| 1. |
- Chen, Zhuo Yuan, et al.
(author)
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Initial NaCl- Particle Induced Atmospheric Corrosion of Zinc-Effect of CO2 and SO2
- 2008
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 50:1, s. 111-123
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Journal article (peer-reviewed)abstract
- Initial corrosion and secondary spreading effects during NaCl particle induced corrosion on zinc was explored using in situ and ex situ FTIR microspectroscopy, optical microscopy, and SEM/EDAX. The secondary spreading effect which occurs upon introduction of humid air on NaCl deposited zinc surfaces was strongly dependent on the CO2 and SO2 content of the introduced air. Ambient level of CO2 (350 ppm) resulted in a relatively low spreading effect, whereas the lower level of CO2 (<5 ppm) caused a much faster spreading over a larger area. In the presence of SO2, the secondary spreading effect was absent which could limit the cathodic process in this case. At <5 ppm CO2, the corrosion is more localized, with the formation of simonkolleite (Zn5(OH)8Cl2 · H2O), zincite (ZnO) and sodium carbonate (Na2CO3), and a larger effective cathodic area. At 350 ppm CO2, the corrosion is more general and formation of simonkolleite, hydrozincite (Zn5(OH)6(CO3)2) and sodium carbonate was observed. Sodium carbonate was mainly formed in more alkaline areas, in the inner edge of the electrolyte droplet and in the secondary spreading area. Oxidation of sulphur and concomitant sulphate formation was enhanced in the presence of NaCl particles, due to the formation of a droplet, the separation of the anodic and cathodic areas and the accompanying differences in chemical composition and pH in the surface electrolyte.
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| 2. |
- Chiavari, C, et al.
(author)
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Atmospheric corrosion of historical organ pipes: The influence of environment and materials
- 2008
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In: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 50:9, s. 2444-2455
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Journal article (peer-reviewed)abstract
- The corrosion of lead-rich pipes in historical organs in different parts of Europe has been investigated. The influence of the environment and the composition and microstructure of the pipe metal was studied. Pipe Corrosion was documented by visual inspection (boroscope). The corrosion attack and the composition and microstructure of the metal were characterized by OM, SEM, XRD, IC and FAAS. It is shown that the degree of corrosion of the pipes is correlated to the concentration of gaseous acetic and formic acid in the organ. The organic acids are emitted by the wood from which the wind system is built. It is also shown that pipe corrosion decreases with increasing tin content in the range 0-4% (wt). Possible conservation strategies are discussed. (c) 2008 Elsevier Ltd. All rights reserved.
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| 3. |
- Cieślik, M., et al.
(author)
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Metal release and formation of surface precipitate at stainless steel grade 316 and Hanks solution interface : Inflammatory response and surface finishing effects
- 2009
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 51:5, s. 1157-1162
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Journal article (peer-reviewed)abstract
- The influence of surface finishing (polishing and passivation) on the release of Cr, Fe, Ni from the stainless steel 316 implant materials to Hanks solution with or without H2O2 (simulating a body inflammatory response) was investigated. The surfaces were characterized by means of SEM EDXS, XPS and Kelvin Probe measurements before and after exposure to the synthetic body fluids. The total metal ions release rates are more than 10 times higher in the presence of H2O2, independently of the surface finishing. In the absence of H2O2, formation of a surface layer consisting mainly of Ca3(PO4)2 was observed, most likely it was responsible for the observed decrease of the release rates. © 2009 Elsevier Ltd. All rights reserved.
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| 4. |
- Cordoba Gallego, Jose Manuel, et al.
(author)
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Morphology influence of the oxidation kinetics of carbon nanofibers
- 2009
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In: CORROSION SCIENCE. - : Elsevier BV. - 0010-938X. ; 51:4, s. 926-930
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Journal article (peer-reviewed)abstract
- This paper reports the stability and oxidation rate of five types of carbon nanofiber (CNF) with distinctly different orientation of their graphite sheets based on conversion to CO2 when heated in the presence of oxygen. A non-isothermal technique was used to determine the oxidation kinetic parameters including the activation energy (E-a) Graphite shows a similar activation energy (E-a = 158 kJ/mol(-1)) to CNF with longitudinal alignment (E-a = 156kJ/mol(-1)). CNF type herringbone (E-a = 126kJ/mol(-1)) and platelet (E-a = 145 kJ/mol(-1)) show the lowest oxidation resistance which improved dramatically after a heat treatment at 3023 K of the herringbone (E-a = 216 kJ/mol(-1)) and platelet (E-a = 174 kJ/mol(-1)) structures.
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| 5. |
- Dong, Q., et al.
(author)
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Platinum-catalyzed high temperature oxidation of metals
- 2007
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 49:8, s. 3348-3360
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Journal article (peer-reviewed)abstract
- Samples of At, Cr, Ni, and Zr were sputter-coated with porous Pt-films with a particle size of 20-30 nm. Thermal oxidation of these samples was studied by gas phase analysis (GPA) and secondary ion mass spectrometry (SIMS). SIMS analysis on partly Pt-coated samples of At, Cr, Ni, and Zr at different oxide depths in areas with Pt and in areas away from Pt indicates an enhanced inward oxide growth in the Pt area and mm-ranged distance from Pt-area. Weight gain measurements on Pt-coated Ni samples show a reduced or increased oxidation rate depending on the amount of porous Pt-coating. Pt has two effects on the thermal oxidation of metals and the overall effect of Pt on the oxidation of metals depends on the mechanism of oxide growth in the absence of Pt.
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| 6. |
- Herting, Gunilla, et al.
(author)
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Factors that influence the release of metals from stainless steels exposed to physiological media
- 2006
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 48:8, s. 2120-2132
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Journal article (peer-reviewed)abstract
- Release rates of chromium, nickel and iron from grade 304 stainless steel with three different surface finishes, BA, 2B and 2D, have been determined after exposure to artificial lysosomal fluid. Metal release rates are discussed in relation to corrosion resistance, compositional changes of the outermost surface film of the stainless steel and to measurements of the effective surface area and roughness. The total metal release decreased in the following sequence: 2D > 2B approximate to BA, and was primarily related to the electrochemically active surface area. No direct correlation was observed between corrosion resistance and metal release rates.
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| 7. |
- Herting, Gunilla, et al.
(author)
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Metal release from various grades of stainless steel exposed to synthetic body fluids
- 2007
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 49:1, s. 103-111
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Journal article (peer-reviewed)abstract
- Release rates of individual alloy constituents have been determined from seven grades of stainless steels exposed to two synthetic body fluids, used as surrogates for different areas of potential exposure in the lung: "Gamble's solution", (pH 7.4) that represents the interstitial fluid of the deep lung, and artificial lysosomal fluid (ALF) that represents the more acidic (pH 4.5-5) milieu of particles following their phagocytosis by macrophages. Total metal release rates from all grades of stainless steel investigated were low (< 5 mu g cm(-2) week(-1)). The more acidic environment of ALF resulted in significantly higher total metal release rates (0.3-4.6 mu g cm(-2) week(-1)) compared to Gamble's solution (< 0.1 mu g cm(-2) week(-1)).
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| 8. |
- Jayamani, Jayaraj, et al.
(author)
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Corrosion behaviour of Ni–Zr–Ti–Si–Sn amorphous plasma spray coating
- 2006
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 48:4, s. 950-964
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Journal article (peer-reviewed)abstract
- Ni59Zr20Ti16Si2Sn3 amorphous material was deposited by a vacuum plasma spraying technique onto steel and copper substrates in order to investigate their behaviour in a corrosive environment. For comparison, the same alloy was prepared as amorphous ribbons by melt spinning. The amorphous nature of the coatings and ribbons was characterized by XRD, DSC and TEM, while XPS and AES analyses were performed to understand the origin of passivation and mode of corrosion. The corrosion behaviour of the coating was studied in H2SO4 and HCl solutions open to air at room temperature. Potentiodynamic polarisation and galvanic coupling tests were carried out on the substrate and the coating. It was found that the formation of Zr-, Ti- and Si-rich passive oxide layers provide a high corrosion resistance in H2SO4 solution while the breakdown of the passive layer by chloride ion adsorption was responsible for pitting corrosion of the Ni59Zr20Ti16Si2Sn3 amorphous ribbons in HCl solution. Galvanic corrosion was the dominant corrosion mechanism for the coating/copper hybrid structure, in contrast to the Ni59Zr20Ti16Si2Sn3 amorphous coating, which efficiently protected the steel substrate in the corrosive environment.
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| 9. |
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| 10. |
- Jonsson, T., et al.
(author)
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An ESEM in situ investigation of the influence of H2O on iron oxidation at 500 degrees C
- 2009
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In: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 51:9, s. 1914-1924
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Journal article (peer-reviewed)abstract
- The initial oxidation of iron and the effect of different O-2/H2O mixtures have been investigated through ESEM in situ exposure and analysis at 500 degrees C. In dry and wet air a two-layered magnetite forms beneath a thin, fine-grained hematite layer. while only a two-layered magnetite forms in H2O. The two-layered magnetite is separated by a straight interface (in all environments), which is suggested to be the original metal surface. The presence of low levels of water vapour (similar to 1% H2O) produces a thicker hematite layer (compared to dry air), exhibiting a large number of whiskers. At least four different factors are suggested to influence the local growth rate: the surface of the metal grain, the thickness of the hematite layer, the oxide grain size and the exposure environment. The ESEM in situ exposures have in addition been shown to have high quality and reproducibility.
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