WorldWideScience

Sample records for atmospheric corrosivity maps

  1. Corrosivity maps of Spain for zinc in rural atmospheres; Mapas de Espana de corrosividad del zinc en atmosferas rurales

    Energy Technology Data Exchange (ETDEWEB)

    Chico, B.; Fuente, D. de la,; Vega, J.M.; Morcillo, M.

    2010-07-01

    Atmospheric corrosivity maps provide useful information on the extent of atmospheric corrosion phenomena in a given geographic scope. The preparation of such maps helps designers to select the most suitable metallic material in terms of corrosion resistance and economy and to define the right type of protection for a given durability. This is a difficult task, due to the numerous climate-related factors upon which atmospheric corrosion depends. This work summarizes a funded project by BP Solar to develop atmospheric corrosivity maps of Spain for zinc considering both annual corrosion and long term (15 years) corrosion, which will determine the protection required for the metal structures used in photovoltaic systems, for practically pollution-free rural atmospheres. The method used has been to apply dose/response equations (damage functions) to estimate the corrosion rate as a function of meteorological variables. These variables have been obtained from information of meteorological stations placed in mainland Spain. (Author). 11 refs.

  2. Atmospheric corrosion mapping of copper surfaces from diffuse light scattering measurements by an optoelectronic sensor system

    Institute of Scientific and Technical Information of China (English)

    Marimuthu PAULVANNA NAYAKI; Arunachalam P. KABILAN

    2009-01-01

    A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.

  3. Investigation on Atmospheric Corrosiveness in Hainan Province

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    According to the results of four-year exposure tests for carbon steel samples in Hainan province, the influences of meteorological factors and Cl- on atmospheric corrosion were investigated. The feature of atmospheric corrosion in this area was summarized. A corrosive map for the area was drawn. The corrosion products on carbon steel at some typical places were analyzed by XRD and XPS.

  4. Development of regional corrosion maps for galvanized steel by linking the RADM engineering model with an atmospheric corrosion model

    Science.gov (United States)

    Spence, John W.; McHenry, John N.

    Annual corrosion rates for galvanized steel standard panels were estimated for eastern North America and part of southern Canada using the Regional Acid Deposition Model Engineering Model Model (ACM). The galvanized steel ACM examines the contributions of wet and dry deposition, including anthropogenic and naturally occurring atmospheric species to galvanized steel structure corrosion. The results show agreement between model-predicted and field-measured annual corrosion rates of galvanized steel panel except for an exposure site located in up-state New York. Further comparison of corrosion rates showed some spatial disagreement of the relative contributions to the individual corrosion processes, particularly for the New York site. In addition, RADM EM MM-4 was used to predict the change in ambient sulfur (S) concentrations and hydrogen ion deposition from a hypothetical uniform 50°, reduction in S emissions. Using the ACM, the effects of the emission reduction on the annually estimated corrosion rates were modeled. The results show a beneficial reduction in regional corrosion rates estimated annually. However, due to nonlinearities associated with wet and dry deposition, the corrosion rates decline in a less than 1:1 proportion to the emissions reduction.

  5. A virtual instrument based on lightwave scattering by surfaces for real-time mapping of atmospheric corrosion of metals

    Science.gov (United States)

    Kabilan, Arunachalam P.; Paulvanna Nayaki, Marimuthu; Sathiyanarayanan, Sadagopan

    2005-02-01

    The present work reports the design and implementation of an optical-sensor based virtual instrument for visualizing and estimating the degree of corrosion of metal surfaces exposed to atmosphere. A platform carrying the specimen plates was driven by a stepper motor assembly horizontally in XY directions. An opto-electronic transmitter-receiver unit was fixed vertically very close to the platform so that the sample surfaces may be scanned by a light beam. The reflected and scattered optical signals from each point in the scanned area were acquired by the sensor module. A parameter incorporating the relative values of these signals proved to be a fairly reliable measure of the surface texture, which in turn consistently represented the degree of corrosion. These signals interfaced with a personal computer enabled 3D visualization of the magnitude of the corrosion level of the surface and 2D mapping of the surface corrosion.

  6. Evaluation of atmospheric corrosion in Orizaba, Mexico

    OpenAIRE

    J. L. RAMÍREZ-REYES; J. URUCHURTU-CHAVARÍN; J. Genescá; R. Longoria-Ramírez

    2012-01-01

    This study evaluated the atmospheric aggressiveness in the city of Orizaba, Veracruz, Mexico, as part of the Atmospheric corrosiveness map of the state of Veracruz project, developed by Universidad Veracruzana from 2007 to 2008. The corrosiveness in marine, industrial and rural environments was determined with the standard method of bolt and wire, and the corrosion levels throughout flat samples of mild steel, galvanized steel, copper and aluminum in accordance to ISO 9223. The corrosion prod...

  7. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, Manuel; Fuente, Daniel de la; Díaz Ocaña, Iván; Cano, Heidis

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morpholog...

  8. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; I. Díaz; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  9. Atmospheric corrosion of mild steel

    Directory of Open Access Journals (Sweden)

    Morcillo, M.

    2011-10-01

    Full Text Available The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a the morphology of steel corrosion products and corrosion product layers; and b long-term atmospheric corrosion ( > 10 years.

    La corrosión atmosférica del acero suave es un tema de gran amplitud que ha sido tratado por muchos autores en numerosas regiones del mundo. Este artículo de compilación incorpora publicaciones relevantes sobre esta temática, en particular sobre la naturaleza de los productos de corrosión atmosférica, mecanismos y cinética de los procesos de corrosión atmosférica, prestando una atención especial a dos aspectos sobre los que la información publicada ha sido menos abundante: a morfología de los productos de corrosión del acero y capas de productos de corrosión, y b corrosión atmosférica a larga duración (> 10 años.

  10. Electrochemical Measurement of Atmospheric Corrosion

    Science.gov (United States)

    DeArmond, Anna H.; Davis, Dennis D.; Beeson, Harold D.

    1999-01-01

    Corrosion of Shuttle thruster components in atmospheres containing high concentrations of nitrogen tetroxide (NTO) and water is an important issue in ground operations of bipropellant systems in humid locations. Measurements of the corrosivities of NTO-containing atmospheres and the responses of different materials to these atmospheres have been accomplished using an electrochemical sensor. The sensor is composed of alternating aluminum/titanium strips separated by thin insulating layers. Under high humidity conditions a thin film of water covers the surface of the sensor. Added NTO vapor reacts with the water film to form a conductive medium and establishes a galvanic cell. The current from this cell can be integrated with respect to time and related to the corrosion activity. The surface layer formed from humid air/NTO reacts in the same way as an aqueous solution of nitric acid. Nitric acid is generally considered an important agent in NTO corrosion situations. The aluminum/titanium sensor is unresponsive to dry air, responds slightly to humid air (> 75% RH), and responds strongly to the combination of humid air and NTO. The sensor response is a power function (n = 2) of the NTO concentration. The sensor does not respond to NTO in dry air. The response of other materials in this type of sensor is related to position of the material in a galvanic series in aqueous nitric acid. The concept and operation of this electrochemical corrosion measurement is being applied to other corrosive atmospheric contaminants such as hydrogen chloride, hydrogen fluoride, sulfur dioxide, and acidic aerosols.

  11. Corrosion Cost and Corrosion Map of Korea - Based on the Data from 2005 to 2010

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. S.; Lim, H. K. [Andong National University, Andong (Korea, Republic of); Kim, J. J. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Hwang, W. S. [Inha University, Incheon (Korea, Republic of); Park, Y. S. [Yonsei University, Seoul (Korea, Republic of)

    2011-04-15

    Corrosion of metallic materials occurs by the reaction with corrosive environment such as atmosphere, marine, soil, urban, high temperature etc. In general, reduction of thickness and cracking and degradation are resulted from corrosion. Corrosion in all industrial facilities and infrastructure causes large economic losses as well as a large number of accidents. Economic loss by corrosion has been reported to be nearly 1-6% of GNP or GDP. In order to reduce corrosion damage of industrial facilities, corrosion map as well as a systematic investigation of the loss of corrosion in each industrial sector is needed. The Corrosion Science Society of Korea in collaboration with 15 universities and institutes has started to survey on the cost of corrosion and corrosion map of Korea since 2005. This work presents the results of the survey on cost of corrosion by Uhlig, Hoar, and input-output methods, and the evaluation of atmospheric corrosion rate of carbon steel, weathering steel, galvanized steel, copper, and aluminum in Korea. The total corrosion cost was estimated in terms of the percentage of the GDP of industry sectors and the total GDP of Korea. According to the result of Input/output method, corrosion cost of Korea was calculated as 2.9% to GDP (2005). Time of wetness was shown to be categories 3 to 4 in all exposure areas. A definite seasonal difference was observed in Korea. In summer and fall, time of wetness was higher than in other seasons. Because of short exposure period (12 months), significant corrosion trends depending upon materials and exposure corrosion environments were not revealed even though increased mass loss and decreased corrosion rate by exposure time.

  12. Corrosion Cost and Corrosion Map of Korea - Based on the Data from 2005 to 2010

    International Nuclear Information System (INIS)

    Corrosion of metallic materials occurs by the reaction with corrosive environment such as atmosphere, marine, soil, urban, high temperature etc. In general, reduction of thickness and cracking and degradation are resulted from corrosion. Corrosion in all industrial facilities and infrastructure causes large economic losses as well as a large number of accidents. Economic loss by corrosion has been reported to be nearly 1-6% of GNP or GDP. In order to reduce corrosion damage of industrial facilities, corrosion map as well as a systematic investigation of the loss of corrosion in each industrial sector is needed. The Corrosion Science Society of Korea in collaboration with 15 universities and institutes has started to survey on the cost of corrosion and corrosion map of Korea since 2005. This work presents the results of the survey on cost of corrosion by Uhlig, Hoar, and input-output methods, and the evaluation of atmospheric corrosion rate of carbon steel, weathering steel, galvanized steel, copper, and aluminum in Korea. The total corrosion cost was estimated in terms of the percentage of the GDP of industry sectors and the total GDP of Korea. According to the result of Input/output method, corrosion cost of Korea was calculated as 2.9% to GDP (2005). Time of wetness was shown to be categories 3 to 4 in all exposure areas. A definite seasonal difference was observed in Korea. In summer and fall, time of wetness was higher than in other seasons. Because of short exposure period (12 months), significant corrosion trends depending upon materials and exposure corrosion environments were not revealed even though increased mass loss and decreased corrosion rate by exposure time

  13. Atmospheric corrosion in nuclear waste storage

    International Nuclear Information System (INIS)

    The following topics were dealt with: storage of conditioned radioactive wastes in metallic containers, atmospheric corrosion effects, long-term behavior prediction, numerical modelling of surface corrosion effects under thermohygrometric fluctuations according ISO/DIS 9223

  14. Marine atmospheric corrosion of carbon steels

    OpenAIRE

    Morcillo, Manuel; Alcántara, Jenifer; Díaz, Iván; Chico, Belén; Simancas, Joaquín; de la Fuente, Daniel

    2015-01-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products...

  15. Atmospheric corrosion of mild steel. Pt. II. Marine atmospheres

    International Nuclear Information System (INIS)

    This paper summarizes the results obtained in the MICAT project for mild steel specimens exposed for 1 to 4 years in 47 marine atmospheres in the Ibero-American region. All these atmospheres were characterized for climatology, pollution and corrosion rates according to ISO standards. Complementary morphological and chemical characterization of the steel corrosion product layers (SCPLs) formed in these atmospheres was carried out. The overall analysis of results contributes to understanding, in a systematic way, how atmospheric corrosivity categories can be correlated with corrosion mechanisms. Special aspects of the atmospheres, from pure to mixed marine, were considered. (orig.)

  16. Atmospheric corrosion in the Gulf of Mexico

    International Nuclear Information System (INIS)

    The corrosion products on steels exposed at two sites in Campeche, Mexico and one site at Kure Beach, USA, have been investigated to determine the extent to which different marine conditions and exposure times control the oxide formation. The corroded coupons were analyzed by Moessbauer, Raman and infrared spectroscopy as well as X-ray diffraction, in order to completely identify the oxides and map their location in the corrosion coating. The coating compositions were determined by Moessbauer spectroscopy using a new parameter, the relative recoilless fraction (F-value) which gives the atomic fraction of iron in each oxide phase from the Moessbauer sub-spectral areas. For short exposure times, less than three months, an amorphous oxyhydroxide was detected after which a predominance of lepidocrocite (γ-FeOOH), and akaganeite (β-FeOOH) were observed in the corrosion coatings with the fraction of the later phase increasing at sites with higher atmospheric chloride concentrations. The analysis also showed that small clusters of magnetite (Fe3O4), and maghemite (γ(Fe2O3), were seen in the micro-Raman spectra but were not always identified by Moessbauer spectroscopy. For longer exposure times, goethite (α-FeOOH), was also identified but little or no β-FeOOH was observed. It was determined by the Raman analysis that the corrosion products generally consisted of inner and outer layers. The protective layer, which acted as a barrier to slow further corrosion, consisted of the α-FeOOH and nano-sized γ-Fe2O3 phases and corresponded to the inner layer close to the steel substrate. The outer layer was formed from high γ-FeOOH and low α-FeOOH concentrations

  17. Development of a geographical information system for risk mapping of reinforced concrete buildings subjected to atmospheric corrosion in Cyprus using optical remote sensing data

    Science.gov (United States)

    Neocleous, Kyriacos; Agapiou, Athos; Christofe, Andreas; Themistocleous, Kyriacos; Achillides, Zenon; Panayiotou, Marilia; Hadjimitsis, Diofantos G.

    2014-08-01

    Concrete reinforced with steel rebars remains one of the most widely used construction materials. Despite its excellent mechanical performance and expected service life of at least 50 years, reinforced concrete is subjected to corrosion of the steel rebars which normally leads to concrete spalling, deterioration of the reinforced concrete's (RC) mechanical properties and eventual reduction of the structural load capacity. In Cyprus, especially in coastal regions where almost 60% of the population resides, many structural problems have been identified in RC structures, which are mainly caused by the severe corrosion of steel rebars. Most RC buildings, located in coastal areas, show signs of corrosion within the first 15-20 years of their service life and this affects their structural integrity and reliability, especially against seismic loading. This paper presents the research undertaken as part of the STEELCOR project which aims to extensively evaluate the steel corrosion of RC buildings in coastal areas of Cyprus and conduct a risk assessment relating to steel corrosion. Non-destructive testing of corroded RC structures measurements were used to estimate the simplified index of structural damage. These indices were imported into a Geographical Information System to develop a digital structural integrity map of Cyprus which would show the areas with high risk of steel corrosion of RC buildings. In addition, archive optical remote sensing dataset was used to map the urban expansion footprint during the last 30 years in Cyprus with the aim of undertaking corrosion risk scenarios by utilizing the estimated indices.

  18. Atmospheric corrosion model and monitor for low cost solar arrays

    Science.gov (United States)

    Kaelble, D. H.; Mansfeld, F. B.; Jeanjaquet, S. L.; Kendig, M.

    1981-01-01

    An atmospheric corrosion model and corrosion monitoring system has been developed for low cost solar arrays (LSA). The corrosion model predicts that corrosion rate is the product of the surface condensation probability of water vapor and the diffusion controlled corrosion current. This corrosion model is verified by simultaneous monitoring of weather conditions and corrosion rates at the solar array test site at Mead, Nebraska.

  19. Atmospheric corrosion of structural materials in Poland

    International Nuclear Information System (INIS)

    The paper presents investigations of the effects of aggressive atmospheric corrosion agents on the progress of corrosion of metal structure materials: carbon steel, zinc, copper and aluminium. The tests were performed at the corrosion stations according standards: ISO 9223:1992; ISO 9224:1992; ISO 9225:1992; ISO 9226:1992; ISO 8565:1992. As the result of 8 years of experience were determined main atmospheric factors influencing corrosion rates of the several standard metals. It was shown that except factors discussed in the standard ISO 9223:1992 (sulfur dioxide, time of wetness and chloride ion deposition) ozone play a main part in corrosion rates. Ozone accelerates particularly the corrosion of copper, however steel and aluminium too. (author)

  20. Marine atmospheric corrosion of carbon steels

    International Nuclear Information System (INIS)

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  1. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  2. Estimating of a stationary metal atmospheric corrosion rate

    International Nuclear Information System (INIS)

    A function determining stabilized rate of atmospheric corrosion of ferrous and nonferrous metals is suggested. The calculated value of stabilized corrosion rate is used as a standard one for evaluating corrosion resistance of metals in different atmospheric conditions

  3. Atmospheric corrosion of uranium-carbon alloys

    International Nuclear Information System (INIS)

    The authors study the corrosion of uranium-carbon alloys having compositions close to that of the mono-carbide; they show that the extent of the observed corrosion effects increases with the water vapour content of the surrounding gas and they conclude that the atmospheric corrosion of these alloys is due essentially to the humidity of the air, the effect of the oxygen being very slight at room temperature. They show that the optimum conditions for preserving U-C alloys are either a vacuum or a perfectly dry argon atmosphere. The authors have also established that the type of corrosion involved is a corrosion which 'cracks under stress' and is transgranular (it can also be intergranular in the case of sub-stoichiometric alloys). They propose, finally, two hypotheses for explaining this mechanism, one of which is illustrated by the existence, at the fissure interface, of corrosion products which can play the role of 'corners' in the mono-carbide grains. (authors)

  4. Atmospheric corrosion of mild steel in Oman

    Science.gov (United States)

    Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Mossbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  5. Atmospheric corrosion of mild steel in Oman

    International Nuclear Information System (INIS)

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  6. Atmospheric corrosion of mild steel in Oman

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, Abbasher, E-mail: abbasher@squ.edu.om; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K. [College of Science, Department of Physics (Oman)

    2006-01-15

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  7. Review: Introduction to atmospheric corrosion research in China

    OpenAIRE

    Junhua Dong, Enhou Han and Wei Ke

    2007-01-01

    In this paper, we introduce the research on atmospheric corrosion in China. We describe the climate characteristics and the classification of atmospheric corrosivity across the whole country. We also describe the rusting evolution under simulated wet/dry cyclic conditions.

  8. Inhibition of corrosive processes in wet atmosphere

    International Nuclear Information System (INIS)

    Toluylalanine (TALA) is an additive in industrial cleaning baths and an effective temporary inhibitor of the corrosion of steel in neutral and weak alkaline electrolytes as well as in wet atmosphere. In dependence on the relative humidity of the atmosphere and the presence of hygroscopic salts, thin water films condense. The interaction between the metallic surface and the condensed liquid depends strongly on the surface tension. In our case we obtained a hydrophilic effect after the adsorption of the inhibitor. It can be assumed, that the water of the cleaning bath drains off the metal much better than in the case of hydrophobic layers. These effects in the range of monolayers could be studied with the quartz microbalance due to the high sensitivity of this technique. Improving our model, we obtained a lower and homogenous deposition of salt after the dipping in solution with TALA, which causes also a reduced homogenous condensation of water. Thus, corrosive attacks become less probable. The reactions in the cleaning bath and in films of condensed water were investigated by electrochemical methods in bulk electrolytes. In the presence of inhibitor the corrosion potential was shifted into the anodic direction, simultaneously the thickness of the oxide layer was increased in the presence of TALA. The characteristic data of pitting corrosion were obtained from anodic potentiodynamic sweeps. These results show, that pitting is hindered by TALA. Besides the stabilization of the passive layer, the growth of pits is also inhibited and repassivation is accelerated. From the polarization of probes precorroded at wet atmosphere we yielded in solutions with TALA an re-inhibition, too. Additionally we observed in unprotected solutions the sensitivity of this method to active corrosion centers, which cause pitting at lower overvoltages

  9. Atmospheric corrosion of metals in 2010-2039 and 2070-2099

    Science.gov (United States)

    Tidblad, Johan

    2012-08-01

    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.

  10. Atmospheric corrosion of metals in industrial city environment

    OpenAIRE

    Elzbieta Kusmierek; Ewa Chrzescijanska

    2015-01-01

    Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the s...

  11. Marine atmospheric corrosion of carbon steels

    Directory of Open Access Journals (Sweden)

    Morcillo, Manuel

    2015-06-01

    Full Text Available Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a environmental conditions necessary for akaganeite formation; (b characterisation of akaganeite in the corrosion products formed; (c corrosion mechanisms of carbon steel in marine atmospheres; (d exfoliation of rust layers formed in highly aggressive marine atmospheres; (e long-term corrosion rate prediction; and (f behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camariñas, Galicia in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM/energy dispersive spectrometry (EDS, X-ray diffraction (XRD, Mössbauer spectroscopy and SEM/μRaman spectroscopy.La investigación fundamental en corrosión atmosférica marina de aceros al carbono es un campo científico relativamente joven que presenta grandes lagunas de conocimiento. La formación de akaganeíta en los productos de corrosión que se forman sobre el acero cuando se expone a atmósferas marinas conduce a un incremento notable de la velocidad de corrosión. En el trabajo se abordan las siguientes cuestiones: (a condiciones ambientales necesarias para la formación de akaganeíta, (b caracterización de la akaganeíta en los productos de corrosión formados, (c mecanismos de corrosión del acero al carbono en atmósferas marinas, (d exfoliación de las capas de herrumbre formadas en atmósferas marinas muy agresivas, (e predicción de la velocidad de corrosión a largo plazo, y (f comportamiento de aceros patinables. La

  12. Atmospheric corrosion of carbon steel in the prairie regions

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, W.J. [Calgary Univ., AB (Canada). Dept. of Mechanical and Manufacturing Engineering; Andersson, J.I. [Husky Oil Operations Ltd., Calgary, AB (Canada)

    2010-07-01

    A study of atmospheric corrosion and carbon steel located in the prairie regions of Canada was presented. The study considered corrosion behaviour as well as the standards currently used to establish and predict corrosion in atmospheric conditions. The aim of the study was to develop an accurate predictive method of establishing corrosion amounts over time. The controlling parameters for atmospheric corrosion included acidic rainfall; temperature and humidity; time of wetness; and the presence of major contaminants such as sulfur dioxide (SO{sub 2}). The predictive approach involved the study of a protective film of magnetite iron oxide that establishes itself on carbon steel over time. The presence of the film provides increased atmospheric corrosion resistance. An analysis of the atmospheric corrosion of steel tanks at the Hardisty terminal was used to demonstrate the method. 22 refs., 5 tabs., 7 figs.

  13. Atmospheric corrosion of metals in industrial city environment.

    Science.gov (United States)

    Kusmierek, Elzbieta; Chrzescijanska, Ewa

    2015-06-01

    Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust. PMID:26217736

  14. Atmospheric corrosion of metals in industrial city environment

    Directory of Open Access Journals (Sweden)

    Elzbieta Kusmierek

    2015-06-01

    Full Text Available Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.

  15. Kinetics of atmospheric corrosion of mild steel in marine and rural environments

    Science.gov (United States)

    Palraj, S.; Selvaraj, M.; Maruthan, K.; Natesan, M.

    2015-03-01

    In continuation of the extensive studies carried out to update the corrosion map of India, in this study, the degradation of mild steel by air pollutants was studied at 16 different locations from Nagore to Ammanichatram along the east coast of Tamilnadu, India over a period of two years. The weight loss study showed that the mild steel corrosion was more at Nagapattinam site, when compared to Ammanichatram and Maravakadu sites. A linear regression analysis of the experimental data was attempted to predict the mechanism of the corrosion. The composition of the corrosion products formed on the mild steel surfaces was identified by XRD technique. The corrosion rate values obtained are discussed in the light of the weathering parameters, atmospheric pollutants such as salt content & SO2 levels in the atmosphere, corrosion products formed on the mild steel surfaces.

  16. Use of the gold markers method to predict the mechanisms of iron atmospheric corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E., E-mail: emilien.burger@cea.f [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Aqueuse, F-91191 Gif-sur-Yvette (France); CEA, DSM, IRAMIS, SIS2M, Laboratoire, Archeomateriaux et revision de l' Alteration, UMR3299, F-91191 Gif-sur-Yvette (France); Fenart, M.; Perrin, S. [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Aqueuse, F-91191 Gif-sur-Yvette (France); Neff, D. [CEA, DSM, IRAMIS, SIS2M, Laboratoire, Archeomateriaux et revision de l' Alteration, UMR3299, F-91191 Gif-sur-Yvette (France); Dillmann, P. [CEA, DSM, IRAMIS, SIS2M, Laboratoire, Archeomateriaux et revision de l' Alteration, UMR3299, F-91191 Gif-sur-Yvette (France); LMC IRAMAT UMR5060 CNRS (France)

    2011-06-15

    Highlights: {yields} Corrosion mechanisms investigated by gold markers method coupled with microRaman imaging. {yields} Experimental highlighting of an important internal development of the rust layer. {yields} Microstructural evolution of the corrosion product layer during atmospheric treatment. {yields} Comparison with long-term corrosion layer microstructure. - Abstract: Iron corrosion under atmospheric conditions has been investigated by using the gold markers method. The corrosion experiments were performed in a climatic chamber with an accelerated treatment. The gold markers localization, carried out by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, revealed that the rust layer growth was essentially due to an internal development. Moreover, microRaman mappings allowed prediction of the mechanism of rust layer evolution during the ageing treatment. Finally these results were compared to samples corroded for several 100 years in order to extrapolate our observations to long term corrosion.

  17. Use of the gold markers method to predict the mechanisms of iron atmospheric corrosion

    International Nuclear Information System (INIS)

    Highlights: → Corrosion mechanisms investigated by gold markers method coupled with microRaman imaging. → Experimental highlighting of an important internal development of the rust layer. → Microstructural evolution of the corrosion product layer during atmospheric treatment. → Comparison with long-term corrosion layer microstructure. - Abstract: Iron corrosion under atmospheric conditions has been investigated by using the gold markers method. The corrosion experiments were performed in a climatic chamber with an accelerated treatment. The gold markers localization, carried out by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, revealed that the rust layer growth was essentially due to an internal development. Moreover, microRaman mappings allowed prediction of the mechanism of rust layer evolution during the ageing treatment. Finally these results were compared to samples corroded for several 100 years in order to extrapolate our observations to long term corrosion.

  18. Kinetics of Atmospheric Corrosion of Mild Steel in Marine and Rural Environments

    Institute of Scientific and Technical Information of China (English)

    S. Palraj; M.Selvaraj; K.Maruthan; M.Natesan

    2015-01-01

    In continuation of the extensive studies carried out to update the corrosion map of India, in this study, the degradation of mild steel by air pollutants was studied at 16 different locations from Nagore to Ammanichatram along the east coast of Tamilnadu, India over a period of two years. The weight loss study showed that the mild steel corrosion was more at Nagapattinam site, when compared to Ammanichatram and Maravakadu sites. A linear regression analysis of the experimental data was attempted to predict the mechanism of the corrosion. The composition of the corrosion products formed on the mild steel surfaces was identified by XRD technique. The corrosion rate values obtained are discussed in the light of the weathering parameters, atmospheric pollutants such as salt content & SO2 levels in the atmosphere, corrosion products formed on the mild steel surfaces.

  19. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

    2011-01-01

    Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

  20. Study on influence of native oxide and corrosion products on atmospheric corrosion of pure Al

    International Nuclear Information System (INIS)

    Highlights: •Corrosion products layer is only formed in coastal atmosphere. •In coastal atmosphere, rate controlling step is diffusion process. •In rural atmosphere, rate controlling step is charge transfer process. •Pitting area increases greatly in coastal site, but slightly in rural site. -- Abstract: Effects of native oxide and corrosion products on atmospheric corrosion of aluminium in rural and coastal sites were studied by electrochemical impedance spectroscopy (EIS), open-circuit potential (OCP) and scanning electron microscope (SEM) techniques after outdoor exposure. In the rural atmosphere, only the compact, adhesive native oxide layer exists, and the rate controlling step is diffusion process, while in the coastal atmosphere, another loose, inadhesive corrosion products layer exists, and a charge transfer process controls the corrosion process. The pitting area in the coastal atmosphere increases over time more obviously than that in the rural atmosphere

  1. Atmospheric corrosion: statistical validation of models

    International Nuclear Information System (INIS)

    In this paper we discuss two different methods for validation of regression models, applied to corrosion data. One of them is based on the correlation coefficient and the other one is the statistical test of lack of fit. Both methods are used here to analyse fitting of bi logarithmic model in order to predict corrosion for very low carbon steel substrates in rural and urban-industrial atmospheres in Uruguay. Results for parameters A and n of the bi logarithmic model are reported here. For this purpose, all repeated values were used instead of using average values as usual. Modelling is carried out using experimental data corresponding to steel substrates under the same initial meteorological conditions ( in fact, they are put in the rack at the same time). Results of correlation coefficient are compared with the lack of it tested at two different signification levels (α=0.01 and α=0.05). Unexpected differences between them are explained and finally, it is possible to conclude, at least in the studied atmospheres, that the bi logarithmic model does not fit properly the experimental data. (Author) 18 refs

  2. Production, properties and application of steels resistant to atmospheric corrosion

    International Nuclear Information System (INIS)

    Steels, resistant to atmospheric corrosion, applied in the USSR and abroad, are reviewed. The influence of alloying elements (Cu, P, Cr, Si, Ni, Mo, Mn, As etc) upon resistance against atmospheric corrosion and mechanical properties of rolled steel is discussed. Technological properties, fields of the above steels application as well as the data on the range of product, are presented

  3. New fundamental and environmental aspects of atmospheric corrosion

    International Nuclear Information System (INIS)

    Atmospheric corrosion involves chemical, electrochemical, and physical processes in three phases (solid, liquid, and gas) and two interfaces (solid/liquid and liquid/gas). Because of inherent experimental and conceptual difficulties, scientific efforts to characterize this highly complex interfacial regime came relatively late into the field. With the access and development of surface and interface sensitive analytical techniques, it has lately become possible to perform molecular in situ analyses of the interfaces involved in atmospheric corrosion. This lecture presents some highlights from our fundamental research in atmospheric corrosion, performed at the Royal Institute of Technology in Stockholm, Sweden. It includes results from the most recent efforts in our research group to provide a molecular understanding of the interfacial regime that governs atmospheric corrosion. Using copper or zinc as substrate and carboxylic acid as corrosion stimulator in the humidity-containing atmosphere, results have been obtained with particular emphasis on probing the metal oxide/water interface (by infrared reflection absorption spectroscopy (IRAS) combined with the quartz crystal microbalance (QCM) and sum frequency generation (SFG)) and the water/gas interface (by SFG), respectively. While research in atmospheric corrosion traditionally has aimed at understanding how the environment influences the metal, the opposite question- how the metal influences the environment during atmospheric corrosion- may be of equally technical importance. Some examples of on-going research on new environmental aspects of atmospheric corrosion of zinc will also be presented. (Author) 9 refs

  4. Review: Introduction to atmospheric corrosion research in China

    Directory of Open Access Journals (Sweden)

    Junhua Dong, Enhou Han and Wei Ke

    2007-01-01

    Full Text Available In this paper, we introduce the research on atmospheric corrosion in China. We describe the climate characteristics and the classification of atmospheric corrosivity across the whole country. We also describe the rusting evolution under simulated wet/dry cyclic conditions.

  5. New fundamental and environmental aspects of atmospheric corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Leygraf, C.

    2009-07-01

    Atmospheric corrosion involves chemical, electrochemical, and physical processes in three phases (solid, liquid, and gas) and two interfaces (solid/liquid and liquid/gas). Because of inherent experimental and conceptual difficulties, scientific efforts to characterize this highly complex interfacial regime came relatively late into the field. With the access and development of surface and interface sensitive analytical techniques, it has lately become possible to perform molecular in situ analyses of the interfaces involved in atmospheric corrosion. This lecture presents some highlights from our fundamental research in atmospheric corrosion, performed at the Royal Institute of Technology in Stockholm, Sweden. It includes results from the most recent efforts in our research group to provide a molecular understanding of the interfacial regime that governs atmospheric corrosion. Using copper or zinc as substrate and carboxylic acid as corrosion stimulator in the humidity-containing atmosphere, results have been obtained with particular emphasis on probing the metal oxide/water interface (by infrared reflection absorption spectroscopy (IRAS) combined with the quartz crystal microbalance (QCM) and sum frequency generation (SFG)) and the water/gas interface (by SFG), respectively. While research in atmospheric corrosion traditionally has aimed at understanding how the environment influences the metal, the opposite question- how the metal influences the environment during atmospheric corrosion- may be of equally technical importance. Some examples of on-going research on new environmental aspects of atmospheric corrosion of zinc will also be presented. (Author) 9 refs.

  6. Initial Atmospheric Corrosion of Carbon Steel in Industrial Environment

    Science.gov (United States)

    Han, Wei; Pan, Chen; Wang, Zhenyao; Yu, Guocai

    2015-02-01

    The initial corrosion behavior of carbon steel subjected to Shenyang industrial atmosphere has been investigated by weight-loss measurement, scanning electron microscopy observation, x-ray diffraction, auger electron spectroscopy, and electron probe microanalysis. The experimental results reveal that the corrosion kinetics of the initial corrosion of carbon steel in industrial atmosphere follows empirical equation D = At n , and there is a corrosion rate transition from corrosion acceleration to deceleration; the corrosion products are composed of γ-FeOOH, α-FeOOH, Fe3O4, as well as FeS which is related to the existence of sulfate-reducing bacteria in the rust layers. The effect of dust particles on the corrosion evolution of carbon steel has also been discussed.

  7. Evolutionary Computation Techniques for Predicting Atmospheric Corrosion

    Directory of Open Access Journals (Sweden)

    Amine Marref

    2013-01-01

    Full Text Available Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a material in a particular environment plays a vital role in evaluating the residual life of the material. In this paper we investigate the use of genetic programming and genetic algorithms in the derivation of corrosion-rate expressions for steel and zinc. Genetic programming is used to automatically evolve corrosion-rate expressions while a genetic algorithm is used to evolve the parameters of an already engineered corrosion-rate expression. We show that both evolutionary techniques yield corrosion-rate expressions that have good accuracy.

  8. Long-term atmospheric corrosion of mild steel

    International Nuclear Information System (INIS)

    Research highlights: → Atmospheric corrosion rate stabilises after the first 4-6 years of exposure. → Great compaction of the rust layers in rural and urban atmospheres. → Corrosion (in rural and urban) deviates from common behaviour of bilogarithmic law. → Typical structures of lepidocrocite, goethite and akaganeite are identified. → Formation of hematite (industrial atmosphere) and ferrihydrite (marine atmosphere). - Abstract: A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4-6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals).

  9. Long-term atmospheric corrosion of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Fuente, D. de la; Diaz, I.; Simancas, J.; Chico, B. [National Centre for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo, 8, 28040 Madrid (Spain); Morcillo, M., E-mail: morcillo@cenim.csic.e [National Centre for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo, 8, 28040 Madrid (Spain)

    2011-02-15

    Research highlights: {yields} Atmospheric corrosion rate stabilises after the first 4-6 years of exposure. {yields} Great compaction of the rust layers in rural and urban atmospheres. {yields} Corrosion (in rural and urban) deviates from common behaviour of bilogarithmic law. {yields} Typical structures of lepidocrocite, goethite and akaganeite are identified. {yields} Formation of hematite (industrial atmosphere) and ferrihydrite (marine atmosphere). - Abstract: A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4-6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals).

  10. Atmospheric Corrosion on Steel Studied by Conversion Electron Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    In order to investigate initial products on steel by atmospheric corrosion, conversion electron Moessbauer measurements were carried out at temperatures between 15 K and room temperature. From the results obtained at low temperatures, it was found that the corrosion products on steel consisted of ferrihydrite.

  11. Review: Results of studying atmospheric corrosion in Vietnam 1995–2005

    Directory of Open Access Journals (Sweden)

    Le Thi Hong Lien, Pham Thy San and Hoang Lam Hong

    2007-01-01

    Full Text Available Vietnam is situated in the wet tropical zone; thus, atmospheric conditions are characterized by high temperatures and a long time of wetness (TOW. In addition, the salt air coming in from the sea causes a high chloride concentration in coastal areas. Furthermore, Vietnam is a developing country, which means that air pollution is increasing with the development of industry. These factors result in significant damage to materials by atmospheric corrosion. In this report, the results of a recent study on the corrosion of carbon steel and zinc-galvanized steel at 6–8 testing sites in Vietnam over 10 recent years (1995–2005 are focused on as well as the effects of environmental factors on atmospheric corrosion. The results showed that the corrosion of carbon steel is dominated by TOW, whereas zinc-galvanized-steel corrosion strongly depends on the chloride ion concentration in the air. The corrosion losses of both carbon- and zinc-galvanized steel fit the power model well with high correlation coefficients. In addition, the characteristics of the Vietnamese climate are introduced in the form of distribution maps of temperature (T, relative humidity (RH, total rainfall and TOW. A relationship between TOW, T and RH was found that enabled the calculation of TOW from T and RH data, which are available at meteorological stations. Finally, atmospheric corrosivity is determined on the basis of data on TOW, Cl− and SO2 concentrations, and the carbon steel corrosion rate. It is shown that in Vietnam, TOW is so long that the corrosion rate of carbon steel is in the C3 category; nevertheless, Cl− and SO2 concentrations in the atmosphere are not high.

  12. Evolutionary Computation Techniques for Predicting Atmospheric Corrosion

    OpenAIRE

    Amine Marref; Saleh Basalamah; Rami Al-Ghamdi

    2013-01-01

    Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a ...

  13. Corrosion Products and Formation Mechanism During Initial Stage of Atmospheric Corrosion of Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    XIAO Kui; DONG Chao-fang; LI Xiao-gang; WANG Fu-ming

    2008-01-01

    The formation and development of corrosion products on carbon steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM)and Raman spectroscopy.The results showed that two different shapes of corrosion products,that is,ring and chain,were formed in the initial stage of corrosion.MnS clusters were found in the nuclei of corrosion products at the active local corrosion sites.The ring-shaped products were composed of lepidocrocite (γ-FeOOH) and maghemite(γ-Fe2 O3) transformed from lepidocrocite.The chain-type products were goethite (α-FeOOH).A formation mechanism of the corrosion products is proposed.

  14. A Study on Atmospheric Corrosion of 304 Stainless Steel in a Simulated Marine Atmosphere

    Science.gov (United States)

    Lv, Wangyan; Pan, Chen; Su, Wei; Wang, Zhenyao; Liu, Shinian; Wang, Chuan

    2015-07-01

    The atmospheric corrosion behavior of 304 stainless steel in a simulated marine atmosphere has been investigated using scanning electron microscope, optical microscope, x-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The experimental results indicate that the main corrosion type of 304 stainless steel in a simulated marine atmosphere is pitting corrosion and the initiation of pits is associated with the dissolution of MnS inclusion. The maximum pit depth of 304 stainless steel increased in linear relationship with the extension of corrosion time. XPS results reveal that the corrosion products possess more hydroxide, and the ratio of [Cr]/{[Cr]+[Fe]} in the corrosion products gradually increases with the increasing time. The protective ability of corrosion products formed on 304 stainless steel has also been discussed.

  15. Atmospheric corrosion of mild steel. Pt. I. Rural and urban atmospheres

    International Nuclear Information System (INIS)

    This paper summarizes the results obtained in the MICAT project for mild steel specimens exposed for 1 to 4 years in 22 rural and urban atmospheres in the Ibero-American region. Test site characterization and chemical and morphological determination of the steel corrosion product layers (SCPLs) contributed to understanding the corrosion phenomena involved. It was observed how some climatological factors could affect steel corrosion rates and SCPL properties. Although the studied atmospheres were classified into different ISO groups, steel corrosion rates did not differ significantly between them. The only common characteristic of these atmospheres was an increase in SCPLs protectiveness with exposure time. (orig.)

  16. Atmospheric corrosion of the container during long term storage

    International Nuclear Information System (INIS)

    During the storage of metallic containers for long time, the containers walls may be exposed to cyclic wet and dry periods and will suffer from indoor atmospheric corrosion at room temperature. This one is an electrochemical process needing aqueous conditions for its occurrence. In order to obtain a predictive estimation of the damages due to the atmospheric corrosion during long period, this work, which belongs to the COCON research and development program, has been divided in two modules. The first module is the development of a phenomenological modelling. This model describes the condensation phenomena on the container wall and enables a first estimation of the corrosion rate. The second module is a mechanistic modelling of the phenomena occurring during a typical wet dry cycle in order to obtain a more relevant and robust prediction of the corrosion rate. (authors)

  17. The role of marine aerosols in atmospheric corrosion of metals

    International Nuclear Information System (INIS)

    The next problems are discussed: 1) connection between quantity of deposited sea chloride aerosols and wind regime at the Russian corrosion stations and in some points of the Far East; 2) effect of the distance from the sea cost on the chloride carrying out and metal corrosion: 3) effect of rain precipitation on the chloride surface concentration; 4) some results of atmospheric tests of main structural materials (carbon steel, copper, zinc, aluminium). 18 refs., 7 figs., 7 tabs

  18. Copper Corrosion by Atmospheric Pollutants in the Electronics Industry

    OpenAIRE

    Benjamin Valdez Salas; Michael Schorr Wiener; Roumen Zlatev Koytchev; Gustavo López Badilla; Rogelio Ramos Irigoyen; Monica Carrillo Beltrán; Nicola Radnev Nedev; Mario Curiel Alvarez; Navor Rosas Gonzalez; Jose María Bastidas Rull

    2013-01-01

    Hydrogen sulphide (H2S) is considered one of the most corrosive atmospheric pollutants. It is a weak, diprotic, reducing acid, readily soluble in water and dispersed into the air by winds when emitted from natural, industrial, and anthropogenic sources. It is a pollutant with a high level of toxicity impairing human health and the environment quality. It attacks copper forming thin films of metallic sulphides or dendrite whiskers, which are cathodic to the metal substrate, enhancing corrosion...

  19. Atmospheric corrosion of nickel in various outdoor environments

    International Nuclear Information System (INIS)

    As part of a field exposure program in the north-west of France on atmospheric corrosion of metal and alloys, this study presents the results of the behaviour of nickel panels exposed in industrial, urban and rural atmospheres. Mass measurements were investigated during the exposure and adherent corrosion layers were followed by means of several methods of analysis: Fourier transform infrared reflection-absorption spectroscopy, X-ray diffraction and scanning electron microscopy with X-ray microanalysis. In order to determine all the chemical species formed in the corrosion layers, corrosion products released from the surface by rainfall were also studied by collecting the streaming water from the nickel surfaces. Anionic and cationic quantities in the streaming water were determined respectively with ionic chromatography and polarography. The nickel attack appears as a pitting corrosion process accompanied by the formation of soluble corrosion products in dry exposure periods, these being regularly dissolved by rainfall events. Pits are associated with the formation of nickel salts, mainly sulphates and chlorides with small amounts of nitrate, and surrounded by carbonate species. The corrosion rate increases from rural to industrial areas

  20. Accelerated atmospheric corrosion testing of electroplated gold mirror coatings

    Science.gov (United States)

    Chu, C.-T.; Alaan, D. R.; Taylor, D. P.

    2010-08-01

    Gold-coated mirrors are widely used in infrared optics for industrial, space, and military applications. These mirrors are often made of aluminum or beryllium substrates with polished nickel plating. Gold is deposited on the nickel layer by either electroplating or vacuum deposition processes. Atmospheric corrosion of gold-coated electrical connectors and contacts was a well-known problem in the electronic industry and studied extensively. However, there is limited literature data that correlates atmospheric corrosion to the optical properties of gold mirror coatings. In this paper, the atmospheric corrosion of different electroplated gold mirror coatings were investigated with an accelerated mixed flowing gas (MFG) test for up to 50 days. The MFG test utilizes a combination of low-level air pollutants, humidity, and temperatures to achieve a simulated indoor environment. Depending on the gold coating thickness, pore corrosion started to appear on samples after about 10 days of the MFG exposure. The corrosion behavior of the gold mirror coatings demonstrated the porous nature of the electroplated gold coatings as well as the variation of porosity to the coating thickness. The changes of optical properties of the gold mirrors were correlated to the morphology of corrosion features on the mirror surface.

  1. Metallic corrosion in the polluted urban atmosphere of Hong Kong.

    Science.gov (United States)

    Liu, Bo; Wang, Da-Wei; Guo, Hai; Ling, Zhen-Hao; Cheung, Kalam

    2015-01-01

    This study aimed to explore the relationship between air pollutants, particularly acidic particles, and metallic material corrosion. An atmospheric corrosion test was carried out in spring-summer 2012 at a polluted urban site, i.e., Tung Chung in western Hong Kong. Nine types of metallic materials, namely iron, Q235 steel, 20# steel, 16Mn steel, copper, bronze, brass, aluminum, and aluminum alloy, were selected as specimens for corrosion tests. Ten sets of the nine materials were all exposed to ambient air, and then each set was collected individually after exposure to ambient air for consecutive 6, 13, 20, 27, 35, 42, 49, 56, 63, and 70 days, respectively. After the removal of the corrosion products on the surface of the exposed specimens, the corrosion rate of each material was determined. The surface structure of materials was observed using scanning electron microscopy (SEM) before and after the corrosion tests. Environmental factors including temperature, relative humidity, concentrations of gaseous pollutants, i.e., sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), and particulate-phase pollutants, i.e., PM₂.₅ (FSP) and PM₁₀ (RSP), were monitored. Correlation analysis between environmental factors and corrosion rate of materials indicated that iron and carbon steel were damaged by both gaseous pollutants (SO₂ and NO₂) and particles. Copper and copper alloys were mainly corroded by gaseous pollutants (SO₂ and O₃), while corrosion of aluminum and aluminum alloy was mainly attributed to NO₂ and particles. PMID:25400029

  2. Real time corrosion monitoring in atmosphere using automated battery driven corrosion loggers

    DEFF Research Database (Denmark)

    Prosek, T.; Kouril, M.; Hilbert, Lisbeth Rischel;

    2008-01-01

    A logger enabling continuous measurement of corrosion rate of selected metals in indoor and outdoor atmospheres has been developed. Principle of the measurement method is based on the increasing electrical resistance of a measuring element made of the material concerned as its cross-sectional are....... The logger lifetime in medium corrosive environments is designed to be 2 years with full autonomy. Data on the sensor corrosion rate are available any time through GPRS connection or by a non-contact inductive reading without the need of retracting the logger from the exposure site....

  3. Corrosion product formation during NaCl induced atmospheric corrosion of magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Magnesium alloy AZ91D was exposed in humid air at 95% relative humidity (RH) with a deposition of 70 μg/cm-2 NaCl. The corrosion products formed and the surface electrolyte were analysed after different exposure times using ex situ and in situ FTIR spectroscopy, X-ray diffraction and Ion Chromatography. The results show that magnesium carbonates are the main solid corrosion products formed under these conditions. The corrosion products identified were the magnesium carbonates hydromagnesite (Mg5 (CO3)4 (OH)24H2O) and nesquehonite (MgCO3 3H2O). The corrosion attack starts with the formation of magnesite at locations with higher NaCl contents. At 95% RH, a sequence of reactions was observed with the initial formation of magnesite, which transformed into nesquehonite after 2-3 days. Long exposures result in the formation of pits containing brucite (Mg(OH2)) covered with hydromagnesite crusts. The hydromagnesite crusts restrict the transport of CO2 and O2 to the magnesium surface and thereby favour the formation of brucite. Analysis of the surface electrolyte showed that the NaCl applied on the surface at the beginning was essentially preserved during the initial corrosion process. Since the applied salt was not bound in sparingly soluble corrosion products a layer of NaCl electrolyte was present on the surface during the whole exposure. Thus, Na+ and Cl- ions can participate in the corrosion process during the whole time and the availability of these species will not restrict the atmospheric corrosion of AZ91D under these conditions. It is suggested that the corrosion behaviour of AZ91D is rather controlled by factors related to the microstructure of the alloy and formation of solid carbonate containing corrosion products blocking active corrosion sites on the surface

  4. Corrosion product formation during NaCl induced atmospheric corrosion of magnesium alloy AZ91D

    Energy Technology Data Exchange (ETDEWEB)

    Joensson, Martin [Corrosion and Metals Research Institute (KIMAB), Drottning Kristinas vaeg 48, SE-114 28 Stockholm (Sweden)]. E-mail: martin.jonsson@kimab.com; Persson, Dan [Corrosion and Metals Research Institute (KIMAB), Drottning Kristinas vaeg 48, SE-114 28 Stockholm (Sweden); Thierry, Dominique [Institut de la Corrosion, 220 Rue Rivoalon, 29200 Brest (France)

    2007-03-15

    Magnesium alloy AZ91D was exposed in humid air at 95% relative humidity (RH) with a deposition of 70 {mu}g/cm{sup -2} NaCl. The corrosion products formed and the surface electrolyte were analysed after different exposure times using ex situ and in situ FTIR spectroscopy, X-ray diffraction and Ion Chromatography. The results show that magnesium carbonates are the main solid corrosion products formed under these conditions. The corrosion products identified were the magnesium carbonates hydromagnesite (Mg{sub 5} (CO{sub 3}){sub 4} (OH){sub 2}4H{sub 2}O) and nesquehonite (MgCO{sub 3} 3H{sub 2}O). The corrosion attack starts with the formation of magnesite at locations with higher NaCl contents. At 95% RH, a sequence of reactions was observed with the initial formation of magnesite, which transformed into nesquehonite after 2-3 days. Long exposures result in the formation of pits containing brucite (Mg(OH{sub 2})) covered with hydromagnesite crusts. The hydromagnesite crusts restrict the transport of CO{sub 2} and O{sub 2} to the magnesium surface and thereby favour the formation of brucite. Analysis of the surface electrolyte showed that the NaCl applied on the surface at the beginning was essentially preserved during the initial corrosion process. Since the applied salt was not bound in sparingly soluble corrosion products a layer of NaCl electrolyte was present on the surface during the whole exposure. Thus, Na{sup +} and Cl{sup -} ions can participate in the corrosion process during the whole time and the availability of these species will not restrict the atmospheric corrosion of AZ91D under these conditions. It is suggested that the corrosion behaviour of AZ91D is rather controlled by factors related to the microstructure of the alloy and formation of solid carbonate containing corrosion products blocking active corrosion sites on the surface.

  5. Initial atmospheric corrosion of Zinc sprayed with NaCl

    Institute of Scientific and Technical Information of China (English)

    屈庆; 严川伟; 张蕾; 刘光恒; 曹楚南

    2003-01-01

    Regularities of the initial atmospheric corrosion of zinc sprayed with different amount of NaCl exposed to air at 80% relative humidity and 25 ℃ were investigated via quartz crystal microbalance in laboratory. The results show that NaCl can accelerate the corrosion of zinc. Mass gain of zinc increases with the exposure time increasing, which can be correlated by using exponential decay function. The relationship between mass gain and amount of NaCl sprayed at a certain exposure time follows a quadratic function. Meanwhile, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and electron dispersion X-ray analysis were used to characterize the corrosion surface and products. Zn5(OH)8Cl2*H2O and ZnO are the dominant corrosion products, which unevenly distribute on the surface of zinc in the presence of NaCl. A probable mechanism is simply presented to explain the experimental results.

  6. Atmospheric corrosion evaluation of galvanised steel by thin layer activation

    International Nuclear Information System (INIS)

    The release of certain metals, such as zinc, from outdoor constructions due to atmospheric corrosion is of some concern. For risk assessments the evaluation of the amount of released metal is of importance. Various methods can be used to study the release of metals. These include those using radiotracers, such as thin layer activation (TLA). To verify the reliability of TLA with respect to conventional techniques in the evaluation of atmospheric corrosion, galvanised steel was exposed to a mild marine environment. The amount of zinc in the corrosion products, released through artificial leaching, at different time intervals was evaluated by TLA and atomic absorption spectroscopy (AAS). A good correlation between the results was found indicating the feasibility of TLA for these release studies

  7. Some Clarifications Regarding Literature on Atmospheric Corrosion of Weathering Steels

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; Chico, B.; Cano, H.; I. Díaz

    2012-01-01

    Extensive research work has thrown light on the requisites for a protective rust layer to form on weathering steels (WSs) in the atmosphere, one of the most important is the existence of wet/dry cycling. However, the abundant literature on WS behaviour in different atmospheres can sometimes be confusing and lacks clear criteria regarding certain aspects that are addressed in the present paper. What corrosion models best fit the obtained data? How long does it take for the rust layer to stabil...

  8. 49 CFR 193.2627 - Atmospheric corrosion control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Atmospheric corrosion control. 193.2627 Section 193.2627 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY...

  9. 49 CFR 192.479 - Atmospheric corrosion control: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Atmospheric corrosion control: General. 192.479 Section 192.479 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY...

  10. 49 CFR 192.481 - Atmospheric corrosion control: Monitoring.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Atmospheric corrosion control: Monitoring. 192.481 Section 192.481 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS...

  11. Corrosion behavior on aluminum alloy LY12 in simulated atmospheric corrosion process

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-yao; MA Teng; HAN Wei; YU Guo-cai

    2007-01-01

    The corrosion behavior of typical high-strength aluminum alloy LY12 was studied by accelerated corrosion tests of cyclic wet-dry-immersion containing media of NaHSO3 and NaCl to simulate the corrosion process in different atmosphere environment, and the corrosion mechanism was also discussed. The main experimental techniques include mass loss, morphological check, analysis of corrosion products and electrochemical measurement. The result shows that the mass loss of LY12, with or without cladding, has linear relationship with test time in the three kinds of chemical media, 0.02 mol/L NaHSO3, 0.006 mol/L NaCl and 0.02 mol/L NaHSO3+0.006 mol/L NaCl, respectively. A layer of cladding on high-strength aluminum alloy can raise evidently the resistance of atmospheric corrosion. Cl- can promote pitting generation on the oxide film of LY12 when HOS3- exists, LY12 can react much intensely with HOS3- derived from anions.

  12. A review of the atmospheric corrosion of zinc in outdoor an indoor atmospheres

    International Nuclear Information System (INIS)

    Good behaviour of zinc against atmospheric corrosion has leaded this material to be widely used, mainly for protection of steel. For this reason since approximately 50 years it have been making systematic studied in order to understand the mechanisms of its interaction with the atmosphere and nowadays it continues being object of intensive research. In this paper a review of the state-of-the-art in the knowledge of atmospheric corrosion of zinc is presented, when it is exposed in both outdoor and indoor atmospheres. (Author) 94 refs

  13. Influence of the corrosion products of copper on its atmospheric corrosion kinetics in tropical climate

    International Nuclear Information System (INIS)

    In the present paper, the identification of the corrosion product phases formed on copper under different atmospheres of Cuban tropical climate is reported. Cuprite (Cu2O), paratacamite (Cu2Cl(OH)3), posnjakite (Cu4SO4(OH)6 · 2H2O) and brochantite (Cu4SO4(OH)6) were the main phases identified by X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR). Copper corrosion products are known to have a protective effect against corrosion. However, a different behaviour was obtained under sheltered coastal conditions. This can be due to the corrosion products morphology and degree of crystallisation, rather than their phase composition. A higher time of wetness and the accumulation of pollutants not washed away from the metal surface can also play an important role

  14. Characterisation of initial atmospheric corrosion carbon steels by field exposure and laboratory simulation

    International Nuclear Information System (INIS)

    The early stages of the evolution of atmospheric corrosion of carbon steels exposed in both a laboratory simulated and a natural atmosphere environment in Shenyang have been observed by in situ scanning electron microscopy. In the case of laboratory cyclic wet-dry tests, even though the chloride content level is very low, filiform corrosion is initiated in the early stage. The filiform corrosion grows in random directions, forming a network of ridges. White nodules nucleate and grow on the ridges during continued corrosion and eventually connect with each other to form the initial corrosion scale. Pits were also found on the surface beneath corrosion products. In the case of a natural atmospheric environment, both filiform corrosion and other localized corrosion, such as pitting and inter-granular attack take place in the initial stage. It is obvious that there is variety of localized corrosion in the initial stage of atmospheric corrosion

  15. Atmospheric corrosion kinetics and dynamics of karachi onshore areas

    International Nuclear Information System (INIS)

    Atmospheric corrosion kinetics and dynamics (rate and factors) of Karachi coastal city was ascertained at a couple of locations in the vicinity of Arabian seashore i.e. Hawksbay and Seaview Township by complying ISO 9223, ASTM G01 and ASTM G50 norms. Both exposure test sites were located at west to south-westward wind corridor. Data was collected for exposure of mild steel coupons at these two locations and their meteorological conditions were logged for a period from March 2005 to April 2007. Chloride and Sulfur dioxide were measured by employing ISO 9225 standard. Severe degree of material depletion for mild steel coupons was observed at both test locations. Mass loss was higher at Hawksbay test site than at Sea view Township. Maximum mass loss was observed during monsoon period probably due to rainfall and strong sea wave action which produced enriched marine aerosols and boosted chloride deposition rates. Although paucity of rainfall was observed but substantial relative humidity level was recorded during test period. Comparison of the results indicated that corrosion rate was higher at Hawksbay test site as compared to Seaview test site. Goethite and lepidocrocite were identified as major corrosion products by Scanning electron microscopy while it was also revealed that major portion of lepidocrocite phase was transformed into goethite at Seaview test site. As goethite phase is thermodynamically more stable and less vulnerable to further recurrence of corrosion as compared to lepidocrocite phase which may be attributed to less corrosion rate measured at Seaview test site. Since corrosion rate at both locations were gauged in the range of 65> rcorr <= 150 in terms of mu m.year-1 so this study ranked the corrosivity of these two test locations as C5 i.e. very high marine corrosivity. (author)

  16. Material concepts for coatings in highly corrosive atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Wilden, J. [Technische Universitaet Berlin (Germany). Fachgebiet Fuege- und Beschichtungstechnik; Schuetze, M.; Durham, R. [Karl-Winnacker-Institut, DECHEMA e. V., Frankfurt a. M (Germany); Drescher, V.E.

    2010-07-15

    Although well known, corrosion processes are still a problem for technical constructions. Although different coating technologies and materials have been developed and approved to prevent base metals from being destroyed, industrial applications dealing with aggressive atmospheres, require new material concepts to protect them. Using the example of two different applications, on the one hand heat exchangers in waste incineration plants and on the other hand permanent-molds used for casting non-ferrous metals, innovative material concepts for corrosion protection are given. Heat exchangers in waste incineration plants are exposed to highly corrosive atmospheres especially due to high temperatures in combination with chlorine containing atmospheres. Wire arc sprayed coatings made of iron-based alloys containing chromium, silicon and boron provide a new approach for these applications and, compared to standard nickel-based alloys, they are cheaper and potentially more resistant coatings. In the case of permanent-molds corrosion, mainly occurs due to direct dissolution of the base material by the liquid metal. Tungsten-based pseudoalloys are known to be extremely resistant against liquid metals and therefore sintered inlays of these materials are sometimes used in extremely stressed regions. These materials have not previously been applied as a coating. Therefore different coating technologies have to be considered and the metallurgical behaviour of the material due to the associated higher cooling rates must be investigated. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. Advance in the studies of atmospheric corrosion in Colombia

    International Nuclear Information System (INIS)

    A recount of the works is made carried out in the last ten years to investigate different variables of the atmospheric corrosion in Colombia. it understand studies in the Cartagena Bay and in several areas of Antioquia; additionally, laboratory results are included. The studied materials have been steels to the carbon. Zinc, aluminum and copper, in some cases with paintings like protection form. Meteorological results are shown, of contamination and of speed of corrosion in the different areas. In the procedures national and international norms have been used

  18. Corrosion of steel reinforced concrete in the tropical coastal atmosphere of Havana City, Cuba

    Directory of Open Access Journals (Sweden)

    Abel Castañeda

    2013-01-01

    Full Text Available The influence of chloride deposition rate on concrete using an atmospheric corrosion approach is rarely studied in the literature. Seven exposure sites were selected in Havana City, Cuba, for exposure of reinforced concrete samples. Two significantly different atmospheric corrosivity levels with respect to corrosion of steel reinforced concrete were observed after two years of exposure depending on atmospheric chloride deposition and w/c ratio of the concrete. Changes in corrosion current are related to changes in chloride penetration and chloride atmospheric deposition. The influence of sulphur compound deposition could also be a parameter to consider in atmospheric corrosion of steel reinforced concrete.

  19. Corrosion of steel reinforced concrete in the tropical coastal atmosphere of Havana City, Cuba

    OpenAIRE

    Abel Castañeda; Juan José Howland; Francisco Corvo; Tezozomoc Pérez

    2013-01-01

    The influence of chloride deposition rate on concrete using an atmospheric corrosion approach is rarely studied in the literature. Seven exposure sites were selected in Havana City, Cuba, for exposure of reinforced concrete samples. Two significantly different atmospheric corrosivity levels with respect to corrosion of steel reinforced concrete were observed after two years of exposure depending on atmospheric chloride deposition and w/c ratio of the concrete. Changes in corrosion current are...

  20. New fundamental and environmental aspects of atmospheric corrosion

    Directory of Open Access Journals (Sweden)

    Leygraf, C.

    2009-06-01

    Full Text Available Atmospheric corrosion involves chemical, electrochemical, and physical processes in three phases (solid, liquid, and gas and two interfaces (solid/liquid and liquid/gas. Because of inherent experimental and conceptual difficulties, scientific efforts to characterize this highly complex interfacial regime came relatively late into the field. With the access and development of surface and interface sensitive analytical techniques, it has lately become possible to perform molecular in situ analyses of the interfaces involved in atmospheric corrosion. This lecture presents some highlights from our fundamental research in atmospheric corrosion, performed at the Royal Institute of Technology in Stockholm, Sweden. It includes results from the most recent efforts in our research group to provide a molecular understanding of the interfacial regime that governs atmospheric corrosion. Using copper or zinc as substrate and carboxylic acid as corrosion stimulator in the humidity-containing atmosphere, results have been obtained with particular emphasis on probing the metal oxide/water interface (by infrared reflection absorption spectroscopy (IRAS combined with the quartz crystal microbalance (QCM and sum frequency generation (SFG and the water/gas interface (by SFG, respectively. While research in atmospheric corrosion traditionally has aimed at understanding how the environment influences the metal, the opposite question- how the metal influences the environment during atmospheric corrosion- may be of equally technical importance. Some examples of on-going research on new environmental aspects of atmospheric corrosion of zinc will also be presented.

    La corrosión atmosférica implica procesos químicos, electroquímicos y físicos en tres fases (sólido, liquido y gas y dos interfases (sólido/líquido y líquido/gas. A causa de dificultades experimentales y conceptuales los esfuerzos científicos para caracterizar el proceso, interfacial

  1. Some Clarifications Regarding Literature on Atmospheric Corrosion of Weathering Steels

    Directory of Open Access Journals (Sweden)

    I. Díaz

    2012-01-01

    Full Text Available Extensive research work has thrown light on the requisites for a protective rust layer to form on weathering steels (WSs in the atmosphere, one of the most important is the existence of wet/dry cycling. However, the abundant literature on WS behaviour in different atmospheres can sometimes be confusing and lacks clear criteria regarding certain aspects that are addressed in the present paper. What corrosion models best fit the obtained data? How long does it take for the rust layer to stabilize? What is the morphology and structure of the protective rust layer? What is an acceptable corrosion rate for unpainted WS? What are the guideline environmental conditions, time of wetness (TOW, SO2, and Cl−, for unpainted WS? The paper makes a review of the bibliography on this issue.

  2. Atmospheric corrosion rate expressed as a function of time. Effects of atmospheric conditions and alloying elements on corrosion resistance of steels and cast irons

    International Nuclear Information System (INIS)

    On the basis of function describing a change in atmospheric corrosion rate (K) in time (t) the published results of long-standing corrosion tests of a great number of cast irons and steels were statistically processed. The effect of chloride - ions, sulfur dioxide, alloying elements (Cu, Ni, Cr, Mn, Si, V, C) on the rate of initial corrosion on the active surface (K0), passivation properties (α0) of corrosion products and corrosion resistance (α0/K0) of iron-carbonic alloys in different climatic areas was revealed. The data permit further investigation of the mechanism of alloying element effect on atmopsheric corrosion of steels

  3. New fundamental and environmental aspects of atmospheric corrosion

    OpenAIRE

    Leygraf, C.

    2009-01-01

    Atmospheric corrosion involves chemical, electrochemical, and physical processes in three phases (solid, liquid, and gas) and two interfaces (solid/liquid and liquid/gas). Because of inherent experimental and conceptual difficulties, scientific efforts to characterize this highly complex interfacial regime came relatively late into the field. With the access and development of surface and interface sensitive analytical techniques, it has lately become possible to perform molecular in...

  4. Electrochemical protection of pointed metallic structures from atmospheric corrosion

    International Nuclear Information System (INIS)

    Efficiency of electrochemical protection (ECP) of steel against atmospheric corrosion under thin electrolyte films is investigated. It is shown that the zone of ECP action is restricted by a low conductivity of moisture films, occurring on metals under natural conditions. A method of increasing ECP efficiency by means of using electroconducting coatings applied to standard paint and varnish coatings, is proposed. 6 refs., 2 figs

  5. Chloride-catalyzed corrosion of plutonium in glovebox atmospheres

    International Nuclear Information System (INIS)

    Characterization of glovebox atmospheres and the black reaction product formed on plutonium surfaces shows that the abnormally rapid corrosion of components in the fabrication line is consistent with a complex salt-catalyzed reaction involving gaseous hydrogen chloride (HCl) and water. Analytical data verify that chlorocarbon and HCl vapors are presented in stagnant glovebox atmospheres. Hydrogen chloride concentrations approach 7 ppm at some locations in the glovebox line. The black corrosion product is identified as plutonium monoxide monohydride (PuOH), a product formed by hydrolysis of plutonium in liquid water and salt solutions at room temperature. Plutonium trichloride (PuCl3) produced by reaction of HCl at the metal surface is deliquescent and apparently forms a highly concentrated salt solution by absorbing moisture from the glovebox atmosphere. Rapid corrosion is attributed to the ensuing salt-catalyzed reaction between plutonium and water. Experimental results are discussed, possible involvement of hydrogen fluoride (HF) is examined, and methods of corrective action are presented in this report

  6. Looking Back on Contributions in the Field of Atmospheric Corrosion Offered by the MICAT Ibero-American Testing Network

    OpenAIRE

    Morcillo, M.; Chico, B.; de la Fuente, D.; Simancas, J.

    2012-01-01

    The Ibero-American Map of Atmospheric Corrosiveness (MICAT) project was set up in 1988 sponsored by the International Ibero-American programme “Science and Technology for Development (CYTED)” and ended in 1994 after six years of activities. Fourteen countries were involved in this project: Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Panama, Peru, Portugal, Spain, Uruguay, and Venezuela. Research was conducted both at laboratories and in a network of 75 atmospheric e...

  7. Atmospheric corrosion of galvanized steel in a marine environment

    International Nuclear Information System (INIS)

    Atmospheric corrosion is the electrochemical process of metal deterioration from the action of atmospheric factors, both meteorological as well as chemical. Metals deteriorate due to their spontaneous oxidation when their surface is moistened with a film of condensed water, dew, fog or rain and this process leads to the formation of a protective film that acts as a physical barrier between the metal and the environment. However, this layer of corrosion can become a non protective film, due to a physical discharge or a partial dissolution of some soluble corrosion products of the material (galvanized steel) during rainfall or in condensed water on the material's surface. This process is known as metal runoff. In order to estimate the runoff process for galvanized steel and to study its behavior to atmospheric corrosion in a marine environment, samples of 10x10x0,6cm galvanized steel, with a coating thickness of 100 m Zn, were exposed in the city of Valparaiso, Region V, Chile. The atmospheric station is located at lat. 32AS and long. 71oW, classified according to ISO 9223 to 9226 as C2, S1 and P1, with a humidification time of 0.6 and chloride ion and sulfur dioxide content of 40.65 mgm-2day-1 and 7.18 mgm-2day-1, respectively. The deterioration of the galvanized steel was evaluated by weight loss measurements, determination of 'in situ' corrosion potential and morphology of the attack using scanning electron microscopy (SEM). The composition of the corrosion products was determined by X-ray diffraction (XRD). The runoff solutions collected after the rainfall events were analyzed with different techniques to determine the content of Cl- ions, SO4-2 and dissolved solids, and pH and conductivity were measured as well. The concentration of Zn+2 is obtained by atomic adsorption spectroscopy. After four months of exposure of the test pieces preliminary results show that the potential for corrosion of the galvanized steel increased over time, which corroborates the

  8. Atmospheric corrosion of metals in tropics and subtropic. 2. Corrosion resistance of different metals and alloys

    International Nuclear Information System (INIS)

    Data from 169 sources concerning corrosion of different metals, alloys and means of protection, obtained for a 30-year period (up to 1987) in different continent including Europe (Bulgaria, Spain, Italy, France, USSR); America (USA, Panama, Cuba, Venezuela, Brasil, Argentine); Africa (Nigeria, SAR); Australia, New Zeland, Papua-Newguinea, Philippines, are systemized. Actual results of full-scal atmospheric testings of iron, zinc, copper, cadmium, aluminium, tin, lead, carbon, low-alloys. Stainless steels, cast irons, halvanic coatings, copper, aluminium, nickel, titanium, magnesium alloys are presented. Data on the fracture rate can be used for creating the data base in banks on atmospheric resistance of metal materials

  9. Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment

    OpenAIRE

    Zhongyu Cui; Xiaogang Li; Huan Zhang; Kui Xiao; Chaofang Dong; Zhiyong Liu; Liwei Wang

    2015-01-01

    Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular ...

  10. Influence of A1 Content on the Atmospheric Corrosion Behaviour of Magnesium-Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Ruiling Jia; Chuanwei Yan; Fuhui Wang

    2009-01-01

    The influence of Al content on the Mg-Al alloys corrosion performance during sodium chloride induced atmospheric corrosion has been studied. It was found that the corrosion rate of three Mg-Al alloys was accelerated with increasing Al content. The poor corrosion resistance was attributed to the galvanic coupling between the β phase and eutectic phase or α phase and the formation of porous corrosion products.

  11. Characterization of corrosion products formed on steels in the first months of atmospheric exposure

    OpenAIRE

    Antunes Renato Altobelli; Costa Isolda; Faria Dalva Lúcia Araújo de

    2003-01-01

    The corrosion products of carbon steel and weathering steel exposed to three different types of atmospheres, at times ranging from one to three months, have been identified. The steels were exposed in an industrial site, an urban site (São Paulo City, Brazil), and a humid site. The effect of the steel type on the corrosion products formed in the early stages of atmospheric corrosion has been evaluated. The corrosion products formed at the various exposure locations were characterized by Raman...

  12. Atmospheric deposition maps for the Rocky Mountains

    Science.gov (United States)

    Nanus, L.; Campbell, D.H.; Ingersoll, G.P.; Clow, D.W.; Mast, M.A.

    2003-01-01

    Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the Rocky Mountains by using spatial statistics. A parameter-elevation regressions on independent slopes model (PRISM) was incorporated to account for variations in precipitation amount over mountainous regions. Chemical data were obtained from the National Atmospheric Deposition Program/National Trends Network and from annual snowpack surveys conducted by the US Geological Survey and National Park Service, in cooperation with other Federal, State and local agencies. Surface concentration maps were created by ordinary kriging in a geographic information system, using a local trend and mathematical model to estimate the spatial variance. Atmospheric-deposition maps were constructed at 1-km resolution by multiplying surface concentrations from the kriged grid and estimates of precipitation amount from the PRISM model. Maps indicate an increasing spatial trend in concentration and deposition of the modeled constituents, particularly nitrate and sulfate, from north to south throughout the Rocky Mountains and identify hot-spots of atmospheric deposition that result from combined local and regional sources of air pollution. Highest nitrate (2.5-3.0kg/ha N) and sulfate (10.0-12.0kg/ha SO4) deposition is found in northern Colorado.

  13. Zn-10.2% Fe coating over carbon steel atmospheric corrosion resistance. Comparison with zinc coating

    International Nuclear Information System (INIS)

    Zn-10.2% Fe galvanized coating versus hot galvanized coating over carbon steel corrosion performance has been studied. Different periods of atmospheric exposures in various Valencia Community sites, and salt spray accelerated test have been done. Carbon steel test samples have been used simultaneously in order to classify exposure atmosphere corrosivity, and environmental exposure atmosphere characteristics have been analyzed. Corrosion Velocity versus environmental parameters has been obtained. (Author) 17 refs

  14. A contribution to the modelling of atmospheric corrosion of iron

    International Nuclear Information System (INIS)

    With the aim of predicting the long term atmospheric corrosion behaviour of iron, the characteristics of the rust layer formed during this process and the mechanisms occurring inside the rust layer during a wet-dry cycle are considered. A first step in modelling the behaviour is proposed, based on the description of the cathodic reactions associated with iron oxidation: reduction of a part of the rust layer (lepidocrocite) and reduction of dissolved oxygen on the rust layer. The modelling, by including some composition and morphological data of the rust layer as parameters, is able to account for the metal damage after one Wet-Dry cycle. (authors)

  15. Effect of CO2 on Atmospheric Corrosion of UNS G10190 Steel under Thin Electrolyte Film

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The atmospheric corrosion of UNS G10190 steel under a thin electrolyte film in the atmosphere polluted by CO2 has been studied in the lab using an atmospheric corrosion monitor(ACM) in combination with XRD and SEM observations of the surface of steel. The ACM study indicated that the corrosion rate of the steel increased with increasing carbon dioxide concentration. The XRD and SEM observations showed that no carbonate was found in the corrosion product on the steel surface. The corrosion product consisted of two layers, i. e., inner and outer layer. From the experimental results, it was concluded that CO2 played an enhancing role in the atmospheric corrosion of UNS G10190 steel. The film of the corrosion product showed slight protection.

  16. Standard practice for conducting atmospheric corrosion tests on metals

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers and defines conditions for exposure of metals and alloys to the weather. It sets forth the general procedures that should be followed in any atmospheric test. It is presented as an aid in conducting atmospheric corrosion tests so that some of the pitfalls of such testing may be avoided. As such, it is concerned mainly with panel exposures to obtain data for comparison purposes. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Development and evaluation of an instantaneous atmospheric corrosion rate monitor

    Science.gov (United States)

    Mansfeld, F.; Jeanjaquet, S. L.; Kendig, M. W.; Roe, D. K.

    1985-06-01

    A research program was carried out in which a new instantaneous atmospheric corrosion rate monitor (ACRM) was developed and evaluated, and equipment was constructed which will allow the use of many sensors in an economical way in outdoor exposures. In the first task, the ACRM was developed and tested in flow chambers in which relative humidity and gaseous and particulate pollutant levels can be controlled. Diurnal cycles and periods of rain were simulated. The effects of aerosols were studied. A computerized system was used for collection, storage, and analysis of the electrochemical data. In the second task, a relatively inexpensive electronics system for control of the ACRM and measurement of atmospheric corrosion rates was designed and built. In the third task, calibration of deterioration rates of various metallic and nonmetallic materials with the response of the ACRMs attached to these materials was carried out under controlled environmental conditions using the system developed in the second task. A Quality Assurance project plan was prepared with inputs from the Rockwell International Environmental Monitoring and Service Center and Quality Assurance System audits were performed.

  18. Bearing assembly and the like for use in corrosive and non-corrosive atmospheres

    International Nuclear Information System (INIS)

    This invention relates to a novel machine element characterized by mutually rubbing surfaces which are composed of dissimilar materials having high hardness, a low coefficient of friction, and resistance to corrosion by halogen-containing atmospheres. As exemplified by the preferred embodiment for use in gaseous UF6, the rubbing surfaces are chemically deposited nickel and anodized aluminum. These surfaces permit jam-free operation despite long-term exposure to UF6. Preferably, both surfaces have a hardness of at least about 500 HV100 on the Vickers hardness scale, and preferably the anodized-aluminum surface is of type having comparatively little tendency to sorb uranium hexafluoride

  19. Atmosphere corrosion behavior of plasma sprayed and laser remelted coatings on copper

    Institute of Scientific and Technical Information of China (English)

    Gongying Liang; T. T. Wong; Geng An; J. M. K. MacAlpine

    2006-01-01

    Nickel and chromium coatings were produced using plasma spraying and laser remelting on the copper sheet. The corrosion test was carried out in an acidic atmosphere, and the corrosive behaviors of both coatings and original copper samples were investigated by using an impedance comparison method. Experimental results show that nickel and chromium coatings display better corrosion resistance properties relative to the original pure copper sample. The corrosion rate of chromium coating is less than that of nickel coating, and corrosion resistances of laser remelted nickel and chromium samples are better thanthose of plasma sprayed samples. The corrosion deposit film of copper is loose compared with nickel and chromium.

  20. Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment

    Directory of Open Access Journals (Sweden)

    Zhongyu Cui

    2015-01-01

    Full Text Available Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular corrosion with the extension of exposure time, resulting in the reduction of the mechanical properties.

  1. Exfoliation Corrosion Behavior of 2B06 Aluminum Alloy in a Tropical Marine Atmosphere

    Science.gov (United States)

    Cui, Z. Y.; Li, X. G.; Xiao, K.; Dong, C. F.; Wang, L. W.; Zhang, D. W.; Liu, Z. Y.

    2015-01-01

    In this study, corrosion behavior of 2B06 aluminum alloy was investigated after exposure to a tropical marine atmosphere for up to 4 years. After 6 months, the specimen showed exfoliation corrosion as well as rapid increase in thickness loss and corrosion rate. Exfoliation corrosion was found to initiate from hydrogen-assisted intergranular cracks and propagate extensively due to the wedge effect of the corrosion products. During the exposure test, corrosion on the groundward surface was considerably more severe than that on the skyward surface, which could be attributed to the different exposure conditions on the two surfaces.

  2. Atmosphere corrosion behavior of plasma sprayed and laser remelted coatings on copper

    Science.gov (United States)

    Liang, Gongying; Wong, T. T.; An, Geng; MacAlpine, J. M. K.

    2006-01-01

    Nickel and chromium coatings were produced using plasma spraying and laser remelting on the copper sheet. The corrosion test was carried out in an acidic atmosphere, and the corrosive behaviors of both coatings and original copper samples were investigated by using an impedance comparison method. Experimental results show that nickel and chromium coatings display better corrosion resistance properties relative to the original pure copper sample. The corrosion rate of chromium coating is less than that of nickel coating, and corrosion resistances of laser remelted nickel and chromium samples are better than those of plasma sprayed samples. The corrosion deposit film of copper is loose compared with nickel and chromium.

  3. Development of an Accelerated Test Method for the Determination of Susceptibility to Atmospheric Corrosion

    Science.gov (United States)

    Ambrose, John R.

    1991-01-01

    The theoretical rationale is presented for use of a repetitive cyclic current reversal voltammetric technique for characterization of localized corrosion processes, including atmospheric corrosion. Applicability of this proposed experimental protocol is applied to characterization of susceptibility to crevice and pitting corrosion, atmospheric corrosion and stress corrosion cracking. Criteria upon which relative susceptibility is based were determined and tested using two iron based alloys commonly in use at NASA-Kennedy; A36 (a low carbon steel) and 4130 (a low alloy steel). Practicality of the procedure was demonstrated by measuring changes in anodic polarization behavior during high frequency current reversal cycles of 25 cycles per second with 1 mA/sq cm current density amplitude in solutions containing Cl anions. The results demonstrated that, due to excessive polarization which affects conductivity of barrier corrosion product layers, A36 was less resistant to atmospheric corrosion than its 4130 counterpart; behavior which was also demonstrated during exposure tests.

  4. Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

    International Nuclear Information System (INIS)

    As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n, where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis

  5. The effect of fluorine-containing inhibitors of corrosion of copper in atmospheric conditions

    OpenAIRE

    M. G. Ivanov; Nechaev, A. V.; Mokrushin, V. S.; Ostroukhova, O. I.

    2016-01-01

    The effect of fluorine-containing inhibitors of corrosion of copper in atmospheric conditions was studied by method of removing anodic polarization curves and corrosion of full-scale tests. The introduction of the inhibiting compositions as corrosion inhibitor of copper polyfluorinated amines leads to a decrease of the peak current of active dissolution of copper, which increases the corrosion resistance of copper wire rod during transportation in various climate conditions.

  6. A comparative study of accelerated tests to simulate atmospheric corrosion

    International Nuclear Information System (INIS)

    In this study, specimens coated with five organic coating systems were exposed to accelerated tests for periods up to 2000 hours, and also to weathering for two years and six months. The accelerated tests consisted of the salt spray test, according to ASTM B-117; Prohesion (ASTM G 85-98 annex 5A); Prohesion combined with cyclic exposure to UV-A radiation and condensation; 'Prohchuva' a test described by ASTM G 85-98 using a salt spray with composition that simulated the acid rain of Sao Paulo, but one thousand times more concentrated, and 'Prohchuva' combined with cyclic exposure to UV-A radiation and condensation. The coated specimens were exposed with and without incision to expose the substrate. The onset and progress of corrosion at and of the exposed metallic surface, besides coating degradation, were followed by visual observation, and photographs were taken. The coating systems were classified according to the extent of corrosion protection given to the substrate, using a method based on ASTM standards D-610, D-714, D-1654 and D-3359. The rankings of the coatings obtained from accelerated tests and weathering were compared and contrasted with classification of the same systems obtained from literature, for specimens exposed to an industrial atmosphere. Coating degradation was strongly dependent on the test, and could be attributed to differences in test conditions. The best correlation between accelerated test and weathering was found for the test Prohesion alternated with cycles of exposure to UV-A radiation and condensation. (author)

  7. Middle Atmosphere Electrodynamics (MAE). Middle atmospheric electrodynamics during MAP

    Science.gov (United States)

    Goldberg, R. A.

    1989-01-01

    The recent revival and strong motivation for research in middle atmospheric electrodynamics can be attributed, in large part, to the discovery of large (V/m) electric fields within the lower mesosphere during the decade prior to MAP. Subsequent rocket soundings appeared to verify the preliminary findings. During the MAP era, more sophisticated techniques have been employed to obtain measurements which respond positively to criticisms of earlier results, and which provide more insight regarding the character of the fields. The occurrence of mesospheric V/m electric fields now seems to require the presence of aerosols, of local winds and related dynamics, and of an atmospheric electrical conductivity less than 10(-10)S/m. Furthermore, new theoretical ideas describing the origin of the V/m fields are consistent with the measurements. The current status of results regarding V/m fields in the middle atmosphere is reviewed in light of the more widely accepted electric field structure for this region from rocket, balloon and modeling results.

  8. Localisation of oxygen reduction sites in the case of iron long term atmospheric corrosion

    International Nuclear Information System (INIS)

    Highlights: → New findings on long term atmospheric corrosion of iron. → New experiment combining isotopic markers and wet-dry cycling. → Use of ancient iron artefacts with a thick corrosion product layer. → Refining of atmospheric corrosion mechanisms with two possible mechanisms identified. - Abstract: In different fields of civil engineering and cultural heritage, the corrosion behaviour of century old ferrous artefacts must be accurately evaluated, especially under uncontrolled conditions. This approach requires an understanding of the role played by the several hundred micrometre thick corrosion layers formed on ancient metals. Combining the study of historical mild steels and a new re-corroding experiment using isotopic tracers, we show here that mechanisms controlling corrosion kinetics differ according to the nature and the organisation of various microscopic phases, leading to a decoupling of anodic and cathodic reaction or to a homogeneous corrosion.

  9. Volatile corrosion inhibitor film formation on carbon steel surface and its inhibition effect on the atmospheric corrosion of carbon steel

    International Nuclear Information System (INIS)

    A novel volatile corrosion inhibitor (VCI), bis-piperidiniummethyl-urea (BPMU), was developed for temporary protection of carbon steel. Its vapor corrosion inhibition property was evaluated under simulated operational conditions. Electrochemical impedance spectroscopy was applied to study the inhibition effect of BPMU on the corrosion of carbon steel with a thin stimulated atmospheric corrosion water layers. Adsorption of BPMU on carbon steel surfaces was investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The results indicate that BPMU can form a protective film on the metal surface, which protects the metal against further corrosion. The structure of the protective film was suggested as one BPMU molecule chelated with one Fe atom to form a complex with two hexa-rings

  10. Volatile corrosion inhibitor film formation on carbon steel surface and its inhibition effect on the atmospheric corrosion of carbon steel

    Science.gov (United States)

    Zhang, Da-quan; An, Zhong-xun; Pan, Qing-yi; Gao, Li-xin; Zhou, Guo-ding

    2006-11-01

    A novel volatile corrosion inhibitor (VCI), bis-piperidiniummethyl-urea (BPMU), was developed for temporary protection of carbon steel. Its vapor corrosion inhibition property was evaluated under simulated operational conditions. Electrochemical impedance spectroscopy was applied to study the inhibition effect of BPMU on the corrosion of carbon steel with a thin stimulated atmospheric corrosion water layers. Adsorption of BPMU on carbon steel surfaces was investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The results indicate that BPMU can form a protective film on the metal surface, which protects the metal against further corrosion. The structure of the protective film was suggested as one BPMU molecule chelated with one Fe atom to form a complex with two hexa-rings.

  11. Indoor atmospheric corrosion of conventional weathering steels in the tropical atmosphere of Panama

    Science.gov (United States)

    Jaén, Juan A.; Iglesias, Josefina; Adames, Olga

    2014-01-01

    One year indoor atmospheric corrosion examinations have been carried out on two conventional weathering steels for a year, at two test sites, Tocumen and Sherman Breakwater in Panama. They are environmentally classified by ISO 9223 as S1P0 τ 4 and S3P0 τ 5, respectively. In this humid-tropical marine climate corrosion rates are rather high, especially at Sherman Breakwater test site, mainly due to the high deposition of chloride, among other environmental conditions. Our results indicate that indoor corrosion is highly determined by the time of wetness and chloride ions. A-588 weathering steel corroded at a generally lower rate than COR-420 weathering steel. Rust characterization was performed by XRD, FTIR, and Mössbauer spectroscopy. Lepidocrocite, goethite, maghemite and akaganeite were found as corrosion products. Akaganeite is only detected when high chlorides deposition rates are obtained, and no washing effect occurs. This phase, together with maghemite, is obtained when there is greater aggressiveness in the environment.

  12. Study of development and utilization of a multipurpose atmospheric corrosion sensor

    Science.gov (United States)

    Diwan, Ravinder M.; Raman, A.; Bhattacharya, P. K.

    1994-01-01

    There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted.

  13. Corrosion behaviour of Ni–Co alloy coatings at Kish Island (marine) atmosphere

    Indian Academy of Sciences (India)

    Kourosh Sharifi; Mohammad Ghorbani

    2014-05-01

    In this study, the corrosion behaviour of Ni-Co alloys with low Co content, electroplated on steel substrate in sulphate bath, was investigated. The morphology of coatings was studied by optical and SEM microscopy. The corrosion products were analyzed using EDX. The results showed that Ni–1% Co coatings had a better corrosion resistance 0.30, 0.92 and 3.75 mpy for atmospheric, salt spray and polarization tests, respectively. These are 0.41, 1.20 and 5.40 mpy for pure nickel coatings that indicate the least corrosion resistance. Surface analysis revealed the presence of oxides, sulphides and chlorides in corrosion products.

  14. Estimation of the atmospheric corrosion on metal containers in industrial waste disposal.

    Science.gov (United States)

    Baklouti, M; Midoux, N; Mazaudier, F; Feron, D

    2001-08-17

    Solid industrial waste are often stored in metal containers filled with concrete, and placed in well-aerated warehouses. Depending on meteorological conditions, atmospheric corrosion can induce severe material damages to the metal casing, and this damage has to be predicted to achieve safe storage. This work provides a first estimation of the corrosivity of the local atmosphere adjacent to the walls of the container through a realistic modeling of heat transfer phenomena which was developed for this purpose. Subsequent simulations of condensation/evaporation of the water vapor in the atmosphere were carried out. Atmospheric corrosion rates and material losses are easily deduced. For handling realistic data and comparison, two different meteorological contexts were chosen: (1) an oceanic and damp atmosphere and (2) a drier storage location. Some conclusions were also made for the storage configuration in order to reduce the extent of corrosion phenomena. PMID:11489528

  15. Atmospheric corrosion of metals and alloys at the Antarctide station 'Mirnyj'

    International Nuclear Information System (INIS)

    Rates of atmospheric corrosion of St3, copper, cadmium and D-16 aluminium alloy are measured in the temperate climatic region in Antarctide with very strong wing at Mirnyj coastal station. Content of sulfates and chlorides in the corrosion soluble products is determined. Analysis of the results with regard to climatic factors during the test period results in the conclusion about the possibility of metal corrosion development in humid atmosphere under negative temperatures. Comparison with the results of the atmospheric tests of metallic materials in coastal and continental subantarctic regions of Far East is carried out

  16. Long-Term Atmospheric Corrosion of Aluminum Alloy 2024-T4 in a Coastal Environment

    Science.gov (United States)

    Zhang, Teng; He, Yuting; Cui, Ronghong; An, Tao

    2015-07-01

    Aluminum alloy 2024-T4 specimens were exposed to atmosphere for 7, 12, and 20 years, respectively, to study long-term corrosion in a coastal environment. One-directional corrosion region and cross-directional corrosion region were defined according to corrosion characters. The statistical regularities, surface appearance, corrosion products, and cross-sectional morphology of both regions were investigated. It was found that the minimum remaining thicknesses of each region can be described by a normal distribution and linearly decrease as the exposure time is increased from 7 to 20 years. The corrosion pits, chlorine ions, and interlinked inner pits are promoting exfoliation, and the alloy's corrosion susceptibility along the long transverse direction is strongly location dependent due to the restrictions imposed by the side material.

  17. A Molecular view of inital Atmospheric Corrosion : In situ surface studies of zinc based on vibrational spectroscopy

    OpenAIRE

    Hedberg, Jonas

    2009-01-01

    Atmospheric corrosion takes place on most metals as they interact with thesurrounding environment. A degradation of the metal is the common result,which often leads to a shortened lifespan of the material. Hence, knowledge onthe fundamental interaction between a gas containing corrosive constituentsand a metal surface, which is the starting point of atmospheric corrosion, isimportant in many contexts. As the nature of atmospheric corrosion is inherentlycomplex, it imposes demands on the analy...

  18. Modelling the corrosion-induced cracking of reinforced concrete structures exposed to the atmosphere

    International Nuclear Information System (INIS)

    The prediction of concrete cracking due to corrosion in atmospheric/carbonated conditions is a major issue for the evaluation of the durability of structures and the choice of maintenance policies. Because of the complexity of the phenomenon, a fully predictive approach is still missing. The proposed work can be considered as one step in this direction. It deals with a modelling study achieved at the Commissariat a l'Energie Atomique (CEA) with the CAST3M finite elements software. Model is constituted of three components: (1) concrete hydric behaviour, (2) rebar corrosion and (3) mechanical consequences on concrete (mainly concrete cracking). Actual developments consider analogies between rebar corrosion mechanisms and atmospheric corrosion ones, assuming that corrosion processes are influenced by the relative humidity evolution of atmosphere and/or of concrete. (authors)

  19. Corrosion resistance of high-chromium steels in coal gasification atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, S.; Nakagawa, K.; Ohtomo, A.; Kato, M.

    1987-06-01

    The corrosion resistances of AISI 347H and 310 stainless steels (SSs), 35Cr-45Ni steel, and chromized and aluminized AISI 347H SS were evaluated in simulated coal gasification atmospheres at 550, 600, and 650 C. The scales formed were mainly sulfides, with a small amount of oxides. Although the corrosion of AISI 347H and 310 SS increased with increasing temperature the corrosion of high-chromium steels, 35Cr-45Ni steel, and chromized AISI 347H SS remarkably decreased at 650 C. Weight gain decreased with increasing chromium content of steel. However, local corrosion occurred on 35Cr-45Ni steel at 600 C. The aluminized samples were the most corrosion resistant of the materials tested, but some cracks were found in the aluminized layer after 100-h exposure. Addition of HCI to the simulated gasification atmosphere generally accelerated corrosion by the formation of a porous outer scale. Pitting during downtime corrosion occurred only for AISI 347H SS exposed in the simulated gas involving 0.2 vol% HCI. The results of electrochemical measurements suggested that the downtime corrosion might by polythionic acid corrosion and crevice corrosion in the solution involving CI/sup -/.

  20. N,N-diethylaminopropionitrile as a volatile inhibitor of atmospheric corrosion of metals

    International Nuclear Information System (INIS)

    The paper deals with an investigation into protection of steel and copper in aqueous solutions by of N,N-diethylaminopropionitrile, as well as with its impact on the kinetics of electrochemical reactions which cause corrosion is an efficient volatile inhibitor of corrosion of both ferrous and nonferrous metals in industrial and marine atmospheres. 10 refs.; 3 figs.; 3 tabs

  1. Atmospheric Corrosion on Steel Studied by Conversion Electron Mössbauer Spectroscopy

    Science.gov (United States)

    Nakanishi, Akio; Kobayashi, Takayuki

    2004-12-01

    In order to investigate initial products on steel by atmospheric corrosion, conversion electron Mössbauer measurements were carried out at temperatures between 15 K and room temperature. From the results obtained at low temperatures, it was found that the corrosion products on steel consisted of ferrihydrite.

  2. Runoff rates and ecotoxicity of zinc induced by atmospheric corrosion.

    Science.gov (United States)

    Karlén, C; Wallinde, I O; Heijerick, D; Leygraf, C; Janssen, C R

    2001-09-28

    Initiated by regulatory restrictions on the use of zinc for various building and construction applications, together with a lack of knowledge related to the release of zinc induced by atmospheric corrosion, a major interdisciplinary research project was implemented to generate data to be used in future risk assessment. Runoff rates from a large number of commercially available zinc-based materials have been determined on panels inclined 45 degrees from the horizon, facing south, during a 1-year atmospheric exposure in an urban environment in Sweden. Possible environmental effects of runoff water immediately after leaving the surface of the various materials have been evaluated during two different sampling periods of varying season and zinc concentration, using the standard growth inhibition test with algae. Raphidocelis subcapitata (formerly Selenastrum capricornutum). Zinc-specific biosensors with the bacterial strain of Alcaligenes eutrophus, and computer modeling using the water-ligand model MINTEQA2 and the humic aquatic model WHAM, have been used to assess the bioavailability and chemical speciation of zinc in the runoff water. An excellent consistency between the different methods was observed. The results show considerably lower runoff rates of zinc (0.07-3.5 g m(-2) year(-1)) than previously being used for regulatory restrictions, and the concentration of zinc to be predominantly responsible for the observed toxicity of the runoff water towards the green algae. The majority of the released zinc quantity was found to be present as free hydrated zinc ions and, hence, bioavailable. The data do not consider changes in bioavailability and chemical speciation or dilution effects during entry into the environment, and should therefore only be used as an initial assessment of the potential environmental effect of zinc runoff from building applications. This interdisciplinary approach has the potential for studies on the environmental fate of zinc in soil or

  3. Atmospheric corrosion resistance of MnCuP weathering steel in simulated environments

    International Nuclear Information System (INIS)

    Highlights: → Atmospheric corrosion resistance of a low cost MnCuP weathering steel was investigated by simulated wet/dry cyclic tests. → The steel shows high corrosion resistance in simulated coastal, industrial, and coastal-industrial atmospheres. → Mn and Cu are identified in bivalent and univalent respectively, leading to cation-selectivity of the rust layer. → Phosphorus promotes the formation of non-soluble phosphates that may act as corrosion inhibitor in rust layer. - Abstract: In this work, atmospheric corrosion resistance of low cost MnCuP weathering steel in simulated coastal, industrial, and coastal-industrial atmospheric environments was investigated by wet/dry cyclic acceleration corrosion tests. The results indicate that MnCuP weathering steel exhibits high corrosion resistance in the three atmospheres. Besides, the alloying effect of Mn, Cu, and P elements on the anti-corrosion mechanism of MnCuP weathering steel was discussed by techniques of X-ray photoelectron spectroscopy, potential-pH diagram, and electron probe microanalysis.

  4. 49 CFR 195.581 - Which pipelines must I protect against atmospheric corrosion and what coating material may I use?

    Science.gov (United States)

    2010-10-01

    ... corrosion and what coating material may I use? 195.581 Section 195.581 Transportation Other Regulations... Corrosion Control § 195.581 Which pipelines must I protect against atmospheric corrosion and what coating... atmosphere, except pipelines under paragraph (c) of this section. (b) Coating material must be suitable...

  5. A brief review on the atmospheric corrosion of mild steel in Iran

    OpenAIRE

    Shafiei, E.; Zeinali., M; A Nasiri; H. Charroostaei; M.A. Gholamalian

    2014-01-01

    This paper presents a review on the atmospheric corrosion of steel, at three sites, in Iran. Corrosion rate values, time of wetness, and the level of pollutants, namely of SO2 and chlorides were determined for the first year of exposure in order to establish the aggressiveness of the atmospheres. The results obeyed well with the empirical kinetics equation of the form C = Ktn.

  6. A brief review on the atmospheric corrosion of mild steel in Iran

    Directory of Open Access Journals (Sweden)

    E. Shafiei

    2014-12-01

    Full Text Available This paper presents a review on the atmospheric corrosion of steel, at three sites, in Iran. Corrosion rate values, time of wetness, and the level of pollutants, namely of SO2 and chlorides were determined for the first year of exposure in order to establish the aggressiveness of the atmospheres. The results obeyed well with the empirical kinetics equation of the form C = Ktn.

  7. GALVANIC CORROSION AND PROTECTION OF GECM/LY12CZ COUPLES UNDER DIFFERENT ATMOSPHERIC EXPOSURE CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    F.Lu; Q.P.Zhong; 等

    2003-01-01

    Galvanic compatibility between graphite epoxy composite materials (GECM) and LY12CZ aluminum alloy was evaluated in different atmospheric corrosion environ-ments and by laboratory electrochemical measurements.Open circuit potential elec-trochemical measurements showed a relatively large potemtial difference about 1 volt between the GECM and LY12CZ aluminum alloy,and this difference provided the driving force for galvanic corrosion of the LY12CZ aluminum alloy as an anode. Having been exposed for 1,3or 5years in Beijing,Tuandao and Wanning station,GECM/LY12CZ couples showed significant losses of strength and elongation.Protec-tive coatings and non-conductive barriers breaking the galvanic corrosion circuit were evaluated under the same atmospheric corrosive conditions.Epoxy primer paint,glass cloth barriers and LY12CZ anodizing were effective in glvanic corrosion control for GECM/LY12CZ couples.

  8. INITIAL ATMOSPHERIC CORROSION OF ZINC IN THE PRESENCE OF NH4Cl

    Institute of Scientific and Technical Information of China (English)

    Q.Qu; C.W.Yan; L.Li; L.Zhang; G.H.Liu; C.N.Cao

    2004-01-01

    Influence of NH4 Cl on the initial atmospheric corrosion of zinc was investigated via quartz crystal microbalance(QCM)in laboratory at 80%RH and 25℃.The results show that NH4 Cl can accelerate the initial corrosion of zinc.Mass gain increase with the exposure time,but mass gain in the later doesn't change obviously due to the formation of the insoluble simonkolleite on zinc surface in the presence of NH4 Cl.Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)was used to characterize the corrosion products.Zn5 Cl2(OH)s.H2 O,(NH4)2ZnCl4 and ZnO are the corrosion products on zinc.Brief discussion on the mechanisms of atmospheric corrosion of zinc in the presence of NH4 Cl was introduced.

  9. GALVANIC CORROSION AND PROTECTION OF GECM/LY12CZ COUPLES UNDER DIFFERENT ATMOSPHERIC EXPOSURE CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    F. Lu; Q.P. Zhong; C.X. Cao

    2003-01-01

    Galvanic compatibility between graphite epoxy composite materials (GECM) andLY12CZ aluminum alloy was evaluated in different atmospheric corrosion environ-ments and by laboratory electrochemical measurements. Open circuit potential elec-trochemical measurements showed a relatively large potential difference about 1 voltbetween the GECM and LY12CZ aluminum alloy, and this difference provided thedriving force for galvanic corrosion of the LY12CZ aluminum alloy as an anode.Having been exposed for 1, 3 or 5 years in Beijing, Tuandao and Wanning station,GECM/L Y12CZ couples showed significant losses of strength and elongation. Protec-tive coatings and non-conductive barriers breaking the galvanic corrosion circuit wereevaluated under the same atmospheric corrosive conditions. Epoxy primer paint, glasscloth barriers and LY12CZ anodizing were effective in galvanic corrosion control forGECM/L Y12CZ couples.

  10. Image analysis of atmospheric corrosion of field exposure high strength aluminium alloys

    Science.gov (United States)

    Tao, Lei; Song, Shizhe; Zhang, Xiaoyun; Zhang, Zheng; Lu, Feng

    2008-08-01

    The corrosion morphology image acquisition system which can be used in the field was established. In Beijing atmospheric corrosion exposure station, the image acquisition system was used to capture the early stage corrosion morphology of five types of high strength aluminium alloy specimens. After the denoise treatment, wavelet-based image analysis method was applied to decompose the improved images and energies of sub-images were extracted as character information. Based on the variation of image energy values, the corrosion degree of aluminium alloy specimens was qualitatively and quantitatively analyzed. The conclusion was basically identical with the result based on the corrosion weight loss. This method is supposed to be effective to analysis and quantify the corrosion damage from image of field exposure aluminium alloy specimens.

  11. A mechanistic study of initial atmospheric corrosion kinetics using electrical resistance sensors

    International Nuclear Information System (INIS)

    This paper describes a novel experimental approach to the study of atmospheric corrosion of iron and zinc, utilising electrical resistance sensors that are sensitive to corrosion losses of the order of one atomic monolayer. Using such devices, a mechanistic study of the initial stages in the atmospheric corrosion of iron and zinc was performed in a rectangular flow cell using controlled relative humidity (RH), temperature and gas flow rate. Additionally, the effects of SO2 contamination in the gas phase and prior NaCl contamination of the metal surface were studied. It was found that the initial corrosion kinetics of iron and zinc are, not unexpectedly, dominated by the development of surface corrosion product films, but that the growth kinetics vary with metal, humidity, etc. Specifically, in the presence of gas-phase SO2, activation energies and kinetic and chemical rate orders were consistent with control of the atmospheric corrosion process by solution-phase oxidation of sulphite-sulphate ion. For iron, this implies that the well-known sulphate-nest theory is inoperative at least during the early stages of atmospheric corrosion. In contrast, for chloride-contaminated zinc, the data were consistent with a rate-controlled diffusion of a species, probably water vapour or oxygen, through a thickening corrosion product film. Finally, the kinetic and chemical rate orders for corrosion of chloride-contaminated iron precluded a diffusion-controlled mechanism, but were consistent with a rate-controlling process involving some regeneration of chloride: e.g. as in metal-ion hydrolysis in a pit or similar localised corrosion events

  12. Atmospheric corrosion tests along the Norwegian-Russian border. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, J.F.; Mikhailov, A.A.

    1997-12-31

    A bilateral exposure programme was carried out along the Norwegian-Russian border in 1990-1991, 1992-1993 and 1993-1994 to evaluate quantitatively the effect of sulphur pollutants on the atmospheric corrosion of important materials in sub-arctic climate. The first part of the programme demonstrated that also in subarctic climate do metals corrode depending on the atmospheric corrosivity, and dose-response functions were derived which combined the effects of SO{sub 2} and time of wetness. The second part of the programme, which is described in this report, involved exposures of carbon steel, zinc and copper at two sites in Norway and three sites in Russia. It is concluded that the accelerated atmospheric corrosion of metals in regions along the border is mainly due to dry deposition of sulphur. At some sites, dry deposition of Cl contributes because of sea-salt aerosols. The corrosivity of acid precipitation is certain but could not be represented as a function because of the small differences observed in the pH values at the different sites. At all test sites the kinetics of corrosion of steel, zinc and copper are characterized by a reduced corrosion rate after one year of exposure. Time of wetness is an important parameter in predicting atmospheric corrosion of metals even on a regional scale. Hence, for monitoring and for trend-effect analysis, it is very important to determine the corrosivity of SO{sub 2} with time of wetness. In accordance with dose-response functions obtained, the yearly corrosion rate for steel and zinc are higher for the areas with higher amounts of dry deposition of Cl than for areas with analogous but only SO{sub 2}-containing atmosphere. 6 refs., 8 figs., 15 tabs.

  13. The effect of environmental variables on atmospheric corrosion of carbon steel in Shenyang

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; WANG ZhenYao; KE Wei

    2009-01-01

    A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H_2S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.

  14. EFFECT OF CHLORIDE ON THE ATMOSPHERIC CORROSION OF SIMULATED ARTIFACT IRON IN NO3-BEARING POLLUTANT ENVIRONMENT

    Institute of Scientific and Technical Information of China (English)

    X. Cao; C.C. Xu

    2006-01-01

    The effect of chloride in nitrogen-bearing pollutant on the atmospheric corrosion of cast iron was investigated by using periodic wet-dry test, electrochemical experiment and surface tension test.Scanning electron microscopy (SEM) with energy disperse atomic X-ray (EDAX) was used to identify the corrosion processes and products. The results of the weight loss measurement showed that the whole corrosion kinetics can be approximately described by: AW=AtB. With the addition of NaC1, B increases. The result presented that Cl- accelerated the corrosion rate obviously during the whole corrosion process. The initial corrosion process was investigated from the viewpoint of surface tension. At the initial corrosion period, the corrosion rate was proportion to the adsorption of anions contained the solutions. And as corrosion went on, the penetration effect of anions and different characteristics of the corrosion products began to dominant the corrosion process, which led to the accelerated effect.

  15. Mechanism of Na2SO4-induced corrosion of molybdenum containing nickel-base superalloys at high temperatures. I - Corrosion in atmospheres containing O2 only. II - Corrosion in O2 + SO2 atmospheres

    Science.gov (United States)

    Misra, A. K.

    1986-01-01

    Kinetics of the Na2SO4-induced corrosion of the molybdenum-containing nickel-base superalloys, B-1900 and Udimet 700, coated with Na2MoO4, has been studied in oxygen atmosphere at temperatures ranging from 750 to 950 C. Because the gas turbine atmosphere always contains some SO2 and SO3, the effect of atmospheric SO2 content on corrosion of Udimet-700 has also been studied. It was found that in the O2 atmosphere the melt in the catastrophic corrosion phase consists of Na2MoO4 plus MoO3, with the onset of the catastrophic corrosion coinciding with the appearance of MoO3. In the presence of low levels of atmospheric SO2 (below 0.24 percent), the melt during catastrophic corrosion contains, in addition to Na2MoO4 and MoO3, some quantities of Na2SO4. At the levels of SO2 above 1 percent, no catastrophic corrosion was observed. At these SO2 levels, internal sulfidation appears to be the primary mode of degradation.

  16. Electrochemical evaluation of the corrosion behaviour for structural steel SAE 1005 exposed to two different atmospheres (urban and industrial) and comparison with atmospheric corrosion gravimetric measurements

    Science.gov (United States)

    Salas, Y.; Guerrero, L.; Castiblanco, H.; Torres, C.; Palacios, A.

    2016-02-01

    The Atmospheric corrosion is a phenomenon we see every day in our environment that arises due to environmental pollution we generate, there is currently very little information on atmospheric corrosion in the department of Boyacá and in general, in Colombia. The aim of this paper is to analyse which of these two environments is more aggressive and wherein the steel corrodes faster. To analyse these phenomenon specimens made in steel SAE 105 exposed for five months to the atmosphere in the municipalities of Tunja and Nobsa (an urban atmosphere and other industrial atmosphere) were installed, a control was carried to verify the amount of time that will be exposed each of these samples to the atmosphere, of Thus it may determine the lifetime of a structural steel. For the analysis of these samples electrochemical tests were carried out to calculate the rate of corrosion and resistance to polarization, also the gravimetric method be conducted to compare what was the amount of mass lost during the time of exposure to each of the samples.

  17. Atmospheric corrosion monitoring at the US Department of Energy's Oak Ridge K-25 Site

    International Nuclear Information System (INIS)

    Depleted uranium hexafluoride (UF6) at the US Department of Energy's K-25 Site at Oak Ridge, TN has been stored in large steel cylinders which have undergone significant atmospheric corrosion damage over the last 35 years. A detailed experimental program to characterize and monitor the corrosion damage was initiated in 1992. Large amounts of corrosion scale and deep pits are found to cover cylinder surfaces. Ultrasonic wall thickness measurements have shown uniform corrosion losses up to 20 mils (0.5 mm) and pits up to 100 mils (2.5 mm) deep. Electrical resistance corrosion probes, time-of-wetness sensors and thermocouples have been attached to cylinder bodies. Atmospheric conditions are monitored using rain gauges, relative humidity sensors and thermocouples. Long-term (16 years) data are being obtained from mild steel corrosion coupons on test racks as well as attached directly to cylinder surfaces. Corrosion rates have been found to intimately related to the times-of-wetness, both tending to be higher on cylinder tops due to apparent sheltering effects. Data from the various tests are compared, discrepancies are discussed and a pattern of cylinder corrosion as a function of cylinder position and location is described

  18. Characterization of Atmospheric Corrosion of 2A12 Aluminum Alloy in Tropical Marine Environment

    Science.gov (United States)

    Li, T.; Li, X. G.; Dong, C. F.; Cheng, Y. F.

    2010-06-01

    In this work, corrosion product formed on 2A12 aluminum (Al) alloy after 3 months of natural exposure in South China Sea atmosphere was characterized by various surface analysis techniques, including scanning electron microscopy, energy-dispersive x-ray analysis, x-ray photoelectron spectroscopy, and x-ray diffraction. The atmospheric corrosion mechanism of Al alloy in marine environment was derived. Results demonstrated that Al alloy specimen experiences serious general corrosion and pitting corrosion. Al and O are enriched in the product film, and Ca and Cl are also found in the film and corrosion pits in Al alloy substrate. The main component compounds existing in the film include Al2O3, Al(OH)3, and AlOOH while AlCl3 and CaCO3 are also identified. Al alloy encounters corrosion under tropical marine atmosphere. Although somewhat protective, the formed surface film on Al alloy specimen is attacked by chloride ions, resulting in significant pitting corrosion of Al alloy.

  19. Annual and long-term prediction of the atmospheric corrosion of metals

    International Nuclear Information System (INIS)

    The atmospheric corrosion of metals is known to be a discontinuous electrochemical process which takes place only when the metallic surface is wet or moistened by different meteorological phenomena (rain, humidity condensation, fog, etc.) The magnitude of atmospheric corrosion would be relatively low if it were not for the presence of certain pollutants in the atmosphere, mainly sulphur dioxide (anthropogenic pollutant) and marine chlorides (natural pollutant). The literature contains different models for predicting the atmospheric metals over short periods (generally one year) and long periods (15, 20 or more years) of atmospheric exposure. In addition to the different meteorological factors (volume of precipitation, days of rain, relative humidity (RH), T, etc.), atmospheric SO2 deposition rate and atmospheric salinity (Cl-) appear as independent variables in all of these models. (Author)

  20. Factors influencing the durability of anti corrosive painting systems on steel in atmospheric exposures

    International Nuclear Information System (INIS)

    The experimental results obtained with ten typical painting systems exposed during eight years in ten Spanish atmospheres are summarized. The effects of the type of atmosphere, characteristics of the paint systems (generic type and thickness), and teel surface preparation in the anti corrosive performance are analysed. (Author) 6 refs

  1. Atmospheric corrosion tests of metals in SO2-polluted cold atmosphere in Northern Norway and along its border with Russia

    International Nuclear Information System (INIS)

    The Norwegian Institute of air studies and the Institute of physical chemistry of the PAS carried out the corrosion tests in the town of Sulitelma. Two stages of the more detailed studies were carried out: in 1990-1991 and 1992-1994. The main results of these studies are summarized. The maps of the carbon steel and zink corrosion in the area of the Russian-Norwegian boundary are presented for the first time. It is shown, that the corrosion development temperature threshold is between -2 and -4 Deg C. The annual corrosion data for all the tested material correlate well with the SO2 levels in the town of Sulitelma and with the SO2 levels in the area of Russian-Norwegian boundary

  2. Long-Term Corrosion of Copper in Hot and Dry Atmosphere in Turpan, China

    Science.gov (United States)

    Kong, D. C.; Dong, C. F.; Fang, Y. H.; Xiao, K.; Guo, C. Y.; He, G.; Li, X. G.

    2016-05-01

    Atmospheric exposure tests were conducted on pure copper exposed to the atmosphere for a four-year period in Turpan, China, a typical hot and dry environment. The experiments included weight-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.24 g/m2/year, and an uneven distribution of corrosion products was observed by scanning electron microscopy. This was attributed to the dehydration process that occurred during wet-dry and cold-hot cycles. The corrosion products mainly comprised cuprite (Cu2O) and atacamite (Cu2Cl(OH)3). Electrochemical measurements showed that deposits on copper improved its resistance to corrosion, but the protectiveness decreased with increasing temperature.

  3. Hot Corrosion Resistance and Mechanical Behavior of Atmospheric Plasma Sprayed Conventional and Nanostructured Zirconia Coatings

    Science.gov (United States)

    Saremi, Mohsen; Keyvani, Ahmad; Heydarzadeh Sohi, Mahmoud

    Conventional and nanostructured zirconia coatings were deposited on In-738 Ni super alloy by atmospheric plasma spray technique. The hot corrosion resistance of the coatings was measured at 1050°C using an atmospheric electrical furnace and a fused mixture of vanadium pent oxide and sodium sulfate respectively. According to the experimental results nanostructured coatings showed a better hot corrosion resistance than conventional ones. The improved hot corrosion resistance could be explained by the change of structure to a dense and more packed structure in the nanocoating. The evaluation of mechanical properties by nano indentation method showed the hardness (H) and elastic modulus (E) of the YSZ coating increased substantially after hot corrosion.

  4. Kinetics and structural studies of the atmospheric corrosion of carbon steels in Panama

    International Nuclear Information System (INIS)

    The corrosion of a carbon steel was studied in different atmospheres at sites in the Republic of Panama. The weight loss (corrosion penetration) suffered by the carbon steel is related to time by a bilogarithmic law. Moessbauer spectroscopy indicated the rust was composed of non-stoichiometric magnetite (Fe3-xO4), maghemite (γ-Fe2O3), goethite (α-FeOOH) of intermediate particle size, lepidocrocite (γ-FeOOH) and superparamagnetic particles. Magnetite formation is related to the alternating dry-wet cycles. Goethite is related to corrosion penetration by a saturation type of behavior, following a Langmuir type of relationship. Goethite in rust protects steel against further atmospheric corrosion

  5. Long-Term Corrosion of Copper in Hot and Dry Atmosphere in Turpan, China

    Science.gov (United States)

    Kong, D. C.; Dong, C. F.; Fang, Y. H.; Xiao, K.; Guo, C. Y.; He, G.; Li, X. G.

    2016-07-01

    Atmospheric exposure tests were conducted on pure copper exposed to the atmosphere for a four-year period in Turpan, China, a typical hot and dry environment. The experiments included weight-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.24 g/m2/year, and an uneven distribution of corrosion products was observed by scanning electron microscopy. This was attributed to the dehydration process that occurred during wet-dry and cold-hot cycles. The corrosion products mainly comprised cuprite (Cu2O) and atacamite (Cu2Cl(OH)3). Electrochemical measurements showed that deposits on copper improved its resistance to corrosion, but the protectiveness decreased with increasing temperature.

  6. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  7. Atmospheric corrosion of copper under wet/dry cyclic conditions

    International Nuclear Information System (INIS)

    The polarization resistance of copper subjected to NaCl and an ammonium sulfate solution under wet/dry cycling conditions was monitored using an EIS impedance technique. The copper samples were exposed to 1 h of immersion using different solutions of pH, temperature and surface orientation and 7 h of drying. The copper plates corroded more substantially on the skyward side than those for a ground ward side. The degree of protection copper oxide provides decrease in an acidic medium (pH 4) more than in a neutral medium (pH 7). The corrosion rate of copper increases rapidly during the initial stages of exposure then decreases slowly and eventually attains the steady state during the last stages of exposure. The corrosion products were analyzed using X-ray diffraction. The corrosion mechanism for copper studied under wet/dry cyclic conditions was found to proceed under the dissolution-precipitation mechanism

  8. The Moessbauer spectroscopy in the characterization of atmospheric corrosion products

    International Nuclear Information System (INIS)

    A study of corrosion products on mild steel formed after 1 and 5 years exposure in two industrial coastal weathering stations in the Bay from Matanzas City, Cuba, has been carried out. Structural analysis was conducted using mainly transmission Moessbauer Spectroscopy and the X-ray diffraction as complementary technique. The main phases found in the specimen exposed to high chloride containing environment were: lepidocrocite (γ- FeOOH), goethite (α- FeOOH) and magnetite concentration was the lowest, the phases found were γ- FeOOH and α- FeOOH, and the phase transformation proposed was γ- FeOOh -> α- Fe-OOH. In this station were found also amorphous corrosion products. There amorphous phases could be responsible for the lowest levels of corrosion on steel in this station

  9. ATMOSPHERIC CORROSION OF STRUCTURAL STEELS EXPOSED IN THE 2004 TSUNAMI-AFFECTED AREAS OF ACEH

    OpenAIRE

    M. Ridha; S. Fonna; S. Huzni; J. Supardi; A.K. Ariffin

    2013-01-01

    Aceh province located at the northwestern tip of Sumatra Island in Indonesia has a coastal environment and a coastline of around 1660 km. Banda Aceh, Aceh Besar, and Aceh Barat are among the districts of Aceh Province located on those coastlines. The earthquake and tsunami that struck Aceh in December 2004 caused much of these districts to be submerged by seawater. Thus, the environment of these areas might become more corrosive. This study investigates atmospheric corrosion of structural ste...

  10. The Atmospheric Corrosion of Magnesium Alloys : Influence of Microstructure and Environments

    OpenAIRE

    Jönsson, Martin

    2007-01-01

    The low density and high specific strength of magnesium alloys have created a great deal of interest in the use of these alloys in the automotive and aerospace industries and in portable electronics. All of these industries deal with applications in which weight is extremely important. However, an obstacle to overcome when using magnesium alloys in engineering applications are their unsatisfactory corrosion properties. This thesis is devoted to the atmospheric corrosion of the two magnesium a...

  11. Atmospheric Corrosion in Indoor of Seafood Industry in the Norwest of Mexico

    OpenAIRE

    Gustavo López-Badilla; Benjamín Valdez-Salas; Michaer Schorr-Wiener

    2012-01-01

    The metallic cans used to packed seafood are made from rolls of steel sheet coated with appropriate films. The exposure of steel cans to aggressive environments generates internal and external damage of these containers, and for this reason are necessary use coatings. The main air pollutants that cause atmospheric corrosion (AC) in steel cans in the northwest of Mexico where are located the city of Ensenada, are the chloride ions (Cl-) and sulfur oxides (SOX) principally. The corrosion in foo...

  12. Utilization of a thin layer electrochemical system to study the atmospheric corrosion

    International Nuclear Information System (INIS)

    In the radioactive wastes deep underground disposal, it is necessary to forecast the aging of metallic containers over millions of years. The deterioration results particularly of the atmospheric corrosion. The aim of this study is to propose models describing the corrosion processes during the storage, in order to evaluate the containers design. In this framework the influence of a thin electrolyte film in contact with the metal is studied. (A.L.B.)

  13. Indoor atmospheric corrosion of electronic materials in tropical-mountain environments

    Energy Technology Data Exchange (ETDEWEB)

    Gil, H. [Corrosion and Protection Group, University of Antioquia, Street 62 No 52-59, Medellin (Colombia)], E-mail: harveth@gmail.com; Calderon, J.A. [Corrosion and Protection Group, University of Antioquia, Street 62 No 52-59, Medellin (Colombia)], E-mail: jacalder@udea.edu.co; Buitrago, C.P.; Echavarria, A.; Echeverria, F. [Corrosion and Protection Group, University of Antioquia, Street 62 No 52-59, Medellin (Colombia)

    2010-02-15

    Indoor corrosion rate during one year exposure for carbon steel, copper, nickel, and tin was determined in three different atmospheres in Colombia. In addition, pollutants deposition rates and environmental parameters were also measured during indoor-outdoor conditions. The results show higher pollutant deposition in outdoor conditions, while inside metallic boxes the pollutant deposition significantly diminishes. No difference for relative humidity values was found between inside and outside measurements. For all samples, except nickel, the corrosion rate decrease with exposure time. The nature of corrosion products was found to be related to the exposure conditions.

  14. Indoor atmospheric corrosion of electronic materials in tropical-mountain environments

    International Nuclear Information System (INIS)

    Indoor corrosion rate during one year exposure for carbon steel, copper, nickel, and tin was determined in three different atmospheres in Colombia. In addition, pollutants deposition rates and environmental parameters were also measured during indoor-outdoor conditions. The results show higher pollutant deposition in outdoor conditions, while inside metallic boxes the pollutant deposition significantly diminishes. No difference for relative humidity values was found between inside and outside measurements. For all samples, except nickel, the corrosion rate decrease with exposure time. The nature of corrosion products was found to be related to the exposure conditions.

  15. 不锈钢的大气腐蚀%REVIEW ON ATMOSPHERIC CORROSION OF STAINLESS STEELS

    Institute of Scientific and Technical Information of China (English)

    李巧霞; 王振尧; 韩薇; 韩恩厚

    2009-01-01

    Research on atmospheric corrosion of stainless steels is reviewed.The characteristics of stainless steels ale discussed in terms of corrosion rate,influencing factors as well as the relevant pitting corrosion mechanism in detail.%综述了国内外不锈钢大气腐蚀研究状况,重点从点蚀机理、腐蚀速率和影响因素方面分析了不锈钢大气腐蚀的点蚀特征.

  16. Atmospheric corrosion of Sm-Fe-N alloys produced by different methods

    International Nuclear Information System (INIS)

    The structural, magnetic and corrosion properties of high coercivity Sm-Fe-N type alloys manufactured by three different technological routes have been compared. The mechanical alloying (MA) and mechanical milling (MM) methods allow to obtain nanocrystalline (10-40 nm) structures whereas the hydrogenation-desorption-decrepitation-recombination (HDDR) method gives rise to one order of magnitude greater grain size of the material. Tiny grained materials show more advantageous magnetic properties and increased resistance to atmospheric corrosion as compared with the material obtained by the HDDR method. Generally, the corrosion behaviour of the Sm-Fe-N materials is comparable with that of medium-carbon steel. (author)

  17. Looking Back on Contributions in the Field of Atmospheric Corrosion Offered by the MICAT Ibero-American Testing Network

    Directory of Open Access Journals (Sweden)

    M. Morcillo

    2012-01-01

    Full Text Available The Ibero-American Map of Atmospheric Corrosiveness (MICAT project was set up in 1988 sponsored by the International Ibero-American programme “Science and Technology for Development (CYTED” and ended in 1994 after six years of activities. Fourteen countries were involved in this project: Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Panama, Peru, Portugal, Spain, Uruguay, and Venezuela. Research was conducted both at laboratories and in a network of 75 atmospheric exposure test sites throughout the Ibero-American region, thus considering a broad spectrum of climatological and pollution conditions. Although with its own peculiarities, the project basically followed the outline of the ISOCORRAG and ICP/UNECE projects, with the aim of a desirable link between the three projects. This paper summarizes the results obtained in the MICAT project for mild steel, zinc, copper, and aluminum specimens exposed for one year in different rural, urban, and marine atmospheres in the Ibero-American region. Complementary morphological and chemical studies were carried out using scanning electron microscopy (SEM coupled with energy dispersive spectrometry (EDS, X-ray diffraction (XRD, and fourier transform infrared Spectroscopy (FTIR techniques, in order to correlate climatic and atmospheric conditions and properties of the corrosion products.

  18. Recreation of Marine Atmospheric Corrosion Condition on Weathering Steel in Laboratory

    Science.gov (United States)

    Guchhait, S. K.; Dewan, S.; Saha, J. K.; Mitra, P. K.

    2014-04-01

    Salt spray test, autoclave corrosion test, SO2 salt spray test, and Relative humidity test are generally used to assess atmospheric corrosion in laboratories at accelerated rates. However, no test can absolutely simulate the service condition. One can get only approximate corrosion rates using the aforesaid tests which serve as an indicative of corrosion behavior of the material in a service condition. The present work is aimed at creating specific environmental condition in laboratory to get the corrosion test done in short duration to compare with on field exposure test which would otherwise take years to complete. In this work recreation of atmospheric environment of Digha was tried and it was simulated in such a manner that the results of laboratory test could be compared with long time field exposure at Digha. Weathering steel (WS) was taken for experimentations. Potentiostatic electrochemical tests route was adopted to simulate atmospheric condition of Digha. Laboratory test results compared well with 18 month field exposure data in terms of corrosion rate, SEM and Ramon Spectroscopy matching.

  19. Atmospheric Corrosion of Different Fe-based Alloys in Nanocrystalline State

    Science.gov (United States)

    Sitek, J.; Sedlačková, K.; Seberíni, M.

    2005-07-01

    Nanocrystalline Fe-based alloys are interesting for their soft magnetic properties. Because these alloys are potentially applicable in outdoor-working components, their corrosion behaviour requires careful analysis. This work presents the results of the atmospheric corrosion tests in industrial and rural environments performed for up to 6 months. We compared the corrosion behaviour of two different compositions of NANOPERM-type alloys: Fe87.5Zr6.5B6 and Fe76Mo8Cu1B15 with classical FINEMET alloys of the nominal composition of Fe73.5Cu1Nb3Si13.5B9 type. The techniques of Mössbauer spectroscopy, conversion electron Mössbauer spectroscopy, X-ray diffraction and transmission electron microscopy have been employed to compare their corrosion rate, characterize corrosion products and inspect the structural changes of the nanocrystalline structure. It was found that the Si-containing FINEMET alloys are the most corrosion-resistant whereas worse corrosion properties were observed for molybdenum-containing Fe76Mo8Cu1B15 alloy. The corrosion product formed on the surface of NANOPERM-type alloys showed a needlelike morphology and a poor crystalline order and has been identified as lepidocrocite, γ-FeOOH.

  20. Rusting Evolution of MnCuP Weathering Steel Submitted to Simulated Industrial Atmospheric Corrosion

    Science.gov (United States)

    Hao, Long; Zhang, Sixun; Dong, Junhua; Ke, Wei

    2012-05-01

    The rusting evolution of MnCuP weathering steel in a simulated industrial atmosphere as a function of corrosion duration was investigated by corrosion weight gain, scanning electron microscopy, X-ray diffraction, and electrochemical methods. The results indicate that the corrosion kinetics is related closely to the rust composition and electrochemical properties. The corrosion rate is higher during the first corrosion stage, and it is lower during the second corrosion stage. During the first corrosion stage, the rust layer is in low density, discontinuous, and loose, with a lower relative abundance of α-FeOOH. During the second corrosion stage, a compact and protective inner rust layer forms with a higher relative abundance of α-FeOOH, contributing to enhanced rust layer resistance. The rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited by the protective rust layer. Electrochemical impedance spectroscopy tests indicate that it is more scientific to evaluate the rust layer protective ability by charge transfer resistance.

  1. GILDES model studies of aqueous chemistry. 5: Initial SO{sub 2}-induced atmospheric corrosion of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Tidblad, J.; Graedel, T.E. [Lucent Technologies, Murray Hill, NJ (United States). Bell Labs.

    1997-08-01

    The authors report in this paper the first theoretical treatment of kinetic and equilibrium chemical processes of the atmospheric corrosion of nickel performed with the multiregime GILDES model. The formulation for exposure of nickel to sulfur dioxide in humidified air involves 67 reactions for 35 species and includes a representation of the protective properties of corrosion products. Two protective mechanisms are investigated: transport through the corrosion products of corrosive agents and blocking of the active surface area. The latter appears to dominate. Results for corrosion products and corrosion rate are compared with those for laboratory exposures at 210 ppb SO{sub 2}, and agreement is excellent.

  2. Application Of Fractal Dimension On Atmospheric Corrosion Of Galvanized Iron Roofing Material

    Directory of Open Access Journals (Sweden)

    Issa A.K

    2015-08-01

    Full Text Available Abstract Corrosion rates of galvanized iron roofing sheet In yola north eastern part of Nigeria were assessed and determined by weight loss method and scanner fractal analysis method. Scanning electronic machine SEM was used to transform corrosion coupons to electronic form for image j processing and analysing software The result of corrosion rates for these two methods after six months of the samples exposure in industrial. Coastal market and urban areas in the region are 1.51 1.079 1.051 0.779 and 1.9941 1.9585 1.9565 1.9059 for weight loss and scanner fractal dimension methods respectively. and the results from the two methods were in agreement This establish the reliability of fractal dimension in measuring atmospheric corrosion this research also provides alternative method of measuring atmospheric corrosion and overcome the limitation of conventional weight loss technique in its inability to measure corrosion rate which is not significantly change over a long period of time moreover weight loss cannot demonstrate the area of concentration of corrosion on the surface of the coupon it rather gives the weight loss value and this will aid in determining the real level or extent of corrosion damage in the material and this can be obtained when measuring the material through fractal analysis these results clearly indicate that corrosion is heavier on locations close to the industrial areas. This also shows the negative impact of industrial activities on the corrodible materials and consequently on the plants and environment.

  3. Atmospheric Corrosion of Ag and Cu with Ozone, UV and NaCl

    Science.gov (United States)

    Lin, Huang

    Ag and Cu are both used for electronics and are susceptible to atmospheric corrosion. They are also good corrosivity monitors used to evaluate aggressiveness of the environment. Unfortunately, laboratory exposure testing does not always represent field environments very well. Discrepancies between lab and field exposure tests are not uncommon. For example, Ag does not corrode in salt spray exposure during ASTM B117 test, while it corrodes everywhere outdoor. This suggests that new laboratory exposure test for Ag needs to be designed and studied. A full factorial experiment was carried out with three factors: ozone, UV intensity and relative humidity (RH). NaCl was loaded by fast evaporation of NaCl/ethanol solution before exposure. After exposure, corrosion products were identified by XRD and quantified by galvanostatic reduction technique. For lab exposure samples, AgCl was identified as the only corrosion product in high RH (87%) environments, while Ag2O and AgO formed as well during exposures at low RH. This result derived a qualitative prediction on corrosion behavior of Ag in field. It predicts that less stable silver compounds such as oxide and sulfate are possible corrosion products in field even silver chloride is the dominant corrosion product forming in field. This prediction was confirmed by analysis of field exposed Ag samples. By quantification of corrosion products, it is determined that UV has two contravening effects on atmospheric corrosion of Ag: photolysis of ozone to generate stronger oxidizing species such as atomic O and photodecomposition of Ag corrosion products by UV radiation. Following its success in Ag corrosion research, the environment of UV, ozone and NaCl was extended to study Cu corrosion. It is determined that UV alone can double Cu corrosion rate by generation of electron-hole pairs in n-type cuprous oxide. It is also found that ozone alone is not as aggressive on Ag as on Cu because protection of naturally formed cuprous oxide

  4. Indoor atmospheric corrosion of historical ferrous alloys. System characterisation, mechanisms and modelling discussion

    International Nuclear Information System (INIS)

    Understanding the mechanisms of indoor atmospheric corrosion in iron alloys is of primary importance in several fields, including for the conservation of Middle Ages monuments or the long term storage of nuclear waste. In this research, a double approach was developed, combining fine characterisation of corrosion systems and design of experiments to answers specific questions related to mechanisms understanding. Iron indoor atmospheric corrosion was investigated on samples coming from the reinforcing chain of the Amiens cathedral (15. century). In the first stage, the corrosion system has been extensively characterised from the macroscopic to the nano-metric scale. In particular, structural micro-analysis (μ-Raman, μ-XRD, μ-XAS) has been used to locate, identify and quantify the oxidised phases. Rust layers are composed of a matrix of nano-metric goethite, with low quantities of lepidocrocite and akaganeite mostly located in the extern part of the corrosion system. In addition, clear marblings are dispersed in the matrix, which are sometimes connected with the metal core. Although these may contain maghemite, these marblings are generally made of ferri-hydrite/feroxyhite phases. In the second stage, specific experiments have been carried out in an unsaturated marked medium to locate oxygen reduction sites in the rust layers. Several cases were evidenced, depending on the rust layer morphology. In addition, reduction processes of model phases have been studied in situ, using an electrochemical cell coupled with structural characterisation techniques. This combination highlighted the influence of reduction mode and pH on the type of reduced phase formed. From the obtained results, several mechanisms are proposed to explain the long term indoor atmospheric corrosion of iron, including rust layers morphology and phases properties. The different hypotheses have been integrated in a proposed method to diagnosis ancient ferrous systems stability. These hypotheses also

  5. Initial corrosion behavior of a copper-clad plate in typical outdoor atmospheric environments

    Science.gov (United States)

    Yi, Pan; Xiao, Kui; Ding, Kangkang; Yan, Lidan; Dong, Chaofang; Li, Xiaogang

    2016-01-01

    A copper-clad printed circuit board (PCB-Cu) was subjected to long-term exposure test under typical Chinese atmospheric environments to study corrosion failure mechanisms. The corrosion behavior was investigated by analyzing electrochemical impedance, scanning Kelvin probes, stereo and scanning electron microscopes, and energy-dispersive spectra. Results showed that the initial surface potential was unevenly distributed. The outdoor PCB-Cu samples suffered severe corrosion caused by dust particles, contaminated media, and microorganisms after long-term atmospheric exposure. The initial localized corrosion was exacerbated and progressed to general corrosion for samples in Turpan, Beijing, and Wuhan under prolonged exposure, whereas PCB-Cu in Xishuangbanna was only slightly corroded. The tendency for electrochemical migration (ECM) of PCB-Cu was relatively low when applied with a bias voltage of 12 V. ECM was only observed in the PCB-Cu samples in Beijing. Contaminated medium and high humidity synergistically affected ECM corrosion in PCB-Cu materials. [Figure not available: see fulltext.

  6. Research on atmospheric corrosion of steel using synchrotron radiation

    International Nuclear Information System (INIS)

    Correlation between local structure around Cr in the protective rust layer on weathering steel and protective performance of the rust layer is presented as an example of corrosion research using synchrotron radiation which has recently been applied in various research fields as a useful tool. In addition, in situ observation of initial process of rust formation on steel is also mentioned. It was pointed out by considering the X-ray absorption fine structure spectra that the nanostructure of the protective rust layer on weathering steel primarily comprises of small Cr-goethite crystals containing surface adsorbed and/or intergranular CrOx3-2X complex anions. This CrOx3-2X explains the protective performance of the rust layer originated by dense aggregation of fine crystals with cation selectivity of the Cr-goethite. It is very advantageous to employ white X-rays for in situ observation of rusting process of a carbon steel covered with electrolyte thin films because rust structure might change very quickly. This in situ observation revealed the effect of ion species on the change in rust phase during wet/dry repeating. It can be said that application of synchrotron radiation on corrosion research is so useful to understand the nanostructure of surface oxides which closely relate to corrosion behavior of metals and alloys. (author)

  7. XAS and XRD in situ characterisation of reduction and reoxidation processes of iron corrosion products involved in atmospheric corrosion

    International Nuclear Information System (INIS)

    Highlights: •In situ structural characterisation with XAS and XRD during electrochemical reduction. •Structural identification of phases formed during the wetting stage of iron AC. •Understanding the reduction and reoxidation processes during the wet–dry cycle of iron AC. -- Abstract: An electrochemical cell has been used for performing in situ X-ray diffraction and absorption spectroscopy structural characterisation by transmission during electrochemical measurements. This cell has been used to reduce lepidocrocite and ferrihydrite, two iron oxides involved in low-carbon steel atmospheric corrosion mechanisms. The reduced phases have been identified in situ as magnetite and iron II hydroxide, two phases that can play a key role in corrosion mechanisms. The reoxidation of the reduced phases was also studied, and lead to the formation of magnetite/maghemite and to the formation of the initial reducible phases lepidocrocite and ferrihydrite

  8. Investigation of the cut-edge corrosion of organically-coated galvanized steel after accelerated atmospheric corrosion test

    Directory of Open Access Journals (Sweden)

    Reşit Yıldız

    2015-11-01

    Full Text Available The cut edge corrosion of organically coated (epoxy, polyurethane and polyester galvanized steel was investigated using electrochemical impedance spectroscopy (EIS. Measurements were performed on specimens that had been tested in an accelerated atmospheric corrosion test. The samples were subjected to 10 s fogging and 1 h awaiting cycles in an exposure cabinet (120 and 180 days with artificial acid rain solution. According to the investigation, the coatings were damaged from the cut edge into the sheet, this distance was about 0.8 cm. These defects were more pronounced at after 180 days in proportion to after 120 days.

  9. In situ structural characterisation of non stable phases involved in atmospheric corrosion of ferrous heritage artefacts

    International Nuclear Information System (INIS)

    The prediction of very long term corrosion of iron and low alloy steel in atmospheric conditions or in hydraulic binder media is a crucial issue for the conservation and restoration of heritage artefacts. For both media, the typical iron corrosion product layers (CPL) can be described as a matrix of goethite (α-FeOOH) crossed by marbling of reactive phases: maghemite (gamma-Fe2O3), ferri-hydrite (Fe5HO8.4H2O), feroxyhyte (δ-FeOOH), etc. The aim of the experiments presented here is to bring new insights on the role that the maghemite could potentially play in the mechanisms of corrosion. For that purpose, electrochemical reductions have been coupled with in situ Raman microspectroscopy. These experiments enable the authors to propose a hypothesis of local mechanisms in the specific case of marbling of maghemite connected to the metallic substrate. These local mechanisms could drastically influence the global corrosion rate. (authors)

  10. Atmospheric corrosion of carbon steel at marine sites in Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Syed, S. [Chemical Engineering Department, King Saud University, Riyadh (Saudi Arabia)

    2010-03-15

    Atmospheric corrosion tests, according to ASTM G50-76, have been carried out in Saudi Arabia, at eight marine sites representing different environmental conditions. Environmental factors such as average temperature, average relative humidity, and deposition rates of atmospheric pollutants (Cl{sup -} and SO{sub 2}) was investigated. X-ray diffraction has been used to determine the composition of the corrosion products. Corrosion rates have been determined for each sample at each of the exposure sites via loss of weight. The obtained data were used for the classification of atmospheric aggressivity, according to ISO 9223. The results obeyed well with the empirical kinetics equation of the form C = Kt{sup n}, where K and C are the corrosion losses in mg/cm{sup 2} after 1 and t years of the exposure respectively, and n is constant. Based on n values, the corrosion mechanism of carbon steel is predicted. The major constituent of the rust formed in marine environment is goethite ({alpha}-FeOOH). Samples also show the presence of a large proportion of lepidocrocite ({gamma}-FeOOH) and small amounts of ferrihydrite and maghemite ({alpha}-Fe{sub 2}0{sub 3}). (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  11. The effects of air pollution and climatic factors on atmospheric corrosion of marble under field exposure

    International Nuclear Information System (INIS)

    The atmospheric corrosion of marble was evaluated in terms of SO2 concentration as air pollution and climatic factors such as rainfall, relative humidity, temperature and so on under the field exposure. Marble of calcite type (CaCO3) was exposed to outdoor atmospheric environment with and without a rain shelter at four test sites in the southern part of Vietnam for 3-month, 1- and 2-year periods from July 2001 to September 2003. The thickness loss of marble was investigated gravimetrically. X-ray diffraction and X-ray fluorescent methods were applied to study corrosion products on marble. The corrosion product of marble was only gypsum (CaSO4 . 2H2O) and was washed out by rain under the unsheltered exposure condition. It was found that the most substantial factors influencing the corrosion of marble were rainfall, SO2 concentration in the air and relative humidity. Based on the results obtained, we estimated the dose-response functions for the atmospheric corrosion of marble in the southern part of Vietnam

  12. Review: Results of studying atmospheric corrosion in Vietnam 1995–2005

    OpenAIRE

    Le Thi Hong Lien, Pham Thy San and Hoang Lam Hong

    2007-01-01

    Vietnam is situated in the wet tropical zone; thus, atmospheric conditions are characterized by high temperatures and a long time of wetness (TOW). In addition, the salt air coming in from the sea causes a high chloride concentration in coastal areas. Furthermore, Vietnam is a developing country, which means that air pollution is increasing with the development of industry. These factors result in significant damage to materials by atmospheric corrosion. In this report, the results of a recen...

  13. ATMOSPHERIC CORROSION OF STRUCTURAL STEELS EXPOSED IN THE 2004 TSUNAMI-AFFECTED AREAS OF ACEH

    Directory of Open Access Journals (Sweden)

    M. Ridha

    2013-06-01

    Full Text Available Aceh province located at the northwestern tip of Sumatra Island in Indonesia has a coastal environment and a coastline of around 1660 km. Banda Aceh, Aceh Besar, and Aceh Barat are among the districts of Aceh Province located on those coastlines. The earthquake and tsunami that struck Aceh in December 2004 caused much of these districts to be submerged by seawater. Thus, the environment of these areas might become more corrosive. This study investigates atmospheric corrosion of structural steels exposed to the environment by the 2004 tsunami. Some typical structural steels, which have five different shapes, were selected for the test. Atmospheric corrosion tests were employed by referring to ASTM G50 standards. Eight locations were selected as the test sites: Peukan Bada, Ulee Lheu, Lingke, Lampulo, Suak Ribee, Suak Pandan, Suak Seuke, and Suak Geudebang. Following a six-month exposure, experimental results show that the atmospheric corrosion rate for Peukan Bada, Ulee Lheu, Lingke, Lampulo, Suak Ribee, Suak Pandan, Suak Seuke, and Suak Geudebang was 0.043–5.451 mpy, 0.035–3.804 mpy, 0.058–5.332 mpy, 0.045–9.727 mpy, 0.265–3.957 mpy, 0.073–2.970 mpy, 0.090–4.101 mpy, and 0.380–6.379 mpy, respectively. The results show that the relative corrosion resistances for all structural steels exposed in these areas can be categorized as good to outstanding. Hence, it is safe to utilize the selected structural steels regarding their atmospheric corrosion resistance.

  14. 49 CFR 195.583 - What must I do to monitor atmospheric corrosion control?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false What must I do to monitor atmospheric corrosion control? 195.583 Section 195.583 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

  15. Surface States of Metal Uranium With Atmospheric Corrosion

    International Nuclear Information System (INIS)

    Variations of microscopic morphology and oxidation products of metal uranium were in-situ investigated from room temperature to 400 degree C in air with micro laser Raman spectroscopy (LRS), Fourier transform infrared (FT-IR) spectroscopy, and scanning Kelvin probe force microscopy (SKPFM), respectively. The results show that the surface microscopic morphology of uranium show pockety global knaggy in room temperature. The surface potential of uranium is higher around the granules and in the hollows, and dot corrosion takes place more easily on the surface of uranium. Furthermore, the surface of uranium can adsorb and subsequently react with oxygen, water and carbon dioxide in air, forming uranium dioxide, uranyl compounds, carbonate, etc.. Heated up under different temperature, some active corroded light spots appear on the surface of uranium at the beginning of heating, and they get together and grow up gradually. The major corrosion product is uranium dioxide (UO2) that begins to change into triuranium octoxide (U3O8) above approximate 260 degree C. (authors)

  16. Effects of NaCl and NH4Cl on the initial atmospheric corrosion of zinc

    International Nuclear Information System (INIS)

    Effects of NaCl and NH4Cl on the initial atmospheric corrosion of zinc were investigated via quartz crystal microbalance (QCM) in laboratory at 80% RH and 25 deg C. The results show that both NaCl and NH4Cl can accelerate the initial atmospheric corrosion of zinc. The combined effect of NaCl and NH4Cl on the corrosion of zinc is greater than that caused by NH4Cl and less than that caused by NaCl. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy and electron dispersion X-ray analysis (SEM/EDAX) were used to characterize the corrosion products of zinc. (NH4)2ZnCl4, Zn5(OH)8Cl2 . H2O and ZnO present on zinc surface in the presence of NH4Cl while Zn5(OH)8Cl2 . H2O and ZnO are the dominant corrosion products on NaCl-treated zinc surface. Probable mechanisms are presented to explain the experimental results

  17. Influence of NaCl Deposition on Atmospheric Corrosion of A3 Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Regularity of the initial atmospheric corrosion of A3 steel in the presence of NaCl was investigated. The results showed that NaCl can accelerate the corrosion of A3 steel. Dry mass gain of A3 steel in the presence of NaCl deposition increases with the exposure time, which can be correlated by using exponential decay function. The relationship between dry mass gain and amount of NaCl deposition at a certain exposure time follows a quadratic function. More amount of NaCl deposition will slow down the corrosion rate to some extent after exposure for a certain time. SEM/EDAX was used to characterize the corrosion surface and products. The surfaces of the NaCl treated A3 steel were obviously uneven, and some tiny crevices appear in the corrosion products that could help O2 transmit to the inner layer. The amount of oxygen in atomic percentage in the corrosion products increases with the amount of NaCl deposition.

  18. The initial atmospheric corrosion of copper and zinc induced by carboxylic acids : Quantitative in situ analysis and computer simulations

    OpenAIRE

    Gil, Harveth

    2011-01-01

    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...

  19. Effect of Superficial Atmospheric Corrosion Upon the Internal Stresses in Structural Steel Elements

    OpenAIRE

    Monel Leiba; Budescu, M.; Elena Axinte; Elena-Carmen Teleman

    2006-01-01

    A research program is presented showing the stress status determined by the corrosion phenomenon inside a specimen of a structural steel element. Several stains are studied their diameters ranging from 1~mm to 6~mm and thickness of the corroded layer under 0.5~mm. The physical modeling is the result of testing in laboratory the phenomenon of superficial atmospheric corrosion and the numerical modeling was developed under a FEM program, ALGOR. A number of 3,200 finite elements of BRICK type we...

  20. Atmospheric Corrosion Investigation in Industrial, Marine and Rural Environments in South-East Brazil

    International Nuclear Information System (INIS)

    ASTM 283-C, AISI 304 and 316-L steel specimens (called coupons) were exposed in marine, industrial and rural area(s) for different periods ranging between 1-12 months, in four different season campaigns. The corrosion rate was determined by chemical loss measurements. Rust characterization was performed by XRD, SEM, optical, and Moessbauer spectroscopy (in transmission and backscattering geometry). Superparamagnetic maghemite and goethite were found as corrosion products. Magnetic goethite and feroxyhite decrease with time of exposure. Lepidochrosite is detected and its intensity increase with the atmospheric exposure time. The results obtained from XRD and Moessbauer are in good agreement.

  1. Heterogeneous corrosion of mild steel under SRB-biofilm characterised by electrochemical mapping technique

    International Nuclear Information System (INIS)

    Highlights: → Highly conductive SRB-biofilm can shield the potential differences of mild steel. → Potential maps fail to indicate the localised corrosion of steel under SRB-biofilm. → Galvanic current maps can detect the location of localised corrosion under biofilm. → SRB-biofilm is super-capacitive due to the conductive sulphide micropores. - Abstract: Heterogeneous corrosion of mild steel under sulphate reducing bacteria (SRB)-biofilm was characterised by wire beam electrode (WBE) technique and electrochemical impedance spectrum. The potential/current distributions of the WBE under SRB-biofilm showed that the potential maps could not indicate the localised corrosion of steels beneath biofilm due to the fact that all wire electrodes were short-circuited by the highly conductive sulphide precipitates embedded in SRB-biofilm. Instead, the galvanic current maps may give a good indication. The characteristic of super-capacitance (0.21 F/cm2) of SRB-biofilm was attributed to the huge specific surface area of conductive pore walls inside biofilm.

  2. Modeling of atmospheric corrosion of metals and its acceleration by increasing temperature in chambers of artificial climate

    International Nuclear Information System (INIS)

    Data are given on studying the effect of temperature on the rates of iron, zinc, cadmium, and copper corrosion in a pure humid atmosphere and in the presence of a thin phase water layer on the metal. The coefficients of corrosion acceleration with temperature have been determined. By conducting the experiments in chambers with artificial climate at 40-60 deg C, it has been shown how the corrosion process can be accelerated on the metals investigated in comparison with real conditions

  3. Characterization of corrosion products formed on steels in the first months of atmospheric exposure

    Directory of Open Access Journals (Sweden)

    Renato Altobelli Antunes

    2003-06-01

    Full Text Available The corrosion products of carbon steel and weathering steel exposed to three different types of atmospheres, at times ranging from one to three months, have been identified. The steels were exposed in an industrial site, an urban site (São Paulo City, Brazil, and a humid site. The effect of the steel type on the corrosion products formed in the early stages of atmospheric corrosion has been evaluated. The corrosion products formed at the various exposure locations were characterized by Raman microscopy, X-Ray diffraction (XRD and their morphology was observed by Scanning Electron Microscopy (SEM. Three regions of different colours (yellow, black and red have been identified over the steel coupons by Raman microscopy. Analysis carried out on each of these areas led to the characterization of the correspondent oxide/hydroxide phases. The main phases present were lepidocrocite (g-FeOOH and goethite (a-FeOOH. Small amounts of magnetite (Fe3O4 were also eventually encountered.

  4. Studies on the initial stages of zinc atmospheric corrosion in the presence of chloride

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.Y. [Department of Materials Science and Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Chung, S.C. [Department of Materials Science and Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Shih, H.C. [Department of Materials Science and Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)]. E-mail: hcshih@mse.nthu.edu.tw

    2006-11-15

    A four-year exposure program was carried out in Taiwan in which 23 test sites with different climatic and pollution conditions were chosen and evaluated according to ISO standards 9223-9226. Examination of the results indicated that most of the tests sites were very corrosive to zinc specimens and there was a severe white rust problem for freshly galvanized items stored in high humidity outdoors environments. In addition, the initial stages of zinc atmospheric corrosion in the presence of chloride were studied quantitatively in a non-aqueous electrolyte (methanol) using ex situ electrochemical impedance spectroscopy (EIS) to determine polarization resistance (R {sub p}). The samples were exposed to the synthetic atmospheres with careful controlled relative humidity, temperature, and contaminating salts. It was observed that a change of R {sub p} was accompanied by a change in the corrosion product on the zinc surface, and that the R {sub p} increased with relative humidity (RH) during pre-exposure. Furthermore, the corrosion products of zinc were analyzed qualitatively by grazing-angle X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Zinc hydroxycarbonate (Zn{sub 5}(CO{sub 3}){sub 2}(OH){sub 6}) and zinc oxide (ZnO) in this surface layer were found to provide protection against chloride contaminants.

  5. Studies on the initial stages of zinc atmospheric corrosion in the presence of chloride

    International Nuclear Information System (INIS)

    A four-year exposure program was carried out in Taiwan in which 23 test sites with different climatic and pollution conditions were chosen and evaluated according to ISO standards 9223-9226. Examination of the results indicated that most of the tests sites were very corrosive to zinc specimens and there was a severe white rust problem for freshly galvanized items stored in high humidity outdoors environments. In addition, the initial stages of zinc atmospheric corrosion in the presence of chloride were studied quantitatively in a non-aqueous electrolyte (methanol) using ex situ electrochemical impedance spectroscopy (EIS) to determine polarization resistance (R p). The samples were exposed to the synthetic atmospheres with careful controlled relative humidity, temperature, and contaminating salts. It was observed that a change of R p was accompanied by a change in the corrosion product on the zinc surface, and that the R p increased with relative humidity (RH) during pre-exposure. Furthermore, the corrosion products of zinc were analyzed qualitatively by grazing-angle X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Zinc hydroxycarbonate (Zn5(CO3)2(OH)6) and zinc oxide (ZnO) in this surface layer were found to provide protection against chloride contaminants

  6. Characterization of initial atmospheric corrosion of conventional weathering steels and a mild steel in a tropical atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.pa [Universidad de Panama, Depto. de Quimica Fisica, CITEN, Lab. No 105, Edificio de Laboratorios Cientificos-VIP (Panama); Munoz, Alcides [Universidad de Panama, Depto. de Fisica, Lab. No 216, Edificio de Laboratorios Cientificos-VIP (Panama); Justavino, Jaime; Hernandez, Cecilio [Universidad Tecnologica de Panama, Laboratorio de Quimica y Fisica Aplicada (Panama)

    2009-07-15

    The phases and compositions of the corrosion products of a mild steel (A-36) and two weathering steels (A-588 and COR 420) formed after 3 months exposure to the tropical marine atmosphere of Panama were examined using FTIR and Moessbauer spectroscopy. The results show that amorphous or crystallized iron oxyhydroxides goethite {alpha}-FeOOH and lepidocrocite {gamma}-FeOOH are early corrosion products. Maghemite {gamma}-Fe{sub 2}O{sub 3} and magnetite Fe{sub 3}O{sub 4} have also been identified and found to be prominent components for steels exposed to the most aggressive conditions. The formation of akaganeite {beta}-FeOOH was observed when chlorides were occluded within the rust. FTIR showed the presence of hematite {alpha}-Fe{sub 2}O{sub 3} in one sample.

  7. Characterization of initial atmospheric corrosion of conventional weathering steels and a mild steel in a tropical atmosphere

    International Nuclear Information System (INIS)

    The phases and compositions of the corrosion products of a mild steel (A-36) and two weathering steels (A-588 and COR 420) formed after 3 months exposure to the tropical marine atmosphere of Panama were examined using FTIR and Moessbauer spectroscopy. The results show that amorphous or crystallized iron oxyhydroxides goethite α-FeOOH and lepidocrocite γ-FeOOH are early corrosion products. Maghemite γ-Fe2O3 and magnetite Fe3O4 have also been identified and found to be prominent components for steels exposed to the most aggressive conditions. The formation of akaganeite β-FeOOH was observed when chlorides were occluded within the rust. FTIR showed the presence of hematite α-Fe2O3 in one sample.

  8. Characterization of initial atmospheric corrosion of conventional weathering steels and a mild steel in a tropical atmosphere

    Science.gov (United States)

    Jaén, Juan A.; Muñóz, Alcides; Justavino, Jaime; Hernández, Cecilio

    2009-07-01

    The phases and compositions of the corrosion products of a mild steel (A-36) and two weathering steels (A-588 and COR 420) formed after 3 months exposure to the tropical marine atmosphere of Panama were examined using FTIR and Mössbauer spectroscopy. The results show that amorphous or crystallized iron oxyhydroxides goethite α-FeOOH and lepidocrocite γ-FeOOH are early corrosion products. Maghemite γ-Fe2O3 and magnetite Fe3O4 have also been identified and found to be prominent components for steels exposed to the most aggressive conditions. The formation of akaganeite β-FeOOH was observed when chlorides were occluded within the rust. FTIR showed the presence of hematite α-Fe2O3 in one sample.

  9. Electrochemical noise evaluation of anodized aluminum. Comparative study against corrosion behaviour in the atmosphere

    International Nuclear Information System (INIS)

    The present work reports the evaluation of aluminum and anodized aluminum by electrochemical noise, as a part of the PATINE/CYTED project of the working group NS5. A visual examination is also made. The samples were exposed at several Ibero-American atmospheres up to 2 years of exposure. Different thickness of anodized aluminum were evaluated. The electrochemical potential noise of the 5 μm unexposed sample (pattern) showed a different behaviour to that showed by the other anodized specimens. This could be due to a slower sealed of the samples of higher thickness. The same behavior was observed on the samples exposed at the rural station. el Pardo. According to the visual examination, the samples of bare aluminum and those of anodized 5 μm thickness were the most affected by pitting corrosion in the highly polluted atmospheres. A good correlation between corrosion behaviour determined by visual examination and EN was obtained. (Author) 4 refs

  10. Electrochemical study of a simulation model of atmospheric corrosion in presence of sulphur dioxide

    International Nuclear Information System (INIS)

    In its first part, this research thesis recalls some theoretical aspects of thin layer electrochemistry (equations of current-voltage characteristics, oxygen transport mechanism), and reports a bibliographical study on the role of oxygen in the behaviour of platinum and nickel electrodes and on the sulphur dioxide electrochemical behaviour. Then, the author reports the development of a simulation tool for the atmospheric corrosion based on thin layer electrochemistry (dosing of the dissolved oxygen by the thin layer electrochemistry method, study of the continuous supply of oxygen in the thin layer). The next part reports the study of the influence of sulphur dioxide on the electrochemical behaviour of platinum in aqueous solution, and the last part reports the simulation of nickel atmospheric corrosion in a thin layer of acid sodium sulphate and in presence of oxygen and sulphur dioxide

  11. The ray-tracing mapping operator in an asymmetric atmosphere

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In a spherically symmetric atmosphere, the refractive index profile is retrieved from bending angle measurements through Abel integral transform. As horizontal refractivity inhomogeneity becomes significant in the moist low atmosphere, the error in refractivity profile obtained from Abel inversion reaches about 10%. One way to avoid this error is to directly assimilate bending angle profile into numerical weather models. This paper discusses the 2D ray-tracing mapping operator for bending angle in an asymmetric atmosphere. Through simulating computations, the retrieval error of the refractivity in horizontal inhomogeneity is assessed. The step length of 4 rank Runge-Kutta method is also tested.

  12. Quantified In Situ Analysis of Initial Atmospheric Corrosion : Surface heterogeneity, galvanic effects and corrosion product distribution on zinc, brass and Galvalume

    OpenAIRE

    Qiu, Ping

    2011-01-01

    The interaction of the surface of a pure metal or an alloy with the surrounding atmosphere occurs in a highly complex interfacial regime. During atmospheric corrosion this interfacial regime involves the metal surface, often covered by a naturally formed oxide layer of a few nanometers thickness; an aqueous adlayer, typically with a thickness of a few to a few tens of nanometers, and the atmosphere from which airborne particles, oxygen, and gaseous pollutants dissolve into the adlayer and inf...

  13. Atmospheric corrosion of hot and cold rolled carbon steel under field exposure in Saudi Arabia

    International Nuclear Information System (INIS)

    Carbon steel (hot and cold rolled) specimens have been exposed to the action of different atmospheres at 20 test sites distributed in Saudi Arabia and was investigated in terms of environmental factors such as average temperature, average relative humidity and deposition rates of atmospheric pollutants (Cl- and SO2). Applying the standard ISO 9223 norm aggressiveness of the atmospheres corresponding to 0the different test sites has been determined. Calculations of corrosion rates were made via loss of weight and characterization of the corrosion products formed on samples has been carried out by means of X-ray diffraction (XRD). The major constituent of the rust formed in marine and marine-industrial environment is goethite (α-FeOOH). These samples also show the presence of a large proportion of lepidocrocite (γ-FeOOH) and small amounts of ferrihydrite and maghemite (γ-Fe2O3). In the case of urban and rural samples goethite is the major constituent of corrosion layers. The rust formed under the urban environment also contains large amounts of ferrihydrite and in a lesser proportion, of goethite and maghemite

  14. A Study on the Effect of Electrolyte Thickness on Atmospheric Corrosion of Carbon Steel

    International Nuclear Information System (INIS)

    Effect of electrolyte layer thickness and increase in concentration of electrolyte during electrolyte thining on the atmospheric corrosion of carbon steel were investigated using EIS and cathodic polarization technique. The electrolyte layer thickness was controlled via two methods : one is mechanical method with microsyringe applying a different amount of electrolyte onto the metal surface to give different electrolyte thickness with the same electrolyte concentration. The other is drying method in which water layer thickness decreases through drying, causing increase in concentration of electrolyte during electrolyte thinning. In the region whose corrosion rate is controlled by cathodic reaction, corrosion rate for mechanical method is larger than that for drying method. However, for the electrolyte layers thinner than 20 ∼ 30 m, increase in concentration of electrolyte cause a higher corrosion rate for the case of the mechanical method compared with that of drying method. For a carbon steel covered with 0.1M Na2SO4, maximum corrosion rate is found at an electrolyte thickness of 45 ∼ 55 μm for mechanical method. However, maximum corrosion rate is found at an electrolyte thickness of 20 ∼ 35 μm for drying method. The limiting current is inversely proportional to electrolyte thickness for electrolyte thicker than 20 ∼ 30 μm. However, further decrease of the electrolyte thickness leads to an electrolyte thickness-independent limiting current reagion, where the oxygen rate is controlled by the solvation of oxygen at the electrolyte/gas interface. Diffusion limiting current for drying method is smaller compared with that for mechanica control. This can be attributed to decreasing in O2 solubility caused by increase in concentration of electrolyte during electrolyte thining

  15. STEEL CORROSION AT 600°C IN SINGLE AND DUAL CONDITION IN OXYFUEL ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Daniel Massari de Souza Coelho

    2014-10-01

    Full Text Available Coal-fired power plants using the Oxyfuel process are being developed to produce electricity with zero CO2 emission. Steels used in this and other processes are often exposed to different atmospheres in each side of the material, especially in heat exchangers and solid oxide fuel cells. Some studies have shown that steels exposed to different hydrogen partial pressures in each side have a different corrosion behavior from steels exposed to a single atmosphere condition. In this investigation, two experimental steels were studied at 600°C and 1 atm in dual atmospheres containing water vapor in one side and flue gas in the other and they were compared to steels oxidized in single atmospheres. The gas composition used is similar to the ones found in Oxyfuel coal power plants, where there is a great concentration of CO2, and also H2O and SO2. Analyses were made using SEM and TEM.

  16. Corrosion of Iron and Four Commercial Steels in a Cl-Containing Oxidizing Atmosphere at 500~600℃

    Institute of Scientific and Technical Information of China (English)

    Ke ZHANG; Yah NIU; Chaoliu ZENG; Weitao WU

    2004-01-01

    The corrosion behaviors of Fe and four commercial steels with different Cr contents were investigated in an oxidizing atmosphere containing HCI at 500~600℃, which simulated the environment to which materials are usually exposed in waste incineration. All the test materials underwent an accelerated corrosion in this atmosphere and small amounts of chlorine could be detected at the metal/scale interface. The corrosion mechanism is discussed on the basis of thermodynamic considerations for the reactions between metals and mixed O-CI gases.

  17. Reduction of air pollutants-a tool for control of atmospheric corrosion

    International Nuclear Information System (INIS)

    In most urban areas in Europe and Northern American serious corrosion impacts on buildings and cultural monuments have been caused by emissions of pollutants. The rapidly increasing pollution levels in many of the developing countries also exert a serious threat to materials. Beside the very important role of SO2 also the direct or synergistic effect of NO2 and O3, the particulates and rain acidity may contribute in an important way to materials degradation. Results from extensive international field exposure programmes i. e. within the UN/ECE have enabled development of dose-response relations which describe the effect of dry and wet deposition of pollutants on corrosion of different material groups. In most of the industrialized countries decreasing trends of sulphur and nitrogen pollutants and of acidity of precipitation have resulted in decreased corrosion rates. The concept of acceptable levels of pollutants is a useful tool in planning of abatement strategies and for defining of conditions for a suitable development in the field of corrosion of construction in the atmosphere. (Author) 12 refs

  18. Mechanical properties and corrosion behavior of materials exposed to an experimental, atmospheric fluidized-bed combustor

    International Nuclear Information System (INIS)

    A joint materials test program developed by the Institute for Mining and Minerals Research (IMMR) and the Tennessee Valley Authority (TVA) involved the postexposure mechanical properties and corrosion behavior of candidate structural materials in an experimental, atmospheric fluidized-bed combustor (AFBC). This combustor was operated by Accurex Corporation at Research Triangle Park, North Carolina, under the direction of TVA. The materials studied were Type 304, Type 310, and INCOLOY alloy 800 in the form of disc coupons with and without crevice configurations. Type 304 was also used for mechanical property measurements. The alloys were exposed to the combustor environment at about8400C for approximately 330 hours. The ranking in terms of decreasing weight loss was: (1) Type 304, (2) Type 310, and (3) INCOLOY alloy 800. The presence of tight crevices did not enhance the corrosion rate. In addition, the corrosion rates, based on the weight loss (typically 1 to 6 mpy), indicated that the alloys performed reasonably well when considering materials wastage. However, optical microscopy observations showed intergranular corrosion penetration in INCOLOY alloy 800 and Type 304. The mechanical properties of Type 304 were inferior to the unexposed alloy. A comparison of the data obtained from the combustor-exposed 304ss tensile samples with data from control samples exposed in vacuum to a similar thermal history indicated that the chemistry of the AFBC environment did not play a major role in the observed degradation of the mechanical properties

  19. In situ structural characterisation of non stable phases involved in atmospheric corrosion of ferrous heritage artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.; Perrin, S. [CEA Saclay, DEN, DPC, SCCME, LECA, F-91191 Gif Sur Yvette (France); Burger, E.; Neff, D.; Faiz, H.; Dillmann, P. [CEA Saclay, UMR CEA CNRS, UMR 3299, IRAMIS, SIS2M, LAPA, F-91191 Gif Sur Yvette (France); Legrand, L. [Univ Evry, CNRS, LAMBE UMR8587, F-91025 Evry (France); Faiz, H. [Nancy Univ, Inst Jean Lamour, UMR CNRS 7198, Nancy (France); L' Hostis, V. [CEA Saclay, DEN, DPC, SCCME, LECBA, F-91191 Gif Sur Yvette (France); Dillmann, P. [CNRS, IRAMAT, LMC, UMR 5060, F-91191 Gif Sur Yvette (France)

    2010-07-01

    The prediction of very long term corrosion of iron and low alloy steel in atmospheric conditions or in hydraulic binder media is a crucial issue for the conservation and restoration of heritage artefacts. For both media, the typical iron corrosion product layers (CPL) can be described as a matrix of goethite ({alpha}-FeOOH) crossed by marbling of reactive phases: maghemite (gamma-Fe{sub 2}O{sub 3}), ferri-hydrite (Fe{sub 5}HO{sub 8}.4H{sub 2}O), feroxyhyte ({delta}-FeOOH), etc. The aim of the experiments presented here is to bring new insights on the role that the maghemite could potentially play in the mechanisms of corrosion. For that purpose, electrochemical reductions have been coupled with in situ Raman microspectroscopy. These experiments enable the authors to propose a hypothesis of local mechanisms in the specific case of marbling of maghemite connected to the metallic substrate. These local mechanisms could drastically influence the global corrosion rate. (authors)

  20. Atmospheric corrosion in subtropical areas: XRD and electrochemical study of zinc atmospheric corrosion products in the province of Santa Cruz de Tenerife (Canary Islands, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain)]. E-mail: jmorales@ull.es; Diaz, F. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain); Hernandez-Borges, J. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain); Gonzalez, S. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain)

    2006-02-15

    In the present paper, zinc sheets have been exposed for 4 years to the action of different atmospheres in 35 test sites located in the province of Santa Cruz de Tenerife, Canary Islands, Spain. Corrosion products formed on the surface of the samples have been identified by means of X-ray diffraction (XRD) for the first and second year of exposure. Zincite, hydrozincite, simonkolleite, zinc chlorohydroxysulphate, zinc oxysulphate and zinc hydroxysulphate have been identified in the test sheets. Preliminary results of an electrochemical study of the breakdown potential of zinc samples are also presented in order to test the protective effect of the film formed on the surface of the samples. It was found that the protective effect of this film increases linearly with exposure time.

  1. Atmospheric corrosion in subtropical areas: XRD and electrochemical study of zinc atmospheric corrosion products in the province of Santa Cruz de Tenerife (Canary Islands, Spain)

    International Nuclear Information System (INIS)

    In the present paper, zinc sheets have been exposed for 4 years to the action of different atmospheres in 35 test sites located in the province of Santa Cruz de Tenerife, Canary Islands, Spain. Corrosion products formed on the surface of the samples have been identified by means of X-ray diffraction (XRD) for the first and second year of exposure. Zincite, hydrozincite, simonkolleite, zinc chlorohydroxysulphate, zinc oxysulphate and zinc hydroxysulphate have been identified in the test sheets. Preliminary results of an electrochemical study of the breakdown potential of zinc samples are also presented in order to test the protective effect of the film formed on the surface of the samples. It was found that the protective effect of this film increases linearly with exposure time

  2. X-rays absorption study on medieval corrosion layers for the understanding of very long-term indoor atmospheric iron corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Monnier, J. [SIS2M UMR 3299 CEA-CNRS, Laboratoire Archeomateriaux et Prevision de l' Alteration (LAPA), Gif/Yvette cedex (France); UMR 7182 CNRS and UPEC, Universite Paris-Est, Institut de Chimie et des Materiaux Paris-Est (ICMPE), Thiais (France); Reguer, S.; Vantelon, D. [Synchrotron SOLEIL, Gif-sur-Yvette (France); Dillmann, P. [SIS2M UMR 3299 CEA-CNRS, Laboratoire Archeomateriaux et Prevision de l' Alteration (LAPA), Gif/Yvette cedex (France); IRAMAT UMR 5060 CNRS, Gif sur Yvette (France); Neff, D. [SIS2M UMR 3299 CEA-CNRS, Laboratoire Archeomateriaux et Prevision de l' Alteration (LAPA), Gif/Yvette cedex (France); Guillot, I. [UMR 7182 CNRS and UPEC, Universite Paris-Est, Institut de Chimie et des Materiaux Paris-Est (ICMPE), Thiais (France)

    2010-05-15

    The study and prediction of very long-term atmospheric corrosion behaviour of ferrous alloys is of great importance in different fields. First the conservation of metallic artefacts in museum and the corrosion diagnosis on ferrous reinforcement used in ancient monuments since medieval times needs reliable data to understand the mechanisms. Second, in the frame of the interim storage of nuclear waste in France, it is necessary to model the long-term corrosion of low alloy steel overcontainer. The nature of phases and elements constituting the corrosion layers can greatly influence the corrosion mechanisms. On the one hand, it is crucial to precisely determine the nature of microscopic phases that can be highly reactive. On the other hand, some elements as P and S could modify this reactivity. To clarify this point and complementary to other studies using Raman micro spectroscopy technique, X-rays Absorption Spectroscopy (XAS) under synchrotron radiation plays a crucial role. It allows one to precisely identify the reactive phases in the corrosion layers. Micro-XAS was required in order to refine the spatial variation, at micrometer scale, of the predominant Fe oxidation state and to characterise the corresponding corrosion products. Moreover, the role of minor elements on phase's stability and the chemical form of these elements in the rust layer, especially phosphorus and sulphur, was investigated. (orig.)

  3. X-rays absorption study on medieval corrosion layers for the understanding of very long-term indoor atmospheric iron corrosion

    Science.gov (United States)

    Monnier, J.; Réguer, S.; Vantelon, D.; Dillmann, P.; Neff, D.; Guillot, I.

    2010-05-01

    The study and prediction of very long-term atmospheric corrosion behaviour of ferrous alloys is of great importance in different fields. First the conservation of metallic artefacts in museum and the corrosion diagnosis on ferrous reinforcement used in ancient monuments since medieval times needs reliable data to understand the mechanisms. Second, in the frame of the interim storage of nuclear waste in France, it is necessary to model the long-term corrosion of low alloy steel overcontainer. The nature of phases and elements constituting the corrosion layers can greatly influence the corrosion mechanisms. On the one hand, it is crucial to precisely determine the nature of microscopic phases that can be highly reactive. On the other hand, some elements as P and S could modify this reactivity. To clarify this point and complementary to other studies using Raman micro spectroscopy technique, X-rays Absorption Spectroscopy (XAS) under synchrotron radiation plays a crucial role. It allows one to precisely identify the reactive phases in the corrosion layers. Micro-XAS was required in order to refine the spatial variation, at micrometer scale, of the predominant Fe oxidation state and to characterise the corresponding corrosion products. Moreover, the role of minor elements on phase’s stability and the chemical form of these elements in the rust layer, especially phosphorus and sulphur, was investigated.

  4. Development of corrosion risk map for Peninsular Malaysia using climatic and air pollution data

    International Nuclear Information System (INIS)

    Malaysia has catapulted to an era of major transition. This rapid transition has also cause impact to the environment. The human activities contribute to pollutions. Buildings and it component's performances are affected directly or indirectly by air pollutions and climate factors. It has triggering and accelerating degradation processes. When deterioration start, service life of the buildings and its components will decrease. This paper presents initial development of corrosion risk map for Peninsular Malaysia using Geographical Information System (GIS). The air pollution and climate data obtained from Malaysia Meteorology Department (MMD). The air pollution data was the salt ion deposition of nitrate, chloride and sulphate in a form of wet fall out (WFO). The corrosion risk map generated using geographical information system (GIS) using inverse distance weighing (IDW) and weighted overlay method. It found that the corrosion risk map can be generated with further site verification and it can be used by engineers for further prediction of service life of building components in achieving sustainable construction design.

  5. High temperature corrosion in chloridizing atmospheres: development of material quasi-stability diagrams and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Doublet, S.; Schuetze, M. [Karl-Winnacker-Institut der DECHEMA e.V., Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany)

    2004-07-01

    Chlorine gas is widely encountered in chemical industries, e. g. in waste incinerators and plastic/polymer decomposition mills. The presence of chlorine may significantly reduce the life-time of the components. Although metallic materials have been widely used under such conditions there is still a need for data on the role of the different alloying elements in commercial alloys. The purpose of this work is to produce a clear picture of which alloying elements play a detrimental role and which elements are beneficial. These results can be used as a tool for general assessment of metallic alloys with regard to their performance in chloridizing high temperature environments. A previous study has already been performed in oxidizing-chloridizing atmospheres and led to the elaboration of material quasi-stability diagrams. As a follow-up the present work has been performed in reducing-chloridizing atmospheres in order to validate these diagrams at low partial pressures of oxygen. The behaviour of 9 commercial materials where the content of the major alloying elements was varied in a systematic manner was investigated in reducing-chloridizing atmospheres (in Ar containing up to 2 vol.% Cl{sub 2} and down to 1 ppm O{sub 2}) at 800 deg. C. As the thermodynamical approach to corrosion in such atmospheres could not explain all the phenomena which occur, kinetics calculations i.e. diffusion calculations were carried out. Pack cementation and High Velocity Oxy-Fuel (HVOF) coatings were also developed from the best alloying elements previously found by the calculations and the corrosion experiments. Corrosion tests on the coated materials were then performed in the same conditions as the commercial alloys. (authors)

  6. [Study on the infrared spectra and raman spectra of steel rusty layer with atmospheric corrosion].

    Science.gov (United States)

    Yang, Xiao-mei

    2006-12-01

    In the present study two methods, infrared and Raman spectral analyses, were used to measure the rusty layer of samples with atmospheric corrosion from Qingdao. The main component rust phase of the rusty layer was observed, showing that the relative content of the rust phase varies with the change in corrosion time. The main component rust phases of the rusty layer were found to be alpha-Fe2O3 , gamma-FeOOH, alpha-FeOOH, delta-FeOOH and Fe3O4, with the relative content of each rust phase of A3 (1) rusty layer sample exhibiting the following relation: gamma-FeOOH> alpha-FeOOH>delta-FeOOH, and the relative contents of other rusty layer samples were found to follow the relation: gamma-FeOOH> delta-FeOOH>alpha-FeOOH. PMID:17361722

  7. Standard guide for estimating the atmospheric corrosion resistance of low-alloy steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This guide presents two methods for estimating the atmospheric corrosion resistance of low-alloy weathering steels, such as those described in Specifications A242/A242M, A588/A588M, A606 Type 4, A709/A709M grades 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M. One method gives an estimate of the long-term thickness loss of a steel at a specific site based on results of short-term tests. The other gives an estimate of relative corrosion resistance based on chemical composition. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  8. Electrochemical study of lepidocrocite reduction and redox cycling for the mechanistic modelling of atmospheric corrosion

    International Nuclear Information System (INIS)

    During the long term storage of low alloy steel containers, the container walls may be exposed to cyclic wet and dry periods and will suffer from indoor atmospheric corrosion at room temperature. In order to predict the damage due to this corrosion for very long period (more than 100 years), a mechanistic modelling has been proposed by considering the phenomena occurring during the three stages of a wet dry cycle: the wetting stage, the wet period and the drying stage. For this modelling, the reduction by iron of one of the phase composing the rust layer, lepidocrocite (γ-FeOOH), plays a significant role on the corrosion processes. It was therefore of importance to gain a confirmation of the galvanic coupling between lepidocrocite and iron, as well as a better description of the electrochemical reduction of this ferric oxi-hydroxide and its possible redox cycling. The electrochemical reduction and redox cycling of lepidocrocite were investigated at ambient temperature in neutral or mildly alkaline solutions containing chloride, sulphate or bicarbonate anions. The working electrodes were either a thin lepidocrocite film electrodeposited on inert gold substrate or a composite electrode made by compacting a graphite / lepidocrocite powder mixture into a platinum grid. Electrochemical measurements were coupled to in-situ electrochemical quartz crystal microbalance (EQCM) and micro- Raman spectroscopy. Ex-situ SEM and FTIR were also used. The reduction of lepidocrocite occurs in any of the electrolytes considered here. Dissolution phenomena during the reduction of thin films are revealed by EQCM measurements. A fraction of the reduced product remains on the film, as adsorbed species or as a precipitate, which may be re-oxidised during a further anodic transient. The efficiency of the reduction process (FeIII to FeII) is lower for composite electrode than for thin film, mainly due to the easier saturation by FeII of the aqueous solution in the pores in the former case

  9. Operational mapping of atmospheric nitrogen deposition to the Baltic Sea

    OpenAIRE

    Hertel, O.; Ambelas Skjøth, C.; Brandt, J.; J.H. Christensen; Frohn, L. M.; J. Frydendall

    2003-01-01

    A new model system for mapping and forecasting nitrogen deposition to the Baltic Sea has been developed. The system is based on the Lagrangian variable scale transport-chemistry model ACDEP (Atmospheric Chemistry and Deposition model), and aims at delivering deposition estimates to be used as input to marine ecosystem models. The system is tested by comparison of model results to measurements from monitoring stations around the Baltic Sea. The comp...

  10. Simulation of long term atmospheric corrosion process on plain and weathering steels

    International Nuclear Information System (INIS)

    Information on weathering steel behaviour and its rust products characteristics after decades of atmospheric exposure are scarce. On the other side, generally accepted laboratory tests for the assessment of its corrosion resistance have not been developed yet. Consequently, simulating corrosion in the laboratory during long periods of time are attractive for the interesting and complete information obtainable from them. In the present work, AISI-SAE 1008 and ASTM-588 B steel samples have been exposed for two years to a immersion-emersion CEBELCOR type test in the laboratory, simulating a moderate urban atmosphere. Two groups of six samples each were tested. After the first year, three samples of each batch were retired for analysis and the rest was kept until they reached two years of exposure. The half cell electrode potentials were measured daily. The rust was characterized by metallographic techniques, Moessbauer spectroscopy (MS). Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Comparison was done with field exposure experiments reported in the literature, and conclusions on the behaviour of tested samples were drawn looking for differences and similarities with samples and structures under actual atmospheric conditions. (Author) 15 refs

  11. Standard Practice for Recording Data from Atmospheric Corrosion Tests of Metallic-Coated Steel Specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers a procedure for recording data of atmospheric corrosion tests of metallic-coated steel specimens. Its objective is the assurance of (1) complete identification of materials before testing, (2) objective reporting of material appearance during visual inspections, and (3) adequate photographic, micrographic, and chemical laboratory examinations at specific stages of deterioration, and at the end of the tests. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Evaluation of atmospheric corrosion on electroplated zinc and zinc nickel coatings by Electrical Resistance (ER) Monitoring

    DEFF Research Database (Denmark)

    Møller, Per

    2013-01-01

    cars for the automotive industry, off-shore construction or component and devices used in harsh industrial environments. The ER monitoring makes it possible to study the corrosion rate on-line in remote locations as a function of temperature, relative humidity and changes in the composition of the...... and magnetic fields. With this technique very important information about the durability of a new conversion coatings for aluminum, zinc and zinc alloys exposed to unknown atmospheric conditions can be gathered. This is expected to have a major impact on a number of industrial segments, such as test...

  13. Atmospheric corrosion Monitoring with Time-of-Wetness (TOW) sensor and Thin Film Electric Resistance (TFER) sensor

    International Nuclear Information System (INIS)

    In this study, TOW sensor was fabricated with the same P. J. Serada's in NRC and was evaluated according to pollutant amount and wet/dry cycle. Laboratorily fabricated thin film electric resistance (TFER) probes were applied in same environment for the measurement of corrosion rate for feasibility. TOW sensor could not differentiate the wet and dry time especially at polluted environment like 3.5% NaCl solution. This implies that wet/dry time monitoring by means of TOW sensor need careful application on various environment. TFER sensor could produce instant atmospheric corrosion rate regardless of environment condition. And corrosion rate obtained by TFER sensor could be differentiated according to wet/dry cycle, wet/dry cycle time variation and solution chemistry. Corrosion behaviors of TFER sensor showed that corrosion could proceed even after wet cycle because of remained electrolyte at the surface

  14. Effect of Superficial Atmospheric Corrosion Upon the Internal Stresses in Structural Steel Elements

    Directory of Open Access Journals (Sweden)

    Monel Leiba

    2006-01-01

    Full Text Available A research program is presented showing the stress status determined by the corrosion phenomenon inside a specimen of a structural steel element. Several stains are studied their diameters ranging from 1~mm to 6~mm and thickness of the corroded layer under 0.5~mm. The physical modeling is the result of testing in laboratory the phenomenon of superficial atmospheric corrosion and the numerical modeling was developed under a FEM program, ALGOR. A number of 3,200 finite elements of BRICK type were created and the evolution of normal and tangential stresses was scrutinized under the process of loosing elementary material transformed into scrap. Stresses in the damaged sphere were graphically put into evidence and determined with accuracy due to the performances of the program, showing the local perturbations and the pattern of stress concentrators. The studies showed the importance of reproducing with both physical and mathematical methods the intricate mechanism and sometimes unpredictable effects of corrosion phenomenon upon the structural steel elements.

  15. Deposition of anti-corrosion coatings by atmospheric pressure plasma jet

    International Nuclear Information System (INIS)

    An atmospheric-pressure, non-equilibrium plasma jet is currently under investigation at Chalk River Laboratories for the application of anti-corrosion coatings. This device produces concentrations of chemically-active species, similar to those observed in low-pressure plasma deposition systems, with the advantage of operating in an ambient pressure atmosphere. This paper describes measurements of the properties of a bench-scale plasma jet operating in etch and deposition mode. The jet effluent was characterized by various methods, including optical emission spectroscopy. Films deposited on metallic and insulating substrates have been characterized by optical microscopy and surface analytical techniques. The potential for scale-up of this process to treatment of reactor components is discussed. (author)

  16. The effect of CO{sub 2} on the corrosion rate in simulated combustion atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Maekipaeae, Martti [VTT Processes, P.O. Box 1601, FIN-02044 VTT, Espoo (Finland); Sroda, Szymon [European Commission, Joint Research Centre, Institute for Energy, P.O. Box 2, NL-1755 ZG Petten (Netherlands)

    2004-07-01

    The aim of the study is to improve the understanding of the corrosion mechanism in biomass and waste combustion processes. Laboratory, pilot and full scale testing of materials are performed. The obtained results are discussed, e.g., with reference to thermodynamic modelling calculations. The laboratory experiments in JRC Plant Simulation Test Laboratory are focused mainly on common ferritic and austenitic steels (X10, X20, 2.25Cr1Mo, AC66, Sanicro28, Esshette 1250 etc), which are used as superheater steel tube materials in such applications. The main aim of this part of the project is to understand the effect of deposition as well as the CO{sub 2} or/and CO/CO{sub 2} content in combustion atmospheres on corrosion rate and mechanism of studied materials. Laboratory tests include the thermogravimetric studies using Cahn thermo-balances and long exposure tests in horizontal/autoclave multi-sample furnaces. Post experimental analyses are made using SEM/EDS + XRD techniques and optical microscopy. The experiments are carried out at isothermal temperature - 535 deg. C in various simulated combustion atmospheres (22%H{sub 2}O + 5%O{sub 2} + xCO{sub 2} + N{sub 2}) with different CO{sub 2} content vary from 0 to 25 vol. % for the samples without deposit and with filter/cyclone ash deposition (long exposure tests). In this stage, following conclusions can be made: - Corrosion rate, for the alloys with and without the deposit, increase with increasing CO{sub 2} content, especially for the ferritic steels; - Corrosion rate for samples with the deposit increase significantly and in this case the internal oxidation of the studied samples was observed; - Thermodynamic model calculations performed resulted, a.o., to the following propositions still of preliminary nature; - Various carbides of metallic alloying elements become less stable at oxide scale-metallic alloy phase boundary with increasing partial pressure of carbon dioxide; - Carbides and oxides of various alloying

  17. Simulation of atmospheric corrosion in different metals in the presence SO2 as the main pollutant

    International Nuclear Information System (INIS)

    This work presents information about the kinetics of corrosion and the characterization of the products formed on zinc, copper, aluminum and low carbon steel, submitted to the following experimental conditions in trials that simulate industrial atmospheres: two alternative temperatures (30oC and 50oC), high relative humidity, constant incidence of short wave UV radiation (254 nm) and a SO2 concentration below 50 ppm. An experimental device to control the different atmospheric variables was used. Among the products of corrosion that were found, aside from the usual oxides and oxohydroxides, were sulfates and sulfites with different compositions and degrees of hydration, distributed in discrete phases. The temperature variation produced an increased weight loss in all the metals tested and did not modify the proportions of the compounds formed in the internal and external phases. In the case of Cu, the same anomalies occurred as for the other metals tested, but its composition also changed after modifying the test temperature (CW)

  18. Recent Research and Development in Solving Atmospheric Corrosion Problems of Steel Industries in Japan

    International Nuclear Information System (INIS)

    A rust layer, so called 'protective' rust layer, on a weathering low-alloy steel has strong protective ability for atmospheric corrosion of the steel. We have recently found through a large number of spectroscopic studies including Moessbauer spectroscopy that the protective rust layer forms after long-term phase transformation. The phase and structure of the rust definitely control the protective ability of the rust layer. From this recent knowledge, some new technologies have been developed. One is the surface-treatment technique that provides a possibility for obtaining the protective rust layer in a relatively short period even in the severe environments such as in marine and chloride (de-icing salts) containing environments. Others are based on selection of effective alloying elements for steel materials. These are particularly important for application in areas where protective rust layer formation may be hindered or prevented. In this paper, we mention recent progress in research and development on rusting protection by rust for atmospheric corrosion of steels in Japan.

  19. Mechanisms of the multi-secular atmospheric corrosion of ferrous alloys: The case of the Metz cathedral reinforcements

    International Nuclear Information System (INIS)

    The study of the mechanisms of the multi-secular atmospheric corrosion of ferrous alloys has various applications, from the preservation and restoration of cultural heritage metals, to the evaluation of their long term behaviour, specifically when they are used for the storage containers surrounding nuclear wastes. The study of the corrosion product layers (CPL) developed during 5 centuries on the Metz cathedral reinforcements brings new results for a better understanding of the complex processes involved in the formation of the atmospheric CPL. The phases and chemical elements constituting the CPL of these reinforcements were characterized at the micrometric scale (μDRX, Raman μ-spectroscopy (μRS), SEM-EDS). Results specifically showed that these CPL differ from other multi-secular systems previously studied by their very high content in ferri-hydrite (5Fe2O3, 9H2O). This very reactive phase is distributed in the whole CPL and mixed at the microscopic scale with goethite (a-FeOOH) and lepidocrocite (g-FeOOH). Diffusion experiments of bromide ions followed by in situ X-ray μ-fluorescence allowed a better understanding of the transport of dissolved species in the porous network of the CPL. Furthermore, a test of the corrosion system behavior in conditions simulating the wetting stage of the RH cycle of atmospheric corrosion, also followed in situ by μRS, highlighted the reduction of ferri-hydrite at the metal/CPL interface. These results allowed to verify for the first time a fundamental hypothesis about the mechanisms of very long term atmospheric corrosion. Finally, re-corrosion experiments of the corrosion system were monitored in a climatic chamber simulating accelerated atmospheric cycles in an 18O-labelled environment. Then the detection of the 18O isotope linked to the precipitated phases, by nuclear reaction analysis using a nuclear microprobe, allowed to localise the formation sites of the new corrosion products. All these results improve the

  20. Study of the corrosion products formed on carbon steels in the tropical atmosphere of Panama

    Directory of Open Access Journals (Sweden)

    Jaén, J. A.

    2003-12-01

    Full Text Available Mössbauer spectroscopy and X-ray powder diffraction (in selected samples have been used to characterize corrosion products on carbon steels after atmospheric exposure to the tropical Panamanian locations of Panama and Colon, classified according to ISO 9223 as C3 and C5, respectively. Goethite (α-FeOOH of intermediate particle size (20-100 nm, lepidocrocite (γ-FeOOH, a spinel phase consisting of non-stoichiometric magnetite (Fe3-xO4 and/or maghemite (γ-Fe2O3 and nano-sized particles were identified in the corrosion products. The spinel phase is related to short term atmospheric exposure transforms in time to other corrosion products. The corrosion resistance increased with fraction of goethite following a saturation-type behavior.

    Se caracterizaron los productos de corrosión de aceros al carbono expuestos a las atmósferas tropicales panameñas localizadas en Panamá y Colón, mediante el uso de la espectroscopia Mössbauer y difracción de rayos-X (en muestras seleccionadas. Las atmósferas se clasifican como C3 y C5, respectivamente, de acuerdo a la norma ISO 9223. Se lograron identificar los compuestos goethita (α-FeOOH de tamaño de partícula intermedio (20-100 nm, lepidocrocita (γ-FeOOH, una fase de espinela consistente en magnetita no estequiométrica (Fe3-xO4 y/o maghemita (γ-Fe2O3, y nanopartículas. La fase de espinela se puede correlacionar con exposiciones cortas a la atmósfera, transformándose en el tiempo en otros productos de corrosión. La resistencia a la corrosión se incrementa con la cantidad de goethita siguiendo una conducta de saturación.

  1. The role of UV illumination on the initial atmospheric corrosion of 09CuPCrNi weathering steel in the presence of NaCl particles

    International Nuclear Information System (INIS)

    Highlights: • UV strongly affects the NaCl-induced atmospheric corrosion of 09CuPCrNi WS. • Positive photo-voltages were obtained on rusted 09CuPCrNi WS. • UV significantly increases the charge carrier density of the corrosion products. • UV affects the processes of the corrosion product formation during exposure. • UV influences the atmospheric corrosion reactions due to the photovoltaic effect. - Abstract: Effect of UV illumination on the NaCl-induced atmospheric corrosion of 09CuPCrNi weathering steel (WS) was qualitatively and quantitatively studied in this work. UV illumination strongly affects the NaCl-induced atmospheric corrosion process of 09CuPCrNi WS mainly through the photovoltaic effect of the corrosion products with semiconductor properties. The photogenerated electrons and holes can directly participate in the cathodic and anodic reactions and thus directly affect the atmospheric corrosion rate of 09CuPCrNi WS. Meanwhile, the photogenerated electrons and holes can directly involve in the corrosion product formation process and therefore affect the performance of the corrosion product layer formed under UV illumination

  2. Microbially Influenced Corrosion of 304 Stainless Steel and Titanium by P. variotii and A. niger in Humid Atmosphere

    Science.gov (United States)

    Zhang, Dawei; Zhou, Feichi; Xiao, Kui; Cui, Tianyu; Qian, Hongchong; Li, Xiaogang

    2015-07-01

    Microbially induced corrosion (MIC) poses significant threats to reliability and safety of engineering materials and structures. While most MIC studies focus on prokaryotic bacteria such as sulfate-reducing bacteria, the influence of fungi on corrosion behaviors of metals has not been adequately reported. In this study, 304 stainless steel and titanium were exposed to two very common fungi, Paecilomyces variotii, Aspergillus niger and their mixtures under highly humid atmosphere. The initial corrosion behaviors within 28 days were studied via scanning Kelvin probe, which showed marked surface ennoblement and increasingly heterogeneous potential distribution upon prolonged fungus exposure. Using stereomicroscopy, fungus growth as well as corrosion morphology of 304 stainless steel and titanium were also evaluated after a long-term exposure for 60 days. The presence of fungi decreased the corrosion resistance for both 304 stainless steel and titanium. Titanium showed higher resistance to fungus growth and the induced corrosion. Exposure to the mixed strains resulted in the highest fungus growth rate but the mildest corrosion, possibly due to the decreased oxygen level by increased fungal activities.

  3. Atmospheric Corrosion of Steel A3 Deposited with Ammonium Sulfate and in the Presence of Sulfur Dioxide

    Institute of Scientific and Technical Information of China (English)

    Ye WAN; Chuanwei YAN; Chunan CAO Jun TAN; Jun TAN

    2003-01-01

    A laboratory study of the atmospheric corrosion of carbon steel deposited with (NH4)2SO4 in the presence of SO2 isreported. The different levels of (NH4)2SO4 (0, 15, 30, 45, 60μg.cm-2) were added on the surface of the samplesbefore the exposure. The corrosion was investigated by a combination of gravimetry, Fourier transform infraredspectroscope and scanning electron microscopy. A detailed knowledge about the corrosion products was acquired,both quantitatively and qualitatively. The results show that the metal loss increased and the increasing tendency ofcorrosion rates slowed down with the increasing exposure time. The phase constituents of the corrosion products aremainly c-FeO(OH), γ-FeO(OH), and δ-FeO(OH).

  4. Inhibition treatment of the corrosion of lead artefacts in atmospheric conditions and by acetic acid vapour: use of sodium decanoate

    International Nuclear Information System (INIS)

    The efficiency of linear sodium decanoate, CH3(CH2)8COONa (noted NaC10), as corrosion inhibitor of lead was determined by electrochemical techniques in two corrosive mediums: ASTM D1384 standard water and acetic acid-enriched solutions. Best results were obtained with 0.05 mol l-1 of NaC10 solution. In these conditions, the inhibition efficiency can be estimated of 99.9%. The corrosion inhibition effect was confirmed by cyclic atmospheric tests in a climatic chamber in two different conditions: water saturated vapour, and acid acetic enriched vapour simulating the atmosphere in the wooden displays in museums. Surface analyses by SEM and X-ray diffraction indicate that the metal protection is due to the formation of a protective layer mainly composed of lead decanoate Pb(C10)2 (metallic soap). This inhibition treatment was applied on objects of metallic cultural heritage: gallo-roman sarcophagus in lead. Electrochemical methods confirm the efficiency of treatment on archaeological materials. In conclusion, this inhibitor treatment seems to be very promising against the atmospheric corrosion and the corrosion by organic acid vapour in museums

  5. Study of archaeological artefacts to refine the model of iron long-term indoor atmospheric corrosion

    International Nuclear Information System (INIS)

    The study of long-term indoor atmospheric corrosion is involved in the field of the interim storage of nuclear wastes. Indeed study of archaeological artefacts is one of the only mean to gather information on very long periods. Concerning ancient items, due to the complexity of the system, it is necessary to couple many analytical techniques from the macro to the microscopic scale. This enables to propose a description of the Amiens cathedral chain rust layers, made of a matrix of goethite, with lepidocrocite and akaganeite locally present and marbling of a poor crystallized phase associated to ferrihydrite. Electrochemical measurements permit to study the reduction capacity of the rust layer and to draw reduction mechanisms of the so-called active phases, by in situ experiments coupled with X-ray diffraction and X-ray absorption spectroscopy

  6. [Main results of experimental studies on the toxicology of inhibitors of atmospheric corrosion of metals].

    Science.gov (United States)

    Paustovskaia, V V

    1990-01-01

    Basing on experimental toxicity research it was established that, out of 50 atmosphere metal corrosion inhibitors, some 14 per cent were found extremely hazardous, 42 per cent--of high level hazardous, 33 percent--of moderate and 11 per cent--of low hazardous. Relationships were identified between the structure of polymethylene amine salts, azole compounds and carbonic acid, and the way they influence human organism. It was also found that inhibitors exercise a polytropic action in man, the toxicity action being concentrated on oxidation processes, and the inhibitors specifically influence protein, carbohydrate and phosphoric metabolisms, as well as the red blood system. This causes functional and structural disorders of CNS and in the parenchymal organs. Inhibitors are characterized by local and skin-resorption actions, their degree and specific features depending on their chemical structures. 22 MACs of working zone inhibitors are proposed, along with early diagnostic tests and preventive measures. PMID:2351297

  7. Rust characterisation of ancient iron artefacts exposed to indoor atmospheric corrosion

    International Nuclear Information System (INIS)

    A corpus of eleven iron artefacts exposed several centuries to indoor atmospheric corrosion has been collected. The general morphology of the rust layers has been studied as well as the iron substrate. Second phase particles (slag inclusions) and minor elements (carbon, phosphorus) were detected. The compositions of the rust layers have been analysed by EPMA on cross sections. The distribution of endogenous and exogenous elements has been studied. An original analytical method (micro XRD under synchrotron radiation) was used to study the structure distribution on thin film transverse sections. Using this technique, the different constitutive crystallized phases in the rust layer have been localised. Goethite has been detected preferentially in inner layers, lepidocrocite in outer layers. The goethite to lepidocrocite content ratio in the rust layers, the so-called protective ability index α/γ has been calculated and compared to values found in literature. (authors)

  8. Study of uncertainty in atmospheric corrosion rate of floe carbon steel

    International Nuclear Information System (INIS)

    The confidence interval of measurements of corrosion rate has been barely reported in the literature. It is a function of both the number of probes and the underlying pdf. We have performed specific experiments with a lot more probes than the standards require, and we evaluated, for exposure times of 1, 2, 3 and 7 months, the effect of using only three (as it is mandatory by the standard for one year exposure time) up to eleven. With the new experimental data, we were able to confirm that the values fit a normal distribution. We also found evidence that the minimum number of probes might depend upon the atmospheric condition and exposure time. The number of probes presently required for studies with exposure times of one year, might not be enough in studies of initial kinetics (exposure times smaller than one year). (Author) 14 refs

  9. Study of archaeological artefacts to refine the model of iron long-term indoor atmospheric corrosion

    Science.gov (United States)

    Monnier, J.; Legrand, L.; Bellot-Gurlet, L.; Foy, E.; Reguer, S.; Rocca, E.; Dillmann, P.; Neff, D.; Mirambet, F.; Perrin, S.; Guillot, I.

    2008-09-01

    The study of long-term indoor atmospheric corrosion is involved in the field of the interim storage of nuclear wastes. Indeed study of archaeological artefacts is one of the only mean to gather information on very long periods. Concerning ancient items, due to the complexity of the system, it is necessary to couple many analytical techniques from the macro to the microscopic scale. This enables to propose a description of the Amiens cathedral chain rust layers, made of a matrix of goethite, with lepidocrocite and akaganeite locally present and marbling of a poor crystallized phase associated to ferrihydrite. Electrochemical measurements permit to study the reduction capacity of the rust layer and to draw reduction mechanisms of the so-called active phases, by in situ experiments coupled with X-ray diffraction and X-ray absorption spectroscopy.

  10. Study of archaeological artefacts to refine the model of iron long-term indoor atmospheric corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Monnier, J. [Laboratoire Pierre Suee - UMR 9956 CEA-CNRS, bat 637 CEA Saclay, 91191 Gif-sur-Yvette (France); Institut de Chimie des Materiaux de Paris Est-equipe MCMC, UMR 7182 CNRS-Universite Paris 12, 2-8 rue Henry Dunant, 94320 Thiais (France)], E-mail: judith.monnier@cea.fr; Legrand, L. [Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, UMR 8587, Evry (France); Bellot-Gurlet, L. [Laboratoire de Dynamique, Interaction et Reactivite (LADIR), UMR 7075 CNRS and Universite Pierre et Marie Curie Paris 6, 2 rue Henry Dunant, 94320 Thiais (France); Foy, E. [Laboratoire Pierre Suee - UMR 9956 CEA-CNRS, bat 637 CEA Saclay, 91191 Gif-sur-Yvette (France); Reguer, S. [Synchrotron SOLEIL, Saint-Aubin BP 4891192 Gif-sur-Yvette (France); Rocca, E. [Laboratoire de Chimie du Solide Mineral, UMR 7555, Universite Henri Poincare-Nancy I (France); Dillmann, P. [Laboratoire Pierre Suee - UMR 9956 CEA-CNRS, bat 637 CEA Saclay, 91191 Gif-sur-Yvette (France); IRAMAT UMR 5060, IPSE - CEA Saclay, Gif-sur-Yvette (France); Neff, D. [Laboratoire Pierre Suee - UMR 9956 CEA-CNRS, bat 637 CEA Saclay, 91191 Gif-sur-Yvette (France); Mirambet, F. [Laboratoire de Recherche des Monuments Historiques, 29, rue de Paris, Champs-sur-Marne (France); Perrin, S. [Laboratoire d' Etude de la Corrosion Aqueuse, SCCME, bat 458 CEA Saclay, 91191 Gif-sur-Yvette (France); Guillot, I. [Institut de Chimie des Materiaux de Paris Est-equipe MCMC, UMR 7182 CNRS-Universite Paris 12, 2-8 rue Henry Dunant, 94320 Thiais (France)

    2008-09-30

    The study of long-term indoor atmospheric corrosion is involved in the field of the interim storage of nuclear wastes. Indeed study of archaeological artefacts is one of the only mean to gather information on very long periods. Concerning ancient items, due to the complexity of the system, it is necessary to couple many analytical techniques from the macro to the microscopic scale. This enables to propose a description of the Amiens cathedral chain rust layers, made of a matrix of goethite, with lepidocrocite and akaganeite locally present and marbling of a poor crystallized phase associated to ferrihydrite. Electrochemical measurements permit to study the reduction capacity of the rust layer and to draw reduction mechanisms of the so-called active phases, by in situ experiments coupled with X-ray diffraction and X-ray absorption spectroscopy.

  11. Corrosion and protection of metals in the rural atmosphere of "El Pardo" Spain (PATINA / CYTED project

    Directory of Open Access Journals (Sweden)

    Simancas, J.

    2003-12-01

    Full Text Available Atmospheric corrosion tests of metallic and organic coatings on steel, zinc and aluminium have been conducted in "El Pardo" (Spain as part of the PATINA/CYTED project "Anticorrosive Protection of Metals in the Atmosphere". This is a rural atmosphere with the following ISO corrosivity categories: C2 (Fe, C2 (Zn, C3 (Cu and Cl (Al. Its average temperature and relative humidity is 13 °C and 62.8 %, respectively, and it has low SO2 and Cl- contents. Results of 42 months exposure are discussed. Atmospheric exposure tests were carried out for the following types of coatings: conventional paint coatings for steel and hot-dip galvanized steel (group 1, new painting technologies for steel and galvanized steel (group 2, zinc-base metallic coatings (group 3, aluminium-base metallic coatings (group 4, coatings on aluminium (group 5 and coil-coatings on steel, hot-dip galvanized steel and 55 % Al-Zn coated steel (group 6.

    Como parte del proyecto PATINA/CYTED "Protección anticorrosiva de metales en la atmósfera" se han llevado a cabo en la estación de ensayo de "El Pardo" (España, ensayos de corrosión atmosférica de recubrimientos metálicos y orgánicos sobre acero, zinc y aluminio. Se trata de una atmósfera rural según la clasificación ISO de grado de corrosividad: C2 (Fe, C2 (Zn, C3 (Cu y Cl (Al. La temperatura y humedad relativa media es de 13 °C y 62,8 %, respectivamente, y tiene bajos contenidos de SO2 y Cl-. Se discuten los resultados obtenidos después de 42 meses de exposición. Los ensayos de corrosión atmosférica se llevaron a cabo para tres tipos de recubrimientos: recubrimientos de pintura convencional sobre acero y acero zincado (grupo 1, nuevas tecnologías en pinturas para acero y acero galvanizado (grupo 2, recubrimientos metálicos base zinc (grupo 3, recubrimientos metálicos base aluminio (grupo 4, recubrimientos sobre aluminio (grupo 5 y recubrimientos de banda en continuo

  12. High temperature corrosion of boiler steels in hydrochloric atmosphere under oil shale ashes

    International Nuclear Information System (INIS)

    Highlights: • High temperature gaseous hydrochloric corrosion analysis of different boiler steels. • Influence on the corrosion of the presence of oil shale ashes and cyclic removing. • Empiric kinetic coherence equation and diagram for corrosion depth versus time. • Additional oxidation tests of all materials investigated. • Qualitative analysis of the present corrosion mechanisms. - Abstract: High temperature corrosion in power plants is a main breakdown criterion in boiler applications. This study is focused on the high-temperature corrosion resistance of several boiler steels used in Estonian power plants, which were experimentally tested in gaseous hydrochloric environment combined with Estonian oil shale ashes in a high temperature corrosion test up to 600 °C. Scanning electron microscopy supported by energy dispersive X-ray spectroscopy was used to reveal different corrosion mechanisms. Results indicate a strong dependence of the boiler steel corrosion to the present anions in the oil shale ash and their removal in the boiler

  13. Initial atmospheric corrosion of zinc in presence of Na2SO4 and (NH4)2SO4

    Institute of Scientific and Technical Information of China (English)

    QU Qing; LI Lei; BAI Wei; YAN Chuan-wei

    2006-01-01

    Initial atmospheric corrosion of zinc in the presence of Na2SO4 and (NH4)2SO4 was investigated via quartz crystal microbalance(QCM) in laboratory at relative humidity(RH) of 80% and 25 °. The results show that both Na2SO4 and (NH4)2SO4 can accelerate the initial atmospheric corrosion of zinc. The combined effect of Na2SO4 and (NH4)2SO4 on the corrosion of zinc is greater than that caused by (NH4)2SO4 and less than that caused by Na2SO4. Fourier transform infrared spectroscopy(FTIR), X-ray diffractometry(XRD) and scanning electron microscopy(SEM) were used to characterize the corrosion products of zinc.(NH4)2Zn(SO4)2, Zn4SO4(OH)6·5H2O and ZnO present on zinc surface in the presence of (NH4)2SO4 while Zn4SO4(OH)6·5H2O and ZnO are the dominant corrosion products on Na2SO4-treated zinc surface. Probable mechanisms are presented to explain the experimental results.

  14. Corrosion Behavior of Field-Exposed 7A04 Aluminum Alloy in the Xisha Tropical Marine Atmosphere

    Science.gov (United States)

    Cui, Z. Y.; Li, X. G.; Man, C.; Xiao, K.; Dong, C. F.; Wang, X.; Liu, Z. Y.

    2015-08-01

    Atmospheric corrosion behavior of 7A04 aluminum alloy exposed to a tropical marine environment for 4 years was investigated by weight loss test, morphology observation, and electrochemical impendence spectroscopy (EIS). The results showed that the weight loss of 7A04 alloy in the log-log coordinates can be approximately fitted with two liner segments, in which the slope value of the second segment is significantly lower than that of the first segment. This was mainly attributed to the protectiveness of the corrosion product layer formed on the specimen exposed for 12 and 24 months, which was further confirmed by the EIS results. Corrosion rate presented a significant fluctuation during the exposure test which is due to the deterioration effect caused by chloride ions and time of wetness and the stabilization process of the corrosion product layer. Intergranular corrosion occurred on the 7A04 alloy and then transformed into exfoliation corrosion because of the synergetic effect of the hydrogen-assisted crack initiation and the wedge effect-induced matrix delamination.

  15. Long term corrosion of iron in concrete and in atmospheric conditions: a contribution of archaeological analogues to mechanism comprehension

    International Nuclear Information System (INIS)

    Full text of publication follows: The prediction of iron (or low alloy steel) corrosion on very long term period is necessary in two different purposes: (i) the preservation and conservation of cultural heritage and (ii) the French storage and repository concept for the radioactive wastes. In order to determine the evolution of corrosion processes for very long period, mechanistic models have been developed. In these models that are based on a phenomenological approach to evaluate the average corrosion rates, two different environments are considered: concrete (steel reinforcements) and atmospheric. The study of archaeological analogues is a very pertinent tool for the validation of these models. First, physico-chemical analysis on old corrosion layers lead to a precise localisation and identification of the phases present in the corrosion system. Moreover, experimental reinduced corrosions of ancient samples under controlled parameters (temperature, relative humidity) bring new insight on the mechanisms involved. In particular, one crucial question related to the wet-dry cycle is the localisation of oxygen reduction sites in the rust layer. For this purpose, specific experiments have been set up to re-corrode the ancient samples in marked medium (using 18O2). Samples were exposed to cycling between high and low relative humidity, produced by saline saturated solutions. Then cross-sections of samples obtained were investigated by nuclear reaction analysis (NRA) 18O(p,α)15N on the Pierre Sue Laboratory nuclear microprobe. In this presentation the 18O distribution profiles are discussed and interpreted in order to bring new insight on corrosion mechanisms. A comparative interpretation is made for each medium (concrete and atmosphere)

  16. System for in situ studies of atmospheric corrosion of metal films using soft x-ray spectroscopy and quartz crystal microbalance

    Science.gov (United States)

    Forsberg, J.; Duda, L.-C.; Olsson, A.; Schmitt, T.; Andersson, J.; Nordgren, J.; Hedberg, J.; Leygraf, C.; Aastrup, T.; Wallinder, D.; Guo, J.-H.

    2007-08-01

    We present a versatile chamber ("atmospheric corrosion cell") for soft x-ray absorption/emission spectroscopy of metal surfaces in a corrosive atmosphere allowing novel in situ electronic structure studies. Synchrotron x rays passing through a thin window separating the corrosion cell interior from a beamline vacuum chamber probe a metal film deposited on a quartz crystal microbalance (QCM) or on the inside of the window. We present some initial results on chloride induced corrosion of iron surfaces in humidified synthetic air. By simultaneous recording of QCM signal and soft x-ray emission from the corroding sample, correlation between mass changes and variations in spectral features is facilitated.

  17. Effect of Microstructure on Atmospheric-Induced Corrosion of Heat-treated Grade 2205 and 2507 Duplex Stainless Steels

    OpenAIRE

    Cem Örnek, Amina H. Ahmed, Dirk Engelberg

    2012-01-01

    Atmospheric-induced corrosion tests under MgCl2 salt deposits were carried out on duplex stainless steel grade 2205 and 2507. As-received and 750°C heat-treated material conditions were investigated, and selected micro-structural sites targeted with salt-laden deposits to determine their corrosion response. Deposits were wetted under controlled climatic conditions at 80°C and 40% relative humidity. Observations of micro-structural attack indicated the presence of net anodic and net cathodic s...

  18. Corrosion-electrochemical behavior of nickel in an alkali metal carbonate melt under a chlorine-containing atmosphere

    OpenAIRE

    Nikitina, E. V.; Kudyakov, V. Y.; Malkov, V. B.; Plaksin, S. V.

    2013-01-01

    The corrosion-electrochemical behavior of a nickel electrode is studied in the melt of lithium, sodium, and potassium (40: 30: 30 mol %) carbonates in the temperature range 500-600°C under an oxidizing atmosphere CO2 + 0.5O2 (2: 1), which is partly replaced by gaseous chlorine (30, 50, 70%) in some experiments. In other experiments, up to 5 wt % chloride of sodium peroxide is introduced in a salt melt. A change in the gas-phase composition is shown to affect the mechanism of nickel corrosion....

  19. Atmospheric corrosion of magnesium alloys AZ31 and AZ61 under continuous condensation conditions

    OpenAIRE

    Feliu Jr., S.; Maffiotte, C.; Galván Sierra, Juan Carlos; Barranco, Violeta

    2011-01-01

    This paper studies the corrosion rate of magnesium alloys AZ31 and AZ61 exposed in humid air under continuous condensation conditions. The shape of the gravimetric curves for corrosion progress suggests that the process is controlled by factors related with the corrosion product layer growing on the metallic surface according to gravimetric results there is an initial period in which only a small part of the corroded metal is incorporated in the corrosion product layer, but after longer testi...

  20. A laboratory evaluation of the performance of an atmospheric corrosion monitor

    International Nuclear Information System (INIS)

    Short term laboratory experiments were conducted to evaluate a corrosion rate monitor designed by F. Mansfield of Rockwell International. Corrosion sensors and metal test panels were exposed to several subparts per million levels of SO2. These exposures included periods when dew was caused to form in sufficient quantities to be collected and analyzed. After each exposure, the test panels were cleaned to remove all corrosion products and the cleaning solutions were also analyzed. By adding the base metal found in the dew to that in the cleaning solution, a corrosion rate can be established to compare to the corrosion monitor's output

  1. [Current problems of occupational hygiene in the manufacture and use of inhibitors of the atmospheric corrosion of metals].

    Science.gov (United States)

    Paustovskaia, V V

    1994-01-01

    On the basis of the data obtained from in-plant hygienic investigations designed to study conditions of labour of employees working with the inhibitors of the metal atmospheric corrosion, acid corrosion, for two-phase systems and hydrogen sulfide corrosion, assessment of these was made in accordance with the "Hygienic classification of labour (as to the indices of health and safety hazards from exposures to factors of an employee's occupational environment, hardness and strenuousness of the work process"), 1986. Degree of hardness of the job done by the workmen engaged in the production and application of the inhibitors in different branches of national economy was assessed. Hygienic and treatment-and-prophylactic requirements were substantiated. PMID:7900368

  2. INFLUENCE OF NaC1 DEPOSITION ON ATMOSPHERIC CORROSION OF A3 STEEL IN THE PRESENCE OF SO2

    Institute of Scientific and Technical Information of China (English)

    Q. Qu; C.W. Yan; L. Zhang; Y. Wan; C.N. Cao

    2002-01-01

    The regularities of atmospheric corrosion of A3 steel deposited with different amountof NaCl exposed to the air containing 1ppm SO2 at 80% RH and 25℃ were studied inlaboratory. NaCl can accelerate the corrosion of A3 steel obviously under such con-dition. The relationship between the weight loss of A3 steel and the amount of NaCldeposition can be well described by using a quadratic function. Fourier transform in-frared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopyand electron dispersion X-ray analysis (SEM/EDAX) were used to characterize thecorrosion products. In the absence of NaCl, FeSO4 xH2O is the dominant corro-sion products, while Fe3O4, FeSO4@ H2O, β-FeOOH and γ-FeOOH dominate in thepresence of NaCl.

  3. Deposition of SiOx on Metal Surface with a DBD Plasma Gun at Atmospheric Pressure for Corrosion Prevention

    Institute of Scientific and Technical Information of China (English)

    HAN Erli; CHEN Qiang; ZHANG Yuefei; CHEN Fei; GE Yuanjing

    2007-01-01

    In this study,SiOx films were deposited by a dielectric barrier discharge(DBD)plasma gun at an atmospheric pressure.The relationship of the film structures with plasma powers Was investigated by Fourier transform infrared spectroscopy(FTIR),and scanning electron microscope(SEM).It was shown that an uniform and cross-linking structure film was formed by the DBD gun.As an application,the SiOx films were deposited on a carbon steel surface for the anti-corrosion purpose.The experiment was carried out in a 0.1 M NaC1 solution.It Was found that a very good anti-corrosive property was obtained,i.e.,the corrosion rate Was decreased c.a.15 times in 5% NaC1 solution compared to the non-SiOx coated steel,as detected by the potentiodynamic polarization measurement.

  4. Electrochemical noise evaluation of anodized aluminum. Comparative study against corrosion behaviour in the atmosphere

    Directory of Open Access Journals (Sweden)

    Betancourt, N.

    2003-12-01

    Full Text Available The present work reports the evaluation of aluminum and anodized aluminum by electrochemical noise, as a part of the PATINA/CYTED project of the working group Nº 5. A visual examination is also made. The samples were exposed at several Ibero-American atmospheres up to 2 years of exposure. Different thickness of anodized aluminum were evaluated. The electrochemical potential noise of the 5 μm unexposed sample (pattern showed a different behaviour to that showed by the other anodized specimens. This could be due to a slower sealed of the samples of higher thickness. The same behaviour was observed on the samples exposed at the rural station El Pardo. According to the visual examination, the samples of bare aluminum and those of anodized 5 μm thickness were the most affected by pitting corrosion in the highly polluted atmospheres. A good correlation between corrosion behaviour determined by visual examination and EN was obtained.

    Como parte de las investigaciones de la Red PATINA el grupo de trabajo Nº 5 dedicó su atención al comportamiento del aluminio desnudo y anodizado con diferentes espesores en diferentes atmósferas de Iberoamérica. En el presente trabajo se presenta una evaluación de patrones de aluminio 99,5 % de pureza desnudo y anodizado con espesores de 15 y 25 μm, mediante ruido electroquímico. Los resultados obtenidos se comparan con el comportamiento determinado en diferentes atmósferas durante un período de 2 años. El ruido de voltaje del patrón de 5 μm de espesor presenta un comportamiento diferente al de los restantes espesores, lo que coincide con una mayor susceptibilidad a la corrosión picadura de este primer anodizado. Se reportan también algunas diferencias en el ruido de corriente. Se concluye que mediante la utilización del ruido electroquímico es posible caracterizar el aluminio con respecto a su sensibilidad a la corrosión picadura en condiciones atmosféricas.

  5. Operational mapping of atmospheric nitrogen deposition to the Baltic Sea

    Directory of Open Access Journals (Sweden)

    O. Hertel

    2003-07-01

    Full Text Available A new model system for mapping and forecasting nitrogen deposition to the Baltic Sea has been developed. The system is based on the Lagrangian variable scale transport-chemistry model ACDEP (Atmospheric Chemistry and Deposition model, and aims at delivering deposition estimates to be used as input to marine ecosystem models. The system is tested by comparison of model results to measurements from monitoring stations around the Baltic Sea. The comparison shows that observed annual mean ambient air concentrations and wet depositions are well reproduced by the model. Diurnal mean concentrations of NHx (sum of  NH3 and NH4 and NO2 are fairly well reproduced, whereas concentrations of total nitrate (sum of HNO3 and NO3 are somewhat overestimated by the model. Wet depositions of nitrate and ammonia are fairly well described for annual mean values, whereas the discrepancy is high for the monthly mean values and the wet depositions are rather poorly described concerning the diurnal mean values. The model calculations show that the atmospheric nitrogen deposition has a pronounced south – north gradient with depositions in the range about 1.0 tonnes N km−2 in south and 0.2 tonnes N km−2 in north. The model results show that in 2000 the maximum deposition to the Danish waters appeared during the summer in the algae growth season. For the northern parts of the Baltic the highest depositions were distributed over most of the year.

  6. Operational mapping of atmospheric nitrogen deposition to the Baltic Sea

    Directory of Open Access Journals (Sweden)

    O. Hertel

    2003-01-01

    Full Text Available A new model system for mapping and forecasting nitrogen deposition to the Baltic Sea has been developed. The system is based on the Lagrangian variable scale transport-chemistry model ACDEP (Atmospheric Chemistry and Deposition model, and aims at delivering deposition estimates to be used as input to marine ecosystem models. The system is tested by comparison of model results to measurements from monitoring stations around the Baltic Sea. The comparison shows that observed annual mean ambient air concentrations and wet depositions are well reproduced by the model. Diurnal mean concentrations of NHx (sum of NH3 and NH4+ and NO2 are fairly well reproduced, whereas concentrations of total nitrate (sum of HNO3 and NO3- are somewhat overestimated. Wet depositions of nitrate and ammonia are fairly well described for annual mean values, whereas the discrepancy is high for the monthly mean values and the wet depositions are rather poorly described concerning the diurnal mean values. The model calculations show that the annual atmospheric nitrogen deposition has a pronounced south--north gradient with depositions in the range about 1.0 T N km-2 in the south and 0.2 T N km-2 in the north. The results show that in 1999 the maximum diurnal mean deposition to the Danish waters appeared during the summer in the algae growth season. For the northern parts of the Baltic the highest depositions were distributed over most of the year. Total deposition to the Baltic Sea was for the year 1999 estimated to 318 kT N for an area of 464 406 km2 equivalent to an average deposition of 684 kg N/km2.

  7. Influence of corrosive atmospheres on the properties of refractories in operation of waste incineration plants; Einfluss korrosiver Bedingungen auf die Eigenschaften feuerfester Werkstoffe in Anlagen der thermischen Abfallverwertung

    Energy Technology Data Exchange (ETDEWEB)

    Tonnesen, Thorsten; Telle, Rainer [RWTH Aachen (Germany). Inst. fuer Gesteinshuettenkunde

    2009-07-01

    The corrosion mechanisms of different refractories in operation of waste incineration plants are presented. A testing method in steam atmosphere according to ASTM was used to determine the oxidation resistance. The experiments at 1000 C proved an excellent stability in shape dimensions of the refractories and low volume change below 1 %. Furthermore vapour phase corrosion experiments with SiC mortars and evaluation of slag corrosion tests of high alumina bricks after use in a waste incineration plant have been performed. (orig.)

  8. Atmospheric corrosion of Cu, Zn, and Cu-Zn alloys protected by self-assembled monolayers of alkanethiols

    Science.gov (United States)

    Hosseinpour, Saman; Forslund, Mattias; Johnson, C. Magnus; Pan, Jinshan; Leygraf, Christofer

    2016-06-01

    In this article results from earlier studies have been compiled in order to compare the protection efficiency of self-assembled monolayers (SAM) of alkanethiols for copper, zinc, and copper-zinc alloys exposed to accelerated indoor atmospheric corrosion conditions. The results are based on a combination of surface spectroscopy and microscopy techniques. The protection efficiency of investigated SAMs increases with chain length which is attributed to transport hindrance of the corrosion stimulators in the atmospheric environment, water, oxygen and formic acid, towards the copper surface. The transport hindrance is selective and results in different corrosion products on bare and on protected copper. Initially the molecular structure of SAMs on copper is well ordered, but the ordering is reduced with exposure time. Octadecanethiol (ODT), the longest alkanethiol investigated, protects copper significantly better than zinc, which may be attributed to the higher bond strength of Cu-S than of Zn-S. Despite these differences, the corrosion protection efficiency of ODT for the single phase Cu20Zn brass alloy is equally efficient as for copper, but significantly less for the heterogeneous double phase Cu40Zn brass alloy.

  9. Reduction of air pollutants - a tool for control of atmospheric corrosion

    Directory of Open Access Journals (Sweden)

    Kucera, V.

    2003-12-01

    Full Text Available In most urban areas in Europe and Northern America serious corrosion impacts on buildings and cultural monuments have been caused by emissions of pollutants. The rapidly increasing pollution levels in many of the developing countries also exert a serious threat to materials. Beside the very important role of SO2 also the direct or synergistic effect of NOx and O3, the particulates and rain acidity may contribute in an important way to materials degradation. Results from extensive international field exposure programs i.e. within the UN/ECE have enabled development of dose-response relations which describe the effect of dry and wet deposition of pollutants on corrosion of different material groups. In most of the industrialized countries decreasing trends of sulphur and nitrogen pollutants and of acidity of precipitation have resulted in decreased corrosion rates. The concept of acceptable levels of pollutants is a useful tool in planning of abatement strategies and for defining of conditions for a suitable development in the field of corrosion of constructions in the atmosphere.

    La contaminación de la atmósfera ha sido la principal razón del grave deterioro de las edificaciones y de los monumentos en numerosas ciudades de Europa y Norteamérica. De otro lado, el acelerado incremento de los niveles de contaminación en los países menos desarrollados está poniendo en peligro la estabilidad de los materiales utilizados. Además del importante papel que en este sentido juega el SO2, la acción directa o el efecto sinérgico de los NOx y el O3, al igual que el material particulado y las lluvias acidas contribuyen a agravar el problema. Resultados de vastos programas internacionales de investigación como, por ejemplo, el UN/ECE, han permitido desarrollar relaciones dosis-respuesta que describen el efecto de la deposición de los contaminantes sobre la corrosión de

  10. High temperature corrosion of iron-base and nickel-base alloys for hydrogen production apparatus by thermochemical method in H2O+SO3 atmosphere

    International Nuclear Information System (INIS)

    Corrosion tests for ten iron-base and nickel-base alloys at 850degC for 1000h in H2O + SO3 atmosphere were carried out to obtain data for selection of candidate container materials in the thermochemical process which produces hydrogen from water by use of iodine and sulfur as circulating materials. The following results were obtained: (1) Oxidation, spallation of corrosion film, uniform corrosion and grain boundary penetration composed of internal oxidation and sulfuration occur in this atmosphere and the corrosion proceeds by grain boundary penetration. (2) SUS304, SUS316 and Hastelloy C276 are inferior in corrosion resistance and SUS329J4L is superior among ten alloys used in this experiment. Alloys such as Alloy 800H and Hastelloy XR show intermediate corrosion resistance. (3) Oxide films of alloys containing iron and chromium are mostly composed of outer iron-oxide and inner chromium-oxide. Sulfur concentrates at scale/metal interfaces and grain boundary penetration portions, and sulfides form. (4) Corrosion in this atmosphere could be expressed using the parabolic law between the grain boundary penetration depth and time. It is considered that causes of the apparently observed parabolic law were a high concentration of SO3 and change of the gas composition caused by catalytic action of the corrosion film formed with the progress of corrosion. (author)

  11. Selection of varnish-and-paint system for protection of 20Kh3MVF steel from atmospheric corrosion

    International Nuclear Information System (INIS)

    A varish-and-paint system has been selected for protecting steel 20Kh3MVF against atmospheric corrosion under conditions of elevated temperatures and humidity. It has been established that optimum protection of steel can be achieved by coating it with epoxy enamel EhP-525 in combination with surface phosphating. For lono.-term protection, enamel ML-12 coatings on the phosphate layer are recommended

  12. Simulation of a long term atmospheric corrosion process on plain and weathering steels

    Directory of Open Access Journals (Sweden)

    Bolivar, F.

    2003-12-01

    Full Text Available Information on weathering steel behaviour and its rust products characteristics after decades of atmospheric exposure are scarce. On the other side, generally accepted laboratory tests for the assessment of its corrosion resistance have not been developed yet. Consequently, simulating corrosion in the laboratory during long periods of time is attractive for the interesting and complete information obtainable from them. In the present work, AISI-SAE 1008 and ASTM-588 B steel samples have been exposed for two years to a immersion-emersion CEBELCOR type test in the laboratory, simulating a moderate urban atmosphere. Two groups of six samples each were tested. After the first year, three samples of each batch were retired for analysis and the rest was kept until they reached two years of exposure. The half cell electrode potentials were measured daily. The rust was characterized by metallographic techniques, Mossbauer spectroscopy (MS, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. Comparison was done with field exposure experiments reported in the literature, and conclusions on the behaviour of tested samples were drawn looking for differences and similarities with samples and structures under actual atmospheric conditions.

    La información sobre el comportamiento y las características de los productos de corrosión de los aceros auto protectores, después de varias décadas de exposición a la atmósfera, es escasa. Por otra parte, aún no se han desarrollado ensayos de laboratorio de aceptación general para evaluar su resistencia a la corrosión. En consecuencia, cada día toman más importancia los ensayos de laboratorio durante largos periodos de exposición. En el presente trabajo, se sometieron muestras de acero AISI-SAE 1008 y ASTM 588-B, durante dos años, a un ensayo de laboratorio de inmersión-emersión tipo CEBELCOR. Se ensayaron dos grupos de seis muestras de cada composición de acero, en una

  13. The role of particles on initial atmospheric corrosion of copper and zinc : lateral distribution, secondary spreading and CO2-/SO2-influence

    OpenAIRE

    Chen, Zhuo Yuan

    2005-01-01

    The role of sodium chloride (NaCl) particles and ammonium sulfate ((NH4)2SO4) particles on the initial atmospheric corrosion of copper and zinc was investigated under in situ and ex situ conditions using microgravimetry, FTIR spectroscopy, ion chromatography, scanning electron microscopy with x-ray microanalysis and the scanning Kelvin probe. For the first time, in situ infrared spectra were collected on a micron level during particle induced atmospheric corrosion using a recently developed e...

  14. Atmospheric corrosion effects of HNO 3—Comparison of laboratory-exposed copper, zinc and carbon steel

    Science.gov (United States)

    Samie, Farid; Tidblad, Johan; Kucera, Vladimir; Leygraf, Christofer

    The influence of nitric acid (HNO 3) on the atmospheric corrosion of copper, zinc and carbon steel was investigated in laboratory exposures at 65% relative humidity (RH), 25 °C and 0.03 cm s -1 air velocity. The deposition velocity ( Vd) of HNO 3 on the specimens, the corrosion rates and corrosion products were determined by gravimetry, ion chromatography, X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) microspectroscopy. Comparisons were also made with literature data on the corrosion effects of sulfur dioxide (SO 2), nitrogen dioxide (NO 2) and ozone (O 3). At 65% RH, the Vd of HNO 3 on all metals was at least 70% of that of an ideal absorbent, i.e., an impregnated filter with perfect absorption for HNO 3. The Vd of HNO 3 was much higher than that of SO 2, NO 2 or O 3, which is mainly attributed to the relatively high sticking coefficient, high solubility and high reactivity of HNO 3 compared to the other gases. During identical exposures to HNO 3, the corrosion rate of carbon steel was nearly three times higher than that of copper or zinc. However, when comparing the corrosion effects induced by HNO 3 with those induced by SO 2 alone or in combination with either NO 2 or O 3, HNO 3 turned out to be far more aggressive than SO 2. Relative to SO 2, zinc is the metal most sensitive to HNO 3, followed by copper and with carbon steel least sensitive to HNO 3.

  15. Atmospheric corrosion effects of HNO 3—Influence of temperature and relative humidity on laboratory-exposed copper

    Science.gov (United States)

    Samie, Farid; Tidblad, Johan; Kucera, Vladimir; Leygraf, Christofer

    The effect of HNO 3 on the atmospheric corrosion of copper has been investigated at varied temperature (15-35 °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 ( Vd) of HNO 3 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 °C, possibly as an effect of lower amount of cuprite due to a thinner adlayer on the metal surface at 35 °C. The Vd of HNO 3 on copper, however, was unaffected by temperature. The corrosion rate and Vd of HNO 3 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 Vd of HNO 3 on copper at ⩾65% RH, 25 °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 HNO 3, the corrosion rate of copper decreased after 14 d and the growth of the oxide levelled off after 7 d of exposure.

  16. Classiifcation and Evaluation of Environment of Atmospheric Corrosion%大气腐蚀环境的分类及腐蚀性评定

    Institute of Scientific and Technical Information of China (English)

    刘凯吉

    2015-01-01

    本文主要介绍了大气腐蚀的原理和构成大气腐蚀的各种腐蚀要素,根据相对湿度和污染物因素确定了大气腐蚀的类型,同时,综合考虑各种腐蚀要素,根据环境腐蚀的严酷性程度对腐蚀环境进行分类.%In this paper, the principle and various factors of atmospheric corrosion were introduced and the types of atmospheric corrosion were determined based on the corrosion relative humidity and pollutant factors, meanwhile, environment of corrosion was classified considering severity of all kinds of corrosion factors.

  17. Role of CO2 in the initial stage of atmospheric corrosion of AZ91 magnesium alloy in the presence of NaCl

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effect of CO2 and NaCl on the initial stage of atmospheric corrosion of AZ91 magnesium alloy was studied.The observation of surface morphology by optical microscopy (OM), scanning electron microscopy (SEM) and the analysis of corrosion products by X-ray diffraction (XRD) were integrated to investigate corrosion evolution. The results showed that NaCl stimulated the corrosion by promoting the formation of thin electrolyte film, increasing the conductivity and breaking the protective film in the absence of CO2. The morphology of the corroded samples with deposited NaCl was more homogenous in the presence of CO2. It was suggested that NaCl-induced corrosion was inhibited in the presence of CO2 by the formation of slightly soluble corrosion products containing hydroxy carbonates and hydroxy chlorides that provided a partly protective layer on the surface of the magnesium alloy.

  18. Atmospheric corrosion effects of HNO 3—Influence of concentration and air velocity on laboratory-exposed copper

    Science.gov (United States)

    Samie, Farid; Tidblad, Johan; Kucera, Vladimir; Leygraf, Christofer

    A recently developed experimental set-up has been used to explore the atmospheric corrosion effects of nitric acid (HNO 3) 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) HNO 3 deposition and weight gain of copper increased linearly with concentration up to 400 μg 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 HNO 3 concentration of the air velocity of 35.4 cm s -1 resulted in a relatively high deposition velocity ( Vd) 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 ( Vd,surf) of 3.6 cm s -1. Results obtained in this study emphasize the importance for future research on the corrosion effects of HNO 3 on materials as very little has so far been done in this field.

  19. Corrosion and protection of metals in the rural atmosphere of El Pardo Spain (PATINA/CYTED project)

    International Nuclear Information System (INIS)

    Atmospheric corrosion tests of metallic and organic coatings on steel, zinc and aluminium have been conducted in el Pardo (Spain) as part of the PATINA/CYTED project Anticorrosive Protection of Metals in the Atmosphere. This is a rural atmosphere with the following ISO corrosivity categories: C2 (Fe), C'' (Zn), Cu (Cu) and C1 (Al). Its average temperature and relative humidity is 13 degree centigrade and 62.8, respectively, and it has low SO2 and C1''- contents. Results of 42 months exposure are discussed. Atmospheric exposure tests were carried out for the following types of coatings: conventional paint coatings for steel and hot-dip galvanized steel (group 1), new painting technologies for steel and galvanized steel (group 2), zinc-base metallic coatings (group 3), aluminium-base metallic coatings (group 4), coatings on aluminium (group 5) and coil-coatings on steel, hot-dip galvanized steel and 55% Al-Zn coated steel (group 6). (Author) 9 refs

  20. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    International Nuclear Information System (INIS)

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 deg. C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH)2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH)2. A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  1. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, S. [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Pardo, A. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain)], E-mail: anpardo@quim.ucm.es; Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Coy, A.E.; Viejo, F.; Arrabal, R. [Corrosion and Protection Centre, School of Materials, University of Manchester, P.O. Box 88, Sackville Street, Manchester M60 1QD (United Kingdom)

    2009-01-15

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 deg. C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH){sub 2} and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH){sub 2}. A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  2. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    Science.gov (United States)

    Feliu, S., Jr.; Pardo, A.; Merino, M. C.; Coy, A. E.; Viejo, F.; Arrabal, R.

    2009-01-01

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 °C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH) 2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH) 2. A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  3. Application Of Fractal Dimension On Atmospheric Corrosion Of Galvanized Iron Roofing Material

    OpenAIRE

    Issa A.K; Abba. M. Aji

    2015-01-01

    Abstract Corrosion rates of galvanized iron roofing sheet In yola north eastern part of Nigeria were assessed and determined by weight loss method and scanner fractal analysis method. Scanning electronic machine SEM was used to transform corrosion coupons to electronic form for image j processing and analysing software The result of corrosion rates for these two methods after six months of the samples exposure in industrial. Coastal market and urban areas in the region are 1.51 1.079 1.051 0....

  4. Atmospheric corrosion effects of HNO 3—method development and results on laboratory-exposed copper

    Science.gov (United States)

    Samie, Farid; Tidblad, Johan; Kucera, Vladimir; Leygraf, Christofer

    The effects of the atmospheric pollutant nitric acid (HNO 3) on materials compared to other corrosive gases, e.g. sulphur dioxide (SO 2), nitrogen dioxide (NO 2) or ozone (O 3), have so far received little or no attention. The high sticking coefficient of HNO 3 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 HNO 3 on materials. HNO 3 concentration measurements up to 1080 μg 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 HNO 3 show that at 63% RH and 25 °C, the deposition of HNO 3 on copper is slightly lower than on a perfect absorber. The loss of HNO 3 during exposure of the samples showed good agreement with the amount of nitrates dissolved from surfaces of the samples after exposure. FT-IR, XRD and IC analyses of copper exposed to HNO 3 and mass loss and mass gain analyses confirmed cuprite (Cu 2O) and the basic copper nitrate, gerhardtite, as the main corrosion products. Deposition, as well as the corrosion effect, of HNO 3 on copper appeared to be greater than that of any of the other above-mentioned pollutants.

  5. Study of uncertainty in atmospheric corrosion rate of floe carbon steel; Estudio de incertidumbre en la velocidad de corrosion atmosferica en acero de bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, V.; Lopez, C.

    2005-07-01

    The confidence interval of measurements of corrosion rate has been barely reported in the literature. It is a function of both the number of probes and the underlying pdf. We have performed specific experiments with a lot more probes than the standards require, and we evaluated, for exposure times of 1, 2, 3 and 7 months, the effect of using only three (as it is mandatory by the standard for one year exposure time) up to eleven. With the new experimental data, we were able to confirm that the values fit a normal distribution. We also found evidence that the minimum number of probes might depend upon the atmospheric condition and exposure time. The number of probes presently required for studies with exposure times of one year, might not be enough in studies of initial kinetics (exposure times smaller than one year). (Author) 14 refs.

  6. Incipient corrosion behavior of Haynes 230 under a controlled reducing atmosphere at high temperatures

    Science.gov (United States)

    Tung, Hsiao-Ming; Stubbins, James F.

    2012-08-01

    In situ thermogravimetry analysis (TGA) was used to investigate the incipient corrosion behavior of alloy 230 exposed under a reducing environment in a temperature range of 850-1000 °C. Both oxidation and loss of alloying elements of alloy 230 were observed to occur concurrently in these conditions. The surface oxide which formed on the substrate does not appear to be as effective in providing a protective layer during the incipient corrosion period.

  7. The atmospheric corrosion of quaternary bronzes: An evaluation of the dissolution rate of the alloying elements

    Science.gov (United States)

    Bernardi, E.; Chiavari, C.; Martini, C.; Morselli, L.

    2008-07-01

    A comparative evaluation of the corrosion behaviour of a G85 bronze in acid rain solutions was performed. As weathering technique, a wet dry device was used to simulate a cyclic exposure to stagnant rain. The weathering solutions were a collected natural rain and an artificial solution reproducing the natural rain. The solutions were periodically monitored as concerns pH and metallic ion concentrations. On the aged specimens, surface studies were performed through OM, SEM and Raman analyses. At the end of weathering tests (40 days), weight loss measurements were carried out. The aim of this work was to examine the reproducibility in laboratory of the corrosive conditions determined by a natural acid rain. The final goal of this research is to investigate the dissolution of a quaternary alloy exposed to acid rains. The results showed slightly different corrosion behaviours as a consequence of the exposure to natural or synthetic rain. Concerning the mechanism of corrosion of G85 bronze, the innovative approach adopted in this study allowed one to point out the contribution of each alloying element to the general corrosion. Actually, while Cu and Pb progressively form insoluble corrosion compounds, Zn continuously dissolves, without forming detectable insoluble products. The absence of dissolved tin is remarkable.

  8. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    OpenAIRE

    Feliu Jr., S.; Pardo, Angel; Merino, M. C.; Coy, A. E.; Viejo, F.; Arrabal, R.

    2009-01-01

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 °C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH)2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of M...

  9. REVIEW ON ATMOSPHERIC CORROSION OF WEATHERING AND CARBON STEELS%碳钢和耐候钢的大气腐蚀

    Institute of Scientific and Technical Information of China (English)

    李巧霞; 王振尧; 韩薇; 韩恩厚

    2009-01-01

    回顾了近年来碳钢和耐候钢大气腐蚀研究,比较了两种钢的腐蚀行为.重点分析了两种钢在腐蚀过程、腐蚀产物组成及影响因素等方面的相似性;同时讨论了两种钢的腐蚀速度和锈层结构的差异性.%The recent progress in the atmospheric corrosion of carbon steel and weathering steel is reviewed. The corrosion behavior of the above two kinds of steels is compared.The similarities in corrosion process, corrosion products,and effect factors of the two steels are analyzed.The differences in the corrosion rate and rust microstructure of the two steels are discussed.

  10. Mapping the concentration changes during the dynamic processes of crevice corrosion by digital

    Directory of Open Access Journals (Sweden)

    HENGLEI JIA

    2009-02-01

    Full Text Available The dynamic process of crevice corrosion during anodic dissolution of a crevice electrode in a 5.0 mmol dm-3 NaCl solution has been studied by digital holographic reconstruction. Digital holographic reconstruction has been proved to be an effective and in situ technique to detect the changes in the solution concentration because useful and direct information can be obtained from the three-dimensional images. It provides a valuable method for a better understanding of the mechanism of crevice corrosion by studying the dynamic processes of changes in the solution concentration at the interface of crevice corrosion.

  11. Where is MAP Going? A review and future potential of modified atmosphere packaging for meat.

    Science.gov (United States)

    McMillin, Kenneth W

    2008-09-01

    Modified atmosphere packaging (MAP) is the removal and/or replacement of the atmosphere surrounding the product before sealing in vapor-barrier materials. While technically different, many forms of MAP are also case-ready packaging, where meat is cut and packaged at a centralized location for transport to and display at a retail store. Most of the shelf life properties of meat are extended by use of MAP, but anoxic forms of MAP without carbon monoxide (CO) do not provide bloomed red meat color and MAP with oxygen (O(2)) may promote oxidation of lipids and pigments. Advances in plastic materials and equipment have propelled advances in MAP, but other technological and logistical considerations are needed for successful MAP systems for raw chilled fresh meat. Current MAP options of air-permeable overwrapped trays in master packs, low O(2) formats of shrunk film vacuum packaging (VP) or MAP with carbon dioxide (CO(2)) and nitrogen (N(2)) and their peelable barrier film derivatives, and high O(2) MAP each have advantages and disadvantages. Packaging technology innovations and ingenuity will continue to provide MAP that is consumer oriented, product enhancing, environmentally responsive, and cost effective, but continued research and development by the scientific and industry sectors will be needed. PMID:22063169

  12. Corrosion of Fe-15Ce alloy in three mixed-gas atmospheres

    Institute of Scientific and Technical Information of China (English)

    付广艳; 牛焱; 吴维(山又)

    2002-01-01

    The corrosion behavior of Fe-15Ce alloy was studied at 700℃ in H2-CO2, H2-H2S and H2-H2S-CO2 mixtures. Internal oxidation occurs on the Fe-15Ce alloy corroded in H2-CO2 mixtures. The complex scales are formed during the corrosion of the alloy in H2-H2S and H2-H2S-CO2 mixtures. No exclusive Ce scales can be founded in any case. This is because of the limited solubility of Ce in the base metal and the presence of intermetallic compounds in the alloy. The corrosion rate of the alloy at 700℃ in H2-H2S-CO2 is lower than that in H2-H2S, and it is the lowest in H2-CO2.

  13. Establishing empirical relationships to predict porosity level and corrosion rate of atmospheric plasma-sprayed alumina coatings on AZ31B magnesium alloy

    OpenAIRE

    D. Thirumalaikumarasamy; K. Shanmugam; Balasubramanian, V

    2014-01-01

    Plasma sprayed ceramic coatings are successfully used in many industrial applications, where high wear and corrosion resistance with thermal insulation are required. In this work, empirical relationships were developed to predict the porosity and corrosion rate of alumina coatings by incorporating independently controllable atmospheric plasma spray operational parameters (input power, stand-off distance and powder feed rate) using response surface methodology (RSM). A central composite rotata...

  14. Corrosion/95 conference papers

    International Nuclear Information System (INIS)

    The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: cathodic protection in natural waters; materials for fossil fuel combustion and conversion systems; modern problems in atmospheric corrosion; innovative ideas for controlling the decaying infrastructure; deposits and their effects on corrosion in industry; volatile high temperature and non aqueous corrosion inhibitors; corrosion of light-weight and precoated metals for automotive application; refining industry corrosion; corrosion in pulp and paper industry; arctic/cold weather corrosion; materials selection for waste incinerators and associated equipment; corrosion measurement technology; environmental cracking of materials; advancing technology in the coating industry; corrosion in gas treating; green inhibition; recent advances in corrosion control of rail equipment; velocity effects and erosion corrosion in oil and gas production; marine corrosion; corrosion of materials in nuclear systems; underground corrosion control; corrosion in potable and industrial water systems in buildings and its impact on environmental compliance; deposit related boiler tube failures; boiler systems monitoring and control; recent developments and experiences in reactive metals; microbiologically influenced corrosion; corrosion and corrosion control for steel reinforced concrete; international symposium on the use of 12 and 13 Cr stainless steels in oil and gas production environments; subsea corrosion /erosion monitoring in production facilities; fiberglass reinforced pipe and tubulars in oilfield service; corrosion control technology in power transmission and distribution; mechanisms and methods of scale and deposit control; closing the loop -- results oriented cooling system monitoring and control; and minimization of aqueous discharge

  15. Effect of Aluminum and Silicon on Atmospheric Corrosion of Low-alloying Steel under Containing NaHSO3 Wet/dry Environment

    International Nuclear Information System (INIS)

    The atmospheric corrosion performance of Al-alloying Si-alloying and Al-Si-alloying steel were studied by wet/dry cyclic corrosion tests (CCT) at 30 .deg. C and 60% relative humidity (RH). The corrosion electrolyte used for CCT was 0.052 wt% NaHSO3 (pH∼4) solution. The result of gravimetry demonstrated that Al-Si-bearing steels showed lower corrosion resistance than other rusted steels. But the rusted 0.7%Si-alloying steel showed a better corrosion resistance than rusted mild steel. Polarization curves demonstrated that Al-/Si-alloying and Al-Si-alloying improved the rest potential of steel at the initial stage: and accelerated the cathodic reduction and anodic dissolution after a rust layer formed on the surfaces of steels. XRD results showed that Al-Si-alloying decreased the volume fraction of Fe3O4 and α-FeOOH. The recycle of acid accelerated the corrosion of steel at the initial stage. After the rust layer formed on the steel, the leak of rust destabilized the rust layer due to the dissolution of compound containing Al (such as FeAl2O4, (Fe, Si)2(Fe, Al)O4). Al-Si-alloying is hence not suitable for improving the anti-corrosion resistance of steel in industrial atmosphere

  16. On the capability of in-situ exposure in an environmental scanning electron microscope for investigating the atmospheric corrosion of magnesium

    International Nuclear Information System (INIS)

    The feasibility of environmental scanning electron microscope (ESEM) in studying the atmospheric corrosion behavior of 99.97% Mg was investigated. For reference, ex-situ exposure was performed. A model system was designed by spraying few salt particles on the metal surface and further promoting the corrosion process using platinum (Pt) deposition in the form of 1×1×1 µm3 dots around the salt particles to create strong artificial cathodic sites. The results showed that the electron beam play a significant role in the corrosion process of scanned regions. This was attributed to the irradiation damage occurring on the metal surface during the ESEM in-situ experiment. After achieving to a reliable process route, in a successful attempt, the morphology and composition of the corrosion products formed in-situ in the ESEM were in agreement with those of the sample exposed ex-situ. - Highlights: • The feasibility of in-situ microscopy and atmospheric corrosion exposures of pure Mg in an ESEM are examined. • A model system was designed using NaCl particles on parts of the metal surface and promoting the corrosion process by depositing 1×1×1 µm3 Pt dots to create strong artificial cathodic sites. • The electron beam used for ESEM imaging affects the in-situ corrosion process. • A proper cleaning procedure for the sample and microscope chamber reducing carbon contamination makes the results from the ESEM in-situ exposures comparable to ex-situ exposures

  17. Effect of Aluminum and Silicon on Atmospheric Corrosion of Low-alloying Steel under Containing NaHSO{sub 3} Wet/dry Environment

    Energy Technology Data Exchange (ETDEWEB)

    Xinhua, Chen; Junhua, Dong; Enhou, Han; Wei, Ke [Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China)

    2008-12-15

    The atmospheric corrosion performance of Al-alloying Si-alloying and Al-Si-alloying steel were studied by wet/dry cyclic corrosion tests (CCT) at 30 .deg. C and 60% relative humidity (RH). The corrosion electrolyte used for CCT was 0.052 wt% NaHSO{sub 3} (pH{approx}4) solution. The result of gravimetry demonstrated that Al-Si-bearing steels showed lower corrosion resistance than other rusted steels. But the rusted 0.7%Si-alloying steel showed a better corrosion resistance than rusted mild steel. Polarization curves demonstrated that Al-/Si-alloying and Al-Si-alloying improved the rest potential of steel at the initial stage: and accelerated the cathodic reduction and anodic dissolution after a rust layer formed on the surfaces of steels. XRD results showed that Al-Si-alloying decreased the volume fraction of Fe{sub 3}O{sub 4} and {alpha}-FeOOH. The recycle of acid accelerated the corrosion of steel at the initial stage. After the rust layer formed on the steel, the leak of rust destabilized the rust layer due to the dissolution of compound containing Al (such as FeAl{sub 2}O{sub 4}, (Fe, Si){sub 2}(Fe, Al)O{sub 4}). Al-Si-alloying is hence not suitable for improving the anti-corrosion resistance of steel in industrial atmosphere.

  18. Evaluation of atmospheric corrosion on electroplated zinc and zinc nickel coatings by Electrical Resistance (ER) Monitoring

    DEFF Research Database (Denmark)

    Møller, Per

    ER (Electrical Resistance) probes provide a measurement of metal loss, measured at any time when a metal is exposed to the real environment. The precise electrical resistance monitoring system can evaluate the corrosion to the level of nanometers, if the conductivity is compensated for temperature...... cars for the automotive industry, off-shore construction or component and devices used in harsh industrial environments. The ER monitoring makes it possible to study the corrosion rate on-line in remote locations as a function of temperature, relative humidity and changes in the composition of the...

  19. Atmospheric Corrosion of Painted Galvanized and 55%Al-Zn Steel Sheets: Results of 12 Years of Exposure

    Directory of Open Access Journals (Sweden)

    C. I. Elsner

    2012-01-01

    Full Text Available Zinc or 55%Al-Zn alloy-coated steel sheets, either bare or covered by different painting systems, have been exposed for 12 years to the action of the urban atmosphere at the CIDEPINT station located in La Plata (34° 50′ South, 57° 53′, West, province of Buenos Aires, Argentina. The samples exposed surface was evaluated through periodical visual inspections, standardized adhesion tests, and electrochemical impedance measurements. The ambient variables monitored were average annual rains and temperatures, time of wetness, sulphur and chloride concentration, relative humidity, and speed and direction of the winds. It was found that in this atmosphere, the corrosion resistance of the bare 55% Al-Zn/steel sheets was higher than of the galvanized steel, and the polyurethane painting system was more protective than the alkyd and epoxy ones, which degraded after 6-7 years of exposure.

  20. A laboratory study of the effect of NO 2 on the atmospheric corrosion of zinc

    Science.gov (United States)

    Castaño, J. G.; de la Fuente, D.; Morcillo, M.

    Studies on the effect of NO x on zinc corrosion are scarce and their results are variable and at times seemingly contradictory. This paper reports laboratory tests involving the dry deposition on zinc surfaces of 800 μg m -3 NO 2, alone and in combination with 800 μg m -3 SO 2, at temperatures of 35 and 25 °C and relative humidities of 90% and 70%. From the gravimetric results obtained and from the characterisation of the corrosion products by optical microscopy, scanning electron microscopy (SEM/EDX), grazing incidence X-ray diffraction (GIXD) and X-ray photoelectron spectroscopy (XPS), it has been verified that the corrosive action of NO 2 alone is negligible compared with SO 2. However, an accelerating effect has been observed when NO 2 acts in conjunction with SO 2 at 25 °C and 90% RH. At 35 °C and 90% RH, the accelerating effect is smaller, and at low relative humidities (70%), the synergistic effect is only slight, which suggests it may be favoured by the presence of moisture. In those cases where an accelerating effect has been observed, a greater proportion of sulphate ions has been found in the corrosion products, and nitrogen compounds have not been detected, indicating that NO 2 participates indirectly as a catalyst of the oxidation of SO 2 to sulphate.

  1. Determination of atmospheric corrosion of coated steel surfaces by in situ infrared reflection absorption spectroscopy (IRRAS)

    International Nuclear Information System (INIS)

    Full text: Infrared reflection absorption spectroscopy (IRRAS) is a sensitive technique for measuring thin layers on metallic surfaces. The principal goal of this IRRAS study was the development of a reproducible and reliable in situ measurement procedure for the determination of corrosion of coated steel surfaces. (author)

  2. Accelerated atmospheric corrosion testing using a cyclic wet/dry exposure test

    International Nuclear Information System (INIS)

    Aluminum corrosion is important in overhead electrical conductors constructed from aluminum wire centrally reinforced by galvanized steel strands. Inspection of conductor after long service has implicated rubber bushing material, on the outside, and the galvanized strands, on the inside, as providing potential galvanic sites for the initiation of rapid aluminum corrosion. Therefore, the galvanic corrosion of aluminum in contact with graphite-loaded neoprene rubber, hot-dip galvanized steel and steel was assessed in a cyclic wet/dry exposure test using mixed-salts spray solutions containing appropriate ratios of sulfate and chloride ion. Aluminum was found to corrode at between 3 to 6 times its uncoupled rate when associated with the rubber material. While the eta-phase, relatively pure Zn, galvanized layer remained intact, galvanic corrosion of aluminum was slow. However, on exposure of the zeta-phase, Zn/Fe intermetallic layer, aluminum corroded about 35 times faster than expected in a solution with a high level of Cl- ion. The importance of these data to conductor lifetime is discussed

  3. Mapping Atmospheric Moisture Climatologies across the Conterminous United States.

    Directory of Open Access Journals (Sweden)

    Christopher Daly

    Full Text Available Spatial climate datasets of 1981-2010 long-term mean monthly average dew point and minimum and maximum vapor pressure deficit were developed for the conterminous United States at 30-arcsec (~800m resolution. Interpolation of long-term averages (twelve monthly values per variable was performed using PRISM (Parameter-elevation Relationships on Independent Slopes Model. Surface stations available for analysis numbered only 4,000 for dew point and 3,500 for vapor pressure deficit, compared to 16,000 for previously-developed grids of 1981-2010 long-term mean monthly minimum and maximum temperature. Therefore, a form of Climatologically-Aided Interpolation (CAI was used, in which the 1981-2010 temperature grids were used as predictor grids. For each grid cell, PRISM calculated a local regression function between the interpolated climate variable and the predictor grid. Nearby stations entering the regression were assigned weights based on the physiographic similarity of the station to the grid cell that included the effects of distance, elevation, coastal proximity, vertical atmospheric layer, and topographic position. Interpolation uncertainties were estimated using cross-validation exercises. Given that CAI interpolation was used, a new method was developed to allow uncertainties in predictor grids to be accounted for in estimating the total interpolation error. Local land use/land cover properties had noticeable effects on the spatial patterns of atmospheric moisture content and deficit. An example of this was relatively high dew points and low vapor pressure deficits at stations located in or near irrigated fields. The new grids, in combination with existing temperature grids, enable the user to derive a full suite of atmospheric moisture variables, such as minimum and maximum relative humidity, vapor pressure, and dew point depression, with accompanying assumptions. All of these grids are available online at http://prism.oregonstate.edu, and

  4. Mapping Atmospheric Moisture Climatologies across the Conterminous United States.

    Science.gov (United States)

    Daly, Christopher; Smith, Joseph I; Olson, Keith V

    2015-01-01

    Spatial climate datasets of 1981-2010 long-term mean monthly average dew point and minimum and maximum vapor pressure deficit were developed for the conterminous United States at 30-arcsec (~800m) resolution. Interpolation of long-term averages (twelve monthly values per variable) was performed using PRISM (Parameter-elevation Relationships on Independent Slopes Model). Surface stations available for analysis numbered only 4,000 for dew point and 3,500 for vapor pressure deficit, compared to 16,000 for previously-developed grids of 1981-2010 long-term mean monthly minimum and maximum temperature. Therefore, a form of Climatologically-Aided Interpolation (CAI) was used, in which the 1981-2010 temperature grids were used as predictor grids. For each grid cell, PRISM calculated a local regression function between the interpolated climate variable and the predictor grid. Nearby stations entering the regression were assigned weights based on the physiographic similarity of the station to the grid cell that included the effects of distance, elevation, coastal proximity, vertical atmospheric layer, and topographic position. Interpolation uncertainties were estimated using cross-validation exercises. Given that CAI interpolation was used, a new method was developed to allow uncertainties in predictor grids to be accounted for in estimating the total interpolation error. Local land use/land cover properties had noticeable effects on the spatial patterns of atmospheric moisture content and deficit. An example of this was relatively high dew points and low vapor pressure deficits at stations located in or near irrigated fields. The new grids, in combination with existing temperature grids, enable the user to derive a full suite of atmospheric moisture variables, such as minimum and maximum relative humidity, vapor pressure, and dew point depression, with accompanying assumptions. All of these grids are available online at http://prism.oregonstate.edu, and include 800-m and 4

  5. Effectiveness of nickel plating in inhibiting atmospheric corrosion of copper alloy contacts

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, T.; Sorensen, R.; Guilinger, T.

    1997-12-31

    A series of tests was run to determine the effect of Ni plating thickness on connector contact resistance. Copper coupons were plated with an electrolytic nickel strike followed by electroless nickel to produce Ni layers of 10, 20, 55 and 100 {micro}in. The coupons were then exposed to a simulated industrial environment. Pore corrosion was observed after the exposure, which correlated with Ni thickness. In a second series of tests, beryllium-copper four-tine contacts with 50 {micro}in of gold plate over electrolytic nickel strike/electroless-nickel plates of varying thickness were exposed the same corrosive environment. Contact resistance of mated pairs was monitored over a two-month period. The degradation in contact resistance correlated with the Ni thickness used in the connectors.

  6. Reduction of air pollutants - a tool for control of atmospheric corrosion

    OpenAIRE

    Kucera, V.

    2003-01-01

    In most urban areas in Europe and Northern America serious corrosion impacts on buildings and cultural monuments have been caused by emissions of pollutants. The rapidly increasing pollution levels in many of the developing countries also exert a serious threat to materials. Beside the very important role of SO2 also the direct or synergistic effect of NOx and O3, the particulates and rain acidity may contribute in an import...

  7. A study of the evolution of rust on Mo–Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

    International Nuclear Information System (INIS)

    Highlights: ► The rusting evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. ► The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. ► Increased content of α-FeOOH and decreased γ-FeOOH and Fe3O4 indicate the enhanced resistance of the rust. ► Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of γ-FeOOH and Fe3O4 decreases and α-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

  8. A study of the evolution of rust on Mo-Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Hao Long [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China); Zhang Sixun [College of Material and Metallurgy, Northeastern University, Wenhua Road 3, Shenyang 110004 (China); Technical Centre of Laiwu Steel Group, Ltd., Changsheng Road 23, Laiwu 271104 (China); Dong Junhua, E-mail: jhdong@imr.ac.cn [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China); Ke Wei [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Wencui Road 62, Shenyang 110016 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer The rusting evolution of a Mo-Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. Black-Right-Pointing-Pointer The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. Black-Right-Pointing-Pointer Increased content of {alpha}-FeOOH and decreased {gamma}-FeOOH and Fe{sub 3}O{sub 4} indicate the enhanced resistance of the rust. Black-Right-Pointing-Pointer Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo-Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of {gamma}-FeOOH and Fe{sub 3}O{sub 4} decreases and {alpha}-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

  9. On the capability of in-situ exposure in an environmental scanning electron microscope for investigating the atmospheric corrosion of magnesium.

    Science.gov (United States)

    Esmaily, M; Mortazavi, N; Shahabi-Navid, M; Svensson, J E; Johansson, L G; Halvarsson, M

    2015-06-01

    The feasibility of environmental scanning electron microscope (ESEM) in studying the atmospheric corrosion behavior of 99.97% Mg was investigated. For reference, ex-situ exposure was performed. A model system was designed by spraying few salt particles on the metal surface and further promoting the corrosion process using platinum (Pt) deposition in the form of 1×1×1 µm(3) dots around the salt particles to create strong artificial cathodic sites. The results showed that the electron beam play a significant role in the corrosion process of scanned regions. This was attributed to the irradiation damage occurring on the metal surface during the ESEM in-situ experiment. After achieving to a reliable process route, in a successful attempt, the morphology and composition of the corrosion products formed in-situ in the ESEM were in agreement with those of the sample exposed ex-situ. PMID:25731810

  10. Atmospheric Corrosion Performance of W450QN Steel%W450QN钢大气腐蚀性能

    Institute of Scientific and Technical Information of China (English)

    刘建容; 张万灵; 蔡捷; 石争鸣; 陈吉清

    2011-01-01

    Three years atmospheric corrosion of W450QN steel made by Wuhan Iron & Steel (Group) Corp was carried out. The results show that the corrosion resistance of W450QN was better than that of Q345, the average corrosion rate in Qingdao, Jiangjin and Qionghai decreased by a third compared with that of Q345. The polarization curves of 3-year exposed rusty steel showed that both of the initial passivity current and maintaining passivity current of W450QN were smaller than those of Q345, indicating a better protective performance of W450QN due to its compact rust layer and higher mass transfer resistance.%对武钢生产的W450QN钢进行了3年的大气暴露试验,结果表明,W450QN钢的耐蚀性优于Q345钢,在青岛站、江津站、琼海站,W450QN钢与Q345钢相比,平均腐蚀速率之比分别为1:1.48,1:1.45,1:1.44.带锈样的极化曲线测试结果显示,W450QN钢的致钝电流密度、维钝电流密度均比Q345钢小,说明其锈层致密、传质能力差,所以防护性能好.

  11. Methodology for the accelerated simulation of the deterioration that by atmospheric corrosion appears in electronic equipment; Metodologia para la simulacion acelerada del deterioro que por corrosion atmosferica se presenta en equipo electronico

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Prado, A.; Schouwenaars, R.; Cerrud Sanchez, S.M. [Facultad de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2002-12-01

    The corrosion resistance of systems and electronic parts which are designed to work in atmospheric conditions have been tested for decades; some of these methods were the Cyclic Humidity Test, Field Tests and Salt Spray (Fog) Testing, the latter was one of the most popular methods. However, the salt spray test and most of the other existing methods do not show strong relationships with the real conditions of service. For this reason, it is necessary to develop appropriated methods and equipment for the accelerated simulation of real atmospheric corrosion phenomena. This article seeks to demonstrate the need to develop a test and the necessary equipment to reproduce the damage in electronic systems and equipment by atmospheric corrosion. [Spanish] Para la evaluacion de la resistencia a la corrosion de sistemas y equipo electronico que trabajaran bajo condiciones de deterioro generadas por el medio ambiente, se han aplicado una serie de ensayos, donde el mas popular es el de camara de niebla salina. Sin embargo, este y otros que se han elaborado para tal efecto no tienen ninguna relacion con las condiciones reales de servicio, por lo que es necesario un metodo de evaluacion que permita simular de forma acelerada los fenomenos de deterioro por efectos ambientales. Este articulo pretende demostrar la necesidad de desarrollar una prueba, que en forma acelerada, reproduzca el dano que sufre el material por efecto de la atmosfera; el cual se orienta a la evaluacion de equipo electrico y electronico.

  12. Studies of Evaluation of Hydrogen Embrittlement Property of High-Strength Steels with Consideration of the Effect of Atmospheric Corrosion

    Science.gov (United States)

    Akiyama, Eiji; Wang, Maoqiu; Li, Songjie; Zhang, Zuogui; Kimura, Yuuji; Uno, Nobuyoshi; Tsuzaki, Kaneaki

    2013-03-01

    Hydrogen embrittlement of high-strength steels was investigated by using slow strain rate test (SSRT) of circumferentially notched round bar specimens after hydrogen precharging. On top of that, cyclic corrosion tests (CCT) and outdoor exposure tests were conducted prior to SSRT to take into account the effect of hydrogen uptake under atmospheric corrosion for the evaluation of the susceptibility of high-strength steels. Our studies of hydrogen embrittle properties of high-strength steels with 1100 to 1500 MPa of tensile strength and a prototype ultrahigh-strength steel with 1760 MPa containing hydrogen traps using those methods are reviewed in this article. A power law relationship between notch tensile strength of hydrogen-precharged specimens and diffusible hydrogen content has been found. It has also been found that the local stress and the local hydrogen concentration are controlling factors of fracture. The results obtained by using SSRT after CCT and outdoor exposure test were in good agreement with the hydrogen embrittlement fracture property obtained by means of long-term exposure tests of bolts made of the high-strength steels.

  13. The effect of modified atmosphere packaging (MAP) on the shelf- life of refrigerated, cubed turkey thigh meat

    OpenAIRE

    Ahn, Insook

    1991-01-01

    This research was designed to investigate the effect of Modified Atmosphere Packaging (MAP) on the shelf life of refrigerated, cubed, turkey thigh meat. Modified atmospheres of 25% carbon dioxide and 75% nitrogen and 20% carbon dioxide, 60% oxygen, and 20% nitrogen were used for MAP1 and MAP2 respectively. All sample packages, MAPl, MAP 2 , and Air Control, were stored at O.5°C. Headspace gas analysis, color measurement, sensory evaluation, aerobic plate count, and ox...

  14. The atmospheric corrosion, important technical and economic factor in the construction of nuclear power plants

    International Nuclear Information System (INIS)

    In order to determine the atmospheric effects of the construction of the Juragua NPP some experiments were performed in the reactor site. Samples of carbon steel were placed in experimental stations and the consequent oxidation was measured. The results show that the region's atmosphere aggressiveness may be classified from low to median. 11 refs

  15. Atmospheric corrosion of coated steel; Relationship between laboratory and field testing

    Science.gov (United States)

    Cambier, Severine Marie Noelle

    The lifetime prediction for corrosion-protective coatings on metals is a challenge that has been studied for several decades. Accelerated tests are used in the hope to reproduce in few days the damage that would develop during several years of field exposure. Field exposures are also used because accelerated tests are not always reliable. Several approaches have been taken to reduce the duration of field exposures. One of them is the use of sensitive techniques to assess the coating degradation before visual inspection indicates any damage. Cathodic delamination measured by the scanning Kelvin probe (CD-SKP) was introduced here as a sensitive technique to assess the degradation at the coating/metal interface after weathering exposure. This technique was shown to predict the failure of the coating/steel interface. Several climates were tested in the US continent and on the islands of Hawaii. PVB coated steel environmental degradation was characterized in the field and reproduced in the laboratory. A second approach to shorten coated metal field exposure is to accelerate the degradation using intentionally added through-film scribes. In service, most corrosion mechanism for painted metals, such as filiform corrosion and cathodic delamination, initiate from a mechanical defect. The iron oxides formed under PVB and Eponol were identified with Raman spectroscopy to determine the environment factors that participated in their formation. This investigation was complemented by laboratory exposure. An accelerated test for PVB coated steel was designed to reproduce the environmental degradation observed in the field. The CD-SKP technique to assess interface degradation after weathering exposure was also applied to other coating systems. E-coated, sprayed epoxy primers with a conversion coating or grit blasting treatment, and one full coating system were tested.

  16. A ToF-SIMS investigation of the corrosion behavior of Mg alloy AM50 in atmospheric environments

    Science.gov (United States)

    Esmaily, M.; Malmberg, P.; Shahabi-Navid, M.; Svensson, J. E.; Johansson, L. G.

    2016-01-01

    The redistribution of chloride and sodium ions after the NaCl-induced atmospheric corrosion of Mg alloy AM50 was investigated by means of Time-of-Flight Ion Mass Spectroscopy (ToF-SIMS). The samples were exposed at -4 and 22 °C in the presence of 400 ppm CO2. The results confirm the presence of less conductive electrolyte, and thus, less movement of ionic species (including sodium and chloride) in the electrolyte layer formed on the surface of samples exposed at the sub-zero temperature. Besides, ToF-SIMS analysis showed the presence of an Al-containing surface film formed on the alloy surface after exposure at high relative humidity.

  17. Independent Cooling Controller for Temperature Control of High Strength and Atmosphere Corrosion Resisting Steel in Hot Strip Mills

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol Jae [Daegu University, Kyungsan (Korea, Republic of)

    2015-03-15

    In this paper, we propose an independent cooling control (ICC) scheme for high strength and atmosphere corrosion resisting steel to obtain the desired temperature and properties along the longitudinal direction of the steel in the run-out table (ROT) process. A temperature model of the independent process is developed to divide the ROT into front and back sections. The control concept uses field data, problem analysis, and a time-temperature transformation diagram. The effectiveness of the proposed control is verified using simulation results under a temperature disturbance by the transformation in the middle of the ROT. The results of a hot strip mill field test show that the temperature control performance is significantly improved by the proposed control scheme.

  18. An approach to study the corrosion behaviour of stainless steel containers for packaging of intermediate level radioactive waste during atmospheric storage

    International Nuclear Information System (INIS)

    Full text of publication follows: In the UK, intermediate level radioactive waste (ILW) arising from the decommissioning of power stations and other nuclear installations is generally encapsulated in cement waste forms and packaged within stainless steel containers. The function of the waste package is to immobilise and physically contain the waste in a stable form and to allow its safe storage, transport, handling and eventual disposal in a geological disposal facility. Given such a function, it is important to ensure that the corrosion resistance of the waste container is sufficient to ensure its integrity for long times. This paper discusses the expected corrosion behaviour of ILW containers manufactured in stainless steel 304L and 316L within the current disposal concept, with specific focus on the behaviour of the material during atmospheric storage. In an indoor atmosphere, localised corrosion and stress corrosion cracking may develop on waste containers only if aggressive hygroscopic salts (e.g. MgCl2) accumulate on the container surfaces in certain quantities and in certain humidity ranges. Experimental observation is being carried out in order to better identify conditions in which corrosion damage develops. This type of analysis, together with laboratory and field observation, is being used to identify suitable storage conditions for the packages. On the other hand, extrapolation of short-term data on pit depth in aggressive environments (e.g. marine atmospheres) suggests that penetration of the container walls by pitting over long-time scales is unlikely. Experimental observation and modelling are progressing in order to better understand the mechanistic aspects of propagation and to evaluate whether container penetration by pitting may occur over long timescales. Outstanding uncertainties (e.g. related to the effect of ionising radiation on the atmospheric corrosion behaviour of the packages) will also be outlined

  19. An approach to study the corrosion behaviour of stainless steel containers for packaging of intermediate level radioactive waste during atmospheric storage

    Energy Technology Data Exchange (ETDEWEB)

    Padovani, C.G.; Wood, P. [Nuclear Decommissioning Authority (United Kingdom); Smart, N.R.; Winsley, R.J. [Serco Technical and Assurance Services (United Kingdom); Charles, A.; Albores-Silva, O. [Newcastle upon Tyne Univ. (United Kingdom); Krouse, D. [Industrial Research Limited (New Zealand)

    2009-07-01

    Full text of publication follows: In the UK, intermediate level radioactive waste (ILW) arising from the decommissioning of power stations and other nuclear installations is generally encapsulated in cement waste forms and packaged within stainless steel containers. The function of the waste package is to immobilise and physically contain the waste in a stable form and to allow its safe storage, transport, handling and eventual disposal in a geological disposal facility. Given such a function, it is important to ensure that the corrosion resistance of the waste container is sufficient to ensure its integrity for long times. This paper discusses the expected corrosion behaviour of ILW containers manufactured in stainless steel 304L and 316L within the current disposal concept, with specific focus on the behaviour of the material during atmospheric storage. In an indoor atmosphere, localised corrosion and stress corrosion cracking may develop on waste containers only if aggressive hygroscopic salts (e.g. MgCl{sub 2}) accumulate on the container surfaces in certain quantities and in certain humidity ranges. Experimental observation is being carried out in order to better identify conditions in which corrosion damage develops. This type of analysis, together with laboratory and field observation, is being used to identify suitable storage conditions for the packages. On the other hand, extrapolation of short-term data on pit depth in aggressive environments (e.g. marine atmospheres) suggests that penetration of the container walls by pitting over long-time scales is unlikely. Experimental observation and modelling are progressing in order to better understand the mechanistic aspects of propagation and to evaluate whether container penetration by pitting may occur over long timescales. Outstanding uncertainties (e.g. related to the effect of ionising radiation on the atmospheric corrosion behaviour of the packages) will also be outlined.

  20. The atmospheric corrosion: an important technical-economic and nuclear safety factor during storage in the construction of nuclear power plants

    International Nuclear Information System (INIS)

    The purpose of this work is to show the results of the research performed to determine the atmospheric corrosion in the region of Juragua nuclear power plant and to offer some practical recommendations to increase the efficiency during the storage of materials, considering technical-economic and nuclear safety aspects

  1. Evolution of corrosion of MnCuP weathering steel submitted to wet/dry cyclic tests in a simulated coastal atmosphere

    International Nuclear Information System (INIS)

    Highlights: ► The evolution of rust on MnCuP weathering steel submitted to a simulated coastal atmosphere has been investigated. ► The corrosion evolution of MnCuP weathering steel can be divided into two stages with distinct rust properties. ► A protective rust layer with higher amounts of α-FeOOH and lower Fe3O4 forms as the corrosion proceeds. ► The rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited. - Abstract: The evolution of rust on MnCuP weathering steel submitted to a simulated coastal atmosphere was investigated by corrosion weight gain, scanning electron microscopy, X-ray diffraction, and electrochemical methods. The results indicate that the higher corrosion rate during the first stage than that during the second stage is related closely to the rust composition and electrochemical properties. The corrosion rate evolution is caused by the formation of a protective rust layer with a higher relative amount of α-FeOOH. The rust initially enhances and then stabilizes the cathodic process, but the anodic process tends to be inhibited by the protective rust layer.

  2. Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

    Directory of Open Access Journals (Sweden)

    M. Lainer

    2015-08-01

    Full Text Available The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change. Keeping in mind that the instruments are based on different hardware and calibration setups, a height-dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different data sets, the Microwave Limb Sounder (MLS on the Aura satellite is used to serve as a kind of traveling standard. A domain-averaging TM (trajectory mapping method is applied which simplifies the subsequent validation of the quality of the trajectory-mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW accompanied by the polar vortex breakdown; a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high

  3. Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

    Directory of Open Access Journals (Sweden)

    M. Lainer

    2015-04-01

    Full Text Available The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change. Keeping in mind that the instruments are based on different hardware and calibration setups, a height dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different datasets, the Microwave Limb Sounder (MLS on the Aura satellite is used to serve as a kind of travelling standard. A domain-averaging TM (trajectory mapping method is applied which simplifies the subsequent validation of the quality of the trajectory mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW accompanied by the polar vortex breakdown, a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high

  4. Atmospheric Corrosion Resistance of EH36 Ocean Platform Steel%EH36级平台钢耐海洋大气腐蚀性能

    Institute of Scientific and Technical Information of China (English)

    唐荻; 张明洁; 武会宾; 张杰

    2012-01-01

    采用干湿交替周期浸润腐蚀试验模拟了三种设计的EH36级平台钢在海洋大气环境中的腐蚀行为。结果表明,降低碳含量并且提高铬含量有利于腐蚀锈层致密化,且腐蚀产物主要为对耐蚀性比较有益的α-FeOOH和γ-FeOOH,此类腐蚀产物在腐蚀后期能够明显抑制腐蚀速率的继续增长。%The atmospheric corrosion behaviors of three kinds of EH36 ocean platform steels with different compositions were investigated by cyclic wet-dry corrosion experiments. The results showed that the rust layer tended to be more compact by lowering C content and increasing Cr content. Protective corrosion products goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) were the major constituents of the rust. The corrosion products can inhibit the increase of corrosion rates significantly during the later stage of corrosion.

  5. On the capability of in-situ exposure in an environmental scanning electron microscope for investigating the atmospheric corrosion of magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Esmaily, M., E-mail: mohsen.esmaily@chalmers.se [Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Mortazavi, N. [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Shahabi-Navid, M.; Svensson, J.E.; Johansson, L.G. [Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Halvarsson, M. [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden)

    2015-06-15

    The feasibility of environmental scanning electron microscope (ESEM) in studying the atmospheric corrosion behavior of 99.97% Mg was investigated. For reference, ex-situ exposure was performed. A model system was designed by spraying few salt particles on the metal surface and further promoting the corrosion process using platinum (Pt) deposition in the form of 1×1×1 µm{sup 3} dots around the salt particles to create strong artificial cathodic sites. The results showed that the electron beam play a significant role in the corrosion process of scanned regions. This was attributed to the irradiation damage occurring on the metal surface during the ESEM in-situ experiment. After achieving to a reliable process route, in a successful attempt, the morphology and composition of the corrosion products formed in-situ in the ESEM were in agreement with those of the sample exposed ex-situ. - Highlights: • The feasibility of in-situ microscopy and atmospheric corrosion exposures of pure Mg in an ESEM are examined. • A model system was designed using NaCl particles on parts of the metal surface and promoting the corrosion process by depositing 1×1×1 µm{sup 3} Pt dots to create strong artificial cathodic sites. • The electron beam used for ESEM imaging affects the in-situ corrosion process. • A proper cleaning procedure for the sample and microscope chamber reducing carbon contamination makes the results from the ESEM in-situ exposures comparable to ex-situ exposures.

  6. Analysis of Corrosion in Atmospheric - vacuum Distillation and Testing%常减压蒸馏装置腐蚀分析与检测

    Institute of Scientific and Technical Information of China (English)

    张中洋; 高明; 李静

    2011-01-01

    When the refinery began to process low - quality crudes, the occurrence frequency of corrosion - related accidents and corrosion degrees are increased, which demands higher requirements for corrosion testing, corrosion protection and corrosion management of oil refining companies. The main corrosion problems in the atmospheric - vacuum distillation units are analyzed, inefficiency and shortcomings in fixed -point thickness measurement are summarized, and new corrosion testing concepts are proposed. In corrosion testing, the original data of equipment are first systematically analyzed to know the corrosion locations and forms and analyze the risk class of equipment. Based upon the corrosion mechanisms and results of RBI risk analysis, the thickness measurement points distribution of main equipment are proposed, piping is classified and associated testing principles are determined. The relationship between process corrosion prevention testing and corrosion testing is described. Recommendations are proposed for control of crude quality and electric desahing, monitoring of corrosion in tower overhead low - temperature section, online electrical probe testing, random equipment corrosion testing management and analysis, which provides good experience for corrosion testing and corrosion management of atmospheric - vacuum distillation units.%国内炼油企业因腐蚀问题影响装置稳定运行的情况十分普遍,严重者造成安全事故。加工劣质油后,出现腐蚀事故的频次及程度不断增加,从而各炼油企业对防腐检测、防护及管理工作提出了更高的要求。对常减压蒸馏装置存在的主要腐蚀问题进行了分析,通过总结定点测厚工作存在的缺点和不足,提出全新的腐蚀检测理念。腐蚀检测通过对设备原始资料进行统计分析,识别腐蚀存在部位及表现形式,分析设备风险等级;根据腐蚀机理和RBI风险分析结果,提出主要设备的测厚布点,

  7. Control of Fe(O,OH)6 nano-network structures of rust for high atmospheric-corrosion resistance

    International Nuclear Information System (INIS)

    A new-type of weathering steel containing 3.0 mass% Ni and 0.4 mass% Cu ('advanced weathering steel') exhibits good atmospheric-corrosion resistance in an atmosphere containing relatively high air-born salinity. Here, we show that the high performance was successfully achieved by controlling Fe(O,OH)6 nano-network structures of rust formed on their surfaces. A novel technique using synchrotron radiation has been developed for the in situ observation of rust-formation during wet-dry cycles. It has been revealed that the evolution of Fe(O,OH)6 nano-network structures of rust formed on the advanced weathering steel was more unique than those of conventional weathering steel and mild steel. At an early stage of reaction, Fe2NiO4 and CuO phases precipitate, which provide sites for the nucleation of the Fe(O,OH)6 nano-network resulting in the formation of rust composed of fine and dense-packed grains. The existence of Fe2NiO4 in the nano-network changes the ion-exchanging properties of rust from anion to cation selective. Then, the rust on the advanced weathering steel 'breathes out' chloride ions from the rust/steel interface, and protects steel for more than a century by reducing the life cycle maintenance cost in an environment-friendly manner

  8. Moessbauer study of corrosion products formed on Fe80B20 and Fe40Ni40 (MoB)20 amorphous alloys in an SO2-polluted atmosphere

    International Nuclear Information System (INIS)

    ICEMS, XPS, XRD, and AES have been used to study the corrosion layers formed on two metallic glasses, Fe80B20 and Fe40Ni40(MoB)20 (2605 and 2826 MB, Allied Company), exposed to an SO2-polluted humid atmosphere. The iron-containing corrosion products are the same found for pure iron in the same environment, but different relative concentrations were clearly evidenced by ICEMS results. Elemental sulphur, Ni(OH)2, and B(OH)3, the latter enriched at the surface, were found by XPS, XRD and AES. (orig.)

  9. Corrosion performance of atmospheric plasma sprayed alumina coatings on AZ31B magnesium alloy under immersion environment

    OpenAIRE

    D. Thirumalaikumarasamy; K. Shanmugam; Balasubramanian, V

    2014-01-01

    Plasma sprayed ceramic coatings are successfully used in many industrial applications, where high wear and corrosion resistance with thermal insulation are required. The alumina powders were plasma sprayed on AZ31B magnesium alloy with three different plasma spraying parameters. In the present work, the influence of plasma spray parameters on the corrosion behavior of the coatings was investigated. The corrosion behavior of the coated samples was evaluated by immersion corrosion test in 3.5 w...

  10. Stress Corrosion of Carbon Steel in Three Different Atmospheric Environments%碳钢在三种大气环境中的应力腐蚀

    Institute of Scientific and Technical Information of China (English)

    曹公望; 王振尧; 刘雨薇; 汪川

    2015-01-01

    ABSTRACT:Objective To research the stress corrosion failure of No.45 and Q235 carbon steels in different kinds of atmospheric environments. Methods No.45 and Q235 carbon steels were used to prepare U-shape samples and tensile samples. The corrosion test in atmospheric exposure for three years was conducted in atmospheric environment in Wanning, Jiangjin and Xishuangbanna. The rust layer depth analysis and the tensile failure analysis were performed to investigate the stress corrosion of carbon steel in different atmospheric environments. Results The u-shaped sample under the influence of the tensile stress in the three kinds of atmospheric environment had different depth of corrosion pits. Strength of extension had declined in a short period of time and failured in Wanning atmospheric environment, while it declined slowly in xishuangbanna and Jiangjin atmospheric environment. Conclusion Due to difference inatmospheric contaminants, the corrosion degree varied for U-shape samples under the influence of tensile stress. The tensile strength of tensile samples was periodically decreased during the process of corrosion.%目的:研究45#碳钢和Q235碳钢在不同大气环境中的应力腐蚀失效。方法将45#碳钢和Q235碳钢制备成U型样和拉伸试样,分别在万宁、江津和西双版纳三种大气环境下进行为期3年的暴露试验,利用截面锈层深度分析和拉伸断裂分析两种手段,分析两种碳钢在不同大气环境下的应力腐蚀行为。结果拉应力影响下的U型样在三种大气环境中出现了不同深度的腐蚀坑。拉伸试样在万宁大气环境下短时间内抗拉强度急剧下降并失效,在西双版纳和江津大气环境下抗拉强度缓慢下降。结论在拉应力影响下U型样的腐蚀进程随大气污染物的不同,腐蚀程度不同,拉伸试样的抗拉强度随腐蚀进程的发展而呈周期性衰减。

  11. Atmospheric corrosion of low carbon steel in a polar marine environment. Study of the effect of wind regime; Corrosion atmosferica del acero bajo en carbono en un ambiente marino polar. Estudio del efecto del regimen de vientos

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, S.; Chico, B.; Fuente, D. de la; Morcillo, M.

    2007-07-01

    The present work studies the atmospheric corrosion of carbon steel (UNE-EN 10130) in a sub-polar marine environment (Artigas Antarctic Scientific Base (BCAA), Uruguay) as a function of site atmospheric salinity and exposure time. A linear relationship is established between corrosion rate and airborne salinity deposition rate, valid in the deposition range encountered (125-225 mg Cl-l/m{sup 2}.d) and a bi logarithmic relationship established between corrosion and exposure time (1-4 years). Atmospheric salinity is related with the monthly wind speed average, based on the concept of the wind run. chloride ion deposition rates of less than 300 mg Cl-l/m{sup 2}.d are related with remote (oceanic) winds and coastal winds basically of speeds between 1-40 km/h, while higher deposition rates (300-700 mg Cl-/m{sup 2}.d) correspond to coastal marine winds of a certain persistence with speeds of between 41-80 km/h. (Author) 39 refs.

  12. A Review of Mapping Functions for the Radio Path Delay in the Neutral Atmosphere, GT-PR-NMA-2152

    DEFF Research Database (Denmark)

    Elgered, Gunnar; Jensen, Anna B. O.

    2004-01-01

    We present a review of developed mapping functions used to map the radio wave propagation delay, caused by the neutral atmosphere, from the zenith direction to a given elevation angle or vice versa. Mapping functions exist for the total delay, the hydrostatic (sometimes incorrectly referred to as...

  13. An overall view on corrosion and bio-fouling problems in sea water cooling systems at MAPS

    International Nuclear Information System (INIS)

    MAPS is a twin unit-220 MWe Pressurised Heavy Water Reactor (PHWR) nuclear power station using seawater as cooling medium in main steam condensers and in the Process Sea Water Heat Exchangers (PSWHXs). The seawater system consists of intake structure, submarine tunnel, fore-bay and pump house, travelling water screens, associated pumps and piping, heat-exchangers and out-fall structure. The horseshoe type submarine tunnel of length 468 metres and diameter 3.85 metres carrying ∼ 1.3 lakh m3/hr seawater from the intake structure to the pump house is lined with special concrete of 225 mm thickness. The major portion of piping carrying seawater is made of concrete and coal-tar based epoxy coated mild steel. Some portions of the mild steel pipes were gunnited and coated with araldite to minimise corrosion and fouling. The tubes of the condensers and the PSWHXs are of aluminium brass and the tube sheets are of aluminium bronze. The water boxes are rubber-lined with 3 mm thick neoprene and 2% magnesium iron sacrificial anodes are also provided in the water boxes to minimise corrosion. Plastic inserts are installed at the inlets of the tubes to prevent damage due to impingement attack and erosion. Ferrous sulphate dosing is being carried out to minimize the corrosion of aluminium brass tubes. Biofouling control (both Micro/Macro) is effected by gaseous chlorination at the rate of 30 - 40 Kg/hr for ∼ 20 hrs daily with residuals of 0.20 ppm. Further, booster dose (Liquid chlorine injection through evaporator) is given twice a week with a residual of ∼ 0.50 ppm and the dose required for this treatment is met by using evaporators. The major marine species identified in the intake and forebay were large barnacles and green mussels whereas the species identified in the PSWHXs were small size Barnacles (B. Reticulatus, 3 - 4 mm in size) and Mussels ( M.Striatulus, 5 - 8 mm in size). The main condensers are being cleaned during planned outages whereas it is not possible to

  14. Validation of a chromatographic method and its use in the determination of sulphates in the products of atmospheric corrosion of zinc exposed to SO2 and NO2

    International Nuclear Information System (INIS)

    The role of SO2 and NO2 in the atmospheric corrosion of zinc was studied by determining sulphates as the main products of corrosion when this metal is exposed to atmospheres containing SO2 and NO2, scanning electron microscopy (SEM/EDX) and Ion Exchange Chromatography (IC) were used as instrumental techniques, the former was used to establish the morphology and the elementary qualitative determination of corrosion products, and the latter to quantify sulphates, before conducting the chromatographic analyses a series of parameters such as selectivity, linearity, precision, accuracy, limit of quantification, and detection limit, were evaluated to validate the method and to have the statistical certainty of its utility in the sulphate quantification, the results showed that when the metal is exposed to an atmosphere containing SO2 and NO2, the sulphate formation increases with exposure time, a synergetic effect of both polluting agents on sulphate formation was found with respect to the sulphate formation in atmospheres containing only SO2

  15. Enhanced corrosion resistance and hemocompatibility of biomedical NiTi alloy by atmospheric-pressure plasma polymerized fluorine-rich coating

    International Nuclear Information System (INIS)

    Highlights: • Fluoropolymer is deposited on NiTi alloy via atmospheric-pressure plasma polymerization. • The corrosion resistance of NiTi alloy in SBF and DMEM is evidently improved. • The adsorption ratio of albumin to fibrinogen is increased on the coated surface. • The reduced platelet adhesion number indicates better in vitro hemocompatibility. - Abstract: To improve the corrosion resistance and hemocompatibility of biomedical NiTi alloy, hydrophobic polymer coatings are deposited by plasma polymerization in the presence of a fluorine-containing precursor using an atmospheric-pressure plasma jet. This process takes place at a low temperature in air and can be used to deposit fluoropolymer films using organic compounds that cannot be achieved by conventional polymerization techniques. The composition and chemical states of the polymer coatings are characterized by fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the coated and bare NiTi samples is assessed and compared by polarization tests and electrochemical impedance spectroscopy (EIS) in physiological solutions including simulated body fluids (SBF) and Dulbecco's Modified Eagle's medium (DMEM). The corrosion resistance of the coated NiTi alloy is evidently improved. Protein adsorption and platelet adhesion tests reveal that the adsorption ratio of albumin to fibrinogen is increased and the number of adherent platelets on the coating is greatly reduced. The plasma polymerized coating renders NiTi better in vitro hemocompatibility and is promising as a protective and hemocompatible coating on cardiovascular implants

  16. High temperature corrosion of iron-base and nickel-base alloys for hydrogen production apparatus by thermochemical method in H{sub 2}O+SO{sub 3} atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Yuji; Suzuki, Tomio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Shimizu, Saburo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    2000-03-01

    Corrosion tests for ten iron-base and nickel-base alloys at 850degC for 1000h in H{sub 2}O + SO{sub 3} atmosphere were carried out to obtain data for selection of candidate container materials in the thermochemical process which produces hydrogen from water by use of iodine and sulfur as circulating materials. The following results were obtained: (1) Oxidation, spallation of corrosion film, uniform corrosion and grain boundary penetration composed of internal oxidation and sulfuration occur in this atmosphere and the corrosion proceeds by grain boundary penetration. (2) SUS304, SUS316 and Hastelloy C276 are inferior in corrosion resistance and SUS329J4L is superior among ten alloys used in this experiment. Alloys such as Alloy 800H and Hastelloy XR show intermediate corrosion resistance. (3) Oxide films of alloys containing iron and chromium are mostly composed of outer iron-oxide and inner chromium-oxide. Sulfur concentrates at scale/metal interfaces and grain boundary penetration portions, and sulfides form. (4) Corrosion in this atmosphere could be expressed using the parabolic law between the grain boundary penetration depth and time. It is considered that causes of the apparently observed parabolic law were a high concentration of SO{sub 3} and change of the gas composition caused by catalytic action of the corrosion film formed with the progress of corrosion. (author)

  17. Remote detection and mapping of organic molecules in Titan's atmosphere using ALMA

    Science.gov (United States)

    Cordiner, Martin; Nixon, Conor A.; Charnley, Steven B.; Palmer, Maureen; Mumma, Michael J.; Molter, Edward; Teanby, Nicholas; Irwin, Patrick GJ; Kisiel, Zbigniew; Serigano, Joseph

    2016-06-01

    Titan is the largest moon of Saturn, with a thick (1.45 bar) atmosphere composed primarily of molecular nitrogen and methane. Atmospheric photochemistry results in the production of a wide range of complex organic molecules, including hydrocarbons, nitriles, aromatics and species of possible pre-biotic relevance. Studies of Titan's atmospheric chemistry thus provide a unique opportunity to explore the origin and evolution of complex organic matter in a primitive (terrestrial) planetary atmosphere. Underpinned by laboratory measurements, remote and in-situ observations of hydrocarbons, nitriles and oxygen-bearing species provide important new insights in this regard. The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful new facility, well suited to the study of molecular emission from Titan's upper and middle-atmosphere. This presentation will focus on results from our ongoing studies of Titan using ALMA during the period 2012-2014, including detection and mapping of rotational emission lines from molecules including HNC, CO, HC3N, CH3CN, C2H3CN and C2H5CN, as well minor isotopologues. Possible chemical formation pathways for these species will be discussed, and the the scope for improved understanding of non-aqueous organic chemistry through laboratory experiments and atmospheric/liquid-phase simulations under Titan-like conditions will be examined.

  18. Maps and Masses of Transiting Exoplanets: Towards New Insights into Atmospheric and Interior Properties of Planets

    CERN Document Server

    de Wit, Julien

    2015-01-01

    With over 1800 planets discovered outside of the Solar System in the past two decades, the field of exoplanetology has broadened our perspective on planetary systems. Research priorities are now moving from planet detection to planet characterization. In this context, transiting exoplanets are of special interest due to the wealth of data made available by their orbital configuration. Here, I introduce two methods to gain new insights into the atmospheric and interior properties of exoplanets. The first method aims to map an exoplanet's atmosphere based on the scanning obtained while it is occulted by its host star. I introduce the basics of eclipse mapping, its caveats, and a framework to mitigate their effects via global analyses including transits, phase curves, and radial velocity measurements. I use this method to create the first 2D map and the first cloud map of an exoplanet for the hot-Jupiters HD189733b and Kepler-7b, respectively. Ultimately temperature, composition, and circulation patterns could b...

  19. Corrosion resistance of Ni-50Cr HVOF coatings on 310S alloy substrates in a metal dusting atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Saaedi, J. [Centre for Advanced Coating Technologies, Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario M5S 3E4 (Canada); Department of Materials and Metallurgical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Arabi, H.; Mirdamadi, S.; Ghorbani, H. [Department of Materials and Metallurgical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Coyle, T.W. [Centre for Advanced Coating Technologies, Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario M5S 3E4 (Canada)

    2011-09-15

    Metal dusting attack has been examined after three 168 h cycles on two Ni-50Cr coatings with different microstructures deposited on 310S alloy substrates by the high velocity oxy-fuel (HVOF) thermal-spray process. Metal dusting in uncoated 310S alloy specimens was found to be still in the initiation stage after 504 h of exposure in the 50H{sub 2}:50CO gas environment at 620 C. Dense Ni-50Cr coatings offered suitable resistance to metal dusting. Metal dusting was observed in the 310S substrates adjacent to pores at the interface between the substrate and a porous Ni-50Cr coating. The porosity present in the as-deposited coatings was shown to introduce a large variability into coating performance. Carbon formed by decomposition of the gaseous species accumulated in the surface pores and resulted in the dislodgement of surface splats due to stresses generated by the volume changes. When the corrosive gas atmosphere was able to penetrate through the interconnected pores and reach the coating-substrate interface, the 310S substrate was carburized, metal dusting attack occurred, and the resulting formation of coke in the pores led to local failure of the coating. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. 变电站周围大气腐蚀环境检测分析%Detection and Analysis of Atmospheric Corrosion Environment Around Substation

    Institute of Scientific and Technical Information of China (English)

    王平; 宋国升; 孙心利; 周慧波

    2013-01-01

    This paper analyzed the characteristics of atmospheric corrosion and the sources of pollutants and it was concluded that atmospheric environment detection was an important part in substation equipment corrosion analysis. Through detection and analysis of atmospheric environment around substation, the substation metal material corrosion was mainly due to the high gas composition of H2S, NH3 generated by the production sites around substation, such as sewage, chemical plants, chicken farms. This paper also proposed the prevention and treatment measures, such as strengthening environmental detection, conducting environmental assessment, etc.%  要:分析大气腐蚀的特点及污染物的来源后认为,开展大气环境检测是进行变电站设备腐蚀原因分析的重要内容。通过对某变电站周围大气环境的检测和分析,提出了导致变电站金属材料腐蚀的主要原因在于周围污水、化工厂、养鸡场等生产场所产生的H2S、NH3等气体成分过高所致,同时提出了应加强环境检测、开展环境评价等预防和处理措施建议。

  1. Effect of Chloride on the Atmospheric Corrosion of Cast Iron in Sulphur or Nitrogen-Bearing Pollutant Environment%氯离子在含硫氮污染物的环境中对模拟铁器文物的大气腐蚀的影响

    Institute of Scientific and Technical Information of China (English)

    曹霞; 许淳淳

    2005-01-01

    The effect of chloride on the atmospheric corrosion of cast iron in sulphur or nitrogen-bearing pollutant was investigated by using periodic wet-dry test, electrochemical experiment and surface tension test. Scanning electron microscopy coupled with energy dispersive atomic (EDAX) and stereoscopic microscopy was used to identify the corrosion processes and products. Cl- and NO-3 were shown accelerating effects during the whole corrosion process but depression effects were observed in Cl- and HSO-3 bearing pollutant at the initial corrosion stage.However, with the corrosion going on, the depression effects was less obviously and the initial corrosion process was investigated from the viewpoint of surface activity. At the initial corrosion stage, the corrosion rate was proportional to the adsorptivity of anions, but as corrosion went on, the penetration effect of anions and different characteristics of the corrosion products began to dominate the corrosion process, which led to changes on the corrosion rate.

  2. Study of the effect of the NO{sub 2} in the atmospheric corrosion of copper; Estudio del efecto del NO{sub 2} en la corrosion atmosferica del cobre

    Energy Technology Data Exchange (ETDEWEB)

    Mariaca Rodriguez, Liboria

    1997-12-31

    Factors as the increase of the power consumption and the development of new combustion technologies, together with the increasing campaigns for the diminution of the SO{sub 2} emissions, have given rise to an increase of the relative importance of other atmospheric polluting agents, among which the nitrogen oxides occupy preponderant place. This new situation has motivated that during the last years greater attention is appearing to the effect these oxides can have on the stability of the materials. However, the results still are scarce and sometimes contradictory. With the purpose of contributing to the understanding of the effect of the NO{sub x} in the atmospheric corrosion, the investigation that is shown here was made. The effect that the NO{sub 2} has in the atmospheric corrosion of copper was studied, considering cases with and without the simultaneous presence of SO{sub 2}, with different relative humidities (RH) and temperatures of the atmospheric air. For this purpose one resorted to the simulation of atmospheres of interest by means of laboratory chambers that allowed the control of the temperature, RH and the contamination level. In each atmosphere completely clean copper coupons were exposed, and withdrawn at 7, 14, 21 and 28 days. Gravimetric analyses of gain and loss of mass and one complete characterization the corrosion products formed was made, mainly by means of X ray diffraction techniques by grazing angle (DRS), and photo electronic X ray spectroscopy (XPS or ESCA). Also, the applicability in these conditions of the electrochemical techniques of DC (RP, CP and RE) and of alternating current (EIE). From the results obtained it is worth mentioning as the more important the following ones: The corrosion of copper in atmospheres contaminated solely with NO{sub 2} depends fundamentally on the RH, not existing, as in the case of other metals, a critical RH (CRH), from which the kinetics of the corrosion process increases; all the opposite, the copper

  3. 大气环境下野战输油管道的腐蚀%An Analysis on the Atmospheric Corrosion for the Stacked Pipe

    Institute of Scientific and Technical Information of China (English)

    崔虹; 宋花平; 何建设

    2001-01-01

    In this paper,the mechanism of atmospheric corosion isintroduced.As to the corrosion of stacked pipes,there are two kinds of atmospheric corrosions,that is,clean atmospheric corrosion and industrial or oceanic atmospheric corrosion.Some protective measures to prevent the stacked pipes from atmospheric corroding are presented.%野战输油管道是军队作战时油料保障的重要装备,现配备的DN100野战输油管道系统均采用镀锌防腐。调查发现,长期存放的野战输油管道因受大气腐蚀的影响,均有不同程度的锈蚀。在分析大气腐蚀机理的基础上,对洁净大气条件下的腐蚀、工业及海洋大气条件下的腐蚀进行了讨论,提出了管道生产和储存中的防腐建议。

  4. Water vapor mapping by fusing InSAR and GNSS remote sensing data and atmospheric simulations

    Science.gov (United States)

    Alshawaf, F.; Fersch, B.; Hinz, S.; Kunstmann, H.; Mayer, M.; Meyer, F. J.

    2015-12-01

    Data fusion aims at integrating multiple data sources that can be redundant or complementary to produce complete, accurate information of the parameter of interest. In this work, data fusion of precipitable water vapor (PWV) estimated from remote sensing observations and data from the Weather Research and Forecasting (WRF) modeling system are applied to provide complete grids of PWV with high quality. Our goal is to correctly infer PWV at spatially continuous, highly resolved grids from heterogeneous data sets. This is done by a geostatistical data fusion approach based on the method of fixed-rank kriging. The first data set contains absolute maps of atmospheric PWV produced by combining observations from the Global Navigation Satellite Systems (GNSS) and Interferometric Synthetic Aperture Radar (InSAR). These PWV maps have a high spatial density and a millimeter accuracy; however, the data are missing in regions of low coherence (e.g., forests and vegetated areas). The PWV maps simulated by the WRF model represent the second data set. The model maps are available for wide areas, but they have a coarse spatial resolution and a still limited accuracy. The PWV maps inferred by the data fusion at any spatial resolution show better qualities than those inferred from single data sets. In addition, by using the fixed-rank kriging method, the computational burden is significantly lower than that for ordinary kriging.

  5. Water vapor mapping by fusing InSAR and GNSS remote sensing data and atmospheric simulations

    Directory of Open Access Journals (Sweden)

    F. Alshawaf

    2015-01-01

    Full Text Available Data fusion aims at integrating multiple data sources that can be redundant or complementary to produce complete, accurate information of the parameter of interest. In this work, data fusion of precipitable water vapor (PWV estimated from remote sensing observations and data from the Weather Research and Forecasting (WRF modeling system is applied to provide complete, accurate grids of PWV. Our goal is to infer spatially continuous, precise grids of PWV from heterogeneous data sets. This is done by a geostatistical data fusion approach based on the method of fixed-rank kriging. The first data set contains absolute maps of atmospheric water vapor produced by combining observations from Global Navigation Satellite Systems (GNSS and Interferometric Synthetic Aperture Radar (InSAR. These PWV maps have a high spatial density and an accuracy of submillimeter; however, data are missing in regions of low coherence (e.g., forests and vegetated areas. The PWV maps simulated by the WRF model represent the second data set. The model maps are available for wide areas, but they have a coarse spatial resolution and a yet limited accuracy. The PWV maps inferred by the data fusion at any spatial resolution are more accurate than those inferred from single data sets. In addition, using the fixed-rank kriging method, the computational burden is significantly lower than that for ordinary kriging.

  6. 电网设备用碳钢、镀锌钢和铜的大气腐蚀%Atmospheric Corrosion of Carbon Steel,Galvanized Steel and Cooper for Power Grid Equipments Reserve

    Institute of Scientific and Technical Information of China (English)

    刘争春; 苏伟; 卢思敏; 吕旺燕

    2016-01-01

    Metal materials of power grid equipments serving in atmospheric environment are prone to be invalid caused by at-mospheric corrosion. Therefore,this paper summarizes laws and influencing factors of atmospheric corrosion for backup metal materials for typical power grid equipments including carbon steel,galvanized steel and copper. By analyzing corrosion dynamics,corrosion influencing factors and research method for atmospheric corrosion of carbon steel,galvanized steel and copper in atmospheric environment,it discovers that corrosion loss laws of three metal materials follow power function equa-tion,progress of atmospheric corrosion is mainly affected by natural environment and pollutants in the atmosphere and cor-rosion outcomes of metals in different atmospheric environment are obviously different. It also states two typical types of re-search methods for atmospheric corrosion and respective boundedness including field exposure test and indoor simulation and acceleration test. It thinks to correctly predict speed rate of atmospheric corrosion of metals by combining these two methods and help adopting specific anti-corrosion measures.%服役于大气环境中的电网设备,其金属材料易被大气腐蚀而失效,基于此,综述了典型电网设备用金属材料———碳钢、镀锌钢和铜的大气腐蚀规律和影响因素。通过分析碳钢、镀锌钢和铜在大气环境中的腐蚀动力学,腐蚀影响因素和大气腐蚀研究方法等,发现三种金属材料的腐蚀失重规律都遵循幂函数方程;其大气腐蚀进程主要受大气的自然环境和污染物种类的影响,金属在不同的大气环境下生成的腐蚀产物明显不同。在此基础上,阐述了现场暴晒试验和室内模拟加速试验两种典型大气腐蚀研究方法及其局限性,认为将二者结合能更准确的预测金属的大气腐蚀速率,有助于采取针对性的防腐措施。

  7. An experimental set-up to apply polarization modulation to infrared reflection absorption spectroscopy for improved in situ studies of atmospheric corrosion processes

    Energy Technology Data Exchange (ETDEWEB)

    Wiesinger, R. [Institute of Science and Technology in Art, Academy of Fine Arts, 1010 Vienna (Austria); Schade, U. [Helmholtz-Zentrum für Materialien und Energy GmbH, Elektronenspeicherring BESSY II, 12489 Berlin (Germany); Kleber, Ch. [Centre for Electrochemical Surface Technology, 2700 Wiener Neustadt (Austria); Schreiner, M. [Institute of Science and Technology in Art, Academy of Fine Arts, 1010 Vienna (Austria); Institute for Chemical Technologies and Analytics, Vienna University of Technology, 1060 Vienna (Austria)

    2014-06-15

    A new set-up for improved monitoring of atmospheric corrosion processes in situ and in real-time is presented. To characterize chemical structures of thin films on metal surfaces surface sensitive analytical techniques are required. One possible technique is Infrared Reflection Absorption Spectroscopy (IRRAS) which has become an established method to investigate surface corrosion films of thicknesses less than 200 nm. However, there are limitations related to the sensitivity of these measurements, in case of investigating ultrathin films or absorption bands of interest, surface species are superimposed by atmospheric background absorption, which changes during in situ measurements in ambient atmospheres. These difficulties of in situ surface reflection measurements can be eliminated by availing the polarization selectivity of adsorbed surface species. At grazing angles of incidence the absorption of p-polarized infrared radiation by thin surface films on metals is enhanced, while the absorption of s-polarized light by this film is nearly zero. This different behavior of the polarization properties leads to strong selection rules at the surface and can therefore be used to identify molecules adsorbed on metal surfaces. Polarization Modulation (PM) of the infrared (IR) light takes advantage of this disparity of polarization on sample surfaces and in combination with IRRAS yielding a very sensitive and surface-selective method for obtaining IR spectra of ultra-thin films on metal surfaces. An already existing in situ IRRAS/Quartz Crystal Microbalance weathering cell was combined with PM and evaluated according to its applicability to study in situ atmospheric corrosion processes. First real-time measurements on silver samples exposed to different atmospheres were performed showing the advantage of PM-IRRAS compared to conventional IRRAS for such investigations.

  8. An experimental set-up to apply polarization modulation to infrared reflection absorption spectroscopy for improved in situ studies of atmospheric corrosion processes

    Science.gov (United States)

    Wiesinger, R.; Schade, U.; Kleber, Ch.; Schreiner, M.

    2014-06-01

    A new set-up for improved monitoring of atmospheric corrosion processes in situ and in real-time is presented. To characterize chemical structures of thin films on metal surfaces surface sensitive analytical techniques are required. One possible technique is Infrared Reflection Absorption Spectroscopy (IRRAS) which has become an established method to investigate surface corrosion films of thicknesses less than 200 nm. However, there are limitations related to the sensitivity of these measurements, in case of investigating ultrathin films or absorption bands of interest, surface species are superimposed by atmospheric background absorption, which changes during in situ measurements in ambient atmospheres. These difficulties of in situ surface reflection measurements can be eliminated by availing the polarization selectivity of adsorbed surface species. At grazing angles of incidence the absorption of p-polarized infrared radiation by thin surface films on metals is enhanced, while the absorption of s-polarized light by this film is nearly zero. This different behavior of the polarization properties leads to strong selection rules at the surface and can therefore be used to identify molecules adsorbed on metal surfaces. Polarization Modulation (PM) of the infrared (IR) light takes advantage of this disparity of polarization on sample surfaces and in combination with IRRAS yielding a very sensitive and surface-selective method for obtaining IR spectra of ultra-thin films on metal surfaces. An already existing in situ IRRAS/Quartz Crystal Microbalance weathering cell was combined with PM and evaluated according to its applicability to study in situ atmospheric corrosion processes. First real-time measurements on silver samples exposed to different atmospheres were performed showing the advantage of PM-IRRAS compared to conventional IRRAS for such investigations.

  9. An experimental set-up to apply polarization modulation to infrared reflection absorption spectroscopy for improved in situ studies of atmospheric corrosion processes

    International Nuclear Information System (INIS)

    A new set-up for improved monitoring of atmospheric corrosion processes in situ and in real-time is presented. To characterize chemical structures of thin films on metal surfaces surface sensitive analytical techniques are required. One possible technique is Infrared Reflection Absorption Spectroscopy (IRRAS) which has become an established method to investigate surface corrosion films of thicknesses less than 200 nm. However, there are limitations related to the sensitivity of these measurements, in case of investigating ultrathin films or absorption bands of interest, surface species are superimposed by atmospheric background absorption, which changes during in situ measurements in ambient atmospheres. These difficulties of in situ surface reflection measurements can be eliminated by availing the polarization selectivity of adsorbed surface species. At grazing angles of incidence the absorption of p-polarized infrared radiation by thin surface films on metals is enhanced, while the absorption of s-polarized light by this film is nearly zero. This different behavior of the polarization properties leads to strong selection rules at the surface and can therefore be used to identify molecules adsorbed on metal surfaces. Polarization Modulation (PM) of the infrared (IR) light takes advantage of this disparity of polarization on sample surfaces and in combination with IRRAS yielding a very sensitive and surface-selective method for obtaining IR spectra of ultra-thin films on metal surfaces. An already existing in situ IRRAS/Quartz Crystal Microbalance weathering cell was combined with PM and evaluated according to its applicability to study in situ atmospheric corrosion processes. First real-time measurements on silver samples exposed to different atmospheres were performed showing the advantage of PM-IRRAS compared to conventional IRRAS for such investigations

  10. Processing of Satellite Digital Images for Mapping Atmospheric Transmissivity in Bangladesh

    Directory of Open Access Journals (Sweden)

    Md Shahjahan Ali

    2013-03-01

    Full Text Available This study investigates the potential of determining atmospheric transmissivity (τ from NOAA-AVHRR satellite images using a simple methodology. Using this method, hourly transmissivity values over the land surface area of Bangladesh has been determined. The spatio-temporal distribution of τ has been studied by constructing monthly average maps for the whole country for one complete year (February 2005 to January 2006. Yearly average map has been prepared by integrating monthly average maps. Geographical distribution of τ exhibits patterns and trends. It is observed that the value of τ varies from 0.3 to 0.65 with the average maximum value in the month of April and minimum value in the month of November. It is also observed that for western parts of the country, which is the drought prone area, transmissivity values are little bit higher than that at the eastern parts. Relatively lower values of τ in the dry months (November to January may be due to the effect of particulate or chemical pollution in the atmosphere.

  11. Role of microstructure on corrosion initiation of an experimental tool alloy: A Quantitative Nanomechanical Property Mapping study

    International Nuclear Information System (INIS)

    Highlights: • We present a new approach to identify prepitting events in metal alloys. • NaCl solution initiates the formation of small particles in the tool alloy. • These particles are located in regions with low chromium content of the tool alloy. • We assume that these particles are related to prepitting events. • Adhesion differences in the tool alloy are ascribed to its N and V contents. - 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

  12. Establishing empirical relationships to predict porosity level and corrosion rate of atmospheric plasma-sprayed alumina coatings on AZ31B magnesium alloy

    Directory of Open Access Journals (Sweden)

    D. Thirumalaikumarasamy

    2014-06-01

    Full Text Available Plasma sprayed ceramic coatings are successfully used in many industrial applications, where high wear and corrosion resistance with thermal insulation are required. In this work, empirical relationships were developed to predict the porosity and corrosion rate of alumina coatings by incorporating independently controllable atmospheric plasma spray operational parameters (input power, stand-off distance and powder feed rate using response surface methodology (RSM. A central composite rotatable design with three factors and five levels was chosen to minimize the number of experimental conditions. Within the scope of the design space, the input power and the stand-off distance appeared to be the most significant two parameters affecting the responses among the three investigated process parameters. A linear regression relationship was also established between porosity and corrosion rate of the alumina coatings. Further, sensitivity analysis was carried out and compared with the relative impact of three process parameters on porosity level and corrosion rate to verify the measurement errors on the values of the uncertainty in estimated parameters.

  13. Corrosion control for low-cost reliability

    International Nuclear Information System (INIS)

    This conference was held September 19-24, 1993 in Houston, Texas to provide a forum for exchange of state-of-the-art information on corrosion. Topics of interest focus on the following: atmospheric corrosion; chemical process industry corrosion; high temperature corrosion; and corrosion of plant materials. Individual papers have been processed separately for inclusion in the appropriate data bases

  14. Corrosion performance of atmospheric plasma sprayed alumina coatings on AZ31B magnesium alloy under immersion environment

    Directory of Open Access Journals (Sweden)

    D. Thirumalaikumarasamy

    2014-12-01

    Full Text Available Plasma sprayed ceramic coatings are successfully used in many industrial applications, where high wear and corrosion resistance with thermal insulation are required. The alumina powders were plasma sprayed on AZ31B magnesium alloy with three different plasma spraying parameters. In the present work, the influence of plasma spray parameters on the corrosion behavior of the coatings was investigated. The corrosion behavior of the coated samples was evaluated by immersion corrosion test in 3.5 wt% NaCl solution. Empirical relationship was established to predict the corrosion rate of plasma sprayed alumina coatings by incorporating process parameters. The experiments were conducted based on a three factor, five-level, central composite rotatable design matrix. The developed relationship can be effectively used to predict the corrosion rate of alumina coatings at 95% confidence level. The results indicate that the input power has the greatest influence on corrosion rate, followed by stand-off distance and powder feed rate.

  15. APPLICATION OF QUARTZ CRYSTAL MICROBALANCE IN ATMOSPHERIC CORROSION INVESTIGATION%石英晶体微天平(QCM)在大气腐蚀研究中的应用

    Institute of Scientific and Technical Information of China (English)

    严川伟; 曹楚南; 林海潮

    2001-01-01

    石英晶体微天平(QCM)作为一种高灵敏度的质量检测手段,已经用于金属材料大气腐蚀动力学及其环境因素和缓蚀剂存在的影响规律的研究,对QCM在大气腐蚀研究中的应用进行了综述.%The application of quartz crystal microbalance (QCM) in the study of atmospheric corrosion is reviewed. QCM is available to measure mass changes of a nanngram order and has widely been used for in-situ investigations of atmospheric corrosion. The effects of environmental factors,corrosive gas constituents and gas-phase inhibitors on the atmospheric corrosion mechanism of metal materials have been studied with QCM. In the recent years, the atmospheric corrosivity probe based on QCM techniques has been developed. The characteristics and developing trend of QCM for atmospheric corrosion investigation and monitoring are analyzed and discussed

  16. 基于数据分析的大气腐蚀等级细化研究%Refinement Research of Atmospheric Corrosion Categories Based on Data Analysis

    Institute of Scientific and Technical Information of China (English)

    吴超; 付冬梅; 李晓刚

    2015-01-01

    ABSTRACT:Objective To propose a new method based on data analysis to refine the atmospheric corrosion categories. Methods The method of ordered sample clustering was used in this paper to analyze the data of carbon steel corrosion rate accumulated in atmospheric corrosion test stations in China during the past years. As a result, the atmospheric corrosion degree of carbon steel was divided into 10 categories. On this basis, the inverse distance weighted interpolation method combined with ISO 9223—2012 standard was used to obtain the estimation table of atmospheric corrosivity categories according to the concentration of sulfur dioxide, concentration of chlorine ion, time of wetnessdata and the corrosion rate data of carbon steel in the corresponding atmospheric environment. Results The result of refined 10 categoried was 0~8μm/a(C1), 8~25μm/a(C2), 25~40μm/a(C3), 40~50μm/a(C4), 50~60μm/a(C5), 60~75μm/a(C6), 75~90μm/a(C7), 90~100μm/a(C8), 100~200μm/a(C9), and 200~700μm/a(C10). Conclusion This 10-category method is more refined in describing atmospheric corrosion.%目的:提出一种基于数据分析的方法对大气腐蚀等级进行细化。方法以碳钢为例,采用有序样本聚类方法,对国内大气腐蚀试验站多年积累的腐蚀速率进行分析,将大气腐蚀等级细化为10级。在此基础上,根据腐蚀速率以及相应大气环境中的二氧化硫浓度、氯离子浓度、润湿时间的数据,采用反距离加权插值法,并结合ISO 9223—2012标准获取等级细化后的碳钢大气腐蚀性等级估计表。结果经过细化之后的大气腐蚀等级10级分级结果为0~8μm/a(C1),8~25μm/a (C2),25~40μm/a(C3),40~50μm/a(C4),50~60μm/a(C5),60~75μm/a(C6),75~90μm/a (C7),90~100μm/a(C8),100~200μm/a(C9),200~700μm/a(C10)。结论该10级分级法将大气腐蚀等级划分得更为细化。

  17. Study of the corrosion of metallic coatings and alloys containing aluminum in a mixed atmosphere - sulphur, oxygen - at high temperatures

    International Nuclear Information System (INIS)

    The objective of this research thesis is the development of materials for a sulphur experimental loop allowing the thermodynamic properties of such an energy cycle to be checked. As solutions must comply with industrial methods, rare materials are excluded as they are too expensive or difficult to implement. Iron-based materials have been tested but could not have at the same time a good corrosion resistance and high temperature forming and mechanical toughness properties. Therefore, metallic coatings have been chosen, specifically alumina. After having reported a bibliographical study on corrosion by sulphur vapour and by oxygen and by sulphur-oxygen, the author presents the experimental materials and methods. Then, the author reports the study of mixed corrosion (by sulphur and oxygen together) of metallic alloys (ferritic and austeno-ferritic alloys, aluminium and titanium alloys), and of the corrosion of FeAlx coatings, of AlTix alloys

  18. Enhanced corrosion resistance and hemocompatibility of biomedical NiTi alloy by atmospheric-pressure plasma polymerized fluorine-rich coating

    Energy Technology Data Exchange (ETDEWEB)

    Li, Penghui; Li, Limin [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wang, Wenhao [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Division of Spine Surgery, Department of Orthopaedics and Traumatology, Pokfulam, Hong Kong (China); Jin, Weihong [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Liu, Xiangmei [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062 (China); Yeung, Kelvin W.K. [Division of Spine Surgery, Department of Orthopaedics and Traumatology, Pokfulam, Hong Kong (China); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2014-04-01

    Highlights: • Fluoropolymer is deposited on NiTi alloy via atmospheric-pressure plasma polymerization. • The corrosion resistance of NiTi alloy in SBF and DMEM is evidently improved. • The adsorption ratio of albumin to fibrinogen is increased on the coated surface. • The reduced platelet adhesion number indicates better in vitro hemocompatibility. - Abstract: To improve the corrosion resistance and hemocompatibility of biomedical NiTi alloy, hydrophobic polymer coatings are deposited by plasma polymerization in the presence of a fluorine-containing precursor using an atmospheric-pressure plasma jet. This process takes place at a low temperature in air and can be used to deposit fluoropolymer films using organic compounds that cannot be achieved by conventional polymerization techniques. The composition and chemical states of the polymer coatings are characterized by fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the coated and bare NiTi samples is assessed and compared by polarization tests and electrochemical impedance spectroscopy (EIS) in physiological solutions including simulated body fluids (SBF) and Dulbecco's Modified Eagle's medium (DMEM). The corrosion resistance of the coated NiTi alloy is evidently improved. Protein adsorption and platelet adhesion tests reveal that the adsorption ratio of albumin to fibrinogen is increased and the number of adherent platelets on the coating is greatly reduced. The plasma polymerized coating renders NiTi better in vitro hemocompatibility and is promising as a protective and hemocompatible coating on cardiovascular implants.

  19. Combining point correlation maps with self-organising maps to compare observed and simulated atmospheric teleconnection patterns

    Directory of Open Access Journals (Sweden)

    Freja K. Hunt

    2013-07-01

    Full Text Available We use a new method based on point correlation maps and self-organising maps (SOMs to identify teleconnection patterns in 60 yr of National Centres for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR sea level pressure (SLP re-analysis data. The most prevalent patterns are the El Nino Southern Oscillation (ENSO, the North Atlantic Oscillation (NAO and the Southern Annular Mode (SAM. Asymmetries are found between base points in opposite centres of action of the NAO and the Pacific North America pattern (PNA. The SOM-based method is a powerful tool that allows us to efficiently assess how realistically teleconnections are reproduced in any climate model. The degree of agreement between modelled and re-analysis-based teleconnections (or between different models can be summarised in a single plot. Here, we illustrate this by assessing the skill of the medium complexity climate model FORTE (Fast Ocean Rapid Troposphere Experiment. FORTE reproduces some realistic teleconnections, such as the Arctic Oscillation (AO, the NAO, the PNA, the SAM, the African Monsoon and ENSO, along with several other teleconnections, which resemble to varying degrees the corresponding NCEP patterns. However, FORTE tends to underestimate the strength of the correlation patterns and the patterns tend to be slightly too zonal. The accuracy of frequency of occurrence is variable between patterns. The Indian Ocean is a region where FORTE performs poorly, as it does not reproduce the teleconnection patterns linked to the Indian Monsoon. In contrast, the North and equatorial Pacific and North Atlantic are reasonably well reproduced.

  20. Micromechanical and microstructural investigation of steel corrosion layers of variable age developed under impressed current method, atmospheric or saline conditions

    OpenAIRE

    Dehoux, A; Bouchelaghem, Fatiha; BERTHAUD, Y

    2015-01-01

    In this paper, we have gathered the conclusions of an experimental campaign dedicated to the microstructural characterization and the determination of the local elastic properties of various natural and artificial corrosion product layers. The results of micro-indentation testing and Raman spectroscopy coupled with a semi-quantitative analysis have been presented for the whole set of investigated materials, from early-age (2 weeks) corrosion products to 660 years-old massive corroded samples....

  1. 宝钢耐候钢连铸实践%CONTINUOUS CASTING OF ATMOSPHERIC CORROSION-RESISTING STEEL AT BAOSTEEL

    Institute of Scientific and Technical Information of China (English)

    阮晓明

    2001-01-01

    Based on the practice of continuous casting of atmospheric corrosion-resisting steel at Baosteel,some problems in the production were analyzed,and corresponding countermeasures have been put forward.And it has been proved that the measures are effective to improve the slab quality.%根据宝钢耐候钢连铸生产实践,分析了生产中存在的问题,并提出了相应改进措施,取得了较好的效果。

  2. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    OpenAIRE

    Renato Altobelli Antunes; Rodrigo Uchida Ichikawa; Luis Gallego Martinez; Isolda Costa

    2014-01-01

    The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron micr...

  3. Atmosphere

    Science.gov (United States)

    Ghosh, D.; Mitra, S. K.

    2014-05-01

    This paper investigates the high-temperature corrosion behavior of microstructurally different regions of the weldment of 9 Cr-1 Mo steel used in thermal power plant boiler in SO2 + O2 environment. The weldment is produced by tungsten inert gas welding method, and the different regions of the weldment (weld metal, heat-affected zone, and base metal) are exposed in SO2 + O2 (ratio 2:1) environment at 973 K for 120 h. The reaction kinetics and corrosion growth rate of different regions of weldment in isothermal condition are evaluated. The post corroded scales of the different specimens are studied in SEM, EDS, and XRD. The results indicate that the weld metal shows higher corrosion rate followed by HAZ and base metal. The higher rate of corrosion of weldmetal is mainly attributed to the least protective inner scale of Cr2O3 with minimum Cr Content. This is due to the formation of delta ferrite, which leads to the precipitation of the Cr-based secondary phases and depletes the free Cr from the matrix. The thermal cycles during welding at high temperature are favorable for the formation of delta ferrite. On the other hand, in absence of delta ferrite, the base metal and HAZ regions of the weldment show lower corrosion rate than weld metal. The difference in corrosion rate in the three regions of the weldment is supplemented by post-corroded scale characterizations.

  4. The initiation and propagation of chloride-induced transgranular stress-corrosion cracking (TGSCC) of 304L austenitic stainless steel under atmospheric conditions

    International Nuclear Information System (INIS)

    Highlights: • Cracking consistent with corrosion enhanced plasticity model of Magnin. • Cracking stress threshold is 10 MPa, substantially lower than current guidance. • Humidity threshold for cracking is 30%. • Measured length of cracks very dependent on polishing practice. • Cracking could occur at 290–300 K, based on measured activation energy. - Abstract: Bending tests were used to investigate the stress-corrosion cracking of 304L stainless steel in a corrosive atmosphere containing magnesium chloride. Initially smooth specimens showed multiple closely spaced cracks after exposures of up to 500 h. These showed threshold stresses of 10 MPa and a threshold humidity of 30%. Cracking rates increased with stress but were a maximum at plastic strains of 2%. Examination of cracks using focussed ion beam milling and electron diffraction indicated a multi-stage mechanism of propagation via preferential oxidation of slip planes. The apparent activation energy was 34 kJ mol−1 in the temperature range 333–363 K

  5. Effect of surface morphology on atmospheric corrosion behaviour of Fe-based metallic glass, Fe67Co18Si14B1

    Indian Academy of Sciences (India)

    B Vishwanadh; R Balasubramaniam; D Srivastava; G K Dey

    2008-08-01

    The nature of atmospheric corrosion behaviour of an as-cast metallic glass, Fe67Co18Si1B14 ribbon, was evaluated. The wheel side surface of the ribbon was more corroded than the air side surface, due to the higher density of air pockets present. The phases present in atmospheric rust were analysed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) to be goethite, lepidocrocite, magnetite, cobalt oxide and cobalt hydroxide phases. Goethite and lepidocrocite were in amorphous form. The nature of rusting was understood by scanning electron microscopy (SEM). Nucleation of rust started at preferred locations on the surface and grew along the surface in certain directions.

  6. Initial stages of indoor atmospheric corrosion of electronics contact metals in humid tropical climate: tin and nickel

    International Nuclear Information System (INIS)

    Samples of electrolytic tin and nickel have been exposed for 1 to 12 m in indoor environment, inside a box (rain sheltered cabinet), placed in tropical humid marine-urban climate, as a part of Gulf of Mexico. The corrosion aggressiveness of box has been classified as a very high corrosive, based on the monitored chlorides and SO2 deposition rates, and the Temperature/Relative Humidity air daily complex. The annual mass increasing of nickel is approximately twice higher than its values of lass loss (C). the relation between nickel mass loss or increasing and time of wetness (t) of metal surface is linear and does not obey the power equation C=A t''n, which has be found for tin. The SEM images reveal a localized corrosion on nickel and tin surfaces. XRD detects the formation of SnCl2.H2O as a corrosion product. Within the time on the tin surface appear black spots, considered as organic material. (Author) 26 refs

  7. Mapping Atmospheric Ammonia Emissions Using a Mobile Quantum Cascade Laser-based Open-path Sensor

    Science.gov (United States)

    Sun, K.; Tao, L.; Miller, D. J.; Khan, M. A.; Zondlo, M. A.

    2012-12-01

    Ammonia (NH3) is a key precursor to atmospheric fine particulate matter, with strong implications for regional air quality and global climate change. Despite the importance of atmospheric ammonia, its spatial/temporal variation is poorly characterized, and the knowledge of its sources, sinks, and transport is severely limited. Existing measurements suggest that traffic exhaust may provide significant amounts of ammonia in urban areas, which cause greater impacts on particulate matter formation and urban air quality. To capture the spatial and temporal variation of ammonia emissions, a portable, low power sensor with high time resolution is necessary. We have developed a portable open-path ammonia sensor with a detection limit of 0.5 ppbv ammonia for 1 s measurements. The sensor has a power consumption of about 60 W and is capable of running on a car battery continuously for 24 hours. An additional laser has been coupled to the sensor to yield concurrent N2O and CO measurements as tracers for determining various sources. The overall sensor prototype fits on a 60 cm × 20 cm aluminum breadboard. Roadside measurements indicated NH3/CO emission ratios of 4.1±5.4 ppbv/ppmv from a fleet of 320 vehicles, which agree with existing on-ramp measurements. Urban measurements in the Baltimore and Washington, DC metropolitan areas have shown significant ammonia mixing ratios concurrent with carbon monoxide levels from the morning and evening rush hours. On-road measurements of our open-path sensor have also been performed continuously from the Midwest to Princeton, NJ including urban areas such as Pittsburgh, tunnels, and relatively clean conditions. The emission ratios of ammonia against CO and/or CO2 help identify the sources and amounts of both urban and agricultural ammonia emissions. Preliminary data from both spatial mapping, monitoring, and vehicle exhaust measurements suggest that urban ammonia emissions from fossil fuel combustion are significant and may provide an

  8. 几种典型钢在西部大气环境中的腐蚀行为及预测研究%Atmospheric Corrosion of Several Typical Steels in Western Area of China

    Institute of Scientific and Technical Information of China (English)

    丁国清; 张波

    2011-01-01

    分析几种典型的碳钢、耐候钢在西部环境暴露的腐蚀数据,并与东部的环境腐蚀数据进行对比,同时利用新试验站点的环境数据及新钢种的腐蚀数据,验证了"九五"期间建立的大气腐蚀预测模型.结果表明,气候干燥、污染低的拉萨、敦煌,各种钢的腐蚀轻微,远远低于东部试验点,而库尔勒由于污染较重,各种钢的腐蚀较重;东部试验站点新钢种的腐蚀基本符合大气腐蚀预测模型,而西部试验站点新钢种的腐蚀与大气腐蚀预测模型偏差较大.%Atmospheric corrosion data of several typical carbon steels and weathering steels exposed in Western and Eastern areas of China were collected and analyzed with the aim of examing the atmospheric corrosion model proposed on the basis of corrosion data gained from exposure sites of the national network located at Eastern China until the end of last century. The results showed in general that the corrosion amount of steels exposed in exposure sites at the Western China such as Lasa and Dunhuang was far less than those at the Eastern China. However,the steels exposed in the site at Kuerle exhibited rather severe corrosion due to environmental pollution there. Therefore, the existed corrosion model is more suitable to predict the corrosion behavior of steels in harsh corrosive environments rather than that in less corrosive ones.

  9. Accelerated cyclic corrosion tests

    OpenAIRE

    Prošek T.

    2016-01-01

    Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical p...

  10. Anoxic Corrosion of Steel and Lead in Na - Cl ± Mg-Dominated Brines in Atmospheres Containing CO2

    Science.gov (United States)

    Roselle, G. T.; Johnsen, S.; Allen, C.; Roselle, R.

    2009-12-01

    The Waste Isolation Pilot Plant (WIPP) is a deep geologic repository developed by the U.S. Department of Energy for the disposal of transuranic radioactive waste in bedded salt (Permian Salado Fm.). In order to minimize radionuclide release from the repository it is desirable to maintain these species in their least-soluble form (i.e., low oxidation states). Post-closure conditions in the WIPP will control the speciation and solubility of radionuclides in the waste. Microbially-produced CO2 from cellulosic, plastic and rubber materials in the waste may acidify any brine present and increase the actinide solubilities. Thus, the DOE emplaces MgO in the repository to buffer fCO2 and pH within ranges favoring lower actinide solubilities. Large quantities of low-C steel and Pb present in the WIPP may also consume CO2. We present initial results from a series of multiyear experiments investigating the corrosion of steel and Pb alloys under WIPP-relevant conditions. The objective is to determine the extent to which these alloys consume CO2 via the formation of carbonates or other phases, potentially supporting MgO in CO2 sequestration. In these experiments steel and Pb coupons are immersed in brines under WIPP-relevant conditions using a continuous gas flow-through system. The experimental apparatus maintains the following conditions: pO2 EDTA, acetate, citrate, and oxalate); and ERDA-6 with the same organic ligands. Steel coupons removed after 6 months show formation of several phases dependent on the pCO2. SEM analysis with EDS shows the presence of a green Fe (±Mg)-chlori-hydroxide phase at pCO2 values 350 ppm. Multiple cleaning cycles were used to remove all corrosion products from the coupons, which were then weighed to determine corrosive mass loss. These data are used to calculate average corrosion rates for each experimental condition. The data show that steel corrosion rates are a strong function of pCO2 for all brine types. ERDA-6 brines appear to be more

  11. Effect of oxygen level on the oxidative stability of two different retail pork products stored using modified atmosphere packaging (MAP)

    DEFF Research Database (Denmark)

    Spanos, Dimitrios; Ann Tørngren, Mari; Christensen, Mette;

    2016-01-01

    The characteristics and the oxidative stability of pork steaks and of pork mince were investigated during 2, 5 and 7 days of refrigerated storage using oxygen (O2) levels of 0%, 20%, 50% and 80% in modified atmosphere packaging (MAP). Steaks stored during 7 days were not affected by an increase...

  12. Effect of modified atmosphere packaging (map) on the quality of sea buckthorn berry fruits during postharvest storage

    Science.gov (United States)

    The effect of modified atmosphere packaging (MAP) on the quality of the berry fruits of sea buckthorn (SBT) during refrigerated storage was investigated. SBT berries were packaged in 160 and 525 oxygen transmission rate (OTR) films or in vented clamshell containers (air control) and stored at 10C fo...

  13. Atmospheric corrosion of brass in outdoor applications: patina evolution, metal release and aesthetic appearance at urban exposure conditions.

    Science.gov (United States)

    Goidanich, S; Brunk, J; Herting, G; Arenas, M A; Odnevall Wallinder, I

    2011-12-15

    Short (days, weeks) and long-term (months, years) non-sheltered field exposures of brass (15, and 20 wt.% Zn) and copper sheet have been conducted in three European cities (Milan, Stockholm, Madrid) to generate an in-depth time-dependent understanding of patina evolution, corrosion rates, aesthetic appearance, metal release and degree of dezincification in relation to detailed bulk and surface characteristics prior to exposure. This has been accomplished by using a multitude of surface and bulk analytical tools, chemical analysis and colorimetric investigations. Small differences in surface finish and local variations in nobility observed for the non-exposed brass alloys resulted in slight differences in corrosion initiation. Despite different kinetic behaviour and relative surface distributions of zinc- and copper-rich patina constituents, similar phases were identified with copper-rich phases rapidly dominating the outermost patina layer in Milan, compared to Madrid and Stockholm showing both copper- and zinc-rich phases. As a consequence of differences in surface coverage of copper- and zinc-rich corrosion products at the different sites, the release ratios of copper to zinc varied concordantly. The released amount of zinc to copper (Zn/Cu) was for both alloys and test sites always higher compared to the bulk composition showing a preferential release of zinc. The amount of released copper from the brass alloys was on an average 30-40% lower compared to copper sheet at all test sites investigated. Significantly lower annual total release rates of copper and zinc compared with annual corrosion rates were evident for both brass alloys at all sites. PMID:22051551

  14. Atmospheric Drivers of Greenland Surface Melt Revealed by Self-Organizing Maps

    Science.gov (United States)

    Mioduszewski, J. R.; Rennermalm, A. K.; Hammann, A.; Tedesco, M.; Noble, E. U.; Stroeve, J. C.; Mote, T. L.

    2016-01-01

    Recent acceleration in surface melt on the Greenland ice sheet (GrIS) has occurred concurrently with a rapidly warming Arctic and has been connected to persistent, anomalous atmospheric circulation patterns over Greenland. To identify synoptic setups favoring enhanced GrIS surface melt and their decadal changes, we develop a summer Arctic synoptic climatology by employing self-organizing maps. These are applied to daily 500 hPa geopotential height fields obtained from the Modern Era Retrospective Analysis for Research and Applications reanalysis, 1979-2014. Particular circulation regimes are related to meteorological conditions and GrIS surface melt estimated with outputs from the Modèle Atmosphérique Régional. Our results demonstrate that the largest positive melt anomalies occur in concert with positive height anomalies near Greenland associated with wind, temperature, and humidity patterns indicative of strong meridional transport of heat and moisture. We find an increased frequency in a 500 hPa ridge over Greenland coinciding with a 63% increase in GrIS melt between the 1979-1988 and 2005-2014 periods, with 75.0% of surface melt changes attributed to thermodynamics, 17% to dynamics, and 8.0% to a combination. We also confirm that the 2007-2012 time period has the largest dynamic forcing relative of any period but also demonstrate that increased surface energy fluxes, temperature, and moisture separate from dynamic changes contributed more to melt even during this period. This implies that GrIS surface melt is likely to continue to increase in response to an ever warmer future Arctic, regardless of future atmospheric circulation patterns.

  15. 变电站常用金属的大气腐蚀行为及其防护%Atmospheric Corrosion of Common Metals Used in Transformer Substation and Protection Measures

    Institute of Scientific and Technical Information of China (English)

    杨大宁; 汪川; 王振尧; 符传福; 潘辰

    2016-01-01

    综述了变电站常用金属的腐蚀类型及研究现状.对于不锈钢、铝及铝合金,海洋大气中的Cl-引起钝化膜破裂,当其浓度超过临界浓度[Cl-]pit,发生点蚀.对于铜及铜合金,工业大气中的SO2腐蚀作用极为明显.对于锌及锌合金,Cl-增强表面薄液膜的导电性从而加剧其腐蚀.因此,高润湿时间和高Cl-是滨海变电站大气腐蚀的主要原因.%This paper reviewed the types of atmospheric corrosion of common metals used in transformer substations and current status of researches on these corrosions. As to stainless steel, aluminum and aluminum alloy, Cl-in marine atmosphere would lead to crack of passivation coating and pitting would occur when Cl- concentration passes the critical concentration [Cl-]pit. As to copper and copper alloy, the corrosion effect of SO2 is obvious. As to zinc and zinc alloy, Cl- enhances the electrical conductivity of surface liquid film, thus aggravating the corrosion. In conclusion, high wetting time and high Cl- concentration are main causes for atmospheric corrosion of coastal transformer substation.

  16. Fault Tree analysis of Corrosion Failure for Bridge Pot-bearings in Marine Atmosphere%海洋大气中桥梁盆式支座腐蚀失效故障树分析

    Institute of Scientific and Technical Information of China (English)

    郑轩

    2013-01-01

    腐蚀是桥梁盆式支座的常见病害之一,针对引起盆式支座腐蚀失效的各个因素,结合大气腐蚀、防腐涂装失效等机理,建立以盆式支座腐蚀失效为顶事件的故障树,通过布尔代数运算得到故障树的最小割集,从而得出导致支座腐蚀发生的主要因素,分析表明大气环境腐蚀因素、支座后期维护不善、支座局部构造不合理是导致支座腐蚀的主要因素,并针对这些原因提出了相应的改进措施和建议,以降低支座腐蚀失效发生的可能性。%Corrosion is one of the common diseases of bridge pot-bearings.Considering the various of factors that cause corrosion failure,combining with atmospheric corrosion mechanism and anticorrosive coatings failure mechanism,established a fault tree,of which top event is the corrosion failure of pot-bearings.The minimal cut-sets of the fault tree was obtained by Boolean operation,and then the impor-tant bottom events which caused corrosion failure of pot bearings were found.Results show that the main factors which cause corrosion failure of pot-bearings are marine atmospheric corrosive factors,poor main-tenance and unreasonable structure of pot-bearings.Some improvements with respect to the main factors had been proposed,which can reduce the possibility of corrosion failure.

  17. Automatic identification of corrosion damage using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Mariana P.; Ramalho, Geraldo L.B.; Medeiros, Fatima N.S. de; Ribeiro, Elvis S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Medeiros, Luiz C.L. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper proposes a Nondestructive Evaluation (NDE) method for atmospheric corrosion detection on metallic surfaces using digital images. In this study, the uniform corrosion is characterized by texture attributes extracted from co-occurrence matrix and the Self Organizing Mapping (SOM) clustering algorithm. We present a technique for automatic inspection of oil and gas storage tanks and pipelines of petrochemical industries without disturbing their properties and performance. Experimental results are promising and encourage the possibility of using this methodology in designing trustful and robust early failure detection systems. (author)

  18. Initial stages of indoor atmospheric corrosion of electronics contact metals in humid tropical climate: tin and nickel

    Directory of Open Access Journals (Sweden)

    Veleva, L.

    2007-04-01

    Full Text Available Samples of electrolytic tin and nickel have been exposed for 1 to 12 m in indoor environment, inside a box (rain sheltered cabinet, placed in tropical humid marine-urban climate, as a part of Gulf of Mexico. The corrosion aggressiveness of box has been classified as a very high corrosive, based on the monitored chlorides and SO2 deposition rates, and the Temperature/Relative Humidity air daily complex. The annual mass increasing of nickel is approximately twice higher than its values of mass loss (C. The relation between nickel mass loss or increasing and time of wetness (t of metal surface is linear and does not obey the power equation C = A tn, which has be found for tin. The SEM images reveal a localized corrosion on nickel and tin surfaces. XRD detects the formation of SnCl2.H2O as a corrosion product. Within the time on the tin surface appear black spots, considered as organic material.

    Muestras de estaño y níquel electrolíticos han sido expuestas de 1 a 12 m en ambiente interno (indoor, en una caseta (gabinete protegido de lluvia, colocada en clima tropical húmedo marino-urbano del Golfo de México. La agresividad de la caseta ha sido clasificada como muy altamente corrosiva, basada al registro de la velocidad de deposición de cloruros y SO2, y en el complejo diario de temperatura/humedad relativa del aire. El incremento de masa anual de níquel es, aproximadamente, dos veces mayor que del valor de su pérdida de masa (C. La relación entre la pérdida de masa de Ni o su incremento, y el tiempo de humectación (t de la superficie metálica y lineal y no obedece la ley de potencia C = A tn , que ha sido encontrada para el estaño. Las imágenes del SEM revelan una corrosión localizada en las superficie de níquel y estaño. El análisis de rayos-X detecta la formación de SnCl2.H2O como producto de corrosión. Con el tiempo

  19. Corrosion and anticorrosion. Industrial practice

    International Nuclear Information System (INIS)

    This book comprises 14 chapters written with the collaboration of about 50 French experts of corrosion. It is complementary to another volume entitled 'corrosion of metals and alloys' and published by the same editor. This volume comprises two parts: part 1 presents the basic notions of corrosion phenomena, the properties of surfaces, the electrochemical properties of corrosion etc.. Part 2 describes the most frequent forms of corrosion encountered in industrial environments and corresponding to specific problems of protection: marine environment, atmospheric corrosion, galvanic corrosion, tribo-corrosion, stress corrosion etc.. The first 8 chapters (part 1) treat of the corrosion problems encountered in different industries and processes: oil and gas production, chemical industry, phosphoric acid industry, PWR-type power plants, corrosion of automobile vehicles, civil engineering and buildings, corrosion of biomaterials, non-destructive testing for the monitoring of corrosion. The other chapters (part 2) deal with anticorrosion and protective coatings and means: choice of materials, coatings and surface treatments, thick organic coatings and enamels, paints, corrosion inhibitors and cathodic protection. (J.S.)

  20. Prediction of metal corrosion by neural networks

    OpenAIRE

    Jančíková, Zora; Zimný, Ondřej; Koštial, Pavol

    2013-01-01

    The contribution deals with the use of artifi cial neural networks for prediction of steel atmospheric corrosion. Atmospheric corrosion of metal materials exposed under atmospheric conditions depends on various factors such as local temperature, relative humidity, amount of precipitation, pH of rainfall, concentration of main pollutants and exposition time. As these factors are very complex, exact relation for mathematical description of atmospheric corrosion of various metals are...

  1. Prediction of metal corrosion by neural networks

    OpenAIRE

    Jančíková, Z.; Zimný, O.; Koštial, P.

    2013-01-01

    The contribution deals with the use of artificial neural networks for prediction of steel atmospheric corrosion. Atmospheric corrosion of metal materials exposed under atmospheric conditions depends on various factors such as local temperature, relative humidity, amount of precipitation, pH of rainfall, concentration of main pollutants and exposition time. As these factors are very complex, exact relation for mathematical description of atmospheric corrosion of various metals are not known so...

  2. Grey Correlation Research on Atmospheric Corrosion Environment Factors of Aircraft LY12CZ Aluminum Alloy%飞机用LY12CZ材料大气腐蚀环境因子灰色关联性研究

    Institute of Scientific and Technical Information of China (English)

    刘治国; 李旭东; 穆志韬

    2012-01-01

    The atmospheric environment causing atmospheric corrosion of aircraft I.Y12CZ structure is viewed as a grey system. The weather and medium environment factor data of typical climate territories were statistically analyzed to calculate the atmospheric corrosion rate data of aircraft LY12CZ aluminum alloy in different corrosion years. The grey correlation of environment factors was analyzed based on grey system theory with the aim to quantitatively analyze the influence degree of different environment factors on the atmospheric corrosion rate of LY12CZ. The analysis results show that the number of fog days and the CI concentration are the strongest inflence factors on the atmospheric corrosion rate of LY12CZ among all the weather and medium environment factors.%影响LY12CZ材料大气腐蚀的大气环境是灰色系统。选取典型地域的大气环境因子(气象环境和介质环境)统计数据,并利用LY12CZ材料不同腐蚀年限的大气腐蚀速率计算结果,依据灰色系统理论对影响LY12CZ材料大气腐蚀速率的环境因子灰色关联性进行计算分析,量化研究不同环境因子对LY12CZ材料大气腐蚀速率的影响程度。结果表明,雾日数和C1-浓度分别为气象环境因子和介质环境因子中对LY12CZ的大气腐蚀速率影响最大的环境因子。

  3. Corrosion of carbon steel, zinc and copper by air pollution in Chongqing

    Institute of Scientific and Technical Information of China (English)

    YE Di; ZHAO Da-wei; CHEN Gang-cai; ZHANG Dong-bao

    2007-01-01

    This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H+, were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose-response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.

  4. Characteristics and Influencing Factors of Atmospheric Corrosion of Aluminum in Marine and Coastal Environments%海洋和沿海环境铝大气腐蚀特征及影响因素

    Institute of Scientific and Technical Information of China (English)

    胡晓黎; 韩方运; 牛林; 周少玲; 钱兆红; 赵萌; 陈佳川

    2011-01-01

    Atmospheric environments in marine and coastal regions have the characteristics of high humidity, high salinity and strong corrosivity. The research progresses in the atmospheric corrosion of widely used aluminum and its alloys in marine and coastal environments are reviewed. The corrosion characteristics, mechanisms and environmental factors which affecting the corrosion process are investigated to provide valuable references for modeling the life prediction of materials and taking effective measures for corrosion protection.%海洋和沿海大气环境具有高湿度、高盐度以及腐蚀性强的特点。本文综述了具有广泛应用的铝及铝合金在海洋和沿海环境中大气腐蚀的国内外研究动态和进展,探讨了该腐蚀体系的特征、机理及环境(气象、气候)影响因素,旨在为材料的寿命预测模型化和采取有效的腐蚀防护措施提供有价值的参考。

  5. Corrosion Behavior of TP316L of Superheater in Biomass Boiler with Simulated Atmosphere and Deposit%TP316L在模拟生物质锅炉过热器气相和积灰条件下的腐蚀特性

    Institute of Scientific and Technical Information of China (English)

    印佳敏; 吴占松

    2009-01-01

    Corrosion behavior of TP316L was investigated with simulated atmosphere and ash deposition for the superheater in biomass boiler. Corrosion dynamic curves were plotted by mass gain. The results showed that the corrosion was dependent on temperature and was greatly accelerated by ash deposition. The mass gain was distinctly reduced in the presence of SO_2 with and without ash deposition on the specimens. Corrosion rates with ash deposit at different temperatures were calculated. Two feasible methods were provided to avoid serious high-temperature corrosion in the biomass boiler.

  6. Mechanism of corrosion of structural materials in contact with coal chars in coal gasifier atmospheres. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, D.L.; Bhide, V.S.; Vineberg, E.

    1980-05-01

    Six alloys, 310 stainless steel, Hastelloy X, Inconel 671, Incoloy 800, Haynes 188, and FeCrAlY (GE1541 and MA956), were corroded in two chars at 1600 and 1800/sup 0/F. The chars, FMC and Husky, contained 2.7 and 0.9% sulfur, respectively. Various parameters were investigated, including char size, cover gas, char quantity, char replenishment period, gas composition, and the use of coatings. The corrosion process was strictly sulfidation when the char was replenished every 24 hours or less. The kinetics of reaction were nearly linear with time. The reaction resulted in thick external sulfide scales with extensive internal sulfidation in the substrate. The kinetics and reaction-product morphologies suggested that diffusion through the sulfide scale played a minor role and that an interfacial reaction was the rate-controlling step. A mathematical model was developed which supported this hypothesis. The reaction rates showed a relatively minor role on alloy composition, depending upon whether the alloys were tested singularly or in combination with others. Inconel 671, the best alloy in CGA environments, consistently corroded the most rapidly of the chromia-former types regardless of char sulfur content or of the temperature. Type 310 stainless was marginally better than Inconel 671. Incoloy 800 was intermediate, whereas, Haynes 188 and Hastelloy X exhibited the best corrosion resistance. The FeCrAlY alloys reacted very rapidly in the absence of preoxidation treatments. All alloys corroded in char at least 1000 times more rapidly than in the CGA (MPC-ITTRI) environment. None of the alloys will be acceptable for use in contact with char unless coatings are applied.

  7. 石油化工业钢结构的大气腐蚀与防护措施%Corrosion and Protection of Steel Structures in Atmospheric Environment of Petrochemical Industry

    Institute of Scientific and Technical Information of China (English)

    朱晓明; 周学杰; 王玮; 纪方奇; 张琳; 林志坚; 胡章枝

    2013-01-01

    Four kinds of standard metals were tested in exposed atmosphere of petrochemical industry so as to determine the corrosive grade of the corrosive atmosphere. In the meantime, eight kinds of anticorro -sive systems were also tested in the exposed corrosive atmosphere so as to evaluate their protective effect. It was found that high concentrations of corrosive mediums such as sulfur dioxide and hydrogen sulfide were present in the atmosphere of petrochemical industry. The atmospheric corrosion grade was from C4 to C5, corresponding to serious corrosion of carbon steel. Moreover, in terms of various protective systems, the one consisting of sprayed Al primer or Zn-rich primer, epoxy micaceous iron oxide intermediate paint, and fluorocarbon resin finish (or acrylic polyurethane coating) possessed the best corrosion resistance and weatherability.%化工大气环境中含有较多的腐蚀性介质,对钢结构腐蚀严重.为了评价石油化工大气环境的腐蚀性,采用4种标准金属材料进行石油化工大气环境现场暴露试验,对石油化工大气环境腐蚀性进行评级;同时选用8种防腐蚀体系试样进行暴露试验,以评价其防护效果.结果表明:石油化工大气环境中含有较高浓度的二氧化硫、硫化氢等腐蚀介质,腐蚀等级属C4~C5级;保护层体系中,由喷铝或富锌底漆、环氧云铁中间漆、氟碳树脂(或丙烯酸聚氨酯)面漆组成的防护体系的综合耐蚀性和耐候性较好.

  8. Understanding localized corrosion

    Directory of Open Access Journals (Sweden)

    G.S. Frankel

    2008-10-01

    Full Text Available The breakdown of a protective passive film leading to accelerated dissolution at localized sites is an important practical issue and a vexing scientific problem. The small dimensions, short timescale, and dynamic interplay between a heterogeneous surface and changing potential and solution concentration gradients complicate the development of a complete understanding of the phenomena. This review touches on some of the recent developments in the field, including scanning tunneling microscopy imaging of the earliest stages of pitting which supports a new model explaining the localization of attack, pitting in thin aqueous layers relevant to atmospheric corrosion, the factors controlling crevice corrosion, and predictive modeling of localized corrosion.

  9. PIXE elemental mapping on original manuscripts with an external microbeam. Application to manuscripts damaged by iron-gall ink corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Remazeilles, Celine E-mail: cremazei@univ-lr.fr; Quillet, Veronique; Calligaro, Thomas; Claude Dran, Jean; Pichon, Laurent; Salomon, Joseph

    2001-07-01

    Proton-induced X-ray emission (PIXE) mapping and PIXE spot analysis have been performed on three original manuscripts. We observed that the precision of the spot measurements for the analysis of the ink composition is limited by the heterogeneity of the writing. PIXE mapping proved to be a complementary technique which is much more sensitive, and which makes it possible to evaluate the migration of some elements, such as sulphur, iron and calcium around inscriptions.

  10. PIXE elemental mapping on original manuscripts with an external microbeam. Application to manuscripts damaged by iron-gall ink corrosion

    International Nuclear Information System (INIS)

    Proton-induced X-ray emission (PIXE) mapping and PIXE spot analysis have been performed on three original manuscripts. We observed that the precision of the spot measurements for the analysis of the ink composition is limited by the heterogeneity of the writing. PIXE mapping proved to be a complementary technique which is much more sensitive, and which makes it possible to evaluate the migration of some elements, such as sulphur, iron and calcium around inscriptions

  11. Corrosion evaluation technology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Uh Chul; Han, Jeong Ho; Nho, Kye Ho; Lee, Eun Hee; Kim, Hong Pyo; Hwang, Seong Sik; Lee, Deok Hyun; Hur, Do Haeng; Kim, Kyung Mo

    1997-09-01

    A multifrequency ACPD system was assembled which can measure very small crack. Stress corrosion cracking test system with SSRT operating high temperature was installed. Stress corrosion cracking test of newly developed alloy 600 and existing alloy 600 was carried out in steam atmosphere of 400 deg C. No crack was observed in both materials within a test period of 2,000 hrs. Corrosion fatigue test system operating at high temperature was installed in which fatigue crack was measured by CDPD. Lead enhanced the SCC of the Alloy 600 in high temperature water, had a tendency to modify a cracking morphology from intergranular to transgranular. Pit initiation preferentially occurred at Ti-rich carbide. Resistance to pit initiation decreased with increasing temperature up to 300 deg C. Test loop for erosion corrosion was designed and fabricated. Thin layer activation technique was very effective in measuring erosion corrosion. Erosion corrosion of a part of secondary side pipe was evaluated by the Check Family Codes of EPRI. Calculated values of pipe thickness by Check Family Codes coincided with the pipe thickness measured by UT with an error of {+-} 20%. Literature review on turbine failure showed that failure usually occurred in low pressure turbine rotor disc and causes of failure are stress corrosion cracking and corrosion fatigue. (author). 12 refs., 20 tabs., 77 figs.

  12. Atmospheric Corrosion of Painted Galvanized and 55%Al-Zn Steel Sheets: Results of 12 Years of Exposure

    OpenAIRE

    C.I. Elsner; P. R. Seré; Di Sarli, A. R.

    2012-01-01

    Zinc or 55%Al-Zn alloy-coated steel sheets, either bare or covered by different painting systems, have been exposed for 12 years to the action of the urban atmosphere at the CIDEPINT station located in La Plata (34° 50′ South, 57° 53′, West), province of Buenos Aires, Argentina. The samples exposed surface was evaluated through periodical visual inspections, standardized adhesion tests, and electrochemical impedance measurements. The ambient variables monitored were average annual rains and t...

  13. Mapping the spatial distribution of global anthropogenic mercury atmospheric emission inventories

    NARCIS (Netherlands)

    Wilson, Simon J.; Steenhuisen, Frits; Pacyna, Jozef M.; Pacyna, Elisabeth G.

    2006-01-01

    This paper describes the procedures employed to spatially distribute global inventories of anthropogenic emissions of mercury to the atmosphere, prepared by Pacyna, E.G., Pacyna, J.M., Steenhuisen, F., Wilson, S. [2006. Global anthropogenic mercury emission inventory for 2000. Atmospheric Environmen

  14. Biomonitoring of atmospheric pollution (with emphasis on trace elements) - BioMAP. Proceedings of an international workshop

    International Nuclear Information System (INIS)

    Some organisms accumulate atmospheric contaminants over certain periods of time and concentrate them, thus allowing reliable analytical measurements if the organisms are suitably chosen. Measurements of contaminants accumulated by such organisms (biomonitors) provide information on the integrated exposure over an extended period of time. They may also be present in remote areas, and no expensive technical equipment is involved in collecting them. Therefore, biomonitoring can be an effective tool for pollutant mapping and trend monitoring by real time and retrospective analysis. The IAEA is making concerted efforts to promote the practical use of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact human health, and one of the main emphases is on studying air contaminants. The idea of organizing a workshop on biomonitoring atmospheric pollution arose during an IAEA Technical Co-operation Project on Monitoring of Trace Element Air Pollution, carried out at the Instituto Tecnologico e Nuclear (ITN), Portugal, with substantial technical support by the Interfaculty Reactor Institute (IRI) of the Delft University of Technology (TUDelft), Netherlands. The International Workshop on Biomonitoring of Atmospheric Pollution (With Emphasis on Trace Elements) - BioMAP, was held in Lisbon, Portugal, from 21 to 24 September 1997. The meeting was organized in co-operation with the Instituto Tecnologico e Nuclear

  15. 铝合金大气腐蚀行为及其防腐措施研究进展%Research Progress in Atmospheric Corrosion Behavior and Anticorrosion Measures of Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    王彬; 苏艳

    2012-01-01

    综述了铝合金的大气腐蚀机理和大气主要环境因素对铝合金的大气腐蚀的影响.重点介绍了近年来所采用的对环境无害的铝合金无铬防腐蚀处理方法(激光熔覆法、溶胶-凝胶法、聚合物防腐蚀膜等)及其发展前景.%The atmospheric corrosion mechanism and the effect of principal pollutants of atmosphere on corrosion of aluminum alloy were summarized. The emphasis was on current used Cr-free and environment-friendly anticorrosive protection systems (such as laser cladding method, sol-gel method and anticorrosive polymer film) for aluminum alloy and its development prospect.

  16. Study on Grey Prediction Model of Typical Atmospheric Corrosion Mediums%典型大气腐蚀介质的灰色预测模型分析

    Institute of Scientific and Technical Information of China (English)

    黄海军; 李婵; 王俊

    2012-01-01

    利用武汉地区2002-2007年二氧化硫和氯化物含量数据,建立了这2种典型大气腐蚀介质的GM(1,1)预测模型,探讨了不同维数GM(1,1)模型预测结果的差异.另外,对这2种典型大气腐蚀介质GM(1,1)模型进行了检验,结果表明,GM(1,1)模型的预测精度较高,精度检验等级达到1级.%GM(1,1) prediction models were established, which was based on the data of sulfur dioxide and chloride contents from the year 2002 to 2007 in Wuhan. The differences among different dimensions GM(1,1) model prediction results were investigated. Moreover, the GA/(1,1) models of the two typical atmospheric corrosion mediums were tested. The result showed that GA/(1,1) model has high prediction accuracy, and the accuracy class achieves level 1.

  17. Standard practice for measurement of time-of-wetness on surfaces exposed to wetting conditions as in atmospheric corrosion testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1989-01-01

    1.1 This practice covers a technique for monitoring time-of-wetness (TOW) on surfaces exposed to cyclic atmospheric conditions which produce depositions of moisture. 1.2 The practice is also applicable for detecting and monitoring condensation within a wall or roof assembly and in test apparatus. 1.3 Exposure site calibration or characterization can be significantly enhanced if TOW is measured for comparison with other sites, particularly if this data is used in conjunction with other site-specific instrumentation techniques. 1.4 The values stated in SI units are to be regarded as the standard. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  18. Manufacture of high-nitrogen corrosion-resistant steel by an aluminothermic method in a high-pressure nitrogen atmosphere

    Science.gov (United States)

    Dorofeev, G. A.; Karev, V. A.; Kuzminykh, E. V.; Lad'yanov, V. I.; Lubnin, A. N.; Vaulin, A. S.; Mokrushina, M. I.

    2013-01-01

    The conditions of aluminothermic synthesis of high-nitrogen Cr-N and Cr-Mn-N steels in a high-pressure nitrogen atmosphere are studied by thermodynamic simulation and metallurgical experiments. Thermodynamic analysis shows that the aluminothermic reduction reactions are incomplete. The most important synthesis parameter is the ratio of the aluminum to the oxygen content in a charge, and its optimum value ensures a compromise between the degree of oxide reduction, the aluminum and oxygen contents in steel (degree of deoxidation), and steel contamination by aluminum nitride. An analysis of experimental heats demonstrates good agreement between the experimental results and the data calculated by a thermodynamic model. As-cast ingots have the structure of nitrogen pearlite, and quenched ingots have an austenitic structure.

  19. Effects of magnesium chloride-based multicomponent salts on atmospheric corrosion of aluminum alloy 2024%以MgCl2为主的混合盐对2024铝合金大气腐蚀的影响

    Institute of Scientific and Technical Information of China (English)

    王彬彬; 王振尧; 韩薇; 汪川; 柯伟

    2013-01-01

    Atmospheric corrosion of aluminum alloy 2024 (AA2024) with salt lake water was simulated through a laboratoryaccelerated test of cyclic wet-dry and electrochemical techniques.Effects of the soluble magnesium salt contained in the salt water were investigated by scanning electron microscope (SEM),transmission electron microscope (TEM),energy dispersive spectrometer (EDS),electron probe micro analyzer (EPMA),X-ray diffraction (XRD),infrared transmission spectroscope (IR),and atmospheric corrosion monitor (ACM).The results showed that,with the deposition,atmospheric corrosion of AA2024 could occur when the relative humidity (RH) was lower than 30%.A main crystalline component of corrosion products,layered double hydroxides (LDH),[Mg1-xAlx(OH)2]x+ Clx-·mH2O (LDH-Cl),was determined,which meant that magnesium ion played an important role in the corrosion process.It not only facilitated the corrosion as a result of deliquescence,but also was involved in the corrosion process as a reactant.%以盐湖水为腐蚀介质,通过实验室模拟循环干湿交替实验及电偶电流测量等电化学手段,利用扫描电镜(SEM)、透射电镜(TEM)、X射线能谱仪(EDS)、电子探针(EPMA)、X射线衍射(XRD)、红外光谱(IR)和大气腐蚀监测仪(ACM)等分析和测量技术,研究模拟盐湖大气环境下,可溶性镁盐(主要为MgCl2)对2024铝合金大气腐蚀行为的影响.结果表明,在相对湿度低于30%的环境下,仍有腐蚀行为发生;腐蚀产物中出现了含氯的镁铝双金属氢氧化物——[Mg1-xAlx(OH)2]x+Clx-·mH2O (LDH-Cl),并作为主要腐蚀产物.分析表明,以MgCl2为主的混合盐不仅在较低的相对湿度下为金属腐蚀的进行提供所需的液膜环境,同时也作为反应产物参与腐蚀反应.

  20. Corrosion Study of Metals in Marine Environment

    OpenAIRE

    R. T. Vashi; H. K. Kadiya

    2009-01-01

    Atmospheric corrosion rate of Al, Zn and mild steel (MS) as well as salinity and sulphation rate have been determined under outdoor exposure at Tithal (Dist. Valsad) situated in South Gujarat, India. MS samples exposed vertically suffer less corrosion than those exposed at an angle of 45°. Monthly corrosion rate was in the decreasing order of Al

  1. Improved mapping of National Atmospheric Deposition Program wet-deposition in complex terrain using PRISM-gridded data sets

    Science.gov (United States)

    Latysh, Natalie E.; Wetherbee, Gregory Alan

    2012-01-01

    High-elevation regions in the United States lack detailed atmospheric wet-deposition data. The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) measures and reports precipitation amounts and chemical constituent concentration and deposition data for the United States on annual isopleth maps using inverse distance weighted (IDW) interpolation methods. This interpolation for unsampled areas does not account for topographic influences. Therefore, NADP/NTN isopleth maps lack detail and potentially underestimate wet deposition in high-elevation regions. The NADP/NTN wet-deposition maps may be improved using precipitation grids generated by other networks. The Parameter-elevation Regressions on Independent Slopes Model (PRISM) produces digital grids of precipitation estimates from many precipitation-monitoring networks and incorporates influences of topographical and geographical features. Because NADP/NTN ion concentrations do not vary with elevation as much as precipitation depths, PRISM is used with unadjusted NADP/NTN data in this paper to calculate ion wet deposition in complex terrain to yield more accurate and detailed isopleth deposition maps in complex terrain. PRISM precipitation estimates generally exceed NADP/NTN precipitation estimates for coastal and mountainous regions in the western United States. NADP/NTN precipitation estimates generally exceed PRISM precipitation estimates for leeward mountainous regions in Washington, Oregon, and Nevada, where abrupt changes in precipitation depths induced by topography are not depicted by IDW interpolation. PRISM-based deposition estimates for nitrate can exceed NADP/NTN estimates by more than 100% for mountainous regions in the western United States.

  2. 输变电设施周边大气的环境检测与腐蚀原因分析%Detection and Analysis of Atmospheric Corrosion Environment Around Substation

    Institute of Scientific and Technical Information of China (English)

    王平; 孙心利; 马东伟

    2015-01-01

    This paper analyzed the characteristics of atmospheric corrosion and the sources of pollutants and it was concluded that atmospheric environment detection was an important part in substation equipment corrosion analysis. Through detection and analysis of atmospheric environment around substation, the substation metal material corrosion was mainly due to the high gas composition of H2S, NH3 generated by the production sites around substation, such as sewage, chemical plants, chicken farms. This paper also proposed the prevention and treatment measures, such as strengthening environmental detection, conducting environmental assessment, etc.%以某地区为例,开展了大气环境和污染物情况的分析调查.在选择了遭受大气环境腐蚀较为严重的5个站点进行了输变电设施周围典型大气环境检测.分析认为:输变电设施铜、铁、锌等材料特性是产生腐蚀的根本因子;大气环境中的SO2、H2S和NH3是造成输变电设施腐蚀的主要因子;温度、湿度、气压和氧含量等气候条件是促进输变电设施腐蚀加剧的促进因子.

  3. Sensitivity of produce respiration models used in the MAP-DESIGN software on the shelf life simulation of broccoli in the modified atmosphere package

    OpenAIRE

    Weerasak Lertsiriyothin

    2009-01-01

    Optimization for the designing of modified atmosphere packaging (MAP) for broccoli was made by the MAP-DESIGN software (author’s own code). The software is capable of dealing with all parameters required for the designing of MAP for fresh produce, namely packaging materials, package dimensions, storage conditions, and plant respiratory models. Computational algorithms were carefully designed based upon widely-used theories of living plant respiration, gas permeability through packaging film...

  4. EFFECT OF GRAIN SIZE ON ATMOSPHERIC CORROSION RESISTANCE OF ULTRA-LOW CARBON IF STEEL%晶粒尺寸对超低碳IF钢耐大气腐蚀性能的影响

    Institute of Scientific and Technical Information of China (English)

    汪兵; 刘清友; 王向东

    2012-01-01

    采用不同轧制及热处理工艺制备了化学成分相同而晶粒尺寸不同的3种超低碳IF钢试样.采用浸泡腐蚀、周浸腐蚀、原子力显微镜(AFM)及扫描电镜(SEM)微观分析、电化学阻抗测试等手段对晶粒尺寸与IF钢耐大气腐蚀性能之间的规律进行了研究.AFM及SEM微观分析结果表明,随着晶粒尺寸从15μm增加到220 μm,超低碳IF钢浸泡腐蚀后晶界处的局部腐蚀更加严重,腐蚀裂纹处的深度加深,裂纹宽度变宽.超低碳IF钢晶粒尺寸从15μm增加到46μm,周浸腐蚀实验后锈层中空洞和裂纹增多,锈层电阻下降,耐候性下降;晶粒尺寸进一步增大到220 μm后,锈层整体致密性得到增加,锈层电阻上升,耐候性得到增加.对晶粒尺寸影响耐大气腐蚀性能的机理进行了讨论.晶粒尺寸增大后晶界能的减少使得腐蚀表面的宏观总体缺陷数量有所减少,耐候性有所提高;但是晶粒尺寸增大后晶界处因局部腐蚀电流密度增大将会在局部造成更深的腐蚀坑槽并降低耐候性;晶粒尺寸的变化对钢铁材料耐大气腐蚀性能的影响不仅要考虑其对晶界局部腐蚀电流密度的影响,而且还必须考虑对基体整体晶界能所造成的影响.%Three kinds of ultra-low carbon IF steel with different grain sizes, and same chemical composition were prepared by different rolling and heat treat process. The relationship between grain size and atmospheric corrosion resistance of IF steel was investigated by immersion corrosion test, cyclic immersion corrosion test, AFM/SEM micro-analysis and electrochemical test. The results show that the local corrosion in grain boundary increases after immersion corrosion test, the depth of crack in grain boundary becomes deeper and the width of crack becomes wider with grain sizes of IF steel increase from 15 μm to 220 μm. The crack and cavity in the rust after cycle immersion corrosion test are increased and the atmospheric

  5. Fundamentals of corrosion control design

    Energy Technology Data Exchange (ETDEWEB)

    Perrigo, L.D.; Jensen, G.A.

    1979-03-01

    The development of corrosion control design principles and practice is discussed. It is concluded that by applying simple and straightforward principles to the design of systems, buildings and equipment, operational corrosion problems may be reduced or avoided. These corrosion control design principles are concerned with promoting the use of orientation, layout, and configuration to avoid the holdup of solutions, abrupt flow changes, impingement and stagnant areas. Climatic conditions and terrain are important siting considerations in reducing atmospheric corrosion of buildings and facilities. A determined effort is needed to broaden the understanding of anticorrosion design measures and principles because these are not widely known and recognized by designers and architects.

  6. The Boston Methane Project: Mapping Surface Emissions to Inform Atmospheric Estimation of Urban Methane Flux

    Science.gov (United States)

    Phillips, N.; Crosson, E.; Down, A.; Hutyra, L.; Jackson, R. B.; McKain, K.; Rella, C.; Raciti, S. M.; Wofsy, S. C.

    2012-12-01

    Lost and unaccounted natural gas can amount to over 6% of Massachusetts' total annual greenhouse gas inventory (expressed as equivalent CO2 tonnage). An unknown portion of this loss is due to natural gas leaks in pipeline distribution systems. The objective of the Boston Methane Project is to estimate the overall leak rate from natural gas systems in metropolitan Boston, and to compare this flux with fluxes from the other primary methane emissions sources. Companion talks at this meeting describe the atmospheric measurement and modeling framework, and chemical and isotopic tracers that can partition total atmospheric methane flux into natural gas and non-natural gas components. This talk focuses on estimation of surface emissions that inform the atmospheric modeling and partitioning. These surface emissions include over 3,300 pipeline natural gas leaks in Boston. For the state of Massachusetts as a whole, the amount of natural gas reported as lost and unaccounted for by utility companies was greater than estimated landfill emissions by an order of magnitude. Moreover, these landfill emissions were overwhelmingly located outside of metro Boston, while gas leaks are concentrated in exactly the opposite pattern, increasing from suburban Boston toward the urban core. Work is in progress to estimate spatial distribution of methane emissions from wetlands and sewer systems. We conclude with a description of how these spatial data sets will be combined and represented for application in atmospheric modeling.

  7. 航空铝合金材料大气腐蚀环境因子灰色关联分析%Application of Grey Relational Analysis to Environmental Factors of Atmospheric Corrosion of Aerospace Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    王瑞峰; 王国才; 苏维国; 丁文勇

    2013-01-01

      Grey relational method was applied to evaluate the effect of environmental factors on atmospheric corrosion of LY12CZ aluminum alloys combined with the corrosion data obtained from 7 of the national atmospheric corrosion test stations. Analysis results indicated that the influence order of the meteorological factors in atmospheric corrosion exposing for one year, three years, six years and ten years is always the same. For pollutant factors, the sorted result is changeable at different exposure time.%  结合航空铝合金材料LY12CZ在全国7个大气腐蚀试验网站暴晒腐蚀数据,利用灰色关联分析方法计算出铝合金大气腐蚀速率和腐蚀环境因子在不同暴晒时间的关联度,分析大气腐蚀环境因子对铝合金材料大气腐蚀的影响规律。LY12CZ自然暴晒1,3,6,10 a的气象环境因子灰色关联度分析结果表明,各暴露年限气象环境因子关联度排序相对位置均未发生变化;对于腐蚀环境因子而言,各暴露年限的腐蚀环境因子发生了变化。

  8. Effect of NO2 and/or SO2 atmospheric contaminants and relative humidity on copper corrosion

    Directory of Open Access Journals (Sweden)

    Feliu, S.

    2003-08-01

    Full Text Available A study has been made of the individual and combined roles of NO2 and SO2 atmospheric contaminants on corrosion and patina formation on copper in humid atmospheres. In most cases the combined effect of the two contaminants has been greater than the sum of their individual effects, although exception have been found with the mixture of 800 μg/m+3NO2 + 800 μg/m+3 SO2- XPS analysis has revealed important composition changes in the outermost layer of films formed on copper, depending on the nature of the atmospheric contaminant and humidity level. The presence of sulphates and sulphites has been clearly observed in exposure to atmospheres contaminated with SO2 at 50, 70 and 90 % RH. Nitrates and nitrites have been detected in exposure to NO2 at 50 and 70 %RH, but not at 90 % RH. A hydrogenated nitrogen compound has been detected with the mixture of NO2 and SO2 at 90 % RH .In this atmosphere, a certain inhibiting effect has been seen.

    Se ha estudiado el papel de los contaminantes atmosféricos NO2 y SO2 y de una mezcla de ambos, en la corrosión y formación de pátina sobre el cobre expuesto en atmósferas húmedas. Por lo general, el efecto combinado de los dos contaminantes es mayor que la suma de los efectos individuales, aunque se han encontrado excepciones con la mezcla de 800 μg/m+3NO2 + 800 μg/m+3 SO2. El análisis por XPS ha revelado cambios importantes en la composición de las películas superficiales más externas formadas sobre el cobre, según la naturaleza del contaminante y nivel de humedad. En la exposición al SO2 se ha revelado la formación de sulfatos y sulfitos a todas las humedades ensayadas (50, 70 y 90 % HR. En la exposición al NO2 se han detectado nitratos y nitritos, pero sólo cuando la humedad atmosférica era del

  9. Corrosion processes and coalification of ferrtic-martensitic steels in H{sub 2}O-CO{sub 2} atmospheres; Korrosionsprozesse und Aufkohlung von ferritisch-martensitischen Staehlen in H{sub 2}O-CO{sub 2} Atmosphaeren

    Energy Technology Data Exchange (ETDEWEB)

    Huenert, Daniela

    2010-09-20

    The dissertation desribes the corrosion of steels with chromium concentrations of 1-12 percent in H{sub 2}O-CO{sub 2} atmospheres at variable pressure in the temperature range of 500-650 C and shows the corresponding degree of coalification. The investigations were carried out in a specially constructed corrosion unit which enables simulations of the power plant conditions temperature, pressure, gas composition, and gas flow rate. Above 575 C, the experimentally measured corrosion rates decrease, similar to those in hydrogen. Below 575 C, higher corrosion rates are observed in H{sub 2}O-CO{sub 2} atmospheres than in hydrogen, which is assumed to be the result of chromium fixation by the carbon formed in the corrosion process and of the existence of wuestite below this temperature. Below 600 C, temperature and pressure act independently of each other. Investigations between 600 and 625 C showed that pressure and temperature are not independent parameters with regard to oxide layer growth. The combined effect of these parameters results in higher corrosion rates and coalification depths. The dissertation describes this higher corrosion rate and coalification depth by an enhanced transport model. (orig.) [German] In der vorliegenden Arbeit wurde das Korrosionsverhalten an Stahlqualitaeten mit Chromgehalten zwischen 1 und 12 % in H{sub 2}O-CO-2-Atmosphaeren bei unterschiedlichem Druck im Temperaturbereich von 500 bis 650 C dargestellt und die parallel erfolgende Aufkohlung gezeigt. Fuer die Untersuchungen wurde eine Korrosionsanlage aufgebaut, welche die Simulation der Kraftwerksbedingungen Temperatur, Druck und Gaszusammensetzung und -geschwindigkeit erlaubt. Die experimentell bestimmten Korrosionsraten sind oberhalb von 575 C vergleichbar mit denen in Wasserdampf. Unterhalb von 575 C werden hoehere Korrosionsraten in H2O-CO2- Atmosphaeren beobachtet als in Wasserdampf, was als Folge der Fixierung des Chroms durch den waehrend des Korrosionsprozesses gebildeten

  10. Hot Corrosion Performance of AlO-CrO/NiCoCrAlYTa and AlO/NiCoCrAlYTa Coatings Deposited by Atmospheric Plasma Spraying

    Science.gov (United States)

    Tao, Chong; Wang, Lei; Cheng, Nailiang; Hu, Hengfa; Liu, Yang; Song, Xiu

    2016-04-01

    AlO-CrO/NiCoCrAlYTa and AlO/NiCoCrAlYTa coatings were deposited on 316L stainless steel substrate using atmospheric plasma spraying, respectively, in order to improve the oxidation and corrosion resistance. The hot corrosion performance of the coatings at 700 and 900 °C were studied, and the detailed microstructures and phase composition of the coatings were analyzed using x-ray diffraction, scanning electron microscope with energy dispersive spectrometer, and transmission electron microscope. The results show that both coatings are structurally featured by slatted layers, consisting of amorphous phase, Cr2O3, Ni3Al, and Al2O3. The hot corrosion resistance of AlO-CrO/NiCoCrAlYTa coating is better than that of AlO/NiCoCrAlYTa coating. This improvement is attributed to lower porosity and more compact Cr2O3 in AlO-CrO/NiCoCrAlYTa coating which performs better than Al2O3 in blocking further inward progress of corrosion and oxidization.

  11. Investigations of Local Corrosion Behavior of Plasma-Sprayed FeCr Nanocomposite Coating by SECM

    Science.gov (United States)

    Shi, Xi; Shu, Mingyong; Zhong, Qingdong; Zhang, Junliang; Zhou, Qiongyu; Bui, Quoc Binh

    2016-02-01

    FeCr alloy coating can be sprayed on low-carbon steel to improve the corrosion resistance because of FeCr alloy's high anti-corrosion capacity. In this paper, Fe microparticles/Cr nanoparticles coating (NFC) and FeCr microparticles coating (MFC) were prepared by atmospheric plasma spraying and NFC was heat-treated under hydrogen atmosphere at 800 °C (HNFC). EDS mapping showed no penetration of Ni in MFC and NFC while penetration of Ni occurred in HNFC. X-ray diffraction results indicated the form of the NiCrFe (bcc) solid solution in HNFC. SECM testing in 3.5 (wt.%) NaCl revealed that the anti-corrosion capacity of NFC improved compared with MFC, while HNFC improved further.

  12. Mapping correlations between nitrogen concentrations in atmospheric deposition and mosses for natural landscapes in Europe

    OpenAIRE

    Schroder, Winfried; Pesch, Roland; Schonrock, Simon; Harmens, Harry; Mills, Gina; Fagerli, Hilde

    2014-01-01

    Recent investigations proved that nitrogen (N) concentrations in mosses are primarily determined byatmospheric deposition. The correlations are country- and N compound-specific and agree well withspatial patterns and temporal trends across Europe as a whole and in single European countries. Thisstudy investigates whether correlations between the concentration of N in atmospheric deposition andmosses within the units of an ecological land classification of Europe can be established. To this en...

  13. GILDES model studies of aqueous chemistry. 4: Initial (NH{sub 4}){sub 2}SO{sub 4}-induced atmospheric corrosion of copper

    Energy Technology Data Exchange (ETDEWEB)

    Tidblad, J.; Graedel, T.E. [Lucent Technologies, Murray Hill, NJ (United States). Bell Labs.

    1997-08-01

    The GILDES computer model has been used to simulate the exposure of copper at room temperature to ammonium sulfate particles at 93% relative humidity. The dominant corrosion products formed are cuprite and the basic copper sulfate antlerite. The amount of antlerite depends only on the original amount of ammonium sulfate. The effect of drying has been included in the model for the first time; it influences the amount of cuprite formed, as does the presence of metastable corrosion products. Variations in pH during the calculations can be attributed to specific events corresponding to starting or ending points for the dissolution or precipitation of corrosion products.

  14. Characterization of prerusted steels in some Ibero-American atmospheres by electrochemical potential noise measurement

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, E. [INETI/IMP Lab. de Tintas e Revestimentos, Lisboa (Portugal); Mariaca, L.; Rodriguez, A.; Chavarin, J.U.; Veloz, M.A. [IIE Dept. de Fisicoquimica Aplicada, Cuernavaca (Mexico)

    1996-12-31

    The purpose of the MICAT project (Ibero-American Map of Atmospheric Corrosiveness) was to foster collaborative ventures between groups conducting research on atmospheric corrosion. Overall, 14 Ibero-American countries, including Spain and Portugal, are involved with a network of 71 test stations distributed throughout the region and on 4 continents. These test stations represent a broad spectrum of climatological and atmospheric pollution conditions. The objective of the MICAT electrochemical studies was to characterize the protective properties of the corrosion products formed during atmospheric exposure at the different test sites. Prerusted carbon steel specimens at different locations were immersed in a sodium sulfate solution. Some specimens were rust pretreated in phosphoric acid solution with additions of aluminum hydroxide (rust converters) electrochemically evaluated. Electrochemical noise measurements (ENM) and linear polarization resistance (LPR) measurements were performed for different times of immersion. Corrosion rates were related to the presence of the oxides that were initially formed. For specimens rusted in marine atmospheres, the presence of chlorides in the corrosion products promotes localized attack. As to the different rust-converted specimens, ENM revealed the pretreatment evolution and corrosion performance over time. ENM was able to characterize and evaluate the protective properties of oxides and pretreatments according to the nature and environmental conditions to which specimens were exposed.

  15. Accelerated Test Method for Corrosion Protective Coatings Project

    Science.gov (United States)

    Falker, John; Zeitlin, Nancy; Calle, Luz

    2015-01-01

    This project seeks to develop a new accelerated corrosion test method that predicts the long-term corrosion protection performance of spaceport structure coatings as accurately and reliably as current long-term atmospheric exposure tests. This new accelerated test method will shorten the time needed to evaluate the corrosion protection performance of coatings for NASA's critical ground support structures. Lifetime prediction for spaceport structure coatings has a 5-year qualification cycle using atmospheric exposure. Current accelerated corrosion tests often provide false positives and negatives for coating performance, do not correlate to atmospheric corrosion exposure results, and do not correlate with atmospheric exposure timescales for lifetime prediction.

  16. Atmospheric Propagation Modeling Indicates Homing Pigeons use Loft-Specific Infrasonic 'Map' Cues

    Science.gov (United States)

    Hagstrum, J. T.; Baker, L. M.; Spritzer, J. M.; McKenna, M. H.

    2011-12-01

    Pigeons (Columba livia) released at distant sites commonly depart in directions significantly off the actual homeward bearing. Such site-dependent deviations, or biases, for birds from a given loft are generally stable over time, but can also change from hour to hour, day to day, and year to year. At some release sites, birds consistently vanish in random directions and have longer flight times and lower return rates. Release sites characterized by frequent disorientation are not uncommon for pigeon lofts in both Europe and the USA. One such site is the Jersey Hill fire tower in upstate New York located ~120 km W of the Cornell loft in Ithaca. Cornell birds released at Jersey Hill between 1968 and 1987 almost always vanished randomly, although birds from other lofts had little difficulty orienting there. The results for one day, however, stand out: on August 13, 1969, Cornell birds released at Jersey Hill vanished consistently to the NE (r = 0.921; n=7) and returned home after normal flight times. Cornell pigeons released the next day again showed 'normal' behavior for the site and departed randomly. If, in fact, the birds are using acoustic cues to navigate, the long-term acoustic 'dead' zone we propose for Jersey Hill, due to prevailing atmospheric conditions, indicates that the cues are coming from a single, relatively restricted area, most likely surrounding the home loft. We have modeled the transmission of infrasonic waves, presumably coupled to the atmosphere from ocean-generated microseisms (0.14 Hz), between the Cornell loft and a number of release sites using HARPA (Hamiltonian Acoustic Ray-tracing Program for the Atmosphere) and rawinsonde data collected near Albany and Buffalo, NY. The HARPA modeling shows that acoustic signals from the Cornell loft reached Jersey Hill only on a few release days with unusual atmospheric conditions, including August 13, and were launched at angles less than ~2° above horizontal, most likely from steep-sided terrain in

  17. Electrochemical properties of corrosion products formed on Zn-Mg, Zn-Al and Zn-Al-Mg coatings in model atmospheric conditions

    Czech Academy of Sciences Publication Activity Database

    Stoulil, J.; Prošek, T.; Nazarov, A.; Oswald, Jiří; Kříž, P.; Thierry, D.

    2015-01-01

    Roč. 66, č. 8 (2015), s. 777-782. ISSN 0947-5117 Institutional support: RVO:68378271 Keywords : corrosion products * electrochemical properties * zinc coating Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.373, year: 2014

  18. Atmospheric Rawinsonde and Pigeon Release Data Implicate Infrasound as the Long- Range Map Cue in Avian Navigation

    Science.gov (United States)

    Hagstrum, J. T.

    2007-12-01

    Pigeons ( Columba livia) and other birds released from distant familiar and unfamiliar sites generally head in the homeward (loft) direction, but often vanish from view or radio contact consistently off the exact homeward bearing. At some sites the deviation can be a significant and stable amount, while at other sites birds can appear to become completely lost and depart in random directions. These deviations or biases can change from hour to hour, day to day, and year to year, but have not, over the last ~50 years of intensive research, been related to any atmospheric factor. They are, however, still considered to reflect significant irregularities in the pigeons' "map" function. Celestial and geomagnetic "compasses" have been shown to orient avian flight, but how pigeons determine their location in order to select the correct homeward bearing remains controversial. At present the debate is primarily between workers advocating an olfactory "map" and those advocating variations in the direction and intensity of the geomagnetic field as map functions. Alternatively, infrasonic cues can travel 1000s of km in the atmosphere with little attenuation, and can be detected in the laboratory by pigeons at frequencies down to 0.05 Hz. Although infrasound has been considered as a navigational tool for homing and migratory birds, little supporting evidence of its use has been found. Infrasonic ray paths in the atmosphere are controlled primarily by temperature and secondarily by wind. Assuming birds use infrasonic cues, atmospheric conditions could cause the perplexing changes (both geographic and temporal) observed in the mean vanishing bearings (MVBs) of pigeons released from experimental sites. To test for correlations between MVBs and tropospheric conditions, release data collected by the late W.T. Keeton between 1968 and 1980 from around the Cornell University lofts in upstate NY are compared to rawinsonde data from stations near Buffalo and Albany. For example, birds

  19. IIP Tropospheric Infrared Mapping Spectrometers (TIMS) measurements for widely varying terrain and atmospheric paths, example retrievals of albedos and atmospheric constituents

    Science.gov (United States)

    Rairden, R. L.; Kumer, J.; Roche, A.; Mergenthaler, J.; Chatfield, B.

    2008-12-01

    The NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) Tropospheric Infrared Mapping Spectrometers (TIMS) have been developed to demonstrate measurement capability, when deployed in space, for multi-layer retrieval of CO from spectral measurements acquired in the solar reflective (SR) region ~ 4281 to 4301 cm-1 and in the thermal InfraRed (TIR) region ~ 2110 to 2165 cm 1. Measurements in the SR of widely varying terrain types were obtained in a single data frame. The slit was projected in a vertical orientation from a balcony on the Denver University building to a scene that included the foreground at slit bottom, then on going further up the slit to a near foothill range, and finally on top side of the slit to a distant snow capped mountain range. The scene provided albedo data for various surface types including green vegetation, a bright barren spot on the foothill, and the snow cap. It also provides varying path lengths through the atmosphere, e.g., 20 km to the foothill, and 100 km to the snow cap. We'll present examples of albedo retrieved for these various features, and for gasses retrieved along the various path lengths.

  20. Mapping land water and energy balance relations through conditional sampling of remote sensing estimates of atmospheric forcing and surface states

    Science.gov (United States)

    Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido

    2016-04-01

    In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links atmospheric forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on conditional averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.

  1. Biomonitoring of atmospheric pollution (with emphasis on trace elements) - BioMap II. Proceedings of an international workshop

    International Nuclear Information System (INIS)

    Certain types of organisms integrate pollution over time, reducing the need for continuous chemical monitoring, thus avoiding the difficulty of interpreting 'snapshot' measurements and offering the potential of retrospective monitoring. Such organisms enrich the substance to be determined so that the analytical accessibility is improved and the measurement uncertainty reduced. By observing and measuring the changes in an appropriately selected organism, a conclusion as to the kind of pollution, its source, and its intensity can be drawn. The IAEA is making concerted efforts to promote the practical use of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact on human health, and one of the main emphasis is on studying air contaminants. The IAEA has been systematically supporting biomonitoring atmospheric pollution for 10 years in the framework of its project on Environmental Pollution Monitoring and Research Using Nuclear and Related Analytical Techniques. The objective of this project is to identify the source and evaluate the fate of key non-radioactive environmental contaminants and provide the basis for improved health for human populations. The project has been implemented through a Coordinated Research Project on Validation and Application of Plants as Biomonitors of Trace Element Atmospheric Pollution Analysed by Nuclear and Related Techniques, several technical co-operation projects, and some dedicated analytical quality control activities. Within the scope of these efforts, the Second International Workshop on Biomonitoring of Atmospheric Pollution (with Emphasis on Trace Elements) - BioMAP, was organized as a follow-up to the 1997 BioMAP workshop held in Lisbon, Portugal. The proceedings of the first workshop were published in IAEA-TECDOC-1152. The second workshop was held in Praia da Vitoria, Azores Islands, Portugal, from 28 August to 3 September 2000. It was organized in co-operation with the

  2. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    Directory of Open Access Journals (Sweden)

    Renato Altobelli Antunes

    2014-01-01

    Full Text Available The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron microscopy. The main product found was lepidocrocite. Goethite and magnetite were also found on the corroded specimens but in lower concentrations. The results showed that the accelerated test based on the ASTM B117 procedure presented poor correlation with the atmospheric corrosion tests whereas an alternated fog/dry cycle combined with UV radiation exposure provided better correlation.

  3. Corrosion mapping in ducts using the automated ultrasonic technique C-Scan - correlation with results given by pig inspection; Mapeamento de corrosao em dutos atraves da tecnica ultrassonica C-Scan

    Energy Technology Data Exchange (ETDEWEB)

    Feres Filho, Pedro; Moura, Nestor Carlos de [Physical Acoustics South America (PASA), Sao Paulo, SP (Brazil)

    2005-07-01

    In-service inspection has received diverse contributions from technologies and documents with the objective of maximizing equipment availability and minimizing inadequate repairs. Amongst the available technologies, there are the automated ultrasound tests, in the B and C-scan versions. This paper describes an evaluation methodology based on the correlation between the test techniques of instrumented electromagnetic PIG and automated ultrasound, both applied with the purpose of detecting and mapping areas with corrosion in pipes for oil transport. The main objective of the application of the C-scan methodology, in this case, was the measuring and detailing of the corroded area, thus providing an adequate maintenance plan through the substitution or installation of a double gutter. The result demonstrates the correlation between the measurements taken by the PIG and the sizing of the regions done using the C-scan method, consisting of the length, width and thickness values in the points affected by the corrosion. (author)

  4. Corrosion protection

    International Nuclear Information System (INIS)

    This invention describes a corrosion protection device for long-term storage containers of radioactive matter, in particular of irradiated fuel elements stored in geological formations apt for the purpose. This device prevents corrosion of the containers even if water emerges unexpectedly, or, in any case, inhibits and minimizes corrosion. The device comprehends reactive anodes that are connected to the containers by means of conductive connections. (orig.)

  5. The effect of environmental and meteorological variables on atmospheric corrosion of carbon steel, copper, zinc and aluminium in a limited geographic zone with different types of environment

    International Nuclear Information System (INIS)

    Carbon steel, copper, zinc and aluminium test pieces were exposed to a large variety of environmental conditions in a reduced geographic area close to the coastline in order to ascertain the degree of deterioration of the same due to environmental corrosion. Calculations of corrosion rates were made via loss of weight (in the case of carbon steel, zinc and copper) and analysis of surface deterioration (in the case of aluminium) together with X-ray diffraction analyses. The levels of chlorides, SO2 and time of wetness were also registered in order to be able to correlate the data with respect to corrosion rate with the environmental and meteorological parameters, using the potential law and a modified version of the same

  6. Corrosion '98: 53. annual conference and exposition, proceedings

    International Nuclear Information System (INIS)

    This conference was divided into the following sections: Corrosion in Gas Treating; Problems and Solutions in Commercial Building Water Systems; Green Corrosion/Scale Inhibitors; Atmospheric Corrosion; AIRPOL Update/98; Rubber Lining--Answers to Many Problems; Interference Problems; Environmental Assisted Cracking: Fundamental Research and Industrial Applications; Corrosion in Nuclear Systems; New Developments in Scale and Deposit Control; Corrosion and Corrosion Protection in the Transportation Industries; What's All the Noise About--Electrochemical That Is; Refining Industry Corrosion; Corrosion Problems in Military Hardware: Case Histories, Fixes and Lessons Learned; Cathodic Protection Test Methods and Instrumentation for Underground and On-grade Pipelines and Tanks; Recent Developments in Volatile Corrosion Inhibitors; Corrosion in Supercritical Fluids; Microbiologically Influenced Corrosion; Advances in Understanding and Controlling CO2 Corrosion; Managing Corrosion with Plastics; Material Developments for Use in Exploration and Production Environments; Corrosion in Cold Regions; The Effect of Downsizing and Outsourcing on Cooling System Monitoring and Control Practices; New Developments in Mechanical and Chemical Industrial Cleaning; Mineral Scale Deposit Control in Oilfield Related Operations; Biocides in Cooling Water; Corrosion and Corrosion Control of Reinforced Concrete Structures; Materials Performance for Fossil Energy Conversion Systems; Marine corrosion; Thermal Spray--Coating and Corrosion Control; Flow Effects on Corrosion in Oil and Gas Production; Corrosion Measurement Technologies; Internal Pipeline Monitoring--Corrosion Monitoring, Intelligent Pigging and Leak Detection; Cathodic Protection in Natural Waters; Corrosion in Radioactive Liquid Waste Systems; On-line Hydrogen Permeation Monitoring Equipment and Techniques, State of the Art; Water Reuse and Recovery; Performance of Materials in High Temperature Environments; Advances in Motor

  7. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  8. Novel methods for aircraft corrosion monitoring

    Science.gov (United States)

    Bossi, Richard H.; Criswell, Thomas L.; Ikegami, Roy; Nelson, James; Normand, Eugene; Rutherford, Paul S.; Shrader, John E.

    1995-07-01

    Monitoring aging aircraft for hidden corrosion is a significant problem for both military and civilian aircraft. Under a Wright Laboratory sponsored program, Boeing Defense & Space Group is investigating three novel methods for detecting and monitoring hidden corrosion: (1) atmospheric neutron radiography, (2) 14 MeV neutron activation analysis and (3) fiber optic corrosion sensors. Atmospheric neutron radiography utilizes the presence of neutrons in the upper atmosphere as a source for interrogation of the aircraft structure. Passive track-etch neutron detectors, which have been previously placed on the aircraft, are evaluated during maintenance checks to assess the presence of corrosion. Neutrons generated by an accelerator are used via activation analysis to assess the presence of distinctive elements in corrosion products, particularly oxygen. By using fast (14 MeV) neutrons for the activation, portable, high intensity sources can be employed for field testing of aircraft. The third novel method uses fiber optics as part of a smart structure technology for corrosion detection and monitoring. Fiber optic corrosion sensors are placed in the aircraft at locations known to be susceptible to corrosion. Periodic monitoring of the sensors is used to alert maintenance personnel to the presence and degree of corrosion at specific locations on the aircraft. During the atmospheric neutron experimentation, we identified a fourth method referred to as secondary emission radiography (SER). This paper discusses the development of these methods.

  9. Corrosion inhibitors

    International Nuclear Information System (INIS)

    In this paper, we briefly describe the characteristics, cost and electrochemical nature of the corrosion phenomena as well as some of the technologies that are currently employed to minimize its effect. The main subject of the paper however, deals with the description, classification and mechanism of protection of the so-called corrosion inhibitors. Examples of the use of these substances in different aggressive environments are also presented as means to show that these compounds, or their combination, can in fact be used as excellent and relatively cheap technologies to control the corrosion of some metals. In the last part of the paper, the most commonly used techniques to evaluate the efficiency and performance of corrosion inhibitors are presented as well as some criteria to make a careful and proper selection of a corrosion inhibitor technology in a given situation. (Author) 151 refs

  10. NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

    Science.gov (United States)

    Calle, Luz Marina

    2015-01-01

    The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in North America. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the highly corrosive hydrochloric acid (HCl) generated by the solid rocket boosters (SRBs). Numerous failures at the launch pads are caused by corrosion. The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. NASA has over fifty years of experience dealing with unexpected failures caused by corrosion and has developed expertise in corrosion control in the launch and other environments. The Corrosion Technology Laboratory at KSC evolved, from what started as an atmospheric exposure test site near NASAs launch pads, into a capability that provides technical innovations and engineering services in all areas of corrosion for NASA, external partners, and customers.This paper provides a chronological overview of NASAs role in anticipating, managing, and preventing corrosion in highly corrosive environments. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

  11. Quartz Crystal Microbalance and Its Applications in Atmospheric Corrosion Studies%石英晶体微天平(QCM)及其在大气腐蚀研究中的应用

    Institute of Scientific and Technical Information of China (English)

    王凤平; 严川伟; 张学元; 杜元龙

    2001-01-01

    Based on the fundamental principle of quartz crystal microbalance, this paper reviews the important applications of QCM in atmospheric corrosion study on the basis of literature investigations and author′s results of studying atmospheric corrosion. It also points out the advantages and limitations of QCM. At the same time,the way of solving these existing problems are given.%从石英晶体微天平的基本原理出发,结合作者的文献调查及近期利用石英晶体微天平对大气腐蚀的研究结果,综述了石英晶体微天平在金属大气腐蚀研究中的重要作用,指出石英晶体微天平在金属大气腐蚀研究中的优点、存在的问题和相应的解决办法。

  12. NANOCOMPOSITE COATING FOR IMPROVED CORROSION RESISTANCE.

    OpenAIRE

    Ramana, M. V.; MADUNURI CHANDRA SEKHAR

    2012-01-01

    Zn-Mg–ZnO nanocomposite electrodeposits have better corrosion resistance to sodium chloride in the atmospheric environment and better than that of other zinc alloys of equal thickness and therefore, provide a better alternative for corrosion protection. Nano zinc coatings are deposited on mild steel by electro deposition.Besides corrosion protection and decoration, nanocoatings sometimes impart to the surface, specific mechanical and physical properties such as wear resistance, hardness, elec...

  13. An Evaluation of the Practicability of Current Mapping Functions using Ray-traced Atmosphere Slant Delays from JMA Mesoscale Numerical Weather Data

    Science.gov (United States)

    Ichikawa, R.; Hobiger, T.; Koyama, Y.; Kondo, T.

    2008-12-01

    The Japan Meteorological Agency (JMA) meso-scale analysis data (MANAL data) which we used in our study provides temperature, humidity, and pressure values at the surface and at 21 height levels (which vary between several tens of meters and about 31 km), for each node in a 10km by 10 km grid that covers Japan islands, the surrounding ocean and eastern Eurasia. The 3-hourly operational products are available by JMA since March, 2006. We have simultaneously evaluated atmospheric parameters (equivalent zenith total delay and linear horizontal delay gradients) and position errors derived from slant path delays obtained by the KAshima RAytracing Tools (KARAT) through the MANAL data. Most of the early mapping functions developed for VLBI and GPS were based on the assumption of azimuthal isotropy. On the other hand, the recent geodetic analyses are carried out by applying the modern mapping functions based on the numerical weather analysis fields. The Global Mapping Function (GMF) by Boehm et al. (2006), and Vienna Mapping Function (VMF) by Boehm and Schuh (2004) have been successfully applied to remove the zenith hydrostatic delay in the recent years. In addition, the lateral spatial variation of wet delay is reduced by linear gradient estimation. Comparisons between KARAT-based slant delay and empirical mapping functions indicate large biases ranging from 18 to 90 mm, which is considered to be caused by significant variability of water vapor. Position error simulation reveal that the highly variability of the errors is clearly associated with severe atmospheric phenomena. Such simulation are very useful to investigate the characteristics of positioning errors generated by local atmospheric disturbances. Finally, we compared PPP processed position solutions using KARAT with those using the latest mapping functions covering a period of two week GEONET data. The KARAT solution is almost identical to the solution using GMF with linear gradient model, but some cases tends to

  14. High-Temperature Corrosion Behavior of Different Regions of Weldment of 2.25Cr-1Mo Steel in SO2 + O2 Atmosphere

    Science.gov (United States)

    Ghosh, D.; Shukla, A. K.; Mitra, S. K.; Satpati, B.

    2016-02-01

    This paper investigates the corrosion behavior of different regions of weldment of 2.25Cr-1Mo steel exposed in mixed oxidation and sulfidation (SO2 + O2) environment up to 500 h at 773 K. Microstructural investigation and characterization of oxide scales are done using SEM, TEM, and XRD. The obtained results infer that heat-affected zone corrodes faster than both base and weld metal. The reaction kinetics follows a parabolic growth rate for all regions. The higher corrosion rate of heat-affected zone is attributed to the formation of Cr23C6 secondary precipitates leading to depletion of protective inner scale of the Cr-rich oxide during welding.

  15. Internal corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Joosten, M. [ConocoPhillips, Bartlesville, OK (United States); Anderson, W. [Spectra Energy Transmission, Vancouver, BC (Canada)

    2007-07-01

    Working Group 11 identified internal corrosion issues in both upstream and downstream oil and gas pipelines and suggested ways to address them through integrity management, modeling, and monitoring. Three sessions were held in an effort to provided a better understanding between integrity professionals engaged in different aspects of pipeline management. Opportunities for reducing cost or improving integrity performance of the whole system were also identified. It was determined that management support is needed in order to monitor and mitigate internal corrosion of pipelines. The role of regulations in ensuring pipeline integrity was also discussed along with rules for pigging and batching of inhibitors. In-line inspections have identified under-deposit corrosion and solids/water deposition as two key problems facing pipeline operators. It was noted that an internal corrosion course offered by the National Association of Corrosion Engineers (NACE) is being well attended and is providing worthwhile training. Other issues discussed by this working group were: bacteria with upstream problems; effects of carbon dioxide, hydrogen sulphide and partial pressures on corrosion; and, procedures and guidelines to maintain clean pipelines. tabs., figs.

  16. Concrete Infrastructure Corrosion

    International Nuclear Information System (INIS)

    It is well known that many reinforced concrete structures are at risk of deterioration due to chloride ion contamination of the concrete or atmospheric carbon dioxide dissolving in water to form carbonic acid, which reacts with the concrete and the reinforcing steel. The environment within the concrete will determine the corrosion product layers, which might, inter alia, contain the oxides and/or hydroxides of iron. Tensile forces resulting from volume changes during their formation lead to the cracking and delamination of the concrete. In the present investigation the handrail of an outside staircase suffered rebar corrosion during 30 year's service, leading to severe delamination damage to the concrete structure. The railings had been sealed into the concrete staircase using a polysulphide sealant, Thiokol. The corrosion products were identified by means of Moessbauer and SEM analyses, which indicated that the corrosion product composition varied from the original steel surface to the outer layers, the former being mainly iron oxides and the latter iron oxyhydroxide.

  17. Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map

    International Nuclear Information System (INIS)

    Incoming shortwave solar radiation is an important parameter in environmental applications. A detailed spatial and temporal analysis of global solar radiation on the earth surface is needed in many applications, ranging from solar energy uses to the study of agricultural, forest and biological processes. At local scales, the topography is the most important factor in the distribution of solar radiation on the surface. The variability of the elevation, the surface orientation and the obstructions due to elevations are a source of great local differences in insolation and, consequently, in other variables as ground temperature. For this reason, several models based on GIS techniques have been recently developed, integrating topography to obtain the solar radiation on the surface. In this work, global radiation is analyzed with the Solar Analyst, a model implemented on ArcView, that computes the topographic parameters: altitude, latitude, slope and orientation (azimuth) and shadow effects. Solar Analyst uses as input parameters the diffuse fraction and the transmittance. These parameters are not usually available in radiometric networks in mountainous areas. In this work, a method to obtain both parameters from global radiation is proposed. Global radiation data obtained in two networks of radiometric stations is used: one located in Sierra Magina Natural Park (Spain) with 11 stations and another one located on the surroundings of Sierra Nevada Natural Park (Spain) with 14 stations. Daily solar irradiation is calculated from a digital terrain model (DTM), the daily diffuse fraction, K, and daily atmospheric transmittivity, τ. Results provided by the model have been compared with measured values. An overestimation for high elevations is observed, whereas low altitudes present underestimation. The best performance was also reported during summer months, and the worst results were obtained during winter. Finally, a yearly global solar irradiation map has been produced

  18. Prediction of metal corrosion by neural networks

    Directory of Open Access Journals (Sweden)

    Z. Jančíková

    2013-07-01

    Full Text Available The contribution deals with the use of artificial neural networks for prediction of steel atmospheric corrosion. Atmospheric corrosion of metal materials exposed under atmospheric conditions depends on various factors such as local temperature, relative humidity, amount of precipitation, pH of rainfall, concentration of main pollutants and exposition time. As these factors are very complex, exact relation for mathematical description of atmospheric corrosion of various metals are not known so far. Classical analytical and mathematical functions are of limited use to describe this type of strongly non-linear system depending on various meteorological-chemical factors and interaction between them and on material parameters. Nowadays there is certain chance to predict a corrosion loss of materials by artificial neural networks. Neural networks are used primarily in real systems, which are characterized by high nonlinearity, considerable complexity and great difficulty of their formal mathematical description.

  19. Minimizing corrosion in coal liquid distillation

    Science.gov (United States)

    Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.

    1985-01-01

    In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.

  20. Atmospheric Corrosion Performance of WGJ510C2 Steel%耐火耐候钢WGJ510C2的大气腐蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    刘建容; 张万灵; 蔡捷; 石争鸣

    2011-01-01

    Five years atmospheric corrosion data collected from three exposure sites at Qingdao, Jiangjin and Qionghai of WISCO made WGJ510C2 steel were analyzed. The results indicate the corrosion resistance of WGJ510C2 is better than Q345 and the relative corrosion resistance for the two steels is 150%, 116% and 146% at Qingdao, Jiangjin and Qionghai respectively. The polarization curves of 5 year exposed rusty steel show that both the initial passivation current and the maintaining passivation current of WGJ510C2 are smaller than that of Q345, which indicates the better protective performance of WGJ510C2 may be due to its more compact rust layer.%分析了武钢生产的WGJ510C2钢在青岛、琼海和江津3个大气暴露试验点,暴露5a的腐蚀数据.结果表明,WGJ510C2钢的耐蚀性均优于Q345钢,两者的相对耐蚀性在青岛站是150%,住江津站是116%、在琼海站是146%.大气暴露5a带锈样的极化曲线测试结果表明,WGJ510C2钢的致钝电流、维钝电流均比对比钢Q345小,说明其锈层致密,防护性能好.

  1. Middle atmosphere program. Handbook for MAP, volume 29. Part 1: Extended abstracts, International symposium on solar activity forcing of the middle atmosphere. Part 2: MASH workshop

    International Nuclear Information System (INIS)

    The proceedings of the symposium is presented. Eight different sessions were presented: (1) Papers generally related to the subject; (2) Papers on the influence of the Quasi Biennial Oscillation; (3) Papers on the influence of the solar electromagnetic radiation variability; (4) Papers on the solar wind and high energy particle influence; (5) Papers on atmospheric circulation; (6) Papers on atmospheric electricity; (7) Papers on lower ionospheric variability; and (8) Solar posters, which are not included in this compilation

  2. CORROSION IN AIRFRAMES

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  3. Corrosion amalgams

    International Nuclear Information System (INIS)

    The release of copper, mercury, silver, tin or zinc from conventional, dispersed phase and spherical high copper content amalgams immersed in artificial saliva solutions for periods up to 30 d has been measured using nuclear tracer techniques. During initial corrosion, i.e. within a few hours, substantial amounts of mercury were found to be present in particulate matter in the three types of amalgams. The release of particulate matter was pronounced for the dispersed phase type of amalgam. After about 30 d electrochemical corrosion was found to be the predominant process for release of various corrosion products. Zinc was demonstrated to be the major corrosion product released to the artificial saliva solutions from conventional as well as dispersed phase amalgams. Due to low radioactivity levels silver and tin could not be quantitatively asayed. However, the upper limits of release of silver and tin in the artificial saliva solutions referring to exposure periods up to 30 d were estimated to 0.1 μg and 25 μg respectively. The chemical state of the various corrosion products has been evaluated. The deposition of CuCl2 . 3 Cu(OH)2 on the surfaces of copper rich amalgams was observed according to X-ray diffraction analysis. (author)

  4. Aeolus: A Markov--Chain Monte Carlo code for mapping ultracool atmospheres. An application on Jupiter and brown dwarf HST light curves

    CERN Document Server

    Karalidi, Theodora; Schneider, Glenn; Hanson, Jake R; Pasachoff, Jay M

    2015-01-01

    Deducing the cloud cover and its temporal evolution from the observed planetary spectra and phase curves can give us major insight into the atmospheric dynamics. In this paper, we present Aeolus, a Markov-Chain Monte Carlo code that maps the structure of brown dwarf and other ultracool atmospheres. We validated Aeolus on a set of unique Jupiter Hubble Space Telescope (HST) light curves. Aeolus accurately retrieves the properties of the major features of the jovian atmosphere such as the Great Red Spot and a major 5um hot spot. Aeolus is the first mapping code validated on actual observations of a giant planet over a full rotational period. For this study, we applied Aeolus to J and H-bands HST light curves of 2MASSJ21392676+0220226 and 2MASSJ0136565+093347. Aeolus retrieves three spots at the top-of-the-atmosphere (per observational wavelength) of these two brown dwarfs, with a surface coverage of 21+-3% and 20.3+-1.5% respectively. The Jupiter HST light curves will be publicly available via ADS/VIZIR.

  5. Differential Pressure Transducer for Corrosion Monitoring of Iron

    OpenAIRE

    Amar Prasad Yadav

    2014-01-01

    In this study, differential pressure transducer (DPT) has been applied as an alternate corrosion monitoring device for monitoring corrosion of iron in atmospheric environment by measuring very small changes in the amount of oxygen. The result of corrosion current obtained from DPT method has been compared with that obtained from AC impedance method. The difference in the value of corrosion current obtained from these two methods was attributed to the error in choosing the value of proportiona...

  6. 轧制工艺对耐大气腐蚀钢综合性能的影响%Effect of rolling process on comprehensive properties of atmospheric corrosion resistant steel

    Institute of Scientific and Technical Information of China (English)

    宋凤明; 杜林秀; 温东辉

    2012-01-01

    分析了轧制工艺参数对耐大气腐蚀钢综合性能的影响。结果表明,终轧温度、卷取温度和轧后冷速均对钢板力学性能有影响,卷取温度对钢板强度的影响高于终轧温度,钢板强度随卷取前冷却速度的提高而增加,冷速超过12℃/s后不再进一步提高。耐大气腐蚀性主要与成分有关。试验成品钢板强度高,屈强比低,具有良好的低温冲击韧性和冷弯加工性能及优良的耐大气腐蚀性。%Effect of rolling process parameters on mechanical properties of weathering steel were analyzed. The results show that the mechanic properties are effected by finish-rolling temperature, coiling temperature and post-rolled cooling rate. The influence of coiling temperature on strength is higher than that of finish-rolling, the steel strength increases with the increase of cooling rate until 12 ℃/s. While the atmospheric corrosion resistance is mainly depend on the chemical compositon. The product of weathering steel exhibits high strength and low yield ratio, and has fine low temperature impact roughness, good cold bending properties and excellent atmospheric corrosion resistance.

  7. Effect of Rare Earth Elements on Marine Atmospheric Corrosion Behavior of Ultrahigh-strength Steel%稀土对超高强度钢耐海洋大气腐蚀性能的影响

    Institute of Scientific and Technical Information of China (English)

    李涛; 刘毅; 郑传奇

    2016-01-01

    目的:提高超高强度钢耐海洋大气腐蚀的性能。方法采用周期浸润腐蚀试验箱模拟一般条件下海洋大气腐蚀试验,通过金相显微镜和扫描电子显微镜观察低合金超高强度钢的组织和夹杂物的形貌,采用失重法和电化学阻抗技术分析腐蚀动力学规律及电化学行为规律。结果稀土在低合金超高强度钢中具有细化组织和变质夹杂物的作用,稀土增强了锈层的致密性,使得低合金超高强度钢的耐蚀性能显著提高,且随着稀土含量的增加,锈层电阻值逐渐增大,即稀土提高了锈层对基体的保护能力。结论在低合金超高强度钢中添加稀土能够细化组织、变质夹杂物。稀土低合金超高强度钢的夹杂物主要为球形稀土复合氧硫化物。稀土质量分数为0.08%的低合金超高强度钢的耐腐蚀性能最好。%ABSTRACT:Objective To improve the resistance of ultrahigh-strength steel to marine atmospheric corrosion. Methods The mi-crostructure and inclusion morphology of low-alloying ultrahigh-strength steel were observed by means of optical microscope and scanning electron microscope using periodic infiltration corrosion test box to simulate marine atmospheric corrosion tests under gen-eral conditions. Results The rare earth elements in the low-alloying ultrahigh-strength steel had the effects of refining microstructure and modifying inclusion. Rare earth enhanced the compactness of the rust layer, which remarkably improved the corrosion resist-ance of low-alloying ultrahigh-strength steel. Moreover, the resistance of the rust layer gradually increased with increasing rare earth content, which meant rare earth improved the protective capability of the rust layer for the substrate. Conclusion Adding rare earth elements in low-alloying ultrahigh-strength steel could refine the microstructure and modify inclusion. The inclusion of rare earth low-alloying ultrahigh-strength steel was

  8. Atmospheric correction in time-series SAR interferometry for land surface deformation mapping - A case study of Taiyuan, China

    Science.gov (United States)

    Tang, Wei; Liao, Mingsheng; Yuan, Peng

    2016-08-01

    The dominant error source of Synthetic Aperture Radar Interferometry (InSAR) is atmospheric phase screen (APS), resulting in phase delay of the radar signal propagating through the atmosphere. The APS in the atmosphere can be decomposed into stratified and turbulent components. In this paper, we introduced a method to compensate for stratified component in a radar interferogram using ERA-Interim reanalysis products obtained from European Centre for Medium-Range Weather Forecasts (ECMWF). Our comparative results with radiosonde data demonstrated that atmospheric condition from ERA-Interim could produce reasonable patterns of vertical profiles of atmospheric states. The stratified atmosphere shows seasonal changes which are correlated with time. It cannot be properly estimated by temporal high-pass filtering which assumes that atmospheric effects are random in time in conventional persistent scatterer InSAR (PSI). Thus, the estimated deformation velocity fields are biased. Therefore, we propose the atmosphere-corrected PSI method that the stratified delay are corrected on each interferogram by using ERA-Interim. The atmospheric residuals after correction of stratified delay were interpreted as random variations in space and time which are mitigated by using spatial-temporal filtering. We applied the proposed method to ENVISAT ASAR images covering Taiyuan basin, China, to study the ground deformation associated with groundwater withdrawal. Experimental results show that the proposed method significantly mitigate the topography-correlated APS and the estimated ground displacements agree more closely with GPS measurements than the conventional PSI.

  9. Middle Atmosphere Program. Handbook for MAP. Volume 14: URSI/SCOSTEP Workshop on Technical Aspects of MST Radar

    Science.gov (United States)

    Bowhill, S. A. (Editor); Edwards, B. (Editor)

    1984-01-01

    Various topics relative to middle atmosphere research were discussed. meteorological and aeronomical requirements for mesosphere-stratosphere-troposphere (MST) radar networks, general circulation of the middle atmosphere, the interpretation of radar returns from clear air, spaced antenna and Doppler techniques for velocity measurement, and techniques for the study of gravity waves and turbulence are among the topics discussed.

  10. Hanford transuranic storage corrosion review

    International Nuclear Information System (INIS)

    The rate of atmospheric corrosion of the transuranic (TRU) waste drums at the US Department of Energy's Hanford Project, near Richland, Washington, was evaluated by Pacific Northwest Laboratory (PNL). The rate of corrosion is principally contingent upon the effects of humidity, airborne pollutants, and temperature. Results of the study indicate that actual penetration of barrels due to atmospheric corrosion will probably not occur within the 20-year specified recovery period. Several other US burial sites were surveyed, and it appears that there is sufficient uncertainty in the available data to prevent a clearcut statement of the corrosion rate at a specific site. Laboratory and site tests are recommended before any definite conclusions can be made. The corrosion potential at the Hanford TRU waste site could be reduced by a combination of changes in drum materials (for example, using galvanized barrels instead of the currently used mild steel barrels), environmental exposure conditions (for example, covering the barrels in one of numerous possible ways), and storage conditions

  11. Detrimental effect of Air pollution, Corrosion on Building Materials and Historical Structures

    Directory of Open Access Journals (Sweden)

    N. Venkat Rao

    2016-08-01

    Full Text Available The economy of any country would be drastically changed if there were no corrosion. The annual cost of corrosion world wise is over 3 % of the worlds GDP. As pet the sources available, India losses $ 45 billion every year on account of corrosion of infrastructure, Industrial machinery and other historical heritage. Keeping this critical and alarming situation in view, this paper focuses on how all these forms of corrosion affect building materials and historical structures. It also tries to bring awareness among the stakeholders of the environment and national heritage. The process of corrosion may be initiated in the form of chemical corrosion and electrochemical corrosion. The chemical may be witnessed in the form of direct oxidation, corrosion by liquid metals, fused halides and non aqueous solutions. Electrochemical corrosion may be seen in the form of immersion corrosion, underground corrosion and atmospheric corrosion.

  12. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  13. Corrosion of melter materials

    International Nuclear Information System (INIS)

    A program was developed to characterize the effects of five variables on the corrosion rate of electrode and refractory materials: temperature, atmosphere inside the melter, composition of the glass, velocity, and electrochemical potential. As a data base for comparison in future tests, the corrosion rate was determined for Monofrax K - 3 (1.2 mils/day) and Inconel 690 (0.7 mils/day) in waste glass of the simulated reference SRP composition at 11500C in air. These tests were carried out as specified in ASTM C-621-68 (American Society for Testing materials) with a slight modification. After the specimens had been heated they were sectioned. The specimens were measured at the melt line cut and at the half down cut (halfway between the melt line cut and the bottom of the specimen). At least two reaction mechanisms occurred between the specimen and the molten glass: (1) Loss of Material reaction mechanisms resulted in a change in the dimensions of the specimen; and (2) Selective Penetration reaction mechanisms caused no change in the dimension of the specimens. The total amount of penetration was defined as the sum of attack by the two reactions. The corrosion rate increased with temperature and was proportional to the exponent 1/T

  14. Effect of the nanocrystallization of amorphous soft magnetic Fe-P-Nb alloys on corrosion resistance in a damp SO2-polluted atmosphere

    Science.gov (United States)

    Vavilova, V. V.; Zabolotnyi, V. T.; Korneev, V. P.; Anosova, M. O.; Baldokhin, Yu. V.

    2014-09-01

    The effect of the nanocrystallization of amorphous soft magnetic Fe-P-Nb alloys on their electrochemical behavior in a damp SO2-polluted industrial atmosphere is studied. It is shown that their electro-chemical characteristics shit toward positive values when the phosphorus content in the Fe-P-Nb alloys increases and when they undergo nanocrystallization from an amorphous state.

  15. Fouling corrosion in aluminum heat exchangers

    Directory of Open Access Journals (Sweden)

    Su Jingxin

    2015-06-01

    Full Text Available Fouling deposits on aluminum heat exchanger reduce the heat transfer efficiency and cause corrosion to the apparatus. This study focuses on the corrosive behavior of aluminum coupons covered with a layer of artificial fouling in a humid atmosphere by their weight loss, Tafel plots, electrochemical impedance spectroscopy (EIS, and scanning electron microscope (SEM observations. The results reveal that chloride is one of the major elements found in the fouling which damages the passive film and initiates corrosion. The galvanic corrosion between the metal and the adjacent carbon particles accelerates the corrosive process. Furthermore, the black carbon favors the moisture uptake, and gives the dissolved oxygen greater chance to migrate through the fouling layer and form a continuous diffusive path. The corrosion rate decreasing over time is conformed to electrochemistry measurements and can be verified by Faraday’s law. The EIS results indicate that the mechanism of corrosion can be interpreted by the pitting corrosion evolution mechanism, and that pitting was observed on the coupons by SEM after corrosive exposure.

  16. High temperature electrochemical corrosion rate probes

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

    2005-09-01

    Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

  17. Electrochemical evaluation of under-deposit corrosion and its inhibition using the wire beam electrode method

    Energy Technology Data Exchange (ETDEWEB)

    Tan Yongjun, E-mail: yj.tan@curtin.edu.a [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia); Fwu, Young; Bhardwaj, Kriti [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia)

    2011-04-15

    Research highlights: A new experiment method for evaluating under-deposit corrosion and its inhibitors. Under-deposit corrosion did not occur in a CO{sub 2} saturated pure brine solution. Inhibitor imidazoline addition and O{sub 2} contamination initiated under-deposit corrosion. Inhibitor imidazoline reduced general corrosion but enhanced localised corrosion. - Abstract: A new experimental method has been applied to evaluate under-deposit corrosion and its inhibition by means of an electrochemically integrated multi-electrode array, namely the wire beam electrode (WBE). Maps showing galvanic current and corrosion potential distributions were measured from a WBE surface that was partially covered by sand. Under-deposit corrosion did not occur during the exposure of the WBE to carbon dioxide saturated brine under ambient temperature. The introduction of corrosion inhibitor imidazoline and oxygen into the brine was found to significantly affect the patterns and rates of corrosion, leading to the initiation of under-deposit corrosion over the WBE.

  18. NANOCOMPOSITE COATING FOR IMPROVED CORROSION RESISTANCE.

    Directory of Open Access Journals (Sweden)

    M.V.RAMANA

    2012-07-01

    Full Text Available Zn-Mg–ZnO nanocomposite electrodeposits have better corrosion resistance to sodium chloride in the atmospheric environment and better than that of other zinc alloys of equal thickness and therefore, provide a better alternative for corrosion protection. Nano zinc coatings are deposited on mild steel by electro deposition.Besides corrosion protection and decoration, nanocoatings sometimes impart to the surface, specific mechanical and physical properties such as wear resistance, hardness, electrical properties, oxidation – resistance and thermal-insulating properties. The effect of addition of ZnO nanoparticles on the morphology of crystal size on zinc deposited surface and corrosion properties are investigated. The results showed that addition of nano additives in the deposition process of zinc significantly increased the corrosion resistance. The surface morphology of the zinc deposits was studied by scanning electron microscopy (SEM.

  19. Report on accelerated corrosion studies.

    Energy Technology Data Exchange (ETDEWEB)

    Mowry, Curtis Dale; Glass, Sarah Jill; Sorensen, Neil Robert

    2011-03-01

    Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that would be consistent with long-term exposure to environments containing humidity and parts per billion (ppb) levels of hydrogen sulfide (H{sub 2}S) that are thought to have been the source of corrosion in electrical components from affected homes. This report documents the test set-up, monitoring of electrical performance of powered electrical components during the exposure, and the materials characterization conducted on wires, screws, and contact plates from selected electrical components. No degradation in electrical performance (measured via voltage drop) was measured during the course of the 8-week exposure, which was approximately equivalent to 40 years of exposure in a light industrial environment. Analyses show that corrosion products consisting of various phases of copper sulfide, copper sulfate, and copper oxide are found on exposed surfaces of the conductor materials including wires, screws, and contact plates. The morphology and the thickness of the corrosion products showed a range of character. In some of the copper wires that were observed, corrosion product had flaked or spalled off the surface, exposing fresh metal to the reaction with the contaminant gasses; however, there was no significant change in the wire cross-sectional area.

  20. Corrosion/94 conference papers

    International Nuclear Information System (INIS)

    The approximately 500 papers from this conference are divided into the following sections: Rail transit systems--stray current corrosion problems and control; Total quality in the coatings industry; Deterioration mechanisms of alloys at high temperatures--prevention and remediation; Research needs and new developments in oxygen scavengers; Computers in corrosion control--knowledge based system; Corrosion and corrosivity sensors; Corrosion and corrosion control of steel reinforced concrete structures; Microbiologically influenced corrosion; Practical applications in mitigating CO2 corrosion; Mineral scale deposit control in oilfield-related operations; Corrosion of materials in nuclear systems; Testing nonmetallics for life prediction; Refinery industry corrosion; Underground corrosion control; Mechanisms and applications of deposit and scale control additives; Corrosion in power transmission and distribution systems; Corrosion inhibitor testing and field application in oil and gas systems; Decontamination technology; Ozone in cooling water applications, testing, and mechanisms; Corrosion of water and sewage treatment, collection, and distribution systems; Environmental cracking of materials; Metallurgy of oil and gas field equipment; Corrosion measurement technology; Duplex stainless steels in the chemical process industries; Corrosion in the pulp and paper industry; Advances in cooling water treatment; Marine corrosion; Performance of materials in environments applicable to fossil energy systems; Environmental degradation of and methods of protection for military and aerospace materials; Rail equipment corrosion; Cathodic protection in natural waters; Characterization of air pollution control system environments; and Deposit-related problems in industrial boilers. Papers have been processed separately for inclusion on the data base

  1. Time Resolved 3-D Mapping of Atmospheric Aerosols and Clouds During the Recent ARM Water Vapor IOP

    Science.gov (United States)

    Schwemmer, Geary; Miller, David; Wilkerson, Thomas; Andrus, Ionio; Starr, David OC. (Technical Monitor)

    2001-01-01

    The HARLIE lidar was deployed at the ARM SGP site in north central Oklahoma and recorded over 100 hours of data on 16 days between 17 September and 6 October 2000 during the recent Water Vapor Intensive Operating Period (IOP). Placed in a ground-based trailer for upward looking scanning measurements of clouds and aerosols, HARLIE provided a unique record of time-resolved atmospheric backscatter at 1 micron wavelength. The conical scanning lidar images atmospheric backscatter along the surface of an inverted 90 degree (full angle) cone up to an altitude of 20 km. 360 degree scans having spatial resolutions of 20 meters in the vertical and 1 degree in azimuth were obtained every 36 seconds. Various boundary layer and cloud parameters are derived from the lidar data, as well as atmospheric wind vectors where there is Sufficiently resolved structure that can be traced moving through the surface described by the scanning laser beam. Comparison of HARLIE measured winds with radiosonde measured winds validates the accuracy of this new technique for remotely measuring atmospheric winds without Doppler information.

  2. corrosion problems and their relationship with the environment in the Colombian productive system

    International Nuclear Information System (INIS)

    As a part of a broad study on the corrosion problems in the Colombian industry, it was included an assessment of the effect of the main corrosive environments (atmosphere, soil, salad and drinking water, and chemicals), on materials stability. On the other hand, the impact of the corrosion processes on the environmental constituents (live species, atmosphere, soil, materials, and water) was also assessed. Main conclusions are: Atmosphere is the more extensively corrosive environment, and, all the environmental constituents are affected by corrosion without significant differences

  3. Stress corrosion of alloy 600: mechanism problems

    International Nuclear Information System (INIS)

    To understand better stress corrosion of alloy 600, we experimentally studied: the simultaneous action of atmosphere and stress, the continuous or discontinuous propagation, the part of the formed oxide, the characteristics and peculiar properties in conditions where the material is sensitive. The results show that the beginning of cracking by stress corrosion may be explained by a limited brittleness of grains boundary (a preferential penetration of this grains boundary by a brittle oxide under a traction stress). 8 refs., 1 fig., 1 tab

  4. Corrosion Properties of a Volcanic Hot Spring

    OpenAIRE

    Lichti, K. L.; Braham, V. J.; Engelberg, D.; Sanada, N.; Kurata, J.; Nanjo, H.; Ikeuchi, J.; Christenson, B.W.

    1998-01-01

    Volcanic hot pools on White Island, New Zealand provide ready access to acidic fluids at atmospheric pressure. These hot pools can be used to study the corrosion properties of construction materials that might be used for energy production from deep-seated and magma-ambient geothermal systems, or from shallow resources producing acidic fluids. corrosion results for a 1,hot pool are presented. A select group of moderate and high alloy materials appear suitable for energy plant applications. Ch...

  5. Task E container corrosion studies: Annual report

    International Nuclear Information System (INIS)

    The Pacific Northwest Laboratory is conducting the Solid Waste Technology Support Program (SWTSP) for Westinghouse Hanford Company (WHC). Task E is the Container Corrosion Study Portion of the SWTSP that will perform testing to provide defensible data on the corrosion of low-carbon steel, as used in drums to contain chemical and radioactive wastes at the Hanford Site. A second objective of Task E is to provide and test practical alternative materials that have higher corrosion resistance than low-carbon steel. The scope of work for fiscal year (FY) 1993 included initial testing of mild steel specimens buried in Hanford soils or exposed to atmospheric corrosion in metal storage sheds. During FY 1993, progress was made in three areas of Task E. First, exposure of test materials began at the Soil Corrosion Test Site where low-carbon steel specimens were placed in the soil in five test shafts at depths of 9 m (30 ft). Second, the corrosion measurement of low-carbon steel in the soil of two solid waste trenches continued. The total exposure time is ∼ 500 days. Third, an atmospheric corrosion test of low-carbon steel was put initiated in a metal shed (Building 2401-W) in the 200 West Area. This annual report describes the Task E efforts and provides a current status

  6. DYNAMO: a Mars upper atmosphere package for investigating solar wind interaction and escape processes, and mapping Martian fields

    DEFF Research Database (Denmark)

    Chassefiere, E.; Nagy, A.; Mandea, M.;

    2004-01-01

    DYNAMO is a small multi-instrument payload aimed at characterizing current atmospheric escape, which is still poorly constrained, and improving gravity and magnetic field representations, in order to better understand the magnetic, geologic and thermal history of Mars. The internal structure and...... evolution of Mars is thought to have influenced climate evolution. The collapse of the primitive magnetosphere early in Mars history could have enhanced atmospheric escape and favored transition to the present and climate. These objectives are achieved by using a low periapsis orbit. DYNAMO has been...... proposed in response to the AO released in February 2002 for instruments to be flown as a complementary payload onboard the CNES Orbiter to Mars (MO-07), foreseen to be launched in 2007 in the framework of the French PREMIER Mars exploration program. MO-07 orbital phase 2b (with an elliptical orbit of...

  7. Multistate atmospheric power production pollution study - MAP3S. Progress report for FY 1977 and FY 1978

    Energy Technology Data Exchange (ETDEWEB)

    MacCracken, Michael C.; Ballantine, David S.

    1979-07-01

    Research progress on the transport, transformation, and fate of pollutants released by energy-related activities is summarized. Information is reported under the following section headings: power production emissions; non-power production emissions; measuring pollutants and their properties; regional pollutant distribution; transport; pollutant transformation; surface removal processes; wet removal processes; weather and climate modification; numerical modeling and analysis; special activities; and, MAP3S research directions. (JGB)

  8. The detection and mapping of the spatial distribution of insect defense compounds by desorption atmospheric pressure photoionization Orbitrap mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Rejšek, Jan; Vrkoslav, Vladimír; Hanus, Robert; Vaikkinen, A.; Haapala, M.; Kauppila, T. J.; Kostiainen, R.; Cvačka, Josef

    2015-01-01

    Roč. 886, Jul 30 (2015), s. 91-97. ISSN 0003-2670 R&D Projects: GA ČR GP13-25137P Grant ostatní: GA AV ČR(CZ) M200551204 Institutional support: RVO:61388963 Keywords : desorption atmospheric pressure photoionization * ambient mass spectrometry * insect chemical defense * exocrine glands * termite * stink bug Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014

  9. Low toxicity corrosion inhibitors

    International Nuclear Information System (INIS)

    This paper discusses the design and testing of low toxicity corrosion inhibitors. New chemistries have been investigated with respect to corrosion protection and impact on the marine environment. The resulting chemicals, while they are effective corrosion inhibitors, present significant improvements in terms of environmental properties over current products. The discussion includes results of the corrosion inhibition, toxicity, biodegradability and partitioning studies

  10. 原位研究 PCB-ENIG 在吸附薄液膜下的大气腐蚀行为%In situ investigation of atmospheric corrosion behavior of PCB-ENIG under adsorbed thin electrolyte layer

    Institute of Scientific and Technical Information of China (English)

    易盼; 肖葵; 丁康康; 李刚; 董超芳; 李晓刚

    2016-01-01

    通过阴极极化曲线、交流阻抗谱以及 SEM、XPS,原位研究了相对湿度对无电镀镍金印制电路板(PCB-ENIG)在吸附薄液膜下的影响机制。结果表明:PCB-ENIG 板在薄液膜下的阴极过程主要包括 O2、腐蚀产物和 H2O 的还原过程。阴极电流密度随相对湿度的增加而增加,并且均小于溶液中阴极电流密度,表明扩散过程并不是阴极氧化还原过程的控制步骤。极化电位较负时,75%和85%相对湿度下的阴极极化电流密度逐渐减小。随着腐蚀产物的增加,试验后期腐蚀过程由阳极过程控制。%The effects of relative humidity (RH) on a printed circuit board finished with electroless nickel immersion gold (PCB-ENIG) under an adsorbed thin electrolyte layer (ATEL) were investigated in situ via the measurement of cathodic polarization curves, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to clearly elaborate the corrosion behavior of PCB-ENIG in the atmospheric environment. Results indicated that the cathodic process of PCB-ENIG under ATEL was dominated by the reduction of dissolved oxygen, corrosion products, and H2O. The cathodic current density of PCB-ENIG increased progressively with increasing RH. Moreover, its cathodic current density in the solution was greater than that under ATEL. This result demonstrated that the diffusion process was not the controlling step during the limiting reduction of cathodic oxygen. When the polarization potentials were located in a more negative region, the cathodic polarization current density gradually decreased under 75% and 85% RH. Notably, the anodic process became the controlling step in the extremely thin liquid film during the remainder of the experiment.

  11. GCR dismantling: corrosion of vessel internals during decay storage

    International Nuclear Information System (INIS)

    Gas-cooled reactor decommissioning confronts EDF with the problem of the corrosion resistance of vessel internals over a decay storage period fixed at 50 years. The layer of magnetite previously formed in the C02 should protect structural steelwork from atmospheric corrosion. In any case, estimated steel corrosion after 50 years may be put at below or equal to 0.1 mm and the corresponding swelling induced by corrosion products at 0.2 mm. There should be no risk of hydrogen embrittlement or stress corrosion cracking of threaded fasteners. Corrosion tests aimed at providing further insight into the effects of the magnetite layer and a program for the surveillance of post-decommissioning structural corrosion should nevertheless be envisaged

  12. Corrosion rate evaluation of the carbon steel trough electrochemical techniques

    OpenAIRE

    Jeimmy González-Masís; Luis Garita-Arce

    2014-01-01

    Usually the atmospheric corrosion studies are cha­racterized by their long duration, months and even years. However electrochemical techniques have been developed, recent in comparison to other methods, allowing obtain real-time data, including corrosion rate. In this research electrochemical noise and lineal polarization resistance tests are valued, so obtained data were analyzed, relations were establis­hed between the graphics form and the corrosion type, as well as the relationship betwee...

  13. Humid-air and aqueous corrosion models for corrosion-allowance barrier material

    International Nuclear Information System (INIS)

    Humid-air and aqueous general and pitting corrosion models (including their uncertainties) for the carbon steel outer containment barrier were developed using the corrosion data from literature for a suite of cast irons and carbon steels which have similar corrosion behaviors to the outer barrier material. The corrosion data include the potential effects of various chemical species present in the testing environments. The atmospheric corrosion data also embed any effects of cyclic wetting and drying and salts that may form on the corroding specimen surface. The humid-air and aqueous general corrosion models are consistent in that the predicted humid-air general corrosion rates at relative humidities between 85 and 100% RH are close to the predicted aqueous general corrosion rates. Using the expected values of the model parameters, the model predicts that aqueous pitting corrosion is the most likely failure mode for the carbon steel outer barrier, and an earliest failure (or initial pit penetration) of the 100-mm thick barrier may occur as early as about 500 years if it is exposed continuously to an aqueous condition at between 60 and 70 degrees C

  14. Development of Copper Corrosion Products and Relation between Surface Appearance and Corrosion Rate

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Tran Thi Ngoc; Binh, Nguyen Thi Thanh [Vietnam National University, Ho Chi Minh (Viet Nam); Tru, Nguyen Nhi [Vietnam Institute for Tropical Technology and Environmental Protection, Ho Chi Minh (Viet Nam); Yoshino, Tsujino [Osaka Prefecture, Osaka (Japan); Yasuki, Maeda [Osaka Prefecture University, Osaka (Japan)

    2008-04-15

    Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.

  15. Corrosion probes for fireside monitoring in coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Covino, Bernard S., Jr.; Bullard, Sophie J.; Ziomek-Moroz, M.; Holcomb, Gordon R.

    2005-01-01

    Corrosion probes are being developed and combined with an existing measurement technology to provide a tool for assessing the extent of corrosion of metallic materials on the fireside in coal-fired boilers. The successful development of this technology will provide power plant operators the ability to (1) accurately monitor metal loss in critical regions of the boiler, such as waterwalls, superheaters, and reheaters; and (2) use corrosion rates as process variables. In the former, corrosion data could be used to schedule maintenance periods and in the later, processes can be altered to decrease corrosion rates. The research approach involves laboratory research in simulated environments that will lead to field tests of corrosion probes in coal-fired boilers. Laboratory research has already shown that electrochemically-measured corrosion rates for ash-covered metals are similar to actual mass loss corrosion rates. Electrochemical tests conducted using a potentiostat show the corrosion reaction of ash-covered probes at 500?C to be electrochemical in nature. Corrosion rates measured are similar to those from an automated corrosion monitoring system. Tests of corrosion probes made with mild steel, 304L stainless steel (SS), and 316L SS sensors showed that corrosion of the sensors in a very aggressive incinerator ash was controlled by the ash and not by the alloy content. Corrosion rates in nitrogen atmospheres tended to decrease slowly with time. The addition of oxygen-containing gases, oxygen and carbon dioxide to nitrogen caused a more rapid decrease in corrosion rate, while the addition of water vapor increased the corrosion rate.

  16. Corrosion behaviour of metallic containers during long term interim storages

    International Nuclear Information System (INIS)

    Two main corrosion phenomena are encountered in long term interim storage conditions: dry oxidation by the air when the temperature of high level nuclear wastes containers is high enough (roughly higher than 100 C) and corrosion phenomena as those encountered in outdoor atmospheric corrosion when the temperature of the container wall is low enough and so condensation is possible on the container walls. Results obtained with dry oxidation in air lead to predict small damages (less than 1μm on steels over 100 years at 100 C) and no drastic changes with pollutants. For atmospheric corrosion, first developments deal with a pragmatic method that gives assessments of the indoor atmospheric corrosivities. (author)

  17. Corrosion behaviour of AZ91D and AM50 magnesium alloys with Nd and Gd additions in humid environments

    International Nuclear Information System (INIS)

    Highlights: ► Mg alloys with additions of Nd and Gd were exposed to high humidity atmosphere. ► The increase of Nd or Gd diminished the effect of micro-galvanic couples. ► Corrosion resistance of the AM50 alloy improved with the addition of Nd or Gd by 43%. ► Nd and Gd had no significant effect on the corrosion resistance of the AZ91D alloy. - Abstract: AM50 and AZ91D alloys modified with rare earths (RE) were evaluated under atmospheric conditions. Nd and Gd additions resulted in formation of Al2RE and Al–Mn–RE compounds and reduction of the fraction of β-phase. According to surface potential maps, RE-containing intermetallics were more noble than the β-phase, but less than Al–Mn inclusions. As a result, the action of micro-galvanic couples depended on the added amount of RE and the initial alloy microstructure. Nd or Gd additions improved the corrosion resistance of the AM50 alloy by up to 43%, but had no significant effect on the corrosion resistance of the AZ91D alloy.

  18. Corrosion behaviour of AZ91D and AM50 magnesium alloys with Nd and Gd additions in humid environments

    Energy Technology Data Exchange (ETDEWEB)

    Arrabal, R., E-mail: raularrabal@quim.ucm.es [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Matykina, E.; Pardo, A.; Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Paucar, K. [Gabinete de Corrosion, Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Cod. Postal 25, Lima (Peru); Mohedano, M.; Casajus, P. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Mg alloys with additions of Nd and Gd were exposed to high humidity atmosphere. Black-Right-Pointing-Pointer The increase of Nd or Gd diminished the effect of micro-galvanic couples. Black-Right-Pointing-Pointer Corrosion resistance of the AM50 alloy improved with the addition of Nd or Gd by 43%. Black-Right-Pointing-Pointer Nd and Gd had no significant effect on the corrosion resistance of the AZ91D alloy. - Abstract: AM50 and AZ91D alloys modified with rare earths (RE) were evaluated under atmospheric conditions. Nd and Gd additions resulted in formation of Al{sub 2}RE and Al-Mn-RE compounds and reduction of the fraction of {beta}-phase. According to surface potential maps, RE-containing intermetallics were more noble than the {beta}-phase, but less than Al-Mn inclusions. As a result, the action of micro-galvanic couples depended on the added amount of RE and the initial alloy microstructure. Nd or Gd additions improved the corrosion resistance of the AM50 alloy by up to 43%, but had no significant effect on the corrosion resistance of the AZ91D alloy.

  19. Use of a Simple GIS-Based Model in Mapping the Atmospheric Concentration of γ-HCH in Europe

    Directory of Open Access Journals (Sweden)

    Pilar Vizcaino

    2014-10-01

    Full Text Available The state-of-the-art of atmospheric contaminant transport modeling provides accurate estimation of chemical concentrations. However, existing complex models, sophisticated in terms of process description and potentially highly accurate, may entail expensive setups and require very detailed input data. In contexts where detailed predictions are not needed (e.g., for regulatory risk assessment or life cycle impact assessment of chemicals, simple models allowing quick evaluation of contaminants may be preferable. The goal of this paper is to illustrate and critically discuss the use of a simple equation proposed by Pistocchi and Galmarini (2010, which can be implemented through basic GIS functions, to predict atmospheric concentrations of lindane (γ-HCH in Europe from both local and remote sources. Concentrations were computed for 1995 and 2005 assuming different modes of use of lindane and consequently different spatial patterns of emissions. Results were compared with those from the well-established MSCE-POP model (2005 developed within EMEP (European Monitoring and Evaluation Programme, and with available monitoring data, showing acceptable correspondence in terms of the orders of magnitude and spatial distribution of concentrations, especially when the background effect of emissions from extracontinental sources, estimated using the same equation, is added to European emissions.

  20. A Comparative Study on causes of corrosion of steel reinforcement in RC structures at Bangalore, India and Kigali, Rwanda

    Directory of Open Access Journals (Sweden)

    Abaho G

    2015-06-01

    Full Text Available Premature failure of reinforced concrete structures occurs primarily due to early corrosion of steel reinforcement. This paper intends to uplift the awareness of people about the role of structure maintenance to prevent or control corrosion in steel reinforced concrete structures. Some data collected using a designed questionnaire were distributed in Bangalore, India and Kigali, Rwanda, about corrosion of steel reinforcement which actually motivated this research. The research finds that without corrosion in steel reinforced concrete structures is just a matter of time. However corrosion map for Kigali is not available. Hence the survey has been conducted in Rwanda. Based on survey corrosion map will be prepared so that vulnerable areas for corrosion can be identified. This map will enable for protective design of structures against corrosion. The new steel RC structures corrosion monitoring systems should be incorporated for future less costly, timely maintenance for their reliable service life.

  1. Corrosion/96 conference papers

    International Nuclear Information System (INIS)

    Topics covered by this conference include: cathodic protection in natural waters; cleaning and repassivation of building HVAC systems; worldwide opportunities in flue gas desulfurization; advancements in materials technology for use in oil and gas service; fossil fuel combustion and conversion; technology of corrosion inhibitors; computers in corrosion control--modeling and information processing; recent experiences and advances of austenitic alloys; managing corrosion with plastics; corrosion measurement technology; corrosion inhibitors for concrete; refining industry; advances in corrosion control for rail and tank trailer equipment; CO2 corrosion--mechanisms and control; microbiologically influenced corrosion; corrosion in nuclear systems; role of corrosion in boiler failures; effects of water reuse on monitoring and control technology in cooling water applications; methods and mechanisms of scale and deposit control; corrosion detection in petroleum production lines; underground corrosion control; environmental cracking--relating laboratory results and field behavior; corrosion control in reinforced concrete structures; corrosion and its control in aerospace and military hardware; injection and process addition facilities; progress reports on the results of reinspection of deaerators inspected or repaired per RP0590 criteria; near 100% volume solids coating technology and application methods; materials performance in high temperature environments containing halides; impact of toxicity studies on use of corrosion/scale inhibitors; mineral scale deposit control in oilfield related operations; corrosion in gas treating; marine corrosion; cold climate corrosion; corrosion in the pulp and paper industry; gaseous chlorine alternatives in cooling water systems; practical applications of ozone in recirculating cooling water systems; and water reuse in industry. Over 400 papers from this conference have been processed separately for inclusion on the data base

  2. Research on the residual stress of SMA 490BW atmospheric corrosion resistant steel treated by ultrasonic impacting%超声冲击对SMA490BW耐候钢焊接残余应力的影响

    Institute of Scientific and Technical Information of China (English)

    荣豪; 周伟; 陈辉; 张卫华

    2011-01-01

    对SMA 490BW耐候钢进行气保焊焊接,利用超声冲击设备对焊接对接接头进行超声处理,并通过盲孔法对超声冲击前后的残余应力进行测试及分析.结果表明,超声冲击对于焊缝及其附近区域残余应力的降低效果十分明显,横向残余应力消除率最高达161%,纵向残余应力最高达118%;超声冲击处理后,同一位置纵向残余应力消除率较横向残余应力要大.%Gas shielded welding was done on SMA490 BW atmospheric corrosion resistant steel,and ultrasonic impact treatment was made to the welded butt joint by ultrasonic impact equipment.The residual stresses were tested and analyzed before and after ultrasonic impact by adopting blind-hole method. Finally, the results show that there is obvious effect on residual stress elimination of welding seam and its area nearby after ultrasonic impact treatment.The highest elimination rate of longitudinal residual stress reaches 161%,while the horizontal residual stress could reach 118%.Moreover,the longitudinal residual stress has a bigger elimination rate than that of horizontal one at the same position.

  3. Metal corrosion for nanofabrication.

    Science.gov (United States)

    Yu, Hai-Dong; Zhang, Zhongping; Han, Ming-Yong

    2012-09-10

    The annual cost of corrosion has been increasing globally, and it has now reached beyond 3% of the world's gross domestic product. It remains a challenge to reduce or prevent unwanted corrosion effectively after many decades of effort. Nowadays, more efforts are being made to develop anti-corrosion platforms for decreasing the huge cost of corrosion. In parallel, it is also highly expected to be able to use corrosion for producing useful materials with reduced energy consumption. In this review, recent progress in how methods for controlling metal corrosion can be used to produce structure-diversified nanomaterials are summarized along with a presentation of their applications. As a valuable addition to the scientists' toolbox, metal corrosion strategies can be applied to different metals and their alloys for the production of various nanostructured materials; this also provides insights into how metal corrosion can be further prevented and into how corrosion wastage can be reduced. PMID:22707341

  4. Stress corrosion cracking and vibration corrosion cracking

    International Nuclear Information System (INIS)

    Under certain conditions of stress practically all metallic materials are subject to such cracking corrosion processes. They are much feared because as a rule they are not recognized until the damage - leakage of a container, fracture of a component part-occurs. They may belong to the category of either stress corrosion cracking or vibration corrosion cracking, depending on the different mechanisms of the damage process. As the denominations indicate, one constitutes the interaction between local corrosion attack and mainly static tensile stress (load stress and/or non-load stress) and the other a combination of varying mechanical stress over time and corrosion. Hydrogen-induced cracking is a special form of stress corrosion cracking characterized by trapping of atomic hydrogen in material and subsequent cracking owing to the interaction with mechanical stress. (orig./HP)

  5. Perspectives of 2D and 3D mapping of atmospheric pollutants over urban areas by means of airborne DOAS spectrometers

    Directory of Open Access Journals (Sweden)

    F. Ravegnani

    2006-06-01

    Full Text Available tants, offering numerous advantages over conventional networks of in situ analysers. We propose some innovative solutions in the field of DOAS (Differential Optical Absorption Spectroscopy remote systems, utilizing diffuse solar light as the radiation source. We examine the numerous potentialities of minor gas slant column calculations, applying the «off-axis» methodology for collecting the diffuse solar radiation. One of these particular approaches, using measurements along horizontal paths, has already been tested with the spectrometer installed on board the Geophysica aircraft during stratospheric flights up to altitudes of 20 km. The theoretical basis of these new measurement techniques using DOAS remote sensing systems are delineated to assess whether low altitude flights can provide 2D and 3D pollution tomography over metropolitan areas. The 2D or 3D trace gas total column mapping could be used to investigate: i transport and dispersion phenomena of air pollution, ii photochemical process rates, iii gas plume tomography, iv minor gas vertical profiles into the Planetary Boundary Layer and v minor gas flux divergence over a large area.

  6. High-temperature corrosion resistance of NiAl(Cr)-Al2O3 coating in N2+9%O2+0.2% HCl+0.08%SO2 atmosphere

    OpenAIRE

    B. Formanek; B. Szczucka-Lasota

    2010-01-01

    Purpose: The aim of this study was to determine the resistance of nickel and aluminium intermetallic phase-based coatings, modified with chromium and aluminum oxides, and to determine the hypothetical mechanism of these materials’ corrosion.Design/methodology/approach: The selected results of high temperature corrosion resistance of HVOF sprayed coatings with NiAl intermetallic phases are presented. The aggressive corrosion gas included: N2+9%O2+0.2% HCl+0.08%SO2. The temperature of cyclic co...

  7. Corrosion of vessel steel during its interaction with molten corium

    Energy Technology Data Exchange (ETDEWEB)

    Bechta, S.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation)]. E-mail: bechta@sbor.spb.su; Khabensky, V.B. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Vitol, S.A. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Krushinov, E.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Granovsky, V.S. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Lopukh, D.B. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Gusarov, V.V. [Institute of Silicate Chemistry of Russian Academy of Science (ISC of RAS), Odoevsky str., b. 24/2, 199155 St. Petersburg (Russian Federation); Martinov, A.P. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Martinov, V.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Fieg, G. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Tromm, W. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Bottomley, D. [Europaeische Kommission, General Direktion GFS, Institut fuer Transurane (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Tuomisto, H. [Fortum Engineering Ltd. 00048 FORTUM, Rajatorpantie 8, Vantaa (Finland)

    2006-07-15

    An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments have been conducted on 'Rasplav-2' test facility and followed up with physico-chemical and metallographic analyses of melt samples and corium-specimen ingots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere above the melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate or corrosion depth of vessel steel in conditions simulated by the experiments.

  8. Differential Pressure Transducer for Corrosion Monitoring of Iron

    Directory of Open Access Journals (Sweden)

    Amar Prasad Yadav

    2014-03-01

    Full Text Available In this study, differential pressure transducer (DPT has been applied as an alternate corrosion monitoring device for monitoring corrosion of iron in atmospheric environment by measuring very small changes in the amount of oxygen. The result of corrosion current obtained from DPT method has been compared with that obtained from AC impedance method. The difference in the value of corrosion current obtained from these two methods was attributed to the error in choosing the value of proportionality constant k of the Stern-Geary equation.

  9. Microbiologically influenced corrosion (MIC) of storage tank bottom plates

    Science.gov (United States)

    Syafaat, Taufik A.; Ismail, Mokhtar Che

    2015-07-01

    Aboveground atmospheric storage tanks (AST) receive crude oil from offshore for storage and further processing. Integrity issue of AST storing crude oil is not only affected by external corrosion but also internal corrosion from crude oil that supports the growth of the microorganisms originating from the reservoir. The objective of this research is to study the effect of sulfate reduction bacteria (SRB) on the corrosion of AST. The results indicates that SRB has significant effect on the corrosion rate of storage tank bottom plate.

  10. Recovery Action Mapping Tool

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Recovery Action Mapping Tool is a web map that allows users to visually interact with and query actions that were developed to recover species listed under the...

  11. NGS Survey Control Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Survey Control Map provides a map of the US which allows you to find and display geodetic survey control points stored in the database of the National...

  12. Scattering length density profile of Ni film under controlled corrosion: A study in neutron reflectometry

    Indian Academy of Sciences (India)

    Surendra Singh; A K Poswal; S K Ghosh; Saibal Basu

    2008-11-01

    We report the density depth profile of an as-deposited Ni film and density profile for the same film after controlled electrochemical corrosion by chloride ions, measured by unpolarized neutron reflectometry. The neutron reflectometry measurement of the film after corrosion shows density degradation along the thickness of the film. The density profile as a function of depth, maps the growth of pitting and void networks due to corrosion. The profile after corrosion shows an interesting peaking nature.

  13. Study of green film-forming corrosion inhibitor based on mussel adhesive protein

    OpenAIRE

    Holmér, Camilla

    2013-01-01

    Today there are numerous methods to slow down a corrosion process of metallic materials. However, due to environmental effects and health risk issues, several traditional corrosion inhibitors have to be phased out. Hence, it is of great importance to develop new corrosion inhibitors that are “green”, safe, smart and multifunctional. In this essay, the focus is on mussel adhesive protein (MAP) and its possibility to reduce the rate of the corrosion process. The protein exhibit great adhesive s...

  14. Noise map

    OpenAIRE

    Němcová, Michaela

    2015-01-01

    The aim of this paper is to introduce the measurement of noise and create a noise map in a geographic information system. The first part is focused on describing the physical properties of sound in space, atmospheric and physiological acoustics. It also deals with the physiological effects of noise on the human body and technology needed for measure and process noise. Other part describes the structure of a geographic information system and noise map. The last part is about the practical crea...

  15. Studies and research work on the reinforcement steel and concrete surface corrosion protection methods

    OpenAIRE

    Gheorghe Croitoru

    2013-01-01

    Methods for reinforcement steel corrosion protection and concrete surface protection are analyzed. Knowing the corrosion process mechanism reinforcement steel can be protected by different protection methods even in the presence of crevices larger than those anticipated by design. The selection of the corrosion protection method depends on the reduction level of the reinforcement steel corrosion which in its turn is determined by the atmospheric conditions. The selection of the accelerated co...

  16. Media effects on radiochemical corrosion at high-output gamma irradiation facilities

    International Nuclear Information System (INIS)

    Gamma irradiation of metals at high dose rate conditions may induce or accelerate a wide variety of electrochemical corrosion processes. Examination of failures encountered in irradiation facilities due to corrosion indicated that, above a threshold value for atmospheric humidity, the electrode reactions are chiefly controlled by the action of radiolytic products arising from the electrolyte during gamma irradiation. Thus, the nature of the corrosive medium provides the decisive variable factor influencing the overall effect of radiochemical corrosion. (author)

  17. Study on Drill Pipe with Mud Membrane Corrosion Mechanics Under Atmospheric Environment%泥浆膜在大气环境下对钻杆的腐蚀机理研究

    Institute of Scientific and Technical Information of China (English)

    刘婉颖; 施太和; 曾德智; 朱泽华; 贾华明; 卢强; 刘鹏

    2011-01-01

    High temperatures and pressures autoclave were used to simulate the field environment of Tarim oil deposit. And corrosion behavior and mechanism of S135 drill pipe in lignosulfonate mud were studied. Topographic features of mud cake adhereing to the drill pipe and the corrosion product of drill pipe were analyzed by XRD and SEM. The results showed that S135 drill pipe emerged local oxidation corrosion. Features were ulcer-like corrosion and local contiguous corrosion and pit corrosion. Main corrosion products were orthorhombic crystal system's allcharite. The main reason of drill pipe corrosion was unscraped mud while hoisting. Moisture from mud membrane volatilized on the air and formed mud cake shell. Then iron hematite, barite, bentonite powder,and calcium powder were left as the framework for solid phase substrates. That was called scale buildup. It contacted drill pipe's surface and three interrelated local corrosions,which were differential oxygen concentration, bimetallic corrosion and crevice corrosion, were produced.%采用高温高压釜模拟研究塔里木油田现场环境所用聚磺体系钻井液对S135钻杆的腐蚀行为及腐蚀机理.通过对表面黏附有泥饼的挂片进行XRD和SEM观察,分析钻杆表面黏附的泥饼形貌特征及腐蚀行为.结果表明:S135钻杆发生了局部氧腐蚀,特征为溃疡状腐蚀、局部连片腐蚀和深坑蚀.腐蚀产物主要是正交(斜方)晶系的针铁矿.钻杆腐蚀的主要原因是起钻时未刮泥浆,黏附在钻杆外壁的泥浆膜在空气中因水分挥发而形成泥饼壳后,留下铁矿粉、重晶石、土粉、碳酸钙粉等作为骨架的固相物,该固相物称为垢层.垢层与钻杆表面接触,产生三种相互关联的局部腐蚀,即供氧差异微电池腐蚀、电偶腐蚀和缝隙腐蚀.

  18. Corrosion inhibiting organic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  19. Northern Hemisphere Synoptic Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily Series of Synoptic Weather Maps. Part I consists of plotted and analyzed daily maps of sea-level and 500-mb maps for 0300, 0400, 1200, 1230, 1300, and 1500...

  20. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  1. Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric data sets

    Science.gov (United States)

    Wyche, K. P.; Monks, P. S.; Smallbone, K. L.; Hamilton, J. F.; Alfarra, M. R.; Rickard, A. R.; McFiggans, G. B.; Jenkin, M. E.; Bloss, W. J.; Ryan, A. C.; Hewitt, C. N.; MacKenzie, A. R.

    2015-07-01

    Highly non-linear dynamical systems, such as those found in atmospheric chemistry, necessitate hierarchical approaches to both experiment and modelling in order to ultimately identify and achieve fundamental process-understanding in the full open system. Atmospheric simulation chambers comprise an intermediate in complexity, between a classical laboratory experiment and the full, ambient system. As such, they can generate large volumes of difficult-to-interpret data. Here we describe and implement a chemometric dimension reduction methodology for the deconvolution and interpretation of complex gas- and particle-phase composition spectra. The methodology comprises principal component analysis (PCA), hierarchical cluster analysis (HCA) and positive least-squares discriminant analysis (PLS-DA). These methods are, for the first time, applied to simultaneous gas- and particle-phase composition data obtained from a comprehensive series of environmental simulation chamber experiments focused on biogenic volatile organic compound (BVOC) photooxidation and associated secondary organic aerosol (SOA) formation. We primarily investigated the biogenic SOA precursors isoprene, α-pinene, limonene, myrcene, linalool and β-caryophyllene. The chemometric analysis is used to classify the oxidation systems and resultant SOA according to the controlling chemistry and the products formed. Results show that "model" biogenic oxidative systems can be successfully separated and classified according to their oxidation products. Furthermore, a holistic view of results obtained across both the gas- and particle-phases shows the different SOA formation chemistry, initiating in the gas-phase, proceeding to govern the differences between the various BVOC SOA compositions. The results obtained are used to describe the particle composition in the context of the oxidised gas-phase matrix. An extension of the technique, which incorporates into the statistical models data from anthropogenic (i

  2. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    International Nuclear Information System (INIS)

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  3. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boone, M.A., E-mail: marijn.boone@ugent.be [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); Unit Sustainable Materials Management, VITO, Boerentang 200, 2400 Mol (Belgium); De Kock, T.; Bultreys, T. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); De Schutter, G. [Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University, Technologiepark-Zwijnaarde 904, 9052 Ghent (Belgium); Vontobel, P. [Spallation Neutron Source Division, Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Van Hoorebeke, L. [Department of Physics and Astronomy—UGCT, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); Cnudde, V. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium)

    2014-11-15

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  4. Erosion-corrosion

    International Nuclear Information System (INIS)

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment

  5. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management of...... reinforcement corrosion....

  6. Towards Corrosion Detection System

    Directory of Open Access Journals (Sweden)

    B.B.Zaidan

    2010-05-01

    Full Text Available Corrosion is a natural process that seeks to reduce the binding energy in metals. The end result of corrosion involves a metal atom being oxidized. Surface corrosion on aluminum aircraft skins, near joints and around fasteners, is often an indicator of buried structural corrosion and cracking In this paper we proposed a new method on which we are moving towards designing a method to detect the corrosion within the metals, the new method has defined texture analysis as the main method for this approach, the proposed enhancement shows less false positive and less false negative. The main functions used in this approach beside texture analysis are Edge detection, structure element and image dilation. The new approach has designed to detect a part of the image that has been affected by the corrosion, the tested images has showed a good result lying on detecting the corrosion part from the image.

  7. Copper corrosion experiments under anoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ollila, Kaija [VTT Technical Research Centre of Finland, Espoo (Finland)

    2013-06-15

    This report gives results from the corrosion experiments with copper under anoxic conditions. The objective was to study whether hydrogen-evolving corrosion reaction could occur. Copper foil samples were exposed in deaerated deionized water in Erlenmeyer flasks in the glove box with inert atmosphere. Four corrosion experiments (Cu1, Cu2, Cu3 and Cu4) were started, as well as a reference test standing in air. Cu1 and Cu2 had gas tight seals, whereas Cu3 and Cu4 had palladium foils as hydrogen permeable enclosure. The test vessels were stored during the experiments in a closed stainless steel vessel to protect them from the trace oxygen of the gas atmosphere and light. After the reaction time of three and a half years, there were no visible changes in the copper surfaces in any of the tests in the glove box, in contrast the Cu surfaces looked shiny and unaltered. The Cu3 test was terminated after the reaction time of 746 days. The analysis of the Pd-membrane showed the presence of H2 in the test system. If the measured amount of 7.2{center_dot}10{sup 5} mol H{sub 2} was the result of formation of Cu{sub 2}O this would correspond to a 200 nm thick corrosion layer. This was not in agreement with the measured layer thickness with SIMS, which was 6{+-}1 nm. A clear weight loss observed for the Cu3 test vessel throughout the test period suggests the evaporation of water through the epoxy sealing to the closed steel vessel. If this occurred, the anaerobic corrosion of steel surface in humid oxygen-free atmosphere could be a source of hydrogen. A similar weight loss was not observed for the parallel test (Cu4). The reference test standing in air showed visible development of corrosion products.

  8. Copper corrosion experiments under anoxic conditions

    International Nuclear Information System (INIS)

    This report gives results from the corrosion experiments with copper under anoxic conditions. The objective was to study whether hydrogen-evolving corrosion reaction could occur. Copper foil samples were exposed in deaerated deionized water in Erlenmeyer flasks in the glove box with inert atmosphere. Four corrosion experiments (Cu1, Cu2, Cu3 and Cu4) were started, as well as a reference test standing in air. Cu1 and Cu2 had gas tight seals, whereas Cu3 and Cu4 had palladium foils as hydrogen permeable enclosure. The test vessels were stored during the experiments in a closed stainless steel vessel to protect them from the trace oxygen of the gas atmosphere and light. After the reaction time of three and a half years, there were no visible changes in the copper surfaces in any of the tests in the glove box, in contrast the Cu surfaces looked shiny and unaltered. The Cu3 test was terminated after the reaction time of 746 days. The analysis of the Pd-membrane showed the presence of H2 in the test system. If the measured amount of 7.2·105 mol H2 was the result of formation of Cu2O this would correspond to a 200 nm thick corrosion layer. This was not in agreement with the measured layer thickness with SIMS, which was 6±1 nm. A clear weight loss observed for the Cu3 test vessel throughout the test period suggests the evaporation of water through the epoxy sealing to the closed steel vessel. If this occurred, the anaerobic corrosion of steel surface in humid oxygen-free atmosphere could be a source of hydrogen. A similar weight loss was not observed for the parallel test (Cu4). The reference test standing in air showed visible development of corrosion products

  9. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Inamullah; François, Raoul [Université de Toulouse, UPS, INSA, LMDC (Laboratoire Matériaux et Durabilité des Constructions), 135, Avenue de Rangueil, F-31077 Toulouse (France); Castel, Arnaud [Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW (Australia)

    2014-02-15

    This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied.

  10. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams

    International Nuclear Information System (INIS)

    This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied

  11. Metallic plate corrosion and uptake of corrosion products by nafion in polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Bozzini, Benedetto; Gianoncelli, Alessandra; Kaulich, Burkhard; Kiskinova, Maya; Prasciolu, Mauro; Sgura, Ivonne

    2010-07-19

    Nafion contamination by ferrous-alloy corrosion products, resulting in dramatic drops of the Ohmic potential, is a suspected major failure mode of polymer electrolyte membrane fuel cells that make use of metallic bipolar plates. This study demonstrates the potential of scanning transmission X-ray microscopy combined with X-ray absorption and fluorescence microspectroscopy for exploring corrosion processes of Ni and Fe electrodes in contact with a hydrated Nafion film in a thin-layer cell. The imaged morphology changes of the Ni and Fe electrodes and surrounding Nafion film that result from relevant electrochemical processes are correlated to the spatial distribution, local concentration, and chemical state of Fe and Ni species. The X-ray fluorescence maps and absorption spectra, sampled at different locations, show diffusion of corrosion products within the Nafion film only in the case of the Fe electrodes, whereas the Ni electrodes appear corrosion resistant. PMID:20564283

  12. Tribo-corrosion of coatings: a review

    International Nuclear Information System (INIS)

    This paper reviews the available literature relating to the emerging research into the performance of coatings under combined wear and corrosion conditions. Understanding how coatings perform under these tribo-corrosion conditions is essential if the service life of equipment is to be predicted and to allow service life to be extended. Therefore, the tribo-corrosion performance of coatings deposited by a variety of techniques is discussed and the main mechanisms associated with their degradation under combined wear and corrosion highlighted. Coating composition, microstructure, defect level, adhesion, cohesion and substrate properties are seen as some of the critical elements in coating performance when subjected to tribo-corrosion contacts. The importance of post-coating deposition treatments such as laser resurfacing and sealing are also discussed. Interactions between wear and corrosion mechanisms are identified along with some models and mapping techniques that aim to inform coating selection and predict performance. Recent investigations into mono-layer as well as multilayered and functionally graded coatings are reviewed as candidates for wear-corrosion resistant surfaces. The review reveals the need for a more considered approach to tribo-corrosion testing and the way in which the results are analysed and presented. For example, the test conditions should be appropriate to the coating system under test; the level of in situ instrumentation deployed and the post-test analysis of in situ electrochemical data should be carefully selected as well as details given of the composition of any surface tribofilms formed and the identification of the degradation mechanisms

  13. Corrosion of high-density sintered tungsten alloys. Part 3

    International Nuclear Information System (INIS)

    The corrosion behaviour of tungsten and high-density tungsten alloys (W ≥ 90 weight %) has been examined electrochemically through anodic polarization measurements, instantaneous corrosion rate measurements, galvanic coupling, and surface potential mapping. In the anodic polarization tests, pure tungsten and the four alloys studied underwent transitions from an active state to a state where any further increase in potential produced no further increase in current. The presence of chloride ions increased corrosion rates. Predictions of likely trends in corrosion rates from the above electrochemical tests were not in complete agreement with those obtained by the long-term immersion tests. Similarly, a consistent prediction of the likely nature of the corrosion products that would result from long-term immersion testing was not obtained from the above studies. Predictions about which alloys would be susceptible to a crevice effect were in agreement with the immersion testing results, namely those alloys not containing Cu would be the most susceptible. Some insight into the nature of the corrosion mechanism is afforded by the work on galvanic coupling and surface potential mapping. This supported the view that galvanic corrosion plays a part in the corrosion process. 15 refs., 5 tabs., 19 figs

  14. The microbial corrosion; La corrosion microbienne

    Energy Technology Data Exchange (ETDEWEB)

    Beech, I.B. [University of Portsmouth, School of Pharmacy - Biomedical Science, Chemistry-Physics and Radiography, Portsmouth (United Kingdom)

    1999-02-01

    Underestimated for a long time, corrosion due to microorganisms induces degradation, sometimes fulminant, of a lot of metallic structures in the world. Searchers are using plentiful analytical tools to understand this phenomenon. (O.M.)

  15. Corrosion resistance of 2195 aluminum alloy treated by multi-step-heating-rate controlled process

    Institute of Scientific and Technical Information of China (English)

    XU Yue; LIU Yu-feng; GENG Ji-ping

    2006-01-01

    2195 aluminum-lithium alloy was widely applied in the aviation and aerospace industry, but it is highly susceptible to pitting and intergranular corrosion undergoing sever corrosive circumstance and moisture atmosphere. To solve this problem and consequently to prolong its service life, a multi-step-heating-rate(MSRC) process was carried out. Investigations were carried out to find the effect of the MSRC process on the alloys corrosion resistance. It is found that the MSRC process is more favorable for the uniform phase precipitation by comparing the corrosion resistance of samples treated by traditional heat treatments. The potential difference between phases can be reduced and intergranular corrosion is able to be prohibited efficiently. Besides, the rare earth infiltration is beneficial to improving the corrosion resistance. As heating time increases, the corrosion resistance declines gradually,samples treated by artificial aging and solid solution also exhibit a better corrosion resistance.

  16. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    Abstract Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria (SRB). The applicability and reliability of a number of corrosion monitoring techniques for monitoring MIC has been evaluated in experiments...... diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  17. Corrosion of support materials

    International Nuclear Information System (INIS)

    Results from a heavily fouled 19 tube C-E model boiler test to investigate the potential for egg crate corrosion in aggressively fouled AVT chemistry are reported. Substantial support plate and egg crate corrosion was produced in this test. Carbon steel drilled support plates exhibited extensive denting which resulted in flow hole ligament cracking. Corrosion of the carbon steel egg crate, through-wall at areas of tube contact, resulted in denting of the Alloy 600 heat transfer tubes. Corrosion performance of the 409 stainless steel egg crate was improved compared to the carbon steel egg crate although localized through-wall corrosion was noted. The results from the above test and previously reported tests were compared based on the following simplifying assumptions: maximum dent size and/or corrosion penetrations utilized, average bulk water chloride concentrations, pilling bedworth ratios, pot and model boilers data are equivalent, heat flux not significantly variable, and plot is semi-quantitative. Conclusions based on plots of maximum corrosion rates as a function of average bulk water chloride concentrations are presented. Finally, the corrosion performance of the various materials of construction for support systems were ranked for each test. Final material selection for future support systems must be based on a balance of thermal/hydraulic, metallurgical, corrosion and design considerations

  18. Corrosion control. 2. ed.

    International Nuclear Information System (INIS)

    The purpose of this text is to train engineers and technologists not just to understand corrosion but to control it. Materials selection, coatings, chemical inhibitors, cathodic and anodic protection, and equipment design are covered in separate chapters. High-temperature oxidation is discussed in the final two chapters ne on oxidation theory and one on controlling oxidation by alloying and with coatings. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgical or environmental cells, and (3) stress-assisted corrosion. Corrosion is logically grouped according to mechanisms rather than arbitrarily separated into different types of corrosion as if they were unrelated. For those university students and industry personnel who approach corrosion theory very hesitantly, this text will present the electrochemical reactions responsible for corrosion summed up in only five simple half-cell reactions. When these are combined on a polarization diagram, which is also explained in detail, the electrochemical processes become obvious. For those who want a text stripped bare of electrochemical theory, several noted sections can be omitted without loss of continuity. However, the author has presented the material in such a manner that these sections are not beyond the abilities of any high school graduate who is interested in technology

  19. Understanding corrosion via corrosion product characterization: II. Role of alloying elements in improving the corrosion resistance of Zn-Al-Mg coatings on steel

    International Nuclear Information System (INIS)

    Highlights: → Origins of better corrosion resistance of ZnAlMg coatings than galvanized steel. → Comparative study of corrosion products formed on ZnAlMg, ZnMg and Zn coatings. → Modeling of dissolution and precipitation stages of corrosion. → At early stages Mg stabilizes protective zinc basic salts during dry-wet cycling. → At later stages Al dissolves at high pH forming protective layered double hydroxides. - Abstract: Corrosion products are identified on Zn, ZnMg and ZnAlMg coatings in cyclic corrosion tests with NaCl or Na2SO4 containing atmospheres. For Mg-containing alloys the improved corrosion resistance is achieved by stabilization of protective simonkolleite and zinc hydroxysulfate. At later stages, the formation of layered double hydroxides (LDH) is observed for ZnAlMg. According to thermodynamic modeling, Mg2+ ions bind the excess of carbonate or sulfate anions preventing the formation of soluble or less-protective products. A preferential dissolution of Zn and Mg at initial stages of corrosion is confirmed by in situ dissolution measurement. The physicochemical properties of different corrosion products are compared.

  20. Corrosion in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Brondel, D. (Sedco Forex, Montrouge (France)); Edwards, R. (Schlumberger Well Services, Columbus, OH (United States)); Hayman, A. (Etudes et Productions Schlumberger, Clamart (France)); Hill, D. (Schlumberger Dowell, Tulsa, OK (United States)); Mehta, S. (Schlumberger Dowell, St. Austell (United Kingdom)); Semerad, T. (Mobil Oil Indonesia, Inc., Sumatra (Indonesia))

    1994-04-01

    Corrosion costs the oil industry billions of dollars a year, a fact that makes the role of the corrosion engineer an increasingly important one. Attention is paid to how corrosion affects every aspect of exploration and production, from offshore rigs to casing. Also the role of corrosion agents such as drilling and production fluids is reviewed. Methods of control and techniques to monitor corrosion are discussed, along with an explanation of the chemical causes of corrosion. 21 figs., 32 refs.