| 1. |
- Ahlström, Johan, et al.
(författare)
-
Electrochemical properties of oxide scale on steel exposed in saturated calcium hydroxide solutions with or without chlorides
- 2018
-
Ingår i: International Journal of Corrosion. - : Hindawi Limited. - 1687-9325 .- 1687-9333. ; 2018
-
Tidskriftsartikel (refereegranskat)abstract
- The electrochemical properties of various iron oxide scales on steel exposed in saturated calcium hydroxide solutions were investigated. The iron oxide scales were manufactured by different heat treatments and grinding processes and characterized using X-ray diffraction and scanning electron microscope. The electrochemical properties of the scales were assessed by measuring the corrosion potential and using electrochemical impedance spectroscopy and potentiodynamic polarization curves. It was found that wustite and magnetite are less noble compared to hematite but are more effective as cathodic surfaces. The results show that the electrochemical properties of the mill scale can be an important contributing factor in the corrosion of steel in concrete.
|
|
| 2. |
- Ahlström, Johan, et al.
(författare)
-
Galvanic corrosion properties of steel in water saturated concrete
- 2015
-
Ingår i: Materials and corrosion - Werkstoffe und Korrosion. - : Wiley. - 0947-5117 .- 1521-4176. ; 66:1, s. 67-75
-
Tidskriftsartikel (refereegranskat)abstract
- Aluminum-based sacrificial anodes were installed to reinforced concrete to stop ongoing corrosion in cooling water tunnels in a Swedish nuclear power plant. The steel rebars were also unintentionally connected to stainless steel water pumps. Therefore, the consumption rate of the sacrificial anodes was higher than predicted. An experimental and a field study were performed to assess if the steel rebar suffer from galvanic corrosion and if the stainless steel pumps are responsible alone for the high consumption rate. It was found from the experimental study that there is an increased risk of galvanic corrosion for steel rebar when the corrosion potential is raised to -200mV (SCE) for samples with 1% CL- by mass of cement and -500mV (SCE) for samples with 2% Cl- by mass of cement. The experimental results were compared with the corrosion potential measured in the cooling water tunnel where sacri ficial anodes were in use and not mounted at all. The cooling water tunnel without sacrificial anodes had generally more anodic corrosion potentials compared to the tunnel with anodes. The tunnel with anodes had also more anodic potentials closer to the stainless steel pumps than further away which means that the rebar is affected by the stainless steel pumps. However, the measured corrosion potentials in the tunnels were not as anodic as the potentials needed for high galvanic current measured in the experimental study.
|
|
| 3. |
- Ahlström, Johan, et al.
(författare)
-
Influence of chloride and moisture content on steel rebar corrosion in concrete
- 2016
-
Ingår i: Materials and corrosion - Werkstoffe und Korrosion. - : Wiley-VCH Verlag. - 0947-5117 .- 1521-4176. ; 67:10, s. 1049-1058
-
Tidskriftsartikel (refereegranskat)abstract
- Reinforced mortar samples were exposed in humidity chambers with different relative humidity or exposed in cyclic moisture conditions. The rebars were in an “as received” condition meaning that the preexisting oxide scale were intact. The lowest chloride concentration that initiated corrosion was 1% Cl− by mass of cement, corrosion was then observed for samples exposed at 97% relative humidity. It is suggested that the corrosion rate decreases when samples are exposed to a relative humidity lower than 97%. The results indicate that threshold levels should be evaluated at rather humid conditions (97%) despite the fact that the maximum corrosion rate at higher chloride levels is observed in the interval 91–94%. For samples exposed to cyclic moisture conditions, a lower chloride concentration was needed to initiate corrosion compared to samples exposed in static moisture conditions.
|
|
| 4. |
- Tidblad, Johan, et al.
(författare)
-
Atmospheric corrosion effects of air pollution on materials and cultural property in Kathmandu, Nepal
- 2015
-
Ingår i: Materials and corrosion - Werkstoffe und Korrosion. - : Wiley. - 0947-5117 .- 1521-4176. ; 67:2, s. 170-175
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon steel, zinc and limestone samples were exposed in Kathmandu for one year. Their corrosion was measured at ten locations and related to SO2, NO2, O3, HNO3 and PM concentrations and climatic factors. Corrosion rates vary considerably and are correlated mainly with the SO2 concentration. Estimated policy targets for SO2 are most stringent for limestone, in the range 3 to 6μgm-3. The Kathmandu carbon steel and limestone samples matched a general pattern from exposures at more than twenty sites in Asia and Africa. At these Asian/African sites corrosion of copper is generally higher than corrosion of zinc. This is in contrast to experiences from European conditions where corrosion of zinc is higher than corrosion of copper.
|
|
| 5. |
- Zavalis, Tommy, et al.
(författare)
-
Mechanistic Model with Empirical Pitting Onset Approach for Detailed and Efficient Virtual Analysis of Atmospheric Bimetallic Corrosion
- 2023
-
Ingår i: Materials. - : MDPI. - 1996-1944. ; 16:3
-
Tidskriftsartikel (refereegranskat)abstract
- A mechanistic model of atmospheric bimetallic corrosion with a simplified empirical approach to the onset of localized corrosion attacks is presented. The model was built for a typical bimetallic sample containing aluminum alloy 1050 and stainless steel 316L sheets. A strategy was developed that allowed the model to be calibrated against the measured galvanic current, geometrical corrosion attack properties, and corrosion products. The pitting-onset simplification sets all pits to be formed at a position near the nobler metal and treated all pits as being of the same shape and size. The position was based on the location of the highest pitting events and the pit attributes on an average of the deepest pits. For 5 h exposure at controlled RH (85%, 91%, and 97%) and salt load (86 μg NaCl/cm2), the model was shown to be promising: both for analysis of local bimetallic corrosion chemistry, such as pH and corrosion products, and for efficient assessment of pitting damage by computing a single largest pit depth. Parametric studies indicated that the pitting-onset approximation deviated the most at the beginning of exposure and when RH was below 91%. © 2023 by the authors.
|
|
| 6. |
- Bender, R., et al.
(författare)
-
Corrosion challenges towards a sustainable society
- 2022
-
Ingår i: Materials and corrosion - Werkstoffe und Korrosion. - : Wiley. - 0947-5117 .- 1521-4176. ; 73:11, s. 1730-1751
-
Tidskriftsartikel (refereegranskat)abstract
- A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate-resilient energy systems and infrastructures brings with it a long-term direction, so as a result the long-term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind “Corrosion Challenges Towards a Sustainable Society” presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics.
|
|
| 7. |
- Christodoulakis, John, et al.
(författare)
-
Impacts of air pollution and climate on materials in Athens, Greece
- 2017
-
Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 17:1, s. 439-448
-
Tidskriftsartikel (refereegranskat)abstract
- For more than 10 years now the National and Kapodistrian University of Athens, Greece, has contributed to the UNECE (United Nations Economic Commission for Europe) ICP Materials (International Co-operative Programme on Effects on Materials including Historic and Cultural Monuments) programme for monitoring the corrosion/soiling levels of different kinds of materials due to environmental air-quality parameters. In this paper we present the results obtained from the analysis of observational data that were collected in Athens during the period 2003-2012. According to these results, the corrosion/soiling of the particular exposed materials tends to decrease over the years, except for the case of copper. Based on this long experimental database that is applicable to the multi-pollutant situation in the Athens basin, we present dose-response functions (DRFs) considering that "dose" stands for the air pollutant concentration, "response" for the material mass loss (normally per annum) and "function", the relationship derived by the best statistical fit to the data.
|
|
| 8. |
- Gil, Harveth, et al.
(författare)
-
GILDES Model Simulations of the Atmospheric Corrosion of Copper Induced by Low Concentrations of Carboxylic Acids
- 2011
-
Ingår i: Journal of the Electrochemical Society. - : ECS. - 0013-4651 .- 1945-7111. ; 158:12, s. C429-C438
-
Tidskriftsartikel (refereegranskat)abstract
- A computer simulation with a GILDES-based model using the COMSOL multiphysics software was performed for copper exposedto low concentrations of carboxylic acids in humidified air at room temperature. GILDES is a six-regime computer model (Gas,the Interface between gas and liquid, the Liquid, the Deposition layer, the Electrodic region near the surface and the Solid). Thesimulations were compared to previously published in-situ results for copper at the same conditions analysed by a quartz crystalmicrobalance (QCM) and infrared reflection absorption spectroscopy (IRAS). Experimental and calculated results agree with eachother with respect to the effect of corrosion, showing formic acid as the most aggressive followed by acetic and propionic acid.This is supported by a higher ligand- and proton-promoted dissolution found in formic acid exposures, followed by acetic andpropionic exposures. The dominating precipitated phases were Cu2O, Cu(OH)2, Cu(CH3COO)2 · H2O, Cu(HCOO)2 · 4H2O andCu(CH3CH2COO)2 · H2O. Besides Cu2O, the simulations suggest that the hydrated form of the respective carboxylates is the mostlikely compound to be formed in this type of atmospheres.
|
|
| 9. |
- Gil, Harveth, et al.
(författare)
-
GILDES model simulations of the atmospheric corrosion of zinc induced by low concentrations of carboxylic acids
- 2012
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 159:3, s. C123-C128
-
Tidskriftsartikel (refereegranskat)abstract
- The GILDES computer based model was successfully applied to the atmospheric corrosion of zinc exposed to low concentrations of carboxylic acids in humidified air at room temperature. Under these exposure conditions the expected precipitated phases are zinc oxide (ZnO), zinc hydroxide (Zn(OH)(2)) and several forms of hydrated zinc carboxylate, Zn(CH3CH2COO)(2) center dot 2H(2)O, Zn(CH3COO)(2) center dot 2H(2)O and Zn(HCOO)(2) center dot 2H(2)O. The results were compared to those from laboratory exposures obtained in the same conditions. The model correctly predicts the trend for ZnO and zinc carboxylate formation found in experimental exposures for the three acids tested. According to the simulations, surface protonation, surface acid base reactions, as well as ligand- and proton-induced dissolution reactions play a major role in the initial atmospheric corrosion of zinc. Henry's law constant (K-H) is found to be an important parameter but uncertain due to different reported literature values. When K-H is increased the formation rate of zinc carboxylate also increases. K-H increases in the sequence propionic acid < acetic acid < formic acid, the same order as found for the calculated dissolution rate.
|
|
| 10. |
- Gil, Harveth, 1978-
(författare)
-
The initial atmospheric corrosion of copper and zinc induced by carboxylic acids : Quantitative in situ analysis and computer simulations
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Degradation of metals through atmospheric corrosion is a most important and costly phenomenon with significant effects on, e.g., the lifespan of industrial materials, the reliability of electronic components and military equipment, and the aesthetic appearance of our cultural heritage. Atmospheric corrosion is the result of the interaction between the metal and its atmospheric environment, and occurs in the presence of a thin aqueous adlayer. The common incorporation of pollutant species into this adlayer usually enhances the degradation process. During atmospheric corrosion indoors, low concentrations of organic atmospheric constituents, such as formic, acetic, propionic, butyric and oxalic acids, have found to play an accelerating role on a broad range of metals or their alloys, including lead, steel, nickel, copper, cadmium, magnesium and zinc. In this doctoral thesis the initial stages of the atmospheric corrosion of copper exposed to synthetic air, aiming at simulating representative indoor atmospheric environments, have been investigated both experimentally and through a computational method. The experiments have been based on a unique analytical setup in which a quartz crystal microbalance (QCM) was integrated with infrared reflection absorption spectroscopy (IRAS). This enabled the initial atmospheric corrosion of copper to be analyzed during ongoing corrosion in humidified air at room temperature and additions of 120 ppb (parts per volume billions) of acetic, formic or propionic acid. The main phases identified were copper (I) oxide (Cu2O) and various forms of copper carboxylate, and their amounts deduced with the different analytical techniques agree with a relative accuracy of 12% or better. Particular emphasis has been on the identification of different forms of copper (I) oxide generated during these exposures. An electrochemically based model has been proposed to describe how copper oxides, formed in the presence of acetic acid, are electrochemically reduced in neutral solution. The model includes the electrochemical reduction of copper (II) oxide (CuO), amorphous copper (I) oxide (Cu2O)am, intermediate copper (I) oxide (Cu2O)in, and crystalline copper (I) oxide (Cu2O)cr. A good agreement is obtained between the model and experimental data, which supports the idea of a reduction sequence which starts with copper (II) oxide and continues with the reduction of the three copper (I) oxides at more negative potentials. The quantified analytical data obtained in this doctoral study on corrosion products formed on copper, and corresponding data on zinc reported elsewhere, were used as the starting point to develop a computational model, GILDES, that describes the atmospheric corrosion processes involved. GILDES considers the whole interfacial regime in which all known chemical reactions have been considered which are assumed to govern the initial atmospheric corrosion of copper or zinc in the presence of carboxylic acids. The model includes two separate pathways, a proton-induced dissolution of cuprous ions or zinc ions followed by the formation of either copper (I) oxide or zinc (II) oxide, and a carboxylate-induced dissolution followed by the formation of either copper (II) carboxylate or zinc (II) carboxylate. The model succeeds to predict the two main phases in the corrosion products and a correct ranking of aggressiveness of the three acids for both copper and zinc. The ranking has been attributed to differences in acid dissociation constant and deposition velocity of the carboxylic acids investigated.
|
|
| 11. |
- Grøntoft, Terje, et al.
(författare)
-
Cleaning costs for European sheltered white painted steel and modern glass surfaces due to air pollution since the year 2000
- 2019
-
Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 10:4
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports estimated maintenance-cleaning costs, cost savings and cleaning interval increases for structural surfaces and windows in Europe obtainable by reducing the air pollution. Methodology and data from the ICP-materials project were used. The average present (2018) cleaning costs for sheltered white painted steel surfaces and modern glass due to air pollution over background, was estimated to be ~2.5 Euro/m 2 ·year. Hypothetical 50% reduction in the air pollution was found to give savings in these cleaning costs of ~1.5 Euro/m 2 ·year. Observed reduction in the air pollution, from 2002-2005 until 2011-2014, have probably increased the cleaning interval for white painted steel with ~100% (from 12 to 24 years), representing reductions in the single intervention cleaning costs from 7 to 4%/year (= % of one cleaning investment, per year during the cleaning interval) and for the modern glass with ~65% (from 0.85 to 1.3 years), representing reductions in the cleaning cost from 124 to 95%/year. The cleaning cost reductions, obtainable by 50% reduction in air pollution, would have been ~3 %/year for white painted steel and ~60%/year for the modern glass, representing ~100 and 50% additional cleaning interval increases. These potential cleaning cost savings are significantly higher than previously reported for the weathering of Portland limestone ornament and zinc monuments.
|
|
| 12. |
- Irwin, J., et al.
(författare)
-
Air quality policy
- 2009
-
Ingår i: The Effects of Air Pollution on Cultural Heritage. - Boston, MA : Springer US. - 9780387848921 ; , s. 269-295
-
Bokkapitel (refereegranskat)abstract
- There are two main ways to protect cultural heritage objects from air pollution damage. First, by reducing ambient levels of air pollution and second, by instigating local management strategies that either reduce the impact of pollution or repair the damage.
|
|
| 13. |
- Kucera, Vladimir, et al.
(författare)
-
Development of atmospheric corrosion in the changing pollution and climate situation
- 2008
-
Ingår i: 17th International Corrosion Congress 2008: Corrosion Control in the Service of Society. - 9781615674251 ; , s. 1877-1891
-
Konferensbidrag (refereegranskat)abstract
- During a long time SO 2 has been the most important pollutant accelerating atmospheric corrosion of several materials including objects of cultural heritage. The quantification of the effect of pollution has been subject of several projects performed in the last decades in Europe and Northern America ( ICP Materials and MULTI-ASSESS) and in Asia and Southern Africa (RAPIDC). Data from these programmes show that the S-pollution has decreased dramatically in the industrial countries of the temperate zone, while the SO 2 levels are high in several places in the RAPIDC network. Dose-response functions (DRF) have been developed for the new multipollutant situation in the temperate zone containing apart of SO 2 and pH also HNO 3 and particulate matter. The results from temperate zone can not directly be used in subtropical/tropical regions. Recent data will allow development of DRF:s for these regions. The developed DRF:s contain apart of pollution also climatic parameters used in climate change models and they have been used in the NOAHś ARK project for estimations of effects of global climate changes on atmospheric corrosion in Europe. © 2009 by NACE International.
|
|
| 14. |
- Nordänger, Svante, et al.
(författare)
-
Accelerated corrosion testing - A qualification method for field testing?
- 2017
-
Ingår i: Corrosion Management. - : Square One Advertising and Design Limited. - 1355-5243. ; 2017-January:135, s. 13-16
-
Tidskriftsartikel (refereegranskat)abstract
- Accelerated corrosion test methods have been used for a long time to predict performance of coating systems in real applications. These methods have also been used for qualifying individual systems, and for benchmarking different systems in particular applications. Different accelerated methods have been developed over the years depending on which branch of the industry, or company in which they are used. Results from accelerated corrosion testing of paint systems, including pretreatments are described and compared to field testing for 18, 30 and 43 months in a marine atmosphere. Most of the paint systems and pretreatments tested are classified as relatively new, and environmentally friendly.
|
|
| 15. |
- Parker, JL, et al.
(författare)
-
Plasma modification of mica
- 1990
-
Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 134, s. 449-458
-
Tidskriftsartikel (refereegranskat)abstract
- When mica is exposed to a low temperature nonpolymer-forming plasma the surface structure is altered by a combination of sputtering and chemical reaction with reactive species in the plasma. The chemical composition of the surface is altered without a significant increase in surface roughness under optimal conditions. The effect of the plasma process parameters (exposure time, power, flow rate, and pressure) on the extent of surface modification has been investigated by means of ESCA and contact angle measurements. After exposure to water vapor plasma the mica surface becomes reactive to silanation with chlorosilanes in the gas phase. The durability of mica surfaces modified by plasma treatment and subsequent reaction with some chlorosilanes has been investigated. The forces between water plasmatreated surfaces after silanation have been measured using a surface force apparatus.
|
|
| 16. |
- Rosales, B.M., et al.
(författare)
-
Atmospheric corrosion
- 2012
-
Ingår i: International Journal of Corrosion. - : Hindawi Limited. - 1687-9325 .- 1687-9333. ; 2012
-
Tidskriftsartikel (refereegranskat)
|
|
| 17. |
- Samie, Farid, et al.
(författare)
-
Atmospheric corrosion effects of HNO3—Influence of concentration and air velocity on laboratory-exposed copper
- 2006
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 40:20, s. 3631-3639
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 18. |
- Samie, Farid, et al.
(författare)
-
Atmospheric corrosion effects of HNO3—method development and results on laboratory-exposed copper
- 2005
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 39:38, s. 7362-7373
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 19. |
- Samie, Farid, et al.
(författare)
-
Atomospheric corrosion effects on HNO3 - a comparison of laboratory and field exposed copper, zinc and carbon steel
- 2007
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 154:5, s. C249-C254
-
Tidskriftsartikel (refereegranskat)abstract
- The present trends with decreasing ambient SO2 levels and unchanged HNO3 levels has resulted in an increased interest in HNO3 as a corrosive pollutant. Despite the fact that ambient SO2 levels are still in general much higher than HNO3 levels, this study shows that HNO3 plays a significant role for the atmospheric corrosion of copper and zinc but not for carbon steel. A comparison of laboratory and field corrosion effects of HNO3 on copper, zinc, and carbon steel is presented. The quantitative agreement between extrapolated laboratory results and field results are good for both copper and zinc and the total corrosion effect can be represented by the sum of two contributions; one from HNO3 and one from remaining corrosion stimulators, including SO2. However, an extrapolation of laboratory results of HNO3-induced corrosion of carbon steel resulted in corrosion effects much lower than the total effect observed in the field. The field data used for comparison are from the international projects model for multipollutant impact and assessment of threshold levels for cultural heritage, with 29 sites in Europe, and Regional Air Pollution in Developing Countries with 12 sites in Asia and 4 in Africa.
|
|
| 20. |
- Samie, Farid, et al.
(författare)
-
Atomospheric corrosion effects on HNO3 - comparison of laboratory exposed copper, cinc and carbon steel
- 2007
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 41:23, s. 4888-4896
-
Tidskriftsartikel (refereegranskat)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
|
|
| 21. |
- Samie, Farid, et al.
(författare)
-
Atomospheric corrosion effects on HNO3 - influence of temperature and relative humidity on laboratory exposed copper
- 2007
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 41:1, s. 1374-1382
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 22. |
|
|
| 23. |
- Tidblad, Johan
(författare)
-
Air Pollution Damage to Metals
- 2015
-
Ingår i: Urban Pollution and Changes to Materials and Building Surfaces. - : IMPERIAL COLLEGE PRESS. - 9781783268856 ; , s. 143-164
-
Bokkapitel (refereegranskat)
|
|
| 24. |
- Tidblad, Johan, et al.
(författare)
-
Atmospheric corrosion effects of air pollution on materials and cultural property in Asia and Africa
- 2008
-
Ingår i: 17th International Corrosion Congress 2008: Corrosion Control in the Service of Society. - 9781615674251 ; , s. 703-716
-
Konferensbidrag (refereegranskat)abstract
- This project is part of the Swedish International Development Co-operation Agency (Sida) funded Program on Regional Air Pollution in Developing Countries (RAPIDC). The Program is managed on Sida's behalf by the Stockholm Environment Institute (SEI) and the corrosion project is coordinated by Swerea KIMAB AB. Corrosion attack after one (2002-2003 and 2005-2006), two (2002-2004) and four (2002-2006) years of exposure are presented for 12 test sites in Asia (India, Vietnam, Thailand, Malaysia, and China including Hong Kong) and four test sites in Africa (South Africa, Zambia and Zimbabwe). Materials exposed are carbon steel, zinc, copper, limestone and paint coated steel. At each test site, the environment is characterized by SO 2, NO 2, HNO 3, O 3, particles, amount and pH of precipitation, temperature and relative humidity. Preliminary results are also given from the enlargement of the network (2006-) by inclusion of five new test sites in Asia (Taj Mahal/India, Iran, Nepal, Sri Lanka and Maldives) and two new test sites in Africa (Mozambique and Tanzania). SO 2 is the most important parameter but acid rain is also important for all materials while HNO 3 show correlation to corrosion of zinc and limestone, much similar to the situation in Europe. Attempts to predict corrosion values using dose-response functions developed in Europe have failed, especially for limestone. © 2009 by NACE International.
|
|
| 25. |
- Tidblad, Johan
(författare)
-
Atmospheric corrosion of heritage metallic artefacts: Processes and prevention
- 2013
-
Ingår i: Corrosion and Conservation of Cultural Heritage Metallic Artefacts. - : Elsevier Ltd. - 9781782421542 ; , s. 37-52
-
Bokkapitel (refereegranskat)abstract
- This chapter focuses primarily on the common environmental aspects of atmospheric metal corrosion. The effects of climate and pollution on corrosion are reviewed across various timescales, from damage over millennia to the present situation, including short descriptions of the indoor environment and recent developments in international standardisation. The chapter concludes with two sections on future trends in air pollution and climate change. © 2013 Copyright ũ 2013 Woodhead Publishing Limited All rights reserved.
|
|
| 26. |
- Tidblad, Johan
(författare)
-
Atmospheric corrosion of metals in 2010-2039 and 2070-2099
- 2012
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 55, s. 1-6
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 27. |
- Tidblad, Johan, et al.
(författare)
-
Corrosion
- 2009
-
Ingår i: The Effects of Air Pollution on Cultural Heritage. - Boston, MA : Springer US. - 9780387848921 ; , s. 53-103
-
Bokkapitel (refereegranskat)abstract
- Corrosion is a familiar concept-as familiar as the rusting of steel left outside or the green patina of an old copper roof. Corrosion attack is normally seen as a non-desirable effect that causes a loss of aesthetic value and mechanical strength, although many find the patina attractive. This chapter takes those simple concepts and expands them to present the actual mechanisms involved and to relate them to what is happening in the atmosphere. © 2009 Springer-Verlag US.
|
|
| 28. |
- Tidblad, Johan, et al.
(författare)
-
Effects of air pollution on materials and cultural heritage : ICP materials celebrates 25 years of research
- 2012
-
Ingår i: International Journal of Corrosion. - : Hindawi Limited. - 1687-9325 .- 1687-9333. ; 2012
-
Forskningsöversikt (refereegranskat)abstract
- An overview is given of all results from the International Co-operative Programme on Effects on Materials including Historic and Cultural Monuments (ICP Materials), which was launched in 1985. Since then, about twenty different materials have been exposed repeatedly in a network of test sites consisting of more than twenty sites with an extensive environmental characterisation and more than sixty official reports have been issued. Recent results on trends in corrosion, soiling, and pollution show that corrosion of carbon steel, zinc, and limestone is today substantially lower than 25 years ago, but while corrosion of carbon steel has decreased until today, corrosion of zinc and limestone has remained more or less constant since the turn of the century. Unique data are given on measured HNO3 concentrations from 2002-2003, 2005-2006, and 2008-2009, and the relative average decrease was about the same from 2002-2003 to 2005-2006 as it was from 2005-2006 to 2008-2009.
|
|
| 29. |
- Tidblad, Johan, et al.
(författare)
-
ICP materials trends in corrosion, soiling and air pollution (1987-2014)
- 2017
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 10:8
-
Tidskriftsartikel (refereegranskat)abstract
- Results from the international cooperative programme on effects on materials including historic and cultural monuments are presented from the period 1987-2014 and include pollution data (SO2, NO2, O3, HNO3 and PM10), corrosion data (carbon steel, weathering steel, zinc, copper, aluminium and limestone) and data on the soiling of modern glass for nineteen industrial, urban and rural test sites in Europe. Both one-year and four-year corrosion data are presented. Corrosion and pollution have decreased significantly and a shift in the magnitude is generally observed around 1997: from a sharp decrease to a more modest decrease or to a constant level without any decrease. SO2 levels, carbon steel and copper corrosion have decreased even after 1997, which is more pronounced in urban areas, while corrosion of the other materials shows no decrease after 1997, when looking at one-year values. When looking at four-year values, however, there is a significant decrease after 1997 for zinc, which is not evident when looking at the one-year values. This paper also presents results on corrosion kinetics by comparison of one- and four-year values. For carbon steel and copper, kinetics is relatively independent of sites while other materials, especially zinc, show substantial variation in kinetics for the first four years, which needs to be considered when producing new and possibly improved models for corrosion. © 2017 by the authors.
|
|
| 30. |
- Tidblad Lundmark, Sonja, 1966, et al.
(författare)
-
Outer Rotor High Torque Density PM Motors with a Peripheral Position Sensor
- 2016
-
Ingår i: Proceedings 22nd International Conference on Electrical Machines, ICEM 2016. Lausanne; Switzerland; 4-7 September 2016. - 9781509025381 ; , s. 858-864
-
Konferensbidrag (refereegranskat)abstract
- Abstract –A survey of mainly outer rotor permanent magnet(PM) motors, suitable for a patented sensor technology sensing the leakage field from the permanent magnets, is performed with a specified target of high torque density. One motor, known to yield high torque density is used as a reference motor; an electric bike transverse flux motor. Its simulated and measured results are compared with other PM motors such as the axial flux motor, the Vernier motor and flux switching motors. Academic, simulated designs as well as industry developed and manufactured designs are considered. It is found that the reference motor is coming out as a good choice for motors with similar weight and size. Those outer rotor motors that have higher torque density than the reference motor are larger than the reference motor and/or need liquid cooling.
|
|
| 31. |
- Vinka, Tor-Gunnar, et al.
(författare)
-
Korrosion på metaller i kloridhaltig atmosfär på Bohus-Malmön
- 2013
-
Rapport (refereegranskat)abstract
- Rapporten redogör för en exponering under ett år av två olika provtagare för mätning av kloriddeponering och metaller på Bohus-Malmön under perioden 2008-2009. Syftet med exponeringen var att jämföra de två metoderna för kloriddeponering och föreslå den mest lämpliga för framtida mätningar och ta fram systematiska data för korrosion av olika bruksmetaller på platser på Bohus-Malmön med varierande kloridhalt och avstånd från havet. De två metoder som använts för kloriddeponering är ”wet candle”, bestående av en veke med strumpa i kontakt med en lösning av glycerol, samt en provtagare bestående av ett teflonfilter rullat kring en cylinder. Den stora skillnaden mellan de båda metoderna är att ”wet candle” hela tiden är våt medan den passiva provtagaren kan vara torr eller våt, beroende på den omgivande luftens fuktighet. Månadsvisa mätningar har genomförts på tre olika platser på Bohus-Malmön med ett avstånd från havet mellan 50 och 350 m. Båda metoderna och alla tre mätplatserna, totalt sex mätserier visar i stort sett samma årstidsvariation. Den största deponeringen skedde under augusti - oktober och dessa tre månader stod tillsammans för 60 % av den totala kloriddeponeringen. Totalt sett ger dock teflonfiltret systematiskt låga värden på kloriddeponering och kan inte ersätta wet candle i den nuvarande utformningen. Det systematiska felet kan bero på mindre deponering på teflonfiltret, eftersom detta inte alltid är fuktigt, eller på att tidigare deponerad klorid blåses bort av starka vindar. Systematiska data för korrosion av kolstål, koppar, zink, förzinkat stål, och tre olika aluminiumsorter har uppmätts på fem olika platser på Bohus-Malmön med varierande kloridhalt och avstånd från havet. Databasen kan användas för att undersöka inverkan av avstånd från havet samt för att jämföra olika materials känslighet för kloriddeponering. Kloriddeponeringen har det starkaste sambandet med avstånd från havet, varje 100 m i ökat avstånd från havet resulterar i en ungefärlig halvering av kloriddeponeringen. För korrosionen är sambandet betydligt svagare men tydligast för kolstål, koppar och aluminium Al 1050A, följt av zink och Al 3003 och sist förzinkat stål och Al 6063 som praktiskt taget har ingen avklingning alls med avstånd från havet. Uppmätta korrosionshastigheterna för kolstål, zink, koppar och aluminium för första året exponering har jämförts med beräknade korrosionshastigheter med ekvationer i svensk standard SS-EN ISO 9223:2012. De beräknade korrosionshastigheterna var högre än de uppmätta förutom för koppar där uppmätt korrosionshastighet var högre än den beräknade närmast havet.
|
|
| 32. |
|
|
