| 1. |
- Airiskallio, E., et al.
(author)
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High temperature oxidation of Fe-Al and Fe-Cr-Al alloys : The role of Cr as a chemically active element
- 2010
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 52:10, s. 3394-3404
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Journal article (peer-reviewed)abstract
- Good high-temperature corrosion resistance of Fe-Al alloys in oxidizing environments is due to the alpha-Al2O3 film which is formed on the surface provided temperature is above 900 degrees C and the Al-content of the alloy exceeds the critical value. Ab initio calculations combined with experiments on Fe-13Al, Fe-18Al, Fe-23Al and Fe-10Cr-10Al alloys show that the beneficial effect of Cr on the oxidation resistance is significantly related to bulk effects. The comparison of experimental and calculated results indicates a clear correlation between the Fe-Cr chemical potential difference and the formation of the protective oxide scales. (C) 2010 Elsevier Ltd. All rights reserved.
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| 2. |
- Alvarez-Asencio, Ruben, et al.
(author)
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Role of microstructure on corrosion initiation of an experimental tool alloy : A Quantitative Nanomechanical Property Mapping study
- 2014
-
In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 89, s. 236-241
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Journal article (peer-reviewed)abstract
- The adhesion properties of a FeCrVN experimental tool alloy immersed in pure water and sodium chloride solution have been studied by Quantitative Nanomechanical Property Mapping to understand the influence of microstructure on corrosion initiation of this alloy. The approach used here allows early observation and identification of pre-pitting events that may lead to passivity breakdown of the alloy. Adhesion provides a good distinction between the different regions and we ascribe this to their vanadium and nitrogen contents. Finally, the prepitting is characterized by generation of small particles in specific regions of the surface with low chromium content.
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| 3. |
- Binbin, Song, et al.
(author)
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Oxidation properties of self-propagating high temperature synthesized niobium disilicide
- 2014
-
In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 85, s. 311-317
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Journal article (peer-reviewed)abstract
- NbSi2 monoliths were prepared by self-propagating high temperature synthesis (SHS) and hot pressing (HP) and their oxidation behavior was investigated at various temperatures (823-1123 K) in air. The combustion mode of SHS reaction was steady state combustion, and the combustion product was single-phase NbSi2. Oxidation studies show that the highest mass gain was 0.95675 kg m(-2) at 1023 K. In cyclic oxidation, the oxidation rate was reduced and the mass gain was only 0.15507 kg m(-2). A dense protective amorphous SiO2 scale formed at 823 K and 923 K whereas a porous multilayer SiO2 and alpha/beta-Nb2O5 oxide scales formed at and above 1023 K and spalled off. Pest oxidation of NbSi2 monoliths was not observed in hot pressed NbSi2 monoliths.
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| 4. |
- Cieslik, Monika, et al.
(author)
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Silane-parylene coating for improving corrosion resistance of stainless steel 316L implant material
- 2011
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In: Corrosion Science. - : Elsevier. - 0010-938X .- 1879-0496. ; 53:1, s. 296-301
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Journal article (peer-reviewed)abstract
- The corrosion resistance of a two-layer polymer (silane + parylene) coating on implant stainless steel was investigated by microscopic observations and electrochemical measurements Long term exposure tests in Hanks solution revealed that the coating of 2 mu m can be successfully used for corrosion protection However the addition of H2O2 simulating the inflammatory response of human body environment causes a dramatic destruction of the protective coating Analysis of the experimental data in terms of circuit models enables proposing a deterioration mechanism OH radicals formed at the metal surface attack the polymer thus the deterioration starts from the metal/polymer interface and progress towards the outward surface.
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| 5. |
- Cruchley, S, et al.
(author)
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Chromia layer growth on a Ni-based superalloy: Sub-parabolic kinetics and the role of titanium
- 2013
-
In: Corrosion Science. - : Elsevier. - 0010-938X .- 1879-0496. ; 75, s. 58-66
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Journal article (peer-reviewed)abstract
- Oxidation of the Ni-based superalloy RR1000 has been undertaken in air over the temperature range 600-900 degrees C for times up to 5000 h. The surface oxide consisted of a protective Ti-doped chromia layer but with rutile forming on its outer surface. Sub-surface oxidation of Al and Ti also occurred. The thickening kinetics of the chromia layer were sub-parabolic with initial rates around two orders of magnitude higher than expected for Ti-free chromia. This enhancement and the sub-parabolic kinetics are accounted for by Ti-doping of the chromia layer. Over time the enhancement reduced because of Ti-depletion in the alloy.
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| 6. |
- Diler, Erwan, et al.
(author)
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Characterization of corrosion products of Zn and Zn-Mg-Al coated steel in a marine atmosphere
- 2014
-
In: Corrosion Science. - : Elsevier Ltd. - 0010-938X .- 1879-0496. ; 87, s. 111-117
-
Journal article (peer-reviewed)abstract
- The corrosion behaviour of pure zinc and zinc-magnesium-aluminium alloy (ZMA) has been studied during 6months of exposure in marine environment (Brest, France). The composition of corrosion products is analysed using infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). An improved corrosion resistance of ZMA is observed. This improvement is found to be connected to Mg2+ and Al3+ induced quenching of corrosion activity and to the enhancement of NaZn4Cl(OH)6SO4·6H2O in the formed corrosion product.
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| 7. |
- Diler, Erwan, et al.
(author)
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Chemistry of corrosion products of Zn and MgZn pure phases under atmospheric conditions
- 2012
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 65, s. 178-186
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Journal article (peer-reviewed)abstract
- We present a corrosion behaviour study of pure phases of zinc and zinc-magnesium contaminated with NaCl and exposed to humid air for 30days: Zn, Mg 2Zn 11 and MgZn 2. The composition of corrosion products is analysed using infrared spectroscopy (FTIR), X-ray diffraction (XRD), ion chromatography (IC), and X-ray photoelectron spectroscopy (XPS). The improved corrosion stability of MgZn 2 is found to be connected to changes in the surface pH and to the nature of the formed corrosion products. The presence of magnesium modifies the proportion of the OH and CO 3 bonds in the corroded products. This explains the improvement in corrosion resistance.
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| 8. |
- Diler, Erwan, et al.
(author)
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Initial formation of corrosion products on pure zinc and MgZn2 examinated by XPS
- 2014
-
In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 79, s. 83-88
-
Journal article (peer-reviewed)abstract
- A corrosion behaviour study of pure phases of zinc and zinc-magnesium (MgZn2) exposed to humid air at 35°C for 4days is presented. For zinc, hydroxide formation at the surface and zinc oxide in the first innerlayers is observed. The corrosion of the MgZn2 leads to the segregation of magnesium at the surface to mainly form magnesium hydroxycarbonate: the presence of magnesium modifies the corrosion products. At larger depths, metallic zinc coexists with magnesium oxide and hydrozincite. The higher reactivity of MgZn2 alloy can be attributed to the interaction with carbonate ions.
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| 9. |
- Fredriksson, Wendy, 1980-, et al.
(author)
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Corrosion Resistances and Passivation of Powder Metallurgical and Conventionally Cast 316L and 2205 Stainless Steels
- 2013
-
In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 67, s. 268-280
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Journal article (peer-reviewed)abstract
- The corrosion resistances and passivation of austenitic 316L and duplex 2205 powder metallurgical (P/M) steels, produced by employing gas atomizing and hot isostatic pressing (HIP), have been compared with those of their conventional cast and forged counterparts. The P/M 316L steel is shown to have a significantly higher pitting corrosion resistance than the conventional 316L steel in 0.5 M HCl. Since the chemical composition and the total amount of inclusions were analogous for the two steels, the effect is ascribed to the finer grained microstructure for the P/M 316L steel yielding a better passive layer. This is supported by photoelectron spectroscopy data demonstrating differences between the thickness and composition of the passive layers for the two 316 L steels. Differences in the passivation process were also found for the different steels as three mixed potentials were observed in the polarization curves for the P/M and conventional 316L steels whereas only one mixed potential at about +0.7 V vs. Ag/AgCl was observed for the two duplex steels in 0.5 M HCl. The results indicate that discussions of the shapes of polarization curves and mixed potentials should be based on the anodic and cathodic partial currents, including the reduction of oxygen. HIP:ed P/M steels are clearly well-suited for applications requiring high pitting corrosion resistances.
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| 10. |
- Fredriksson, Wendy, et al.
(author)
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XPS analysis of manganese in stainless steel passive films on 1.4432 and the lean duplex 1.4162
- 2010
-
In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 52:7, s. 2505-2510
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Journal article (peer-reviewed)abstract
- Passive films were compared on two stainless steels: the recent lean duplex EN 1.4162 and EN 1.4432 (316L). For alloys with significant amount of manganese and nickel, the Mn 2p(3/2) peak will overlap with the Ni-LMM. To resolve this overlap, Ni 2p(3/2) to Ni-LMM intensity ratios were recorded on 1.4432, compensated for overlayer thickness, and then used to fix the Ni-LMM intensities in the Mn 2p spectra on the duplex material. Manganese was found in oxidation states II and V/VI: its film content was not dependent on the bulk composition. (C) 2010 Elsevier Ltd. All rights reserved.
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