The transition from internal to external oxidation and the formation of interruption bands in silver-indium alloys

Rapp, Robert A.

doi:10.1016/0001-6160(61)90103-1

Cited by 299 publications

(90 citation statements)

References 2 publications

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“…Internal oxidation has been studied for several decades (Ref 8,(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). The mechanism is extensively discussed in the literature.…”

Section: Effect Of Metallic Nanonetwork On the Diffusion Mechanismmentioning

confidence: 99%

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Zeng

Natesan

Cai

et al. 2014

J. of Materi Eng and Perform

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A detailed study was conducted on localized oxidation on Type 321 stainless steel (321ss) using synchrotron x-ray nanobeam analysis along with Raman microscopy. The results showed the presence of metallic nanonetworks in the oxide scales, which plays an important role in the continued oxidation of the alloy at 750°C. A mechanism is proposed to explain the rapid oxidation of 321ss in complex gaseous environments at elevated temperature. Neutral metal atoms could diffuse outward, and carbon atoms could diffuse inward through the metallic nanonetworks in oxide layers. Alternately, diffusion tunnels can dramatically affect the phase composition of the oxide scales. Since the diffusion rate of neutral metal and carbon atoms through the metallic nanonetworks can be much faster than the diffusion of cations through Cr 2 O 3 , the metallic nanonetwork provides a path through the protective Cr 2 O 3 layer for the rapid outward diffusion of metallic chromium and iron atoms to the nonprotective spinel layer. This diffusion process affects the solidstate reaction near the alloy-oxide boundary, and a dense Cr 2 O 3 protective layer does not form. The classic stable structure of the oxide scales, with a dense Cr 2 O 3 layer at the bottom, is damaged by the rapid diffusion through the tunnel at the reaction front, resulting in locally accelerated oxidation. This process can subsequently lead to ''breakaway'' oxidation and catastrophic failure of the alloy.

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“…Internal oxidation has been studied for several decades (Ref 8,(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). The mechanism is extensively discussed in the literature.…”

Section: Effect Of Metallic Nanonetwork On the Diffusion Mechanismmentioning

confidence: 99%

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Zeng

Natesan

Cai

et al. 2014

J. of Materi Eng and Perform

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“…If the value of g Ã exceeds the critical value of 0.3, the internal oxidation begins to change to external oxidation. 10) Substituting eq. (7) into eq.…”

Section: Transition From Internal To External Oxidationmentioning

confidence: 99%

“…The boundary conditions between internal and external oxidation can be obtained by combining eqs. (9) and (10). The most appropriate g Ã value is reported to be 0.3.…”

Section: Transition From Internal To External Oxidationmentioning

confidence: 99%

Calculations of Internal Oxidation Rate Equations and Boundary Conditions between Internal and External Oxidation in Silicon Containing Steels

2010

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The rate constants for internal oxidation of Si containing steels (Fe-Si alloys) at 850 C were calculated in order to clarify the formation mechanism of fayalite scale, which can form as a ''sub-scale'' in Si containing steels. The diffusion coefficient of oxygen in the oxide layer, D O , and the oxygen concentration at specimen surface, N O (s) , which are constituents of the internal oxidation rate constant, (

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“…where g is a critical volume fraction of oxide precipitates, generally approximated as about 0.3, 25 v the stoichiometric coefficient of CrO v (1.5), V m the molar volume of alloy (6.8 cm 3 /mol), V CrOυ the molar volume of the oxide (14.6 cm 3 /mol), D O the diffusion coefficient of oxygen in the alloy, andD Cr the alloy inter-diffusion coefficient. Sample surface treatment by electropolishing, as employed in this work, allows the evaluation of Eq.…”

Section: Discussionmentioning

confidence: 99%

Temperature Effect on Oxidation Behavior of Ni-Cr Alloys in CO₂Gas Atmosphere

Xie

Zhang

Young

2017

J. Electrochem. Soc.

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Model Ni-Cr alloys containing 5, 10, 15, 20, 25 and 30 wt% Cr were oxidized in Ar-20 vol% CO 2 gas mixtures at temperatures of 650, 700 and 800 • C. In general, multi-layered oxide scales were observed on the surface after reaction. With increased alloy Cr content, the oxide structure changed from external NiO, plus intermediate inner oxides and an internal oxidation zone, to forming a thin chromia band at the base of the oxide scale and, at higher Cr levels, an exclusive chromia scale. Increasing temperature accelerated the oxidation kinetics of low chromium-containing alloys, but significantly reduced the oxidation rate of high chromium alloys by promoting formation of the chromia band/scale. The critical Cr concentration required for chromia scale formation and maintenance decreased with increasing temperature, in accord with diffusion theory. Intergranular carbides were formed in high Cr content alloys, indicating elevated carbon activities beneath the oxide scales. In conventional power plants, fossil fuels are burnt in air to generate electricity. This process is of low cost, but can produce a large amount of CO 2 gas, a principal contributor to global warming. To reduce CO 2 emissions, a new technology called oxy-fuel combustion has been developed. In this process, coal is burnt in a mixture of oxygen and recirculated flue gas, so the finally released flue gas consists mainly of CO 2 and water vapor. After condensation of water vapor, sequestering CO 2 gas from the flue gas is relatively easy.Unfortunately, this technology has the potential to exacerbate the corrosion problems encountered in power plants. The CO 2 gas has been found to be very corrosive to the steels of the critical heat exchanging components in boilers, producing severe oxidation and carburization of ferritic-martensitic steels. Exposed to this atmosphere, the chromia-forming steels which are used successfully in air, undergo breakaway oxidation and carburization. [1][2][3][4] In addition, increased operating temperatures to improve boiler heat efficiency are desirable to meet continuously increasing energy demand, e.g. in advanced ultra-supercritical power generation. As a result, the ferritic/martensitic and even austenitic steels currently used in traditional coal-fired power plants will not survive when the operating temperature increases to values higher than 650• C. 5-7 Under these circumstances, nickel-based alloys are alternative candidate materials, owing to their superior creep strength and corrosion resistance at higher temperatures. However, little is known about the corrosion behavior of Ni-based alloys in CO 2 -rich gases at high temperatures.The oxidation of various model Ni-Cr alloys in air and oxygen has been well investigated at temperatures between 800 and 1200• C, [8][9][10][11][12][13] and the oxidation of these alloys in H 2 O-containing environments has also been reported. [14][15][16][17] In air and oxygen environments, it has been generally accepted that binary Ni-Cr alloys with Cr contents lower than 10 wt% oxid...

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The transition from internal to external oxidation and the formation of interruption bands in silver-indium alloys

Cited by 299 publications

References 2 publications

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Calculations of Internal Oxidation Rate Equations and Boundary Conditions between Internal and External Oxidation in Silicon Containing Steels

Temperature Effect on Oxidation Behavior of Ni-Cr Alloys in CO₂Gas Atmosphere

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The transition from internal to external oxidation and the formation of interruption bands in silver-indium alloys

Cited by 299 publications

References 2 publications

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Effect of Element Diffusion Through Metallic Networks During Oxidation of Type 321 Stainless Steel

Calculations of Internal Oxidation Rate Equations and Boundary Conditions between Internal and External Oxidation in Silicon Containing Steels

Temperature Effect on Oxidation Behavior of Ni-Cr Alloys in CO2Gas Atmosphere

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Temperature Effect on Oxidation Behavior of Ni-Cr Alloys in CO₂Gas Atmosphere