Degradation of metals through atmospheric corrosion is a most important and costly phenomenon with significant effects on, e.g., the lifespan of industrial materials, the reliability of electronic components and military equipment, and the aesthetic appearance of our cultural heritage. Atmospheric corrosion is the result of the interaction between the metal and its atmospheric environment, and occurs in the presence of a thin aqueous adlayer. The common incorporation of pollutant species into this adlayer usually enhances the degradation process. During atmospheric corrosion indoors, low concentrations of organic atmospheric constituents, such as formic, acetic, propionic, butyric and oxalic acids, have found to play an accelerating role on a broad range of metals or their alloys, including lead, steel, nickel, copper, cadmium, magnesium and zinc. In this doctoral thesis the initial stages of the atmospheric corrosion of copper exposed to synthetic air, aiming at simulating representative indoor atmospheric environments, have been investigated both experimentally and through a computational method. The experiments have been based on a unique analytical setup in which a quartz crystal microbalance (QCM) was integrated with infrared reflection absorption spectroscopy (IRAS). This enabled the initial atmospheric corrosion of copper to be analyzed during ongoing corrosion in humidified air at room temperature and additions of 120 ppb (parts per volume billions) of acetic, formic or propionic acid. The main phases identified were copper (I) oxide (Cu2O) and various forms of copper carboxylate, and their amounts deduced with the different analytical techniques agree with a relative accuracy of 12% or better. Particular emphasis has been on the identification of different forms of copper (I) oxide generated during these exposures. An electrochemically based model has been proposed to describe how copper oxides, formed in the presence of acetic acid, are electrochemically reduced in neutral solution. The model includes the electrochemical reduction of copper (II) oxide (CuO), amorphous copper (I) oxide (Cu2O)am, intermediate copper (I) oxide (Cu2O)in, and crystalline copper (I) oxide (Cu2O)cr. A good agreement is obtained between the model and experimental data, which supports the idea of a reduction sequence which starts with copper (II) oxide and continues with the reduction of the three copper (I) oxides at more negative potentials. The quantified analytical data obtained in this doctoral study on corrosion products formed on copper, and corresponding data on zinc reported elsewhere, were used as the starting point to develop a computational model, GILDES, that describes the atmospheric corrosion processes involved. GILDES considers the whole interfacial regime in which all known chemical reactions have been considered which are assumed to govern the initial atmospheric corrosion of copper or zinc in the presence of carboxylic acids. The model includes two separate pathways, a proton-induced dissolution of cuprous ions or zinc ions followed by the formation of either copper (I) oxide or zinc (II) oxide, and a carboxylate-induced dissolution followed by the formation of either copper (II) carboxylate or zinc (II) carboxylate. The model succeeds to predict the two main phases in the corrosion products and a correct ranking of aggressiveness of the three acids for both copper and zinc. The ranking has been attributed to differences in acid dissociation constant and deposition velocity of the carboxylic acids investigated. / QC 20111114

It has been the purpose of this PhD program to determine whether current laboratory-based methods of investigating Atmospherically-Induced Stress Corrosion Cracking (AISCC) of austenitic Stainless Steels (SS) are adequate in modelling realistic corrosion processes within a marine aerosol environment. Results obtained throughout the study have sought to address three key aims. Mainly, to understand the nature and behaviour of primary marine aerosol containing organic matter present within oceanic surface waters, the interfacial interactions of such aerosol droplets deposited on to austenitic stainless steels and, ultimately, their impact upon AISCC processes. Based upon the work conducted during this research, several conclusions may be deduced. The presence of primary organic components within a sea-salt aerosol leads to a reduction in surface tension at the liquid-vapour interface; highlighting the surface-active nature of algal exudates. Surface-active constituents also have the potential to aggregate at the liquid-solid interface. The inclusion of exudates, therefore, has the potential to maintain an electrolytic environment on an austenitic steel substrate for an elongated time period under ambient conditions. Following subsequent evaporation, organically-enriched seawater droplets typically produce an organic surface film. The results of these interfacial studies have informed AISCC measurements using U-bend specimens, which demonstrate a correlation between cracking and droplet size. Furthermore, the limiting factor for AISCC may not be a function of deposition density as previously thought but rather of droplet surface area.

No description available.

No description available.

O cobre e suas ligas constitui um dois metais mais amplamente utilizados para a produção de peças com interesse histórico. Isto se deve a sua grande capacidade de combinar com outros compostos, formando pátinas das mais diversas colorações. As peças metálicas do patrimônio histórico se encontram submetidas a condições de exposição atmosférica cada vez mais agressiva, porém frente à necessidade de preservação de nossas memórias históricas este patrimônio deve ser submetido a intervenções de natureza preventiva. O presente trabalho tem por objetivo investigar o comportamento de cobre em águas de chuva sintéticas de São Paulo e de Rio de Janeiro e em solução de NaCl 0,1 M. Investiga-se também o processo de consolidação destas patinas e a ação anticorrosiva das camadas de verniz geralmente utilizado para a proteção do patrimônio histórico (Paraloide B-72) nas soluções e águas de chuva sintéticas. As técnicas eletroquímicas empregadas foram o acompanhamento do potencial de circuito aberto, curvas de polarização anódica e catódica e a espectroscopia de impedância eletroquímica. Como técnicas de caracterização microestrutural e química foram empregadas a microscopia eletrônica de varredura, a difração de raios X e a espectroscopia de fotoelétrons de raios X. Os resultados mostraram que, entre os vernizes empregados para a proteção do patrimônio histórico, os do tipo paralóide são menos suscetíveis à umidade que a cera microcristalina. Para avaliar a resposta do sistema cobre + pátina é importante compreender como o substrato não-tratado responde eletroquimicamente quando é exposto às águas de chuva sintéticas. Os resultados mostraram que na água de chuva sintética do Rio de Janeiro, com baixa concentração de amônio, o ataque prosseguia nas regiões defeituosas da camada de cuprita. Na água de chuva de São Paulo, onde os íons de amônio são abundantes, a regeneração parcial da cuprita ocorre de maneira uniforme melhorando o comportamento eletroquímico. Por sua vez, as pátinas artificiais sobre o substrato de cobre apresentaram uma melhor consolidação quando expostas à atmosfera aberta (Laboratório de Eletroquímica e Corrosão) do que quando expostas a um ambiente com completa ausência de umidade (dessecador). Nos ensaios intermitentes, as pátinas desenvolveram respostas de impedância típica de eletrodo poroso com comprimento de poro semi-infinito seguindo um modelo clássico (DE LEVIE, 1964). Por outro lado, nas amostras de cobre revestidas com paralóide B-72, o grau de diminuição da capacidade protetora após períodos longos de exposição à luz foi atribuída a degradação foto-oxidativa do verniz. A associação do cobre com pátina, sobre a qual se aplicava o verniz Paralóide B-72, mostrou que o sistema de revestimento aumenta a proteção contra a corrosão em ensaios intermitentes. Nos ensaios de imersão contínua, nem as pátinas sozinhas nem quando protegidas com o verniz polaróide, suportaram esses ensaios sem apresentar destacamento. / Copper is one of the metals most widely used to produce metallic artifacts of the artistic and cultural heritage. This is partially due to its great ability to combine with other compounds, forming patinas of different colors. Many of such artifacts are permanently exposed to open air, being thus subjected to the action of atmospheric agents such as rain and pollutants. Thus, these cultural heritage monuments must be submitted to interventions of preventive nature. This work is devoted to investigate the electrochemical behavior of pure copper, with and without an artificial patina layer, in contact with São Paulo and Rio de Janeiro synthetic rainwater and in NaCl 0,1M solution. The consolidation process of these patinas and the anticorrosive action of varnishes generally used for the protection of the cultural heritage were also investigated. The electrochemical techniques used in this work were: cathodic and anodic potentiodynamic polarization curves and electrochemical impedance spectroscopy. Microstructural and chemical characterizations were performed by means of Scanning Electronic Microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results had shown that the varnishes of Paraloid type used for the protection of the historic monuments are less susceptible to the humidity than the microcrystalline wax. The experiments performed with copper in the synthetic rainwater evidenced an important role for the ammonium ions in the corrosion process. Although with a high complexation power towards copper, accelerating its dissolution rate, these ions participate in the partial regeneration of cuprite. Therefore, in the Rio de Janeiro synthetic rainwater, with low ammonium concentration, once the corrosive attack has started it proceeds in the defective regions of the cuprite layer. On the other hand, in the São Paulo synthetic rainwater, where ammonium ions are more abundant, partial regeneration of cuprite occurs and the electrochemical behavior of copper remains stable with time. The experiments performed with copper coated with an artificial patina layer showed better consolidation of these latter when exposed to the open atmosphere (Electrochemistry and Corrosion Laboratory) when compared to samples stored in a dissecator, where humidity is absent. In the intermittent tests patinated samples developed an impedance response which was typical from porous electrode with semi-infinite porous length, in accordance with the classical model proposed by de Levie (DE LEVIE, 1964). On the other hand, Paraloid B-72 coated samples presented a strong degradation when exposed to sunlight for long exposure periods, which was ascribed to the photooxidative degradation of the coating. The system copper plus patina with a Paraloid B-72 layer showed a good protection towards corrosion, as long as photooxidative degradation had not begun. On the other hand, in the continuous immersion tests, neither the patinas nor the Paraloid varnish exhibited a good performance and were detached after relatively short testing period.

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 analytical studies that are neededin order to understand the fundamentals on a molecular level. Consequently,in-situ vibrational techniques, providing molecular information, have beenutilized in this work to study atmospheric corrosion by targeting the initialstages of the interaction between corrosive air and a metal surface. The initialstages (from minutes until days of exposure) were studied as these havea large influence on the atmospheric corrosion for prolonged exposure times. More specifically, the interaction between humidified air to which organicacids were added, and zinc was targeted in order to address a situation inindoor atmospheric corrosion, where organic acids are of importance. Zinc isa constituent in e.g. brass, which is an alloy used in many indoor applications. A systematic investigation utilizing complementary acting vibrational techniquesthus enabled detailed information on the mechanisms of the onsetof atmospheric corrosion of zinc induced by acetic and formic acid. Corrosionproducts of both two dimensional and three dimensional character couldbe separately studied by combining VSFS (interface sensitive), IRAS (nearsurfacesensitive), and CRM (bulk sensitive). The Zn surface was found to be heterogeneous with different hydroxylgroups present on the surface. As this surface was exposed to formic or aceticacid, the OH groups on the surface were rapidly displaced in a ligand exchangewith formate or acetate. These ligands, organised in two dimensionalstructures, promoted corrosion by weakening the bonds of the Zn atoms totheir surrounding matrix. The subsequent growth of three dimensional corrosion products, Zn hydroxyacetate and formate, observed within short exposure times of Zn exposedto acetic and formic acid, was found to be electrochemical in nature.Cathodic areas consisting of more crystalline ZnO were observed. The potentialdifference between these more noble areas on the surface and those of lessnoble character created an electrochemical cell, initiating release of Zn ionsinto the aqueous adlayer in the anodic reactions. These Zn ions precipitatedas localised corrosion products. The cathodic areas increased the local pHon the surface, thereby promoting precipitation in their vicinity. The resultson initial stages of this type of corrosion were found to have similarities withprevious field studies of Zn exposed to real indoor environments. One way to decrease the corrosion rate of zinc is by adsorbing a corrosioninhibitor to the metal surface in order to protect it. As a model for sucha corrosion inhibitor, octadecanethiol (CH3(CH2)17SH) was seen to provideincreased corrosion protection of both reduced and oxidised Zn substrates byforming an adsorbed surface layer with an ordered structure. / QC 20100719

The 1990s has seen an increased awareness of possible environmental effects of corrosion-induced metal release from outdoor constructions. Considerable efforts have been initiated to perform critical assessments of possible risks of selected metals. Gaps of knowledge have been identified and research investigations started. This doctoral thesis is the result of an interdisciplinary research effort in which scientific insight into corrosion, soil chemistry and ecotoxicology has been integrated. The work comprises atmospheric exposure of pure metals and commercial materials for outdoor use. The focus is on release of four metals, copper, zinc, chromium and nickel. Their chemical speciation and bioavailable fraction in metal runoff were determined, both at the release moment and after environmental interaction with, e.g., soil and limestone. Total metal concentrations in runoff are influenced both by material properties (e.g., corrosion product solubility, and specific surface area) and by exposure parameters (e.g., rain volume, intensity, contact time and pollutants). Long-term runoff rates of copper, zinc, chromium and nickel were based on exposures (4-8 years) at standardized conditions (45o inclination facing south) in Stockholm, Sweden. Runoff rates for pure copper range from 1.2 to 1.5 g m-2 yr-1, depending on year. At the copper release moment the potential environmental effect was evaluated using 72 hours growth inhibition test with the green algae Raphidocelis subcapitata. This resulted in a mean value of 15 μg L-1 causing a 50% growth reduction (EC50). Long-term runoff rates for pure zinc range from 1.9 to 2.5 g m-2 yr-1. A considerable variation in average annual runoff rates (0.07-2.5 mg zinc m2yr-1) was observed between different investigated commercial zinc-based materials. An average 72 hour (EC50) value of 69 μg L-1 towards Raphidocelis subcapitata was found for runoff water from zinc-based materials. Long-term runoff rates from stainless steel of grade 304 and 316 range from 0.23 to 0.30 chromium and 0.28 to 0.52 nickel mg m-2 yr-1, with corresponding concentrations in the runoff at the release moment far below reported ecotoxic concentrations for chromium and nickel. Two predictive runoff rate models were successfully developed for transforming copper runoff rate data from Stockholm to other exposure sites. One model is based on rain pH, yearly precipitation and building geometry, and the other on average annual SO2 concentration, yearly precipitation and building geometry. In addition to total metal concentration, adequate effect assessments also require information on chemical speciation of the released metal and its bioavailability. Metal chemical speciation in runoff was determined experimentally through an ion selective electrode (for copper), and also modelled with the Windermere Humic Aquatic model (WHAM (V)). Bioavailability assessments were generated through bioassay tests. At the moment of metal release, all methods show that the majority (60-99%) of the metal in runoff exists in its most bioavailable form, the hydrated metal ion. During subsequent environmental entry the metal undergoes major reductions in concentration and bioavailability. This was evidenced by model column studies of the capacity of soil to retain and immobilize the metal in runoff water, and by model and field column studies of the capacity of limestone to retain copper. The retention by soil of all metals investigated is very high (96-99.8%) until each materials retention capacity is reached. Limestone also exhibits a substantial capacity (5- 47%) to retain copper. The capacity is significantly increased by increased amount and decreased fraction of limestone particles. Any outer or inner surface with significant retention ability and with low possibility of subsequent mobilization is an excellent candidate for neutralizing metal release and its potential ecotoxic effects. This was demonstrated through computer modelling (WHAM(V)) and biosensor tests (Biomet™), which showed the most bioavailable and ecotoxic metal species to be reduced during passage through soil and limestone. Predictions based on the computer model HYDRUS-1D suggest a time-period of between 4 and 8000 years, depending on runoff water and soil characteristics, before saturation in soil retention capacity of copper and zinc is reached. A significant fraction of the retained metal is extractable towards the strong complexing agent EDTA, indicating possible future mobilisation. It is also available for plant uptake, as shown by DGT- (Diffuse Gradients in Thin films-) analysis of copper and zinc in soil. The data generated, presented and discussed are all believed to be important for risk assessment work related to corrosion-induced metal release from outdoor constructions. As evidenced from this doctoral thesis, such work requires a complete set of data on annual runoff rates, concentrations, chemical speciation and bioavailability and its changes during environmental entry, together with knowledge on, e.g., type of material, service life of coating, building geometry, and dewatering system. / QC 20100901

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 experimental set-up for in situ FTIR microspectroscopy. Lateral distribution of corrosion and reaction products on copper and zinc surfaces was determined and could be connected with the mechanisms of the initial particle induced corrosion. The recently discovered secondary spreading effect from NaCl electrolyte droplets on metal surfaces was studied under in situ conditions and the effect of CO2 on the spreading process was elaborated. The ambient level of CO2 (350 ppm, 1 ppm = 10-6 volume parts) results in a relatively low secondary spreading effect, whereas the lower level of CO2 (<5 ppm) causes a much faster secondary spreading effect over a large area. At low CO2 concentration alkaline conditions will prevail in the cathodic area, leading to large changes in the surface tension at the oxide/electrolyte interface in the peripherical parts of the droplet. This induces a surface tension driven convective flow of electrolyte from the NaCl droplet. The continuous growth of the secondary spreading area at low CO2 concentration is possible due to the galvanic coupling with the droplet leading to transport of sodium ions to this region and maintenance of the alkaline conditions. At 350 ppm CO2, carbonate formation in the secondary spreading area results in lowering of the pH, increasing the surface tension of the oxide/electrolyte interface and inhibiting the secondary spreading. CO2 strongly affects the NaCl-induced atmospheric corrosion rate of copper. The overall influence of CO2 and NaCl depends on at least three identified mechanisms. At low NaCl particle density, CO2 affects the secondary spreading effect from the electrolyte droplet. This leads to a larger effective cathodic area at low CO2 concentration and a higher corrosion rate. The more alkaline surface electrolyte present at low CO2 concentration also affects the formation of corrosion products and the amount of soluble copper chloride. Whereas the presence of larger amounts of soluble chloride tends to increase the corrosion rate, the formation of CuO results in a more protective surface film which decreases the corrosion rate. This effect was observed at higher NaCl particle densities, where the secondary spreading areas overlapped with adjacent NaCl particle clusters. The formation of CuO leads to lower corrosion rates compared to ambient CO2 concentration in which this phase was not formed. For zinc, the formation of a more protective corrosion product layer was not observed and the corrosion rate is generally higher for low than for ambient CO2 concentration. The presence of NaCl particles on the metal surfaces strongly affects the SO2 interaction with the metal surfaces. The oxidation of S(IV) turned out to be fast at the area of the NaCl-containing electrolyte droplet, both for copper and zinc. On copper surfaces, both sulphate (SO4 2-) and dithionate (S2O6 2-) ions formed which is consistent with a copper catalysed reaction route for sulfite oxidation including the formation of a Cu(II)–sulfito complex as an important step. For zinc, a surface mediated sulfite oxidation process leads to rapid formation of sulphate in the electrolyte droplet area. The presence of SO2 strongly inhibits the secondary spreading due to the decrease in pH induced by absorption of SO2 in the cathodic areas. The presence of gaseous oxidants, such as NO2 and O3, has previously been considered as an important prerequisite for the oxidation of sulfite on copper. The results obtained here suggest that the formation of local electrochemical cells induced by deposited NaCl particles could be another important route for S(IV)- oxidation to sulfate formation. On copper, SO2 was also found to promote the formation of less soluble copper chlorides, such as paratacamite (Cu2(OH)3Cl) and nantokite (CuCl). The electrolyte droplet was dried after 24 hours of exposure due to the formation of less soluble paratacamite (Cu2(OH)3Cl) and nantokite (CuCl) and led to a decrease in the corrosion rate. Thus, SO2 alone promotes the corrosion rate of copper, whereas in the presence of NaCl particles the corrosion rate of copper may slow down due to the formation of insoluble copper chloride compounds. The lateral distribution of corrosion products after exposure of NaCl contaminated copper and zinc surfaces to humid air with gaseous pollutants is a result of the formation of local electrochemical cells at the particles and concomitant differences in chemical composition and pH. For (NH4)2SO4 deposited copper and zinc surfaces the corrosion effects increase with the amount of pre-deposited particles and with the exposure time. On copper, the size of the particles affects the corrosion rate, smaller particles resulting in a higher corrosion rate than larger particles at equal amount of deposition. The formation of Cu2O was the dominant corrosion product after exposure longer than 10 days. (NH4)2SO4 particles result in enhanced Cu2O formation on copper due to a reaction sequence involving catalysis by NH3. The corrosion of copper by (NH4)2SO4 particles was much larger than that induced by NaCl particles. However, for zinc, the (NH4)2SO4 particles lead to smaller corrosion effects than those of NaCl particles. For both particles, significant corrosion attack was observed at relative humidity (RH) lower than the deliquescence point of the salts. / QC 20101001

<p>The interaction of carboxylic acids with copper is a phenomenon found both outdoors and, more commonly, indoors. The influence on copper of some carboxylic acids (formic, acetic, propionic, and butyric) have so far been studied at concentrations levels at least three or four orders of magnitude higher than actual indoor conditions (< 20 ppb, volume parts per billion), and with only limited emphasis on any mechanistic approach. In this licentiate study a unique analytical setup has been successfully applied for <i>in situ </i>characterization and quantification of corrosion products formed during initial atmospheric corrosion of copper in the presence of acetic, formic or propionic acid. The setup is based on monitoring mass changes by the quartz crystal microbalance (QCM) and simultaneously identifying the chemical species by infrared reflection-absorption spectroscopy (IRAS). Post-analysis of corrosion products was performed by coulometric reduction (mass of copper (I) oxide formed), grazing incidence x-ray diffraction (phase identification) and atomic force microscopy (surface topography).</p><p>The absolute amounts of mass of individual constituents in the corrosion products, mainly copper (I) oxide or cuprite, copper (II) carboxylate and water or hydroxyl groups, have been deduced<i> in situ</i> during exposure in 120 ppb of carboxylic acid concentration, 95% relative humidity and 20ºC. An overall result is the consistency of analytical information obtained. For copper (I) oxide the quantified data estimated from IRAS, QCM or coulomeric reduction agrees with a relative accuracy of 12 % or better.</p><p>The interaction of copper with the carboxylic acids seems to follow two spatially separated main pathways. A proton-induced dissolution of cuprous ions followed by the formation of copper (I) oxide, and a carboxylate-induced dissolution followed by the formation of copper (II) carboxylate. The first pathway is initially very fast but levels off with a more uniform growth over the surface. This pathway dominates in acetic acid. The second pathway exhibits a more constant growth rate and localized growth, and dominates in formic acid. Propionic acid exhibits low rates for both pathways. The difference between the carboxylic acids with respect to both total corrosion rate and carboxylate-induced dissolution can be attributed to differences in acid dissociation constant and deposition velocity.</p>

Tiriamajame magistriniame darbe nagrinėjamos UAB “Anykščių Varis“ kuriamų glaistytųjų elektrodų, skirtų atsparių atmosferiniai korozijai COR-TEN® grupės plienų suvirinimui, charakteristikos. Tyrimų eigoje atlikti bandymai ir kokybės tyrimas, reglamentuojamas standartu LST EN 14532-1. Tyrimo objektais pasirinkti ne tik sukurti eksperimentiniai glaistytieji elektrodai, bet ir panašios cheminės sudėties jau egzistuojantys AV-61 ir UONI-13/55 elektrodai. Atsižvelgiant į specifinę elektrodų paskirtį, remiantis atliktais bandymais ir turima gamintojų patirtimi, naujų elektrodų glaisto sudėtyje yra kiti komponentai. Papildomai glaiste yra Cr ir Ni bei Cr, Ni ir Cu miltelių. Tiriamasis darbas paremtas kuriamų glaistytųjų elektrodų charakteristikų palyginimu su jau egzistuojančiais rinkoje elektrodais. Darbą sudaro šios struktūrinės dalys: paveikslėlių sąrašas, lentelių sąrašas, įvadas, atsparūs atmosferiniai korozijai plienai, glaistytųjų elektrodų gamyba, apžvalga, kokybės ir atitikties vertinimas, tyrimo metodika ir medžiagos, tyrimo rezultatai, išvados ir siūlymai, literatūros sąrašas. Darbo apimtis – 73 psl. teksto be priedų, 38 iliustr., 34 lent., 29 bibliografiniai šaltiniai. / In the final masters degree thesis the characteristics of Ltd. "Anykščių Varis" produced coated electrodes for resistant to atmospheric corrosion COR-TEN® steel group welding are examined. Testing and quality analysis are prepared according the standard LST EN 14532-1. The experimental covered electrodes and similar chemical composition already existing AS-61 and UONI-13/55 covered electrodes used as research object in this work. New covered electrodes coating contains other components due to the specific purpose of the electrodes and experimental practice of producers. In addition, the electrodes coating consists Cr and Ni and Cr, Ni and Cu powders. Research work based on the characteristics of coated electrodes comparison with the already existing market of electrodes and compliance for welding COR-TEN® steels group. The structure of thesis consists: list of pictures, list of tables, introduction, resistant to atmospheric corrosion steels part, manufacture, overview, quality and compliance qualification of covered electrodes part, research methodology and materials, results of research, conclusions and suggestions, references. Thesis consist of: 73 p. text without appendixes, 38 pictures, 34 tables, 29 bibliographical entries.