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Hultquist, Gunnar; Tveten, Bent; Hörnlund, Erik; Limbäck, Magnus; Haugsrud, Reidar

doi:10.1023/a:1010380913380

Cited by 56 publications

(46 citation statements)

References 16 publications

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“…Using isotopically labelled oxygen Hultquist et al [20,21] have shown that the direction of oxide growth can be influenced by adding certain substances to the oxide surface, (e.g. rare-earth oxides and Pt).…”

Section: Discussionmentioning

confidence: 99%

The Effect of Traces of SO2 on Iron Oxidation: A Microstructural Study

et al. 2007

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Pure iron has been exposed to pure O 2 and O 2 with 100 ppm SO 2 at 525°C for 1 and 24 h. The samples were investigated by FIB, SEM, TEM, EDX and EBSD. The oxide scales formed on iron at 525°C in O 2 and in O 2 + 100 ppm SO 2 are dense and adherent and consist of three layers. The outermost layer consists of hematite. Beneath it there is a duplex-magnetite scale. The two magnetite layers are separated by a straight interface. It is concluded that the inner-magnetite layer grows inward while the outer magnetite layer grows outwards. In the presence of SO 2 the inner-magnetite layer is much thinner, iron sulphate forms at the oxide surface and discrete iron sulphide grains nucleate at the metal/oxide interface. The amount of sulphide at the metal/oxide interface increases with exposure time. The oxidation of iron in oxygen at 525°C is inhibited by 100 ppm SO 2 . The inhibitive effect of SO 2 is attributed to iron sulphate that blocks active sites on the hematite surface, slowing down the formation of oxygen ions. This explains the strong inhibition of the inward growth of magnetite by SO 2 . There is also a marked effect on the morphology of the outer oxide, producing hematite whisker growth and a less porous surface in the presence of SO 2 .

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Section: Discussionmentioning

confidence: 99%

The Effect of Traces of SO2 on Iron Oxidation: A Microstructural Study

et al. 2007

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“…Recently, a new family of AFA stainless steels with a promising combination of mechanical properties and oxidation resistance has been developed at Oak Ridge National Laboratory (ORNL) [4, 8,9]. These ORNL AFA alloys are based on Fe- (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)Ni-(12-15)Cr-(2.5-4)Al-(0.6-3)Nb-0.1C weight percent (wt%), have balanced levels of Al, Cr, and Ni to maintain a single phase austenitic matrix microstructure, and utilize MC-base precipitates (M primarily Nb) for creep strength. The compromises adopted to balance mechanical properties with oxidation resistance in these alloys result in a limited temperature range for protective alumina scale formation [8].…”

Section: Introductionmentioning

confidence: 99%

Increasing the Upper Temperature Oxidation Limit of Alumina Forming Austenitic Stainless Steels in Air with Water Vapor

et al. 2011

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A family of alumina-forming austenitic (AFA) stainless steels is under development for use in aggressive oxidizing conditions from *600-900°C. These alloys exhibit promising mechanical properties but oxidation resistance in air with water vapor environments is currently limited to *800°C due to a transition from external protective alumina scale formation to internal oxidation of aluminum with increasing temperature. The oxidation behavior of a series of AFA alloys was systematically studied as a function of Cr, Si, Al, C, and B additions in an effort to provide a basis to increase the upper-temperature oxidation limit. Oxidation exposures were conducted in air with 10% water vapor environments from 800-1000°C, with post oxidation characterization of the 900°C exposed samples by electron probe microanalysis (EPMA), scanning and transmission electron microscopy, and photo-stimulated luminescence spectroscopy (PSLS). Increased levels of Al, C, and B additions were found to increase the upper-temperature oxidation limit in air with water vapor to between 950 and 1000°C. These findings are discussed in terms of alloy microstructure and possible gettering of hydrogen from water vapor at second phase carbide and boride precipitates.

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“…[10][11][12] Another theory is that the hydrogen released when oxides are formed may itself affect the oxidation behavior. [5,13] It is obvious from the above that the water content affects the oxidation behavior in long-term service, but the question of oxidation during production annealing and the effect of water on processability remain to be clarified. Processability in this case mainly refers to the pickling step.…”

Section: Introductionmentioning

confidence: 99%

Fast and Efficient Annealing of Stainless Steel Strip Using Oxyfuel Burners

Lindell

Ekman

Pettersson

2014

steel research int.

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Pilot plant and annealing experiments have been conducted to study the effect of the higher water content in oxyfuel annealing on oxidation and pickling of cold rolled stainless steel. The experiments were conducted on the austenitic grade AISI 304 in a propane-fired furnace using air and pure oxygen as oxidizers. The experiments were conducted at 1050-1200 8C for typically less than 60 s, in order to simulate industrial annealing of thin strip. Supplementary laboratory annealing trials were made to study the evolution of the microstructure during fast heating rates and short hold times. Increasing the water content from 15 to 50 mol% did not alter the oxidation kinetics or the chemistry of the oxide. Since the oxidation is not altered significantly, the pickling performance of the material remains unchanged. The presence of spalled areas increased the pickling efficiency significantly but this was only seen for material annealed at higher temperature compared to industrial practice. Oxyfuel combustion allows higher heat input and therefore faster heating. The 304 grade recrystallizes readily even at moderate cold rolling reductions so the total annealing time can be reduced substantially if the heating rate can be increased. The present work suggests that this can be done without any downstream effects.

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Cited by 56 publications

References 16 publications

The Effect of Traces of SO2 on Iron Oxidation: A Microstructural Study

The Effect of Traces of SO2 on Iron Oxidation: A Microstructural Study

Increasing the Upper Temperature Oxidation Limit of Alumina Forming Austenitic Stainless Steels in Air with Water Vapor

Fast and Efficient Annealing of Stainless Steel Strip Using Oxyfuel Burners

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