| 1. |
- Samie, Farid, et al.
(author)
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Atmospheric corrosion effects of HNO3—Influence of concentration and air velocity on laboratory-exposed copper
- 2006
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In: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 40:20, s. 3631-3639
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Journal article (peer-reviewed)abstract
- `A recently developed experimental set-up has been used to explore the atmospheric corrosion effects of nitric acid (HNO3) on copper, in particular the influence of concentration and air velocity. Characterization and quantification of the corrosion products on exposed samples were performed with Fourier transform infrared (FT-IR) microspectrocscopy, ion chromatography, X-ray diffraction (XRD), micro-balance and microscopy. At low air velocity (0.03 cm s(-1)) HNO3 deposition and weight gain of copper increased linearly with concentration Lip to 400 mu g m(-3) or 156 ppb. The influence of air velocity on corrosion of copper was tested within the range of 0.03-35.4 cm s(-1). Although the air velocity in this study was significantly lower than typical outdoor wind values, a high HNO3 concentration of the air velocity of 35.4 cm s(-1) resulted in a relatively high deposition velocity (V-d) of 0.9 cm s(-1) on the metal surface and 1.2 cm s(-1) on an ideal absorbent, which would imply a limiting deposition velocity on the copper surface (V-d,V-surf) of 3.6 cm s(-1). Results obtained in this study emphasize the importance for future research on the corrosion effects of HNO3 on materials as very little has so far been done in this field.
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| 2. |
- Samie, Farid, et al.
(author)
-
Atmospheric corrosion effects of HNO3—method development and results on laboratory-exposed copper
- 2005
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In: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 39:38, s. 7362-7373
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Journal article (peer-reviewed)abstract
- The effects of the atmospheric pollutant nitric acid (HNO3) on materials compared to other corrosive gases, e.g. sulphur dioxide (SO2), nitrogen dioxide (NO2) or ozone (O-3), have so far received little or no attention. The high sticking coefficient of HNO3 makes this gas one of the most difficult gases to work with. A new apparatus has now successfully been developed for studying the atmospheric corrosion effects of HNO3 Oil materials. HNO3 concentration measurements up to 1080 mu g m(-3) (420 ppb) were performed by dissolving the gas in water and analysing the nitrate concentration with ion chromatography (IC). Small changes in relative humidity (RH) largely affect the concentration of this pollutant in the exposure chamber and the high sticking coefficient of this gas on copper and quartz glass has been shown. The quartz glass surface, however, became saturated after a certain time of exposure and at 82% RH, the number of monolayers on the surface was estimated to be 10-13. Initial results of copper samples exposed to HNO3 show that at 63% RH and 25 degrees C, the deposition of HNO3 on copper is slightly lower than on a perfect absorber. The loss of HNO3 during exposure of the samples showed good agreement with the amount of nitrates dissolved from surfaces of the samples after exposure. FT-I R, XRD and IC analyses of copper exposed to HNO3 and mass loss and mass gain analyses confirmed cuprite (Cu2O) and the basic copper nitrate, gerhardtite, as the main corrosion products. Deposition, as well as the corrosion effect, of HNO3 on copper appeared to be greater than that of any of the other above-mentioned pollutants.
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| 3. |
- Samie, Farid, et al.
(author)
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Atomospheric corrosion effects on HNO3 - comparison of laboratory exposed copper, cinc and carbon steel
- 2007
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In: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 41:23, s. 4888-4896
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Journal article (peer-reviewed)abstract
- The effect of HNO3 on the atmospheric corrosion of copper has been investigated at varied temperature (15-35 degrees C) and relative humidity (0-85% RH). Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) confirmed the existence of cuprite and gerhardtite as the two main corrosion products on the exposed copper surface. For determination of the corrosion rate and for estimation of the deposition velocity (V-d) of HNO3 on copper, gravimetry and ion chromatography has been employed. Temperature had a low effect on the corrosion of copper. A minor decrease in the mass gain was observed as the temperature was increased to 35 degrees C, possibly as an effect of lower amount of cuprite due to a thinner adlayer on the metal surface at 35 degrees C. The V-d of HNO3 on copper, however, was unaffected by temperature. The corrosion rate and V-d of HNO3 on copper was the lowest at 0% RH, i. e. dry condition, and increased considerably when changing to 40% RH. A maximum was reached at 65% RH and the mass gain remained constant when the RH was increased to 85% RH. The V-d of HNO3 on copper at >= 65% RH, 25 degrees C and 0.03 cm s(-1) air velocity was as high as 0.15 +/- 0.03 cm s(-1) to be compared with the value obtained for an ideal absorbent, 0.19 +/- 0.02 cm s(-1). At sub-ppm levels of HN03, the corrosion rate of copper decreased after 14 d and the growth of the oxide levelled off after 7 d of exposure
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| 4. |
- Samie, Farid, et al.
(author)
-
Atomospheric corrosion effects on HNO3 - influence of temperature and relative humidity on laboratory exposed copper
- 2007
-
In: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 41:1, s. 1374-1382
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Journal article (peer-reviewed)abstract
- The effect of HNO3 on the atmospheric corrosion of copper has been investigated at varied temperature (15-35 degrees C) and relative humidity (0-85% RH). Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) confirmed the existence of cuprite and gerhardtite as the two main corrosion products on the exposed copper surface. For determination of the corrosion rate and for estimation of the deposition velocity (V-d) of HNO3 on copper, gravimetry and ion chromatography has been employed. Temperature had a low effect on the corrosion of copper. A minor decrease in the mass gain was observed as the temperature was increased to 35 degrees C, possibly as an effect of lower amount of cuprite due to a thinner adlayer on the metal surface at 35 degrees C. The V-d of HNO3 on copper, however, was unaffected by temperature. The corrosion rate and V-d of HNO3 on copper was the lowest at 0% RH, i. e. dry condition, and increased considerably when changing to 40% RH. A maximum was reached at 65% RH and the mass gain remained constant when the RH was increased to 85% RH. The V-d of HNO3 on copper at >= 65% RH, 25 degrees C and 0.03 cm s(-1) air velocity was as high as 0.15 +/- 0.03 cm s(-1) to be compared with the value obtained for an ideal absorbent, 0.19 +/- 0.02 cm s(-1). At sub-ppm levels of HN03, the corrosion rate of copper decreased after 14 d and the growth of the oxide levelled off after 7 d of exposure.
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| 5. |
- Tidblad, Johan
(author)
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Atmospheric corrosion of metals in 2010-2039 and 2070-2099
- 2012
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In: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 55, s. 1-6
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Journal article (peer-reviewed)abstract
- Climatic parameters and pollution data from the 6FP NOAHs ARK project 'Global Climate Change Impact on Built Heritage and Cultural Landscapes' together with chloride deposition data have been used to predict atmospheric corrosion of metals in 2010-2039 and 2070-2099. Maps of carbon steel and zinc show that future atmospheric corrosion of metals in Europe are dominated by the effects of chloride deposition in coastal and near-coastal areas. The change can in extreme cases be as high as one corrosivity category and in coastal areas of southern Europe corrosion can be higher than the highest values experienced today in Europe.
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