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Zeng, Z.; Natesan, K.; Maroni, V.A.

doi:10.1023/a:1016068625429

Cited by 80 publications

(71 citation statements)

References 24 publications

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“…TEM results for iron (Fig. 6) showed large cementite particles in the graphite close to the carbon-cementite interface, revealing that dusting of iron resulted from disintegration of the Fe 3 C layer, not its chemical decomposition (6,15). It is suggested that this metal dusting resulted from the volume expansion accompanying the inward growth of graphite.…”

Section: Role Of Cementite In Iron Dustingmentioning

confidence: 99%

Understanding Metal Dusting Mechanisms

Young

Zhang

2009

ECS Trans.

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Examination of iron dusting shows that cementite forms as a layer on the surface and as particles in the overlying coke deposit. On this basis, the mechanism of cementite disintegration is deduced to be one of internal graphite nucleation and growth within the scale. Cementite formation on iron is suppressed by alloying with germanium. Nonetheless, dusting occurs via the direct growth of graphite into the metal, producing nanoparticles of ferrite. This process is faster than dusting via cementite formation and disintegration.Austenitic materials cannot form cementite, and dust via formation of graphite at external surfaces and interior grain boundaries. The coke deposit consists of carbon nanotubes with austenite particles at their tips, or graphite particles encapsulating austenite. TEM studies demonstrate the inward growth of graphite within the metal interior. It is therefore concluded that the mechanism of nickel dusting is one of graphite nucleation and growth within the near surface metal. Alloying copper with nickel strongly represses graphite formation, thereby reducing greatly the overall dusting rate.

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Section: Role Of Cementite In Iron Dustingmentioning

confidence: 99%

Understanding Metal Dusting Mechanisms

Young

Zhang

2009

ECS Trans.

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“…It is a major issue in plants for the production of hydrogen, ammonia synthesis processes, methanol-reformer systems, and syngas (H 2 /CO mixtures) systems that are pertinent to chemical and petrochemical industries. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Metal dusting is experienced at high temperatures in oxidizing-carburizing environments that are prevalent in heat-treating industry. The gases used in heat-treating operations mix with oil residue on the work pieces to form gases that are kinetically favorable for metal dusting attack.…”

Section: Project Descriptionmentioning

confidence: 99%

“…However, there is no conclusive evidence that the iron phase is present in every case of metal dusting. 9,10 It is not clear what drives the formation and decomposition of Fe 3 C under the same conditions of temperature, pressure, and composition. Clearly, graphite crystallizes from a supersaturated solution.…”

Section: Introductionmentioning

confidence: 99%

“…9,[11][12][13] Metal dusting in iron-base alloys is considered to be a process of catalytic crystallization of carbon with participation by iron. The difference in the free energy of poorly crystallized carbon and well-crystallized graphite is a driving force for crystallization of carbon.…”

Section: Introductionmentioning

confidence: 99%

“…The difference in the free energy of poorly crystallized carbon and well-crystallized graphite is a driving force for crystallization of carbon. 9 However, this process cannot occur at low temperature because the C-C bonds are too strong to allow movement of carbon atoms. Fe 3 C and iron act as catalysts in the carbon crystallizing process in a manner that tends to improve the crystallinity of the carbon since Fe 3 C and iron have a suitable lattice plane, which has diffraction parameters similar to those of graphite.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Development of Materials Resistant to Metal Dusting Degradation-Vol 2

Natesan¹

2008

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Mechanisms and driving forces of metal dusting

Szakálos

2003

Materials & Corrosion

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The mechanisms of metal dusting as it appears on different ferritic stainless steels and pure iron have been described in detail. A mechanism for metal dusting (MD) of chromia-forming as well as alumina-forming steels is proposed, based on results from laboratory exposures of 26Cr-steel and FeCrAl-alloy at 600 -650 8C for up to 5000 h in a synthesis gas low in water vapour, 25%CO þ 3%H 2 O þ H 2 . Metallographical examinations, FEG-SEM, SEM-EDX analysis and X-ray diffraction, as well as thermodynamic calculations were made in order to identify and describe the different metal dusting processes. The work focuses on the role of carbides and oxides to explain the observations and give a description of the metal dusting phenomenon as it appears in engineering alloys. This mechanism was first observed and identified in a study of an austenitic stainless steel.The driving force for steady state MD on pure iron and low alloyed steels is described and a secondary MD-mechanism, carbon nanotube formation, is described in detail. With these additional results it is now possible to extend understanding of the MD-processes to a wide range of engineering alloys.

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Untitled

Cited by 80 publications

References 24 publications

Understanding Metal Dusting Mechanisms

Understanding Metal Dusting Mechanisms

Development of Materials Resistant to Metal Dusting Degradation-Vol 2

Mechanisms and driving forces of metal dusting

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