare the results obtained after calcination of Al2O3hydroxides and oxidation of alumino-formers alloys. FTIR and XPS signatures were obtained for various oxidation temperatures and compared with those known from the literature about calcination of Al2O3precursors. The aim of this work is to evaluate the use of IR spectroscopy and XPS analysis to probe the structural varieties of Al2O3. For this objective, a study of the PM2000 oxidation at various temperatures was conducted by means of XRD, IR spectroscopy, XPS analysis, EDX analysis, and SEM observations. This allowed us to clearly differentiate the transition Al2O3from theα-Al2O3and, amongst the transition Al2O3, to differentiate the characteristic of the IR spectrum ofγ-δphases from that of theθphase.

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“…Their distinctive chemical composition including alloying elements might lead to different behavior with respect to binary alloys. As a matter of fact, Cr can promote the formation and sustainment of a protective corundum scale on ferritic as well as austenitic steels with a low Al-content via the so-called "third element effect", which is explained in detail elsewhere [51][52][53][54]. The sub-surface of the aluminide coating contained nearly 3 at.% Cr (see Figure 3c), whereas the Cr-content in the sub-surface of the Cr/Al-coating was substantially higher particularly due to the presence of Cr 5 Al 8 precipitates (see Figure 4c).…”

Section: Formation Of Corundum On Al-and Cr/al-coated P91mentioning

confidence: 99%

Scale Formation and Degradation of Diffusion Coatings Deposited on 9% Cr Steel in Molten Solar Salt

et al. 2019

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The employment of ferritic-martensitic steels e.g., P91, as structural materials in concentrated solar power (CSP) plants can significantly increase cost-efficiency. However, their application is strongly restricted by their lower corrosion resistance in molten nitrates, compared to austenitic steels or Ni-based alloys. In this study, Cr-, Al-, and Cr/Al-diffusion coatings were deposited on P91 via pack cementation in order to improve its scaling behavior in molten solar salt (MSS). The corrosion behavior of coated specimens was investigated with respect to uncoated P91 in MSS at 600 °C for up to 1000 h. The exposure in MSS resulted in a thick, highly porous, and multi-layered oxide scale on uncoated P91 consisting of hematite, magnetite, and sodium ferrite. On the other hand, the scale grown on the chromized P91 comprised of a thin Cr-rich inner layer, which shifted breakaway to prolonged exposure durations. The aluminized specimens both formed very thin, highly protective alumina scales with localized protrusions.

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Initial Oxidation of Fe–Al and Fe–Cr–Al Alloys: Cr as an Alumina Booster

Cited by 34 publications

References 39 publications

Diamond Deposition on Iron and Steel Substrates: A Review

Diamond Deposition on Iron and Steel Substrates: A Review

XPS, FTIR, EDX, and XRD Analysis of Al₂O₃Scales Grown on PM2000 Alloy

Scale Formation and Degradation of Diffusion Coatings Deposited on 9% Cr Steel in Molten Solar Salt

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Initial Oxidation of Fe–Al and Fe–Cr–Al Alloys: Cr as an Alumina Booster

Cited by 34 publications

References 39 publications

Diamond Deposition on Iron and Steel Substrates: A Review

Diamond Deposition on Iron and Steel Substrates: A Review

XPS, FTIR, EDX, and XRD Analysis of Al2O3Scales Grown on PM2000 Alloy

Scale Formation and Degradation of Diffusion Coatings Deposited on 9% Cr Steel in Molten Solar Salt

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XPS, FTIR, EDX, and XRD Analysis of Al₂O₃Scales Grown on PM2000 Alloy