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Asteman, Henrik; Svensson, Jan; Johansson, Lars‐Gunnar; Norell, Mats

doi:10.1023/a:1018875024306

Cited by 267 publications

(153 citation statements)

References 6 publications

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“…Rapid metal loss can occur when reactive evaporation of Cr depletes the scale (and sometimes the substrate metal) of Cr. [5][6] Decreased Cr in the scale or metal can lead to the formation of less protective oxides, such as Fe-Cr oxides in Fe-Cr base alloys. Unprotective scales can lead to rapid metal loss, or "break-away" oxidation.…”

Section: Introductionmentioning

confidence: 99%

Calculation of Reactive-evaporation Rates of Chromia

Holcomb

2008

Oxid Met

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A methodology is developed to calculate Cr evaporation rates from Cr 2 O 3 with a flat planar geometry. Variables include temperature, total pressure, gas velocity, and gas composition. The methodology was applied to solid oxide fuel cell conditions for metallic interconnects and to advanced steam turbines conditions. The high velocities and pressures of the advanced steam turbine led to evaporation predictions as high as 5.18 × 10 -8 kg/m 2 /s of CrO 2 (OH) 2 (g) at 760°C and 34.5 MPa. This is equivalent to 0.080 mm per year of solid Cr loss. Chromium evaporation is expected to be an important oxidation mechanism with the types of nickel-base alloys proposed for use above 650°C in advanced steam boilers and turbines. It is shown that laboratory experiments, with much lower steam velocities and usually much lower total pressure than found in advanced steam turbines, would best reproduce chromium evaporation behavior with atmospheres that approach either O 2 +H 2 O or Air+H 2 O with 57% H 2 O.

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Section: Introductionmentioning

confidence: 99%

Calculation of Reactive-evaporation Rates of Chromia

Holcomb

2008

Oxid Met

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“…Jianian et al 8 investigated the mechanism of breakaway oxidation in Fe-Cr alloys at 1173 K in wet oxygen, and they suggested that microchannels or microcracks in the initially formed Cr 2 O 3 scale enabled [9][10][11][12][13][14][15] . Asteman et al [14][15] reported that evaporation of chromia occurred during oxidation of Type 304L at 873 K in humid oxygen.…”

Section: Introductionmentioning

confidence: 99%

“…Asteman et al [14][15] reported that evaporation of chromia occurred during oxidation of Type 304L at 873 K in humid oxygen. They showed that the evaporation of chromia, probably in the form of CrO 2 OH 2 g , resulted in the conversion of a Cr-rich oxide scale into a nonprotective iron-rich oxide scale.…”

Section: Introductionmentioning

confidence: 99%

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Yamauchi

Kurokawa

Takahashi

2003

Oxidation of Metals

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“…Therefore, studying the influence of water vapor on Chromia-forming alloys oxidation at high temperature has great importance. Some works have been done to study the influence of water vapor on oxidation [1][2][3][4][5][6], and several mechanisms have been proposed to explain the influence of water vapor on oxidation, such as Fuji and Meussner [2] proposed a dissociation mechanism, and suggested that hydrogen appears to play an important role in the oxidation process as an oxygen carrier between the separated inner and outer scale layers. Shen Jianian [3] suggested that breakaway oxidation happened in the water vapor containing atmosphere is the result of formation of microcracks and microchannels during oxidation.…”

Section: Introductionmentioning

confidence: 99%

“…Shen Jianian [3] suggested that breakaway oxidation happened in the water vapor containing atmosphere is the result of formation of microcracks and microchannels during oxidation. H. Asteman [4,5] observed the evaporation of Chromia hydroxide. According to J. Ehlers the entry of molecular H 2 O into the oxide scale was the main process leading to breakaway oxidation [6].…”

Section: Introductionmentioning

confidence: 99%

Residual Stress Analysis on Oxide Layers Obtained by High Temperature Oxidation of Chromia-Forming Alloys

Xiao

Prudhomme

et al. 2016

Residual Stresses 2016

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Abstract:The oxide layers formed during high temperature oxidation of metallic alloys depend on experimental conditions (oxidation gas composition, gas pressure, temperature, duration etc…) and often with complex structure or multilayer structure. Residual stress can be generated not only dues to oxide growth at high temperature (growth stress) but also during cooling of layer/metallic alloy system after oxidation (thermal stress). The determination of the level and the distribution of the residual stresses in oxide layers are very important to determine the influence of oxidation condition in one hand and to estimate the mechanical component's durability at high temperature in the other hand. Two Chromia-forming alloys have been studied: a nickel based Inconel 600 alloy (Ni-17%Cr-8%Fe-1%Mn) and a ferritic AISI 430 steel (Fe-17%Cr-1%Mn). Oxidation test has been carried out at different temperatures (from 600°C to 900°C) for various durations (from 2 h to 96 h) under different absolute humilities (from 0% to 19%). After oxidation of Inconel 600, the oxide layers are composed essentially by an external NiO layer and by an internal spinel NiCr 2 O 4 layer. While the AISI 430 steel forms an external spinel Mn 1.5 Cr 1.5 O 4 layer and an internal Cr 2 O 3 layer. The residual stresses (RS) have been analyzed by X-Ray Diffraction (XRD) method in each of oxide layers after oxidation tests. In oxide layers, the RS are compressive and the RS levels are more important in internal layer than those in external layer. Overall, the compressive RS in oxide layers increase with oxidation temperature, oxidation duration and absolute humidity. IntroductionAt high temperature, almost all metals are not thermodynamically stable in air or in atmosphere where oxygen exists, and a solid oxide scale will form on the surface. Oxidation of Chromia-forming alloys has drawn lots of attention in recent years, for their good oxidation resistance and low cost. It is true that lots of studies have been done to study the oxidation behavior of Chromia-forming alloy in dry air, but humidity exists in all stages of oxidation in reality. Therefore, studying the influence of water vapor on Chromia-forming alloys oxidation at high temperature has great importance. Some works have been done to study the influence of water vapor on oxidation [1-6], and several mechanisms have been proposed to explain the influence of water vapor on oxidation, such as Fuji and Meussner [2] proposed a dissociation mechanism, and suggested that hydrogen appears to play an important role in the oxidation process as an oxygen carrier between the separated inner and outer scale layers. Shen Jianian [3] suggested that breakaway oxidation happened in the water vapor containing atmosphere is the result of formation of microcracks and microchannels during oxidation. H. Asteman [4,5] observed the evaporation of Chromia hydroxide. According to J. Ehlers the entry of molecular H 2 O into the oxide scale was the main process leading to breakaway oxidation [6]. Obviously, the mechanis...

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Cited by 267 publications

References 6 publications

Calculation of Reactive-evaporation Rates of Chromia

Calculation of Reactive-evaporation Rates of Chromia

Untitled

Residual Stress Analysis on Oxide Layers Obtained by High Temperature Oxidation of Chromia-Forming Alloys

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