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  • 1.
    Abi Nassif, L.
    et al.
    University Brest, France; University Saint Joseph, France.
    Rioual, S.
    University Brest, France.
    Farah, W.
    University Saint Joseph, France.
    Hellio, C.
    University Brest, France.
    Fauchon, M.
    University Brest, France.
    Trepos, R.
    University Brest, France.
    Abboud, M.
    University Saint Joseph, France.
    Diler, Erwan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Lescop, B.
    University Brest, France.
    Reduction of potential ennoblement of stainless steel in natural seawater by an ecofriendly biopolymer2020In: Journal of Environmental Chemical Engineering, E-ISSN 2213-3437, Vol. 8, no 1, article id 103609Article in journal (Refereed)
    Abstract [en]

    The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1 % of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4 % of the active material is observed authorizing thereby long-term protection of steel in real environment. 

  • 2.
    Becker, Johan
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Pellé, J.
    Univ Brest, France.
    Rioual, S.
    Univ Brest, France.
    Lescop, B.
    Univ Brest, France.
    Le Bozec, Nathalie
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Atmospheric corrosion of silver, copper and nickel exposed to hydrogen sulphide: a multi-analytical investigation approach2022In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 209, article id 110726Article in journal (Refereed)
    Abstract [en]

    The effect of two concentrations of H2S (0.5 and 2.5 ppm), in controlled laboratory conditions (20 °C, 75%RH), on the atmospheric corrosion of pure Ag, Cu and Ni was investigated in this study. The corrosion product morphology and composition were analysed through a multi-technique approach including SEM/EDX, Raman spectroscopy, XPS and XRD. Different corrosion products were identified depending on the type of characterisations providing a better overview of the effect of H2S on the atmospheric corrosion of pure Ag, Cu and Ni. Possible mechanisms involved in the formation of these corrosion products are also discussed in this work. © 2022 The Authors

  • 3.
    Bonin, Pierre
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion. Université de Toulouse, France.
    Roggero, Aurelien
    Université de Toulouse, France.
    Caussé, Nicolas
    Université de Toulouse, France.
    Pébère, Nadine
    Université de Toulouse, France.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Le Bozec, Natalie
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Impedance analysis of the barrier effect of coil-coated materials: Water uptake and glass transition variations2021In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 153, article id 106163Article in journal (Refereed)
    Abstract [en]

    In the present work, an industrial polyester coil-coated steel sample was characterized by electrochemical impedance spectroscopy. The diagrams were obtained for various immersion times in a 0.5 M NaCl solution for three different initial states of the same coil coating (as received, dried and dried after the impedance measurements). The aim of the study was to have a better knowledge of how the water uptake influences the coil coating physical properties and to extract relevant parameters of the ageing processes. From the high-frequency part of the impedance diagrams, the water uptake was calculated using a linear rule of mixtures. Two sorption regions were observed for the dried samples suggesting the presence of porosities already filled with ambient moisture for the as-received sample. It was shown that the water uptake was a slow process and, independently of the initial state of the sample, a saturation plateau was never reached, even after 456 h of immersion. A time constant, clearly visible on the phase angle of the impedance diagrams, was analysed through the dielectric permittivity formalism and attributed to the signature of the dielectric manifestation of the glass transition. This time constant was shifted to higher frequencies with increasing water fraction (increasing immersion time), consistent with a plasticization effect. This result was supported by differential scanning calorimetry measurements. Finally, the data obtained for the different initial states of the coating highlighted that, even if the water uptake was reversible, the sorption kinetics was different for the sample dried after the impedance measurements. This could be of importance in the degradation process of the coil coated steel. 

  • 4.
    Cassagne, Thierry B.
    et al.
    Total EP, France.
    Thierry, Dominique
    RISE, Swerea, KIMAB.
    Larché, Nicolas
    RISE, Swerea, KIMAB.
    Kivisäkk, Ulf
    Sandvik Material Technology, Sweden.
    Eidhagen, Josefin
    Sandvik Material Technology, Sweden.
    Mehus, L.
    Aker Subsea, Norway.
    Van Thoor, Karin
    Aker Subsea, Norway.
    Long term corrosion testing and monitoring of oxygen and corrosion potential in an umbilical design2012In: NACE - International Corrosion Conference Series, 2012, Vol. 2, p. 1096-1108Conference paper (Refereed)
    Abstract [en]

    Subsea umbilicals are used for control and operation of subsea oil and gas production facilities. Typically an umbilical consists of steel tubes, electrical cables, fiber optic cables, weight or strength elements and fillers. Super duplex stainless steel tube material has been used for almost 20 years within the umbilical industry. However, a recent failure on two orbital welds of 25Cr super duplex of an umbilical installed in the South China Sea was reported. From these results some umbilical end users recommended the use of thermoplastic coating to avoid crevice corrosion on 25Cr super duplex stainless steel above 20°C. However, this limit is based on results obtained for super duplex stainless steel in aerated natural seawater and very little is known on the micro-environment formed by the confined seawater between metallic tubes and polymer matrix of an umbilical. This work reports corrosion potential and oxygen content measurements in the confined zone between the metallic tubes and the polymer matrix of an umbilical. These measurements were performed using micro-electrodes on a 2 meter long real umbilical at 30°C in heated natural seawater. From the measurements, it is shown that the oxygen content in the confined zone is rapidly consumed probably due to the passive current on the stainless steel tubes and then remains below 2 ppm over one year exposure period. From the open-circuit potential measurements performed in the confined zone, it is clear that the open circuit potential remained below -150 mV/AgCl. This translates an absence of electrochemical effect of the biofilm in the confined zone. Visual and metallographic examinations of the tubes after exposure confirmed the results obtained by the microelectrodes and clearly indicate that no corrosion initiation occurred on superduplex stainless steel (base metal and welds) under these experimental conditions. The results are discussed in view of the validity of corrosion tests performed under aerated conditions and the need of further developments of new testing procedures to represent the confined situation in the umbilical design.

  • 5.
    Caussé, Nicolas
    et al.
    Université de Toulouse, France.
    Bonin, Pierre
    RISE Research Institutes of Sweden, Materials and Production, Corrosion. Université de Toulouse, France.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion. Université de Toulouse, France.
    Le Bozec, Nathalie
    Université de Lyon, France.
    Roggero, Aurelien
    Université de Lyon, France.
    Pébère, Nadine
    Université de Toulouse, France.
    Ageing processes of coil-coated materials: Temperature-controlled electrochemical impedance analysis2023In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 183, article id 107682Article in journal (Refereed)
    Abstract [en]

    In the present work, an industrial polyester coil-coated steel was characterized by electrochemical impedance spectroscopy (EIS) during immersion in a 0.5 M NaCl solution for different temperatures (30, 40, 50 and 60 °C). The objective was to propose a methodology to follow the ageing of the coil-coated system, from the first stage of water uptake until the blistering appearance. Relevant parameters were extracted from the EIS diagrams to analyse ageing processes of the polymer and of the metal/polymer interface. Water uptake was determined from the high-frequency part of the impedance diagrams using a linear rule of mixtures. By increasing the temperature, both the water uptake kinetics and the water content in the coating increased. The effect of water uptake on the physical structure of the coating (plasticization) was discussed through the analysis of a time constant corresponding to the dielectric manifestation of the polymer glass transition. At 40, 50 and 60 °C, appearance of corrosion was detected on the impedance spectra by a decrease, at low frequency, of the impedance modulus and of the phase angle. For 60 °C, the corroded surface area as a function of time, was assessed from the EIS data analysis with adapted equivalent circuits. The corroded surface areas followed similar trend as blister surface areas determined from images analysis.

  • 6.
    Cooze, N.
    et al.
    Swansea University, UK.
    Sullivan, J.
    Swansea University, UK.
    Lewis, T.
    Swansea University, UK.
    Gallagher, C.
    Swansea University, UK.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Prosek, Tomas
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    A novel time-lapse microscopy technique to study the corrosion mechanisms and effects of phosphate inhibitor during the corrosion of a zinc-magnesium-aluminium alloy coating2017In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017, Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers , 2017Conference paper (Refereed)
  • 7.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Larche, Nicolas
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Degres, Yves
    NKE, France.
    Biofilm sensor for deep sea2014In: 2014 IEEE Sensor Systems for a Changing Ocean, SSCO 2014, Institute of Electrical and Electronics Engineers Inc. , 2014Conference paper (Refereed)
    Abstract [en]

    In natural seawater, surfaces will be rapidly covered by microorganisms which form a thin film called biofilm. It is now generally admitted that biofilms may affect the electrochemical behavior of metals and alloys and thereby may accelerate the corrosion of the material. Biofilms formed in seawater around the World does not necessarily present the same aggressiveness in terms of corrosion risk, and recently some high alloy stainless steel corrosion failures were attributed to the particular aggressiveness of biofilms which form in tropical seawaters. In deep sea, the biofilm activity as well as the corrosion risk induced by these phenomena has to be assessed. The objective of the present study was to develop an autonomous sensor able to characterize seawater biofilms through their electrochemical effects on stainless steel surface. The sensor is able to in-situ detect the potential ennoblement and to quantify the cathodic reduction efficiency of biofilmed stainless steel, which is a major parameter to quantify the risk of corrosion propagation on these alloys, as well as the bacterial presence and activity. This sensor will be able to be deployed down to 3000 m depth for long term measurements.

  • 8.
    Diler, Erwan
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Larché, Nicholas
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Cathodic activity on passive materials in deep seawater2020In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 76, no 4, p. 344-355Article in journal (Refereed)
    Abstract [en]

    In this study, the cathodic activity of biofilmed stainless steel surfaces was investigated at two exposure depths at the same location at 1,020 m and 2,020 m depth. For this purpose, a set of passive materials and sensors were exposed for 11 months in Azores, in the Atlantic Ocean. Characteristic cathodic depolarizations due to biological activity were observed in intermediary and deep water. However, a strong cathodic activity was only measured in deep water. Potential ennoblement appeared between 80 d and 200 d, depending on the exposure depth and the experimental setup used. In a given environment, the biological cathodic activity appears to be strongly related to the limiting parameter of the reaction, which can be anodic or cathodic. The biofilm sensors exposed for the first time in open, deep water appear relevant to discriminate cathodically “strongly-active” and “weakly-active” biological activity. Under cathodic control, a high current density was measured on stainless steel in deep seawater. The experimental setup used is particularly relevant as it allows determination in situ of the maximal cathodic current density.

  • 9.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Larché, Nicolas
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Carbon steel and stainless-steel cathodic protection design data in Deepsea Water - Influence of the environment on the biofilm cathodic activity2019In: NACE - International Corrosion Conference SeriesVolume 2019-March, 2019, Article number 13124Corrosion Conference and Expo 2019; Nashville; United States; 24 March 2019 through 28 March 2019, National Assoc. of Corrosion Engineers International , 2019Conference paper (Refereed)
    Abstract [en]

    In natural seawater, many parameters might influence the cathodic protection current demand such as potential, temperature, dissolved oxygen content, biofilm and fouling activity, and calcareous deposit formation. The actual deepsea environment cannot be easily reproduced at laboratory scale. In this study, the influence of the depth on the cathodic protection criteria of carbon steel and stainless steel was investigated in intermediary (1020 m depth) and deep water (2020 m) at the same location. For this purpose, at set of corrosion and environmental sensors, as well as metallic coupons, were exposed during 11 months in Azores in the Atlantic Ocean. On stainless steel, a strong characteristic cathodic depolarization due to biofilm activity was observed in deep water and not in intermediary water. The biological-induced cathodic activity appears thus to be dependent on the environment, even in open seawater. In presence of an electroactive biofilm high and relatively stable current densities were measured. Under such conditions, an important structure depolarization appears, affecting thus the CP design and efficiency. For carbon steel, the cathodic protection data collected in-situ show that the initial and mean (after 11 months) current densities are higher than those recommended by the DNVGL RP B401 standard. Even if mean current densities are expected to continue to decrease slowly with further exposure time, so probably tending to the standard recommendations, the DNVGL RP B401 standard might not be conservative in terms of current densities criteria for these environments. 

  • 10.
    Diler, Erwan
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Leblanc, Vanessa
    Corrodys, France.
    Gueuné, Herve
    Corrodys, France.
    Larché, Nicolas
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Deydier, Valerie
    ANDRA Agence nationale pour la gestion des déchets radioactifs, France.
    Linard, Yannick
    ANDRA Agence nationale pour la gestion des déchets radioactifs, France.
    Crusset, Didier
    ANDRA Agence nationale pour la gestion des déchets radioactifs, France.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Potential influence of microorganisms on the corrosion of carbon steel in the French high- and intermediate-level long-lived radioactive waste disposal context2021In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 72, no 1-2, p. 218-234Article in journal (Refereed)
    Abstract [en]

    In the context of the high-level radioactive waste disposal CIGEO, the corrosion rate due to microbially influenced corrosion (MIC) has to be evaluated. In France, it is envisaged to dispose of high- and intermediate-level long-lived radioactive waste at a depth of 500 m in a deep geological disposal, drilled in the Callovo-Oxfordian claystone (Cox) formation. To do so, a carbon steel casing will be inserted inside disposal cells, which are horizontal tunnels drilled in the Cox. A specific cement grout will be injected between the carbon steel casing and the claystone. A study was conducted to evaluate the possibility of MIC on carbon steel in the foreseeable high radioactive waste disposal. The corrosiveness of various environments was investigated at 50°C and 80°C with or without microorganisms enriched from samples of Andra's underground research laboratory. The monitoring of corrosion during the experiments was ensured using gravimetric method and real-time corrosion monitoring using sensors based on the measurements of the electrical resistance. The corrosion data were completed with microbiological analyses including cultural and molecular characterizations.

  • 11.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Ledan, Frédéric
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    LeBozec, Nathalie
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Real-time monitoring of the degradation of metallic and organic coatings using electrical resistance sensors2017In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 68, no 12, p. 1365-1376Article in journal (Refereed)
    Abstract [en]

    The development of new metallic coatings to protect steel, as well as the optimization of maintenance operations on site requires obtaining relevant corrosion data as function of the exposure conditions. In atmospheric and aggressive environments such as under accelerated corrosion tests or in coastal zones, electrical resistance (ER) sensors have demonstrated their ability to provide relevant real-time corrosion data. Among the sensors commercially available, only single material such as steel, zinc, copper are proposed. However, even if this allows obtaining interesting corrosion data for such reference materials, these data are not representative of industrial systems, such as galvanized steel. Indeed, zinc-based coatings can contain different alloying elements, e.g., aluminum and magnesium, which impact drastically their resistance to corrosion. In addition, with single material sensors, the influence of the galvanic coupling between the coating and the substrate, in the presence of a defect or a cut edge is not considered. In this study, hot dip galvanized, electrogalvanized, and painted steel ER sensors are exposed in accelerated corrosion tests. The results show that this method is very promising to (i) detect the red rust apparition; (ii) assess the corrosion resistance of industrial zinc and organic coatings; and (iii) obtain relevant data in real-time along the exposure time. 

  • 12.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB. Universite de Brest, France.
    Lescop, Benoit
    Universite de Brest, France.
    Rioual, Stephane
    Universite de Brest, France.
    Nguyen Vien, G.
    Universite de Brest, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Rouvellou, B.
    Universite de Brest, France.
    Initial formation of corrosion products on pure zinc and MgZn2 examinated by XPS2014In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 79, p. 83-88Article in journal (Refereed)
    Abstract [en]

    A corrosion behaviour study of pure phases of zinc and zinc-magnesium (MgZn2) exposed to humid air at 35°C for 4days is presented. For zinc, hydroxide formation at the surface and zinc oxide in the first innerlayers is observed. The corrosion of the MgZn2 leads to the segregation of magnesium at the surface to mainly form magnesium hydroxycarbonate: the presence of magnesium modifies the corrosion products. At larger depths, metallic zinc coexists with magnesium oxide and hydrozincite. The higher reactivity of MgZn2 alloy can be attributed to the interaction with carbonate ions.

  • 13.
    Diler, Erwan
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Peltier, Fabienne
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Becker, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Real-time corrosion monitoring of aluminium alloys under chloride-contaminated atmospheric conditions2021In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 72, no 8, p. 1377-1387Article in journal (Refereed)
    Abstract [en]

    In this study, the use of electrical resistance (ER) sensors to monitor the corrosion of Al94Cu6 alloy is assessed and compared with 2024-T3 coupons. Under uniform corrosion, a good correlation was found between the ER sensors and mass loss on coupons. Three different chloride depositions are studied: (i) pre-contamination with dry/wet cycles, (ii) Volvo standard accelerated corrosion test and (iii) neutral salt spray test. The obtained results show good reproducibility of the ER sensors under all tested conditions. This suggests that ER sensors more levelled the effect of localised corrosion through a large surface evaluation compared with cross-sections. The corrosion thickness obtained with the ER sensors does not correspond to the mean depth obtained by cross-sections. This can be explained by the distribution and size of the localised corrosion events according to a finite element model proposed. The ER method allows obtaining useful real-time corrosion data for the understanding of the corrosion mechanisms and the development of accelerated tests. The chloride concentration, the frequency of salt application and wet/dry cycles have a strong influence on the corrosion rate of aluminium alloys. © 2021 The Authors. 

  • 14.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB. Université de Bretagne Occidentale, France.
    Rioual, Stephane
    Université de Bretagne Occidentale, France.
    Lescop, Benoit
    Université de Bretagne Occidentale, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Rouvellou, B.
    Université de Bretagne Occidentale, France.
    Chemistry of corrosion products of Zn and MgZn pure phases under atmospheric conditions2012In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 65, p. 178-186Article in journal (Refereed)
    Abstract [en]

    We present a corrosion behaviour study of pure phases of zinc and zinc-magnesium contaminated with NaCl and exposed to humid air for 30days: Zn, Mg 2Zn 11 and MgZn 2. The composition of corrosion products is analysed using infrared spectroscopy (FTIR), X-ray diffraction (XRD), ion chromatography (IC), and X-ray photoelectron spectroscopy (XPS). The improved corrosion stability of MgZn 2 is found to be connected to changes in the surface pH and to the nature of the formed corrosion products. The presence of magnesium modifies the proportion of the OH and CO 3 bonds in the corroded products. This explains the improvement in corrosion resistance.

  • 15.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB. Laboratoire de Magnétisme de Bretagne, France.
    Rioual, Stephane
    Laboratoire de Magnétisme de Bretagne, France.
    Lescop, Benoit
    Laboratoire de Magnétisme de Bretagne, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Rouvellou, B.
    Laboratoire de Magnétisme de Bretagne, France.
    Stability of ZnMgO oxide in a weak alkaline solution2012In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, no 7, p. 2819-2823Article in journal (Refereed)
    Abstract [en]

    Zinc oxide (ZnO) is a chemical compound of great interest used, for example, as photocatalyst in the purification of wastewater or polluted air. However, neither dissolution, nor photo-dissolution of ZnO is negligible: indeed, both processes reduce significantly the efficiency of photocatalysis and then lead to a secondary pollution by free Zn 2 +. In the present study, the stability of ZnMgO thin films in weak alkaline solution is investigated. We demonstrate that the replacement of Zn 2 + ion with Mg 2 + ion results in the production of a Zn 0.84Mg 0.16O solid solution, whose stability is higher than that of the ZnO sample. This alloy, thus, constitutes an alternative to the use of ZnO in photocatalysis applications. To gain more insights into the higher resistance of such alloys to the dissolution process, X-Ray photoelectron spectroscopy measurements were performed. They highlighted the role of OH group adsorption in the experimentally observed enhancement of ZnMgO stability.

  • 16.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB. Universite de Bretagne Occidentale, France.
    Rouvellou, B.
    Universite de Bretagne Occidentale, France.
    Rioual, Stephane
    Universite de Bretagne Occidentale, France.
    Lescop, Benoit
    Universite de Bretagne Occidentale, France.
    Nguyen Vien, G.
    Universite de Bretagne Occidentale, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Characterization of corrosion products of Zn and Zn-Mg-Al coated steel in a marine atmosphere2014In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 87, p. 111-117Article in journal (Refereed)
    Abstract [en]

    The corrosion behaviour of pure zinc and zinc-magnesium-aluminium alloy (ZMA) has been studied during 6months of exposure in marine environment (Brest, France). The composition of corrosion products is analysed using infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). An improved corrosion resistance of ZMA is observed. This improvement is found to be connected to Mg2+ and Al3+ induced quenching of corrosion activity and to the enhancement of NaZn4Cl(OH)6SO4·6H2O in the formed corrosion product.

  • 17.
    Duret-Thual, Claude
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Mendibide, Christoph
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Salvatori, I.
    RINA, Italy.
    Alleva, L.
    RINA, Italy.
    Trillo, E.
    SWRI, US.
    Martin, J. W.
    JWM Materials Consulting Ltd, UK.
    Assessment of the hydrogen induced stress cracking resistance of precipitation hardened nickel-based alloys using the slow strain rate tensile test method - Review of a three years test program2019In: NACE - International Corrosion Conference SeriesVolume 2019-March, 2019, Article number 13284Corrosion Conference and Expo 2019; Nashville; United States; 24 March 2019 through 28 March 2019, National Assoc. of Corrosion Engineers International , 2019Conference paper (Refereed)
    Abstract [en]

    Precipitation Hardened (PH) Ni-based alloys have proved to be sensitive to Hydrogen Induced Stress Cracking (HISC), and HISC related failures in the Oil and Gas industry have been experienced in the case of UNS N07718, UNS N07725 and UNS N07716. Slow Strain Rate Tensile (SSRT) tests conducted under cathodic polarization gave encouraging results as a means to evaluate HISC resistance when applied to UNS N07718, enabling the discrimination of acceptable and unacceptable microstructures as according to API 6A CRA. As a consequence, an extensive test program was launched on several PH Ni grades, a program sponsored by several petroleum companies. The main objectives of this program were to develop a test method to allow for the evaluation of HISC resistance, in order to rank materials and possibly define acceptance criteria for each material, and also to better understand the relationship between microstructure and HISC resistance. Twenty-eight industrial heats of PH Ni Alloys of eight material grades were fully characterized (microstructure, mechanical properties) and evaluated using the SSRT test method under applied cathodic polarization. The yield strength of the materials tested was in the range 120 to 160 ksi. The quantitative susceptibility of the materials to HISC was established using the plastic elongation pCP and the plastic elongation ratio pCP/ pinert. Test results showed that some PH alloys that exhibited acceptable microstructures, in accordance with API 6ACRA, did not necessarily exhibit high plastic elongation ratios. The need to implement HISC related tests in the selection of PH Ni base alloys for Oil and Gas applications is indicated

  • 18.
    El Masri, I.
    et al.
    Univ Brest, France.
    Lescop, B.
    Univ Brest, France.
    Talbot, P.
    Univ Brest, France.
    Vien, G. N.
    Univ Brest, France.
    Becker, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Rioual, S.
    Univ Brest, France.
    Development of a RFID sensitive tag dedicated to the monitoring of the environmental corrosiveness for indoor applications2020In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 322, article id 128602Article in journal (Refereed)
    Abstract [en]

    The environmental corrosiveness is governed for indoor applications by the presence of gaseous pollutants in air and levels of temperature and relative humidity. Its determination is a challenging task and requires the monitoring of thickness reduction of selected metals in the range of few tens of nanometers. The present work aims at developing an UHF RFID (Ultra High Frequency Radio Frequency Identification) sensor dedicated to such measurements. The sensor is based on the coupling between the antenna of a commercial RFID tag and a thin layer of copper exposed to the environment. The ability of the proposed sensor to be sensitive to a variation of the metal thickness in the range of tens of nanometers is demonstrated experimentally through exposure tests in a climatic chamber. The results are supported by electromagnetic simulations performed in the case of a coupling between a dipolar antenna and a thin metallic layer.

  • 19.
    Fuertes Casals, Nuria
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Nazarov, Andrej
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Vucko, Flavien
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Pettersson, Rachel
    Jernkontoret, Sweden.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Influence of mechanical stress on the potential distribution on a 301 LN stainless steel surface2015In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 162, no 9, p. C465-C472Article in journal (Refereed)
    Abstract [en]

    The aim of the present work was to study the influence of the stress on the electrode potential of the austenitic stainless steel 301LN using Scanning Kelvin Probe (SKP). It was found that elastic deformation reversibly ennobles the potential whereas plastic deformation decreases the potential in both tensile and compressive deformation mode and this decrease is retained even 24 h after removal of the load. To interpret the stress effects, different surface preparations were used and the composition and thickness of the passive film were determined by GDOES. Slip steps formed due to plastic deformation were observed using AFM. The effect of plastic strain on the potential is explained by the formation of dislocations, which creates more a defective passive film.

  • 20.
    Han, J.
    et al.
    PSL Research University, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Ogle, K.
    PSL Research University, France.
    Temperature dependence of the passivation and dissolution of Al, Zn, and α-phase Zn-68Al2019In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 1, p. 69-79Article in journal (Refereed)
    Abstract [en]

    The reactivity of the α-phase of Al-Zn (Zn-68 wt% Al, Al 5.2 Zn) in deaerated 0.1 M NaOH solution (simulating industrial pretreatments) was investigated and compared with that of pure Al and Zn. The elementary phenomena of metal oxidation, dissolution, oxide formation, and hydrogen evolution were decoupled using atomic emission spectroelectrochemistry. At the open-circuit potential, the Al 5.2 Zn phase reacted similarly as pure Al, undergoing selective Al dissolution to form a Zn(0) enriched layer. The Zn in the alloy shifted the potential to just below the onset of Zn dissolution. Elementary polarization curves showed that Zn dissolution was similar for the Al 5.2 Zn phase as for pure Zn. Near the open-circuit potential, Zn dissolution was faradaic limited by the formation of surface Zn(OH) 2 . At higher temperature, significant amounts of ZnO formed resulting in passivation. For the Al 5.2 Zn phase, the rates of Al and Zn dissolution were determined by a charge transfer mechanism across the ZnO film. Kinetic parameters (activation energies and Tafel slopes) were measured for some of the elementary processes. 

  • 21.
    Han, Junsoo
    et al.
    PSL Research University, France; University of Virginia, USA.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Ogle, Kevin
    PSL Research University, France.
    Zr-based conversion coating on Zn and Zn-Al-Mg alloy coating: Understanding the accelerating effect of Cu(II) and NO3−2020In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 402, article id 126236Article in journal (Refereed)
    Abstract [en]

    The reactivity of a Zn-Al-Mg galvanized steel substrate was monitored during a two-step conversion coating sequence with an alkaline pretreatment followed by conversion coating with hexafluorozirconic acid (H2ZrF6). The main effect of alkaline pretreatment was to remove initial oxides and to selectively dissolve Al, limiting the dissolution of Al in the zirconate bath. The commercial alkaline cleaner dissolved Mg from the MgZn2 intermetallic phase. The effect of NO3− and Cu(II) on the reactivity of a commercial Zn-Al-Mg alloy coating was investigated in H2ZrF6, simulating a Zr-based conversion coating process. NO3− served as an oxidant which enhanced the production of OH− leading to a more consequent ZrO2 deposition. Cu(II) underwent a displacement reaction with Zn (0) to form Cu(0) which catalyzed the reduction of NO3− and H+. The interplay between activation and passivation was demonstrated by the occurrence of oscillations in the both NO3− and Cu(II) containing electrolyte under certain conditions. 

  • 22.
    Helbert, Varvara
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Nazarov, A
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Vucko, Flavien
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Rioual, S.
    Univ Brest, France.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Hydrogen effect on the passivation and crevice corrosion initiation of AISI 304L using Scanning Kelvin Probe2021In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 182, article id 109225Article in journal (Refereed)
    Abstract [en]

    Scanning Kelvin Probe was applied to study passivation of AISI 304L stainless steel after cathodic polarisation. The rate of passivation in air decreased as a function of duration and current density. X-ray Photoelectron Spectroscopy showed enrichment of the surface film by hydroxides of Fe (II) that was the result of hydrogen effusion from the bulk. SKP measured a decreased potential drop in the passive film. Pre-polarisation accelerates the crevice corrosion of steel in presence of chlorides. Using SKP mapping, increased hydrogen sub-surface concentration and lower level of passivity was observed in anodic zones of the crevice.

  • 23.
    Helbert, Varvara
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Nazarov, Andrei
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Taryba, Maryna
    Universidade de Lisboa, Portugal.
    Vucko, Flavien
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Montemor, Fatima
    Universidade de Lisboa, Portugal.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Kinetics of corrosion reactions on press hardened steel in atmospheric conditions under thin electrolyte films2023In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 458, article id 142500Article in journal (Refereed)
    Abstract [en]

    Steels with high mechanical performance are prone to hydrogen embrittlement and environmental assisted cracking. Under atmospheric corrosion conditions, the source of hydrogen can be the steel corrosion process itself or galvanic coupling with a metallic coating. Electrochemical behaviour of Press Hardened Steel (PHS) under electrolyte films of different thicknesses using local electrochemical techniques was studied on a fundamental level. Scanning Vibrated Electrode Technique (SVET) was applied to study the evolution and localization of the corrosion process during PHS immersion in NaCl electrolyte. Kelvin Probe (KP) was used as a reference electrode to obtain cathodic and anodic polarization curves on PHS surfaces which were covered by thin electrolyte films (60 to 500 µm) of 0.1 M NaOH and 0.6 M NaCl. For both electrolytes, a strong increase in the oxygen reduction rate due to the decreasing of electrolyte thickness has been clearly demonstrated. Data are correlated well with a theoretical plot determined by Nernst-Fick equation. The influence of the rust layers on the kinetics of corrosion reactions under thin electrolyte films was investigated using KP. © 2023

  • 24.
    Helbert, Varvara
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Nazarov, Andrei
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Vucko, Flavien
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Larché, Nicolas
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Effect of cathodic polarisation switch-off on the passivity and stability to crevice corrosion of aisi 304l stainless steel2021In: Materials, E-ISSN 1996-1944, Vol. 14, no 11, article id 2921Article in journal (Refereed)
    Abstract [en]

    The effects of cathodic polarisation switch-off on the passivation of AISI 304L stainless steel in air and its crevice corrosion susceptibility in 3.5 wt.% NaCl aqueous electrolyte were investigated. Scanning Kelvin probe (SKP) data showed that the oxide film is significantly destabilised and the rate of steel passivation in air is slowed down. Thermal desorption analysis (TDA) highlighted that hydrogen absorption is proportional to the applied cathodic current density. A special crevice corrosion set-up was designed to realise simultaneous reproducible monitoring of potential and galvanic current to study the impact of prior cathodic polarisation on crevice corrosion onset. © 2021 by the authors.

  • 25.
    Helbert, Varvara
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Rioual, S.
    University of Brest, France.
    Le Bozec, Nathalie
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Corrosion behavior of additively manufactured AISI 316L stainless steel under atmospheric conditions2022In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 73, no 11, p. 1833-Article in journal (Refereed)
    Abstract [en]

    This study investigated the corrosion behavior of AISI 316L produced by direct energy deposition (DED). Microstructural and chemical analysis showed a homogeneous distribution of Si and Si–Mn inclusions of 0.5–1 µm and the Cr and Mo enrichment within interdendritic areas. Scanning Kelvin probe analysis of additively manufactured stainless steel highlighted a regular “striped-like” surface potential feature with a potential gradient of 30 mV for a mean value of 0.320 ± 0.017 V versus standard hydrogen electrode. It can be related to the presence of the residual stress in the oxide film and the complex thermal history due to the fabrication process. A cyclic corrosion test simulating atmospheric conditions revealed the same corrosion properties for stainless steel fabricated by DED compared to cold rolled one. Various surface preparations of 316L were also exposed for corrosion tests. It was found that the “as-received” and “brushed” surfaces exhibited poorer corrosion resistance due to the presence of an as-build defective layer. However, prior passivation of brushed surface, machining, or mechanical grinding down to P1200 improve significantly the corrosion resistance. © 2022 French Corrosion Institute part of RISE Research Institutes of Sweden. Materials and Corrosion published by Wiley-VCH GmbH.

  • 26.
    Jönsson, Martin
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Corrosion product formation during NaCl induced atmospheric corrosion of magnesium alloy AZ91D2007In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 49, no 3, p. 1540-1558Article in journal (Refereed)
    Abstract [en]

    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.

  • 27.
    Jönsson, Martin
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    LeBozec, Nathalie
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Scanning Kelvin probe force microscopy and scanning Kelvin probe in investigation of effect of microstructure on corrosion behaviour of magnesium alloys2007In: Local Probe Techniques for Corrosion Research, Elsevier Inc. , 2007, p. 111-125Chapter in book (Other academic)
  • 28.
    Jönsson, Martin
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    LeBozec, Nathalie
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    The influence of microstructure on the corrosion behaviour of AZ91D studied by scanning Kelvin probe force microscopy and scanning Kelvin probe2006In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 48, no 5, p. 1193-1208Article in journal (Refereed)
    Abstract [en]

    β-Mg17Al12, η-Al8Mn5 and an α-magnesium phase have been synthesized from pure components by controlled solidification procedures. These phases have been studied using different electrochemical techniques including the scanning Kelvin probe (SKP). From the results, it was possible to determine the nobility and the rate of the cathodic reaction of the different phases. Measurements have also been made on an AZ91D Mg-alloy using scanning Kelvin probe force microscopy (SKPFM) and field emission gun scanning electron microscopy (FEG-SEM). The results show that the Volta potentials measured with the scanning Kelvin probe (SKP) on bulk intermetallics are comparable with those recorded with the SKPFM on the AZ91D alloy. It is shown that SKPFM provides information on the local nobility of the different intermetallic particles and phases on the submicron scale. Both the η-Al8Mn5 phase and the β-Mg17Al12 phase in AZ91D showed a more noble potential than the α-magnesium phase. It is also shown that the aluminium-rich coring along the grain boundaries results in measurable changes in the Volta potential. Finally, the role of the β-Mg17Al12 phase and the η-Al8Mn5 phase in the corrosion behaviour of AZ91D is discussed in term of local nobility, surface coverage of the cathode and the cathodic activity of the different phases.

  • 29.
    Kim, Hye-Jin
    et al.
    Hyundai-Steel Company, Republic of Korea; Seoul National University, Republic of Korea.
    Lee, Myoung
    Seoul National University, Republic of Korea.
    Yoon, Seung
    Hyundai-Steel Company, Republic of Korea.
    Vucko, Flavien
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Lee, Chang
    Hyundai Motor Company, Republic of Korea.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Kim, Sung-Ju
    Hyundai-Steel Company, Republic of Korea.
    Diffusible hydrogen behavior and delayed fracture of cold rolled martensitic steel in consideration of automotive manufacturing process and vehicle service environment2020In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 9, no 6, p. 13483-13501Article in journal (Refereed)
    Abstract [en]

    This study aims to elucidate the behavior of diffusible hydrogen and delayed fracture in martensitic steel with 1500 MPa strength during automotive painting process and under vehicle service conditions. A sequential process of automotive pretreatment line and vehicle service environment is simulated to evaluate the hydrogen pick up in each process. In case of the automotive painting line, the absorption of hydrogen is within the common range in the process of phosphating treatment and electrodeposition. The baking process plays an effective role for desorbing the diffusible hydrogen absorbed during the automotive pre-treatment such as zinc-phosphating, and electrodeposition process. In case of the corrosion environment under the automotive driving conditions, hydrogen induced delayed fracture is accelerated as the exposure time increases. Further, it is clarified that severe plastic deformation are the significant factors for hydrogen induced delayed fracture under with low pH value and present of chloride ion in a chemical solution parameter. In summary, hydrogen is transported constantly during electrodeposition sequential line process of automobile manufacturing below the hydrogen content of 0.5 ppm, which is not critical value for leading to hydrogen delayed fracture based on results of slow strain rate tensile tests. However, exposure to extreme conditions under service environment of vehicle, such as acidic solution and chloride chemistry solution that result in high level of hydrogen absorption, severe plastic deformation in the sheared edge, and constantly applied internal or external stresses, can cause the hydrogen induced delayed fracture in the fully martensitic steels. © 2020 The Authors

  • 30.
    Kouøil, M.
    et al.
    University of Chemistry and Technology, Czech Republic.
    Prosek, Tomas
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Dubus, Michel
    Centre de Recherche et de Restauration des Musées de France, France.
    Taube, Michelle
    The National Museum, Denmark.
    Hubert, Vera
    Swiss National Museum, Switzerland.
    Scheffel, Bert
    Fraunhofer, Germany.
    Degres, Yves
    Hennebont, France.
    Jouannic, M.
    Hennebont, France.
    Korozní monitoring v rukách restaurátorù a konzervátorù/Corrosion monitoring in the hands of restorers and conservators2012In: Koroze a Ochrana Materialu, ISSN 0452-599X, Vol. 56, no 3, p. 67-75Article in journal (Refereed)
    Abstract [en]

    A technique for continuous monitoring of atmospheric corrosivity was developed. An electronic unit measures and records changes in the electrical resistance of a thin metal track applied on an insulating substrate. If the metal corrodes, the effective cross-sectional area of the track decreases and the electrical resistance increases. Sensors made of silver, copper, iron / steel, zinc, lead, tin, bronze and brass at thicknesses from 50 nm to 250 Êm were tailored for environments with different corrosivity. The developed technology proved to provide subAngstrom (<10-10 m) sensitivity allowing for real-time corrosion monitoring even in low-corrosive indoor cultural heritage facilities. Laboratory tests showed good reproducibility of the technique with standard deviation of parallel measurements up to ±20% for metals corroding in a given environment mostly uniformly. Since the technique measures the maximal depth of corrosion attack, the response is somewhat higher compared to methods measuring the average corrosion depth. Several examples from a wide testing programme in partner museums, archives, libraries and other institutions were selected to show successful applications of the technique for qualifi cation and comparison of air quality control in indoor premises, assessment of new buildings and storage facilities, air quality control during transport and temporary exhibitions and fundamental studies of optimal conservation and storage procedures. A fi rst outline of a classifi cation system for lead, which is particularly sensitive to presence of carboxylic acids, is given. The technique has a large potential as an independent method of air quality monitoring in facilities.

  • 31.
    Larche, Nicolas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Blanc, Jerome
    DGA Naval Systems, France.
    Iken, I.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Galvanic corrosion induced by the use of high alloy stainless steel in seawater applications2012In: NACE - International Corrosion Conference Series, 2012, Vol. 1, p. 235-253Conference paper (Refereed)
    Abstract [en]

    The galvanic corrosion of carbon steel (UNS G10150) and of copper-nickel 90/10 (UNS C70600) coupled to superduplex stainless steel (UNS S32750) in seawater was investigated from 6°C to 70°C, with different cathode to anode ratios. The effect of chlorination on galvanic corrosion rates was also studied. Continuous monitoring of the open-circuit potentials and galvanic currents were performed to measure the exact evolution and the contribution of the galvanic corrosion on the total corrosion. Results showed that formation of natural biofilms and precipitation of calcareous deposits on surfaces had a very significant impact on the cathodic efficiency, which is directly correlated to the rate of galvanic corrosion. For all the tested configurations, chlorination led to a significant decrease of the measured galvanic currents due to the low cathodic efficiency of surfaces in chlorinated media (i. e. no biofilm). The long term exposure of specimens allowed to draw realistic pseudo-polarization curves which were used in a boundary element modeling software.

  • 32.
    Larché, Nicolas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Blanc, J.
    DGA, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Sagebiel, B.
    KME Germany GmbH and Co. KG, Germany.
    Effect of service conditions on the corrosion of nickel-aluminum bronze and copper-nickels alloys in seawater2019In: NACE - International Corrosion Conference SeriesVolume 2019-March, 2019, Article number 13337Corrosion Conference and Expo 2019; Nashville; United States; 24 March 2019 through 28 March 2019;, National Assoc. of Corrosion Engineers International , 2019Conference paper (Refereed)
    Abstract [en]

    Nickel-Aluminum Bronze (NAB) and Copper-Nickel alloys (CuNi) are commonly used in seawater environments due to their strength combined with a good corrosion resistance and a high resistance to biofouling. However, localized corrosion failures have been reported and are often attributed to abnormal service conditions. The effect of several service condition parameters on the localized corrosion of NAB (UNS C63000, CuAl10Ni5Fe4) and CuNi alloys 90/10 (UNS C70600) and 70/30 (UNS C71500) have been investigated in natural seawater. The results are compared with that of Aluminum-brass (UNS C68700). It includes flow conditions (flowing, quiescent and stagnant), chlorination, sulphide pollution, and crevice geometries. Exposures in both indoor (laboratory) and outdoor tanks (conditions promoting macro fouling) have been tested in temperate and in tropical seawaters. The corrosion stability of the protective oxide layer of the tested copper-based alloys was mainly affected by sulphide pollution in aerated seawater (general corrosion). Under the tested conditions, localized corrosion under-biodeposit clearly appeared as the critical failure for the tested alloys. The conditions for which biodeposit appeared critical for copper-nickel alloys was investigated. 

  • 33.
    Larché, Nicolas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Diler, Erwan
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Crevice and pitting corrosion of stainless-steel and nickel based alloys in deep sea water2019In: NACE - International Corrosion Conference SeriesVolume 2019-March, 2019, Article number 13337Corrosion Conference and Expo 2019; Nashville; United States; 24 March 2019 through 28 March 2019;, National Assoc. of Corrosion Engineers International , 2019Conference paper (Refereed)
    Abstract [en]

    The exploration and exploitation of deep seawater present promising prospects for many industries. Hence, the use of reliable materials resistant to corrosion in deep seawater conditions is required. In natural seawater, many parameters can influence the kinetics of corrosion such as: temperature, oxygen content, biofilm and fouling activity, flow rates and hydrostatic pressure. For passive materials such as Cr Ni Mo stainless steels and nickel-based alloys, the specificity of the above parameters in deep sea environment might have an impact on both initiation and propagation phases of localized corrosion (e.g. pitting and crevice corrosion), and no or limited field data obtained in deep sea can be found in the literature. Currently, there are still many questions on the corrosion behavior of metallic materials in deep seawater since the results obtained in laboratory or from near-surface seawater cannot be extrapolated to deep seawater environments, especially in terms of bacterial activity which can significantly impact the localized corrosion resistance of passive alloys (cf. biofilm-induced ennoblement). In this study, 13-Cr Ferritic, Austenitic, Lean Duplex, Duplex, Super Duplex, Super Austenitic, Hyper Duplex Stainless Steels and Nickel based alloys were exposed during 11 months at 1020 and 2020 m water depth in the Atlantic Ocean to evaluate their corrosion behavior. Structural carbon steel S355 was also exposed under similar conditions. Polyvinylidene difluoride (PVDF) crevice gaskets according to ISO18070:2015 were used to assess the crevice corrosion at two different gasket pressures, namely 3 and 20 N/mm2. Potential monitoring was performed in-situ (at both 1020 m and 2020 m) in order to characterize the formation of electroactive biofilms at the surface of passive alloys in these environments. At each exposure depth, the environment was characterized using environmental sensors, e.g. temperature, flow velocity, dissolved oxygen, salinity. The obtained results allowed i) ranking the passive material in terms of resistance to pitting and crevice corrosion in deep water at 4°C, ii) comparing biofilm electroactivity and corrosion rates at 1020 and 2020 m depth.

  • 34.
    Larché, Nicolas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Dézerville, Phlippe
    Veolia Eau, France.
    Le Flour, Denise
    Ifremer, France.
    Vinzio, Pasqual
    KSB SAS, France.
    Köfler, Karl Heinz
    KSB SAS, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Corrosion of stainless steel components in seawater reverse osmosis desalination plants—investigations on adapted internal cathodic protection2015In: Desalination and Water Treatment, ISSN 1944-3994, E-ISSN 1944-3986, Vol. 55, no 9, p. 2478-2490Article in journal (Refereed)
    Abstract [en]

    Abstract: Stainless steel is widely used in seawater reverse osmosis units (SWRO) for both good mechanical and corrosion resistance properties. However, many corrosion failures of stainless steel in SWRO desalination units have been reported. These failures may often be attributed to un-adapted stainless steel grade selection and/or to the particular aggressive seawater conditions in “warm” regions (high ambient temperature, severe biofouling, etc.). Cathodic protection (CP) is a well-known efficient system to prevent corrosion of metallic materials in seawater. It is successfully used in the oil and gas industry to protect carbon steel structures exposed in open-sea. However, the specific service conditions of SWRO units may seriously affect the efficiency of such anti-corrosion system (high flow rates, large stainless steel surfaces affected by biofouling, confinement limiting protective cathodic current flow, etc.). Hence, CP in SWRO units should be considered with special care and modeling appears as useful tool to assess an appropriate CP design. However, there is a clear lack of CP data that could be transposed to SWRO service conditions (i.e. stainless steel, effect of biofouling, high flow rate, etc.). From this background a Join Industry Program was initiated including laboratory exposures, field measurements in a full scale SWRO desalination plant, and modeling work using PROCOR software. The present paper reviews the main parameters affecting corrosion of stainless steel alloys in seawater reverse osmosis units. CP on specific stainless steel devices was investigated in order to assess its actual efficiency for SWRO units. Severe environmental conditions were intentionally used to promote corrosion on the tested stainless steel products in order to evaluate the efficiency of CP. The study includes a modeling work aiming at predicting and designing adapted CP protection to modeled stainless steel units. An excellent correlation between modeling work and field measurements was found.

  • 35.
    Larché, Nicolas
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Emo, Benoit
    Véolia Water, France.
    Allion, Aaudrey
    Aperam Global Research, France.
    Johansson, Elisabeth
    Outokumpu Stainless AB, Sweden.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Localized corrosion of (lean) duplex stainless steels in immersion units of urban wastewater treatment plants2021In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 72, no 8, p. 1338-Article in journal (Refereed)
    Abstract [en]

    With lower alloying cost and higher mechanical properties, lean duplex stainless steels can be an alternative to the more commonly used austenitic stainless steels. However, these alloys are still not the preferred choice, probably due to a lack of field experience. A study was thus initiated in view of defining the limits of use of selected (lean) duplexes for urban wastewater treatment units. The present paper shows the localized corrosion performance of selected lean duplexes in chloride contaminated solutions. The results are compared with austenitic S30403 and S31603 and with the more standard duplexes S82441 and S32205. The effect of welding was also investigated. Exposures in field municipal wastewater plants were conducted for 1 year in low and high chloride content units. The results show that lean duplexes S32101 and S32202 can be used as alternatives to S30403 and S31603 in low chloride electrolytes. At 500 ppm of chloride content, duplex stainless steel S32304 showed better corrosion resistance than S30403 and S31603. For higher chloride contents (1000 ppm and above) the standard duplexes S82441 and S32205 shall be preferred. 

  • 36.
    Larché, Nicolas
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Emo, Benoit
    Veolia, France.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Duquesnes, Vincent
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Mendibide, Christophe
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Localized corrosion of lean duplex stainless steels in H2S-containing wet atmosphere from urban wastewater treatment units2021In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, no 11, p. 1730-Article in journal (Refereed)
    Abstract [en]

    With lower alloying costs and higher mechanical properties, lean duplex stainless steels can be a good alternative to the more commonly used austenitic stainless steels. A study was initiated to define the limits of the use of lean duplex stainless steels for urban wastewater treatment (WWT) units. This paper gives and discusses the corrosion results in an aerated wet atmosphere containing H2S at different levels. Exposures were performed both at laboratory scale and in the field WWT plant for 1 year. A specific probe was also designed to study the corrosion process below water condensate film contaminated with H2S. Under such conditions, the properties of stainless steel were strongly modified with an enhanced risk of localized corrosion. The results obtained on lean duplex materials (UNS S32101, S32202, and S32304) are compared with austenitic UNS S30403 and UNS S31603 and with the more standard duplexes UNS S82441 and UNS S32205. The results show that lean duplexes can be used in aerated wet atmospheres in case of moderate contamination of H2S (<10 ppm) and chloride (<200 ppm). For higher contaminations (e.g., H2S around 100 ppm/chloride around 1000 ppm) the duplex S32205 should be preferred.

  • 37.
    Larché, Nicolas
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Leballeur, Charles
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Diler, Erwan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Crevice Corrosion of High-Grade Stainless Steels in Seawater: A Comparison Between Temperate and Tropical Locations2023In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 79, no 9, p. 1106-1117Article in journal (Refereed)
    Abstract [en]

    The corrosion risk for stainless steel components is not the same in all seawaters, with more failures generally reported in tropical seas. In this study, the influence of biofilm on electrochemical behavior and corrosion resistance of passive films of high-grade alloys was studied in different seawaters, including temperate seawater (France-Brest, North Atlantic Ocean), tropical seawater (Malaysia-Kelatan, Meridional China Sea), and intermediate conditions in terms of temperature (Brazil-Arraial do Cabo, South Atlantic Ocean). The stabilized open-circuit potentials and the polarization behavior of high-grade stainless steels were measured as a function of temperature in all of the tested field marine stations, providing quantified data and direct comparison of the biofilm-enhanced corrosion risks. Significant differences were measured in tropical and in temperate seawaters in heated conditions. Above 37°C, the biofilm activity was much more pronounced in tropical seawater compared to Atlantic Ocean sites, leading to much higher localized corrosion risk. Crevice corrosion of eight high-grades passive alloys was also studied with the use of crevice formers specifically developed for tube geometries. Duplex UNS S32205, superduplex UNS S32750, hyperduplex UNS S33207 and S32707, and 6Mo stainless steels UNS S31266 have been evaluated together with Ni-based alloys UNS N06845 and N06625. In the more severe conditions, the high-grade alloys UNS S32707 and the 6%Mo UNS S31266, both with pitting resistant equivalent number (PREN) around 50, showed better performance than commonly used superduplex UNS S32750 and UNS S39274 (PREN 40). The corrosion results are discussed regarding the monitored biofilm-induced depolarization measured in the different test conditions.

  • 38.
    Larché, Nicolas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Lang, T.
    Wieland-Werke AG, Germany.
    Internal corrosion of copper-nickel alloy tubes 90/10 and 70/30 in chlorinated seawater for shell and tube heat exchangers2019In: NACE - International Corrosion Conference SeriesVolume 2019-March, 2019, Article number 13338Corrosion Conference and Expo 2019; Nashville; United States; 24 March 2019 through 28 March 2019;ACE - Int. Corros. Conf. Ser., National Assoc. of Corrosion Engineers International , 2019Conference paper (Refereed)
    Abstract [en]

    The corrosion resistance of copper-nickel 90/10 and 70/30 tubes for heat exchangers was evaluated in 0.5 ppm-chlorinated seawater, under controlled service conditions in a bespoke test loop. The results were compared to Al-Brass tubes tested under the same conditions. Copper-Nickel 90/10 tubes were tested with two different geometries: internal smooth surface and internal finned surface (helix geometry). Internal pitting corrosion resistance was evaluated under simulated heat transfer conditions at two controlled skin temperatures from the internal and the external parts of the tubes for 6 months, at 50°C (Tskin-in)/35°C (Tseawater) and 70°C (Tskin-in)/35°C (Tseawater). For all the tested copper alloys, the uniform corrosion was very low and negligible. For both temperatures, CuNi 90/10 was globally more resistant to localized corrosion than CuNi70/30. The most corrosion resistant configuration was the CuNi 90/10 with the internal finned geometry. The best corrosion resistance compared to the smooth geometry might be attributed to different hydrodynamic conditions at the seawater/metal interface.

  • 39.
    Le Bozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Joiret, Suzanne
    CNRS, France.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    The role of chromate conversion coating in the filiform corrosion of coated aluminum alloys2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 12, p. B561-B566Article in journal (Refereed)
    Abstract [en]

    The mechanisms of inhibition of chromate conversion coating on the filiform corrosion of coated aluminum alloy AA6016 was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and Raman microspectroscopy. The results showed that Cr(VI) was preferably leached out at the opening of the filament, whereas Cr(VI) was reduced to Cr(III) at all other locations. The leached out Cr(VI) accumulated mainly in the pitting area, located in the scratch just outside the filament. The chromate released from the CCC was partly reduced to Cr(III) in the pit. The formation of an Al/Cr mixed oxide was observed in the pitting area. The repassivation of pits in the scratch by the chromate leaching from the CCC close to the scratch explains the low propagation of filiform corrosion observed for the chromated surfaces.

  • 40.
    Leballeur, Charles
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Larche, Nicolas
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Potential ennoblement of stainless steel: Influence of oxygen content in sea water and pressure2015In: European Corrosion Congress, EUROCORR 2015, Austrian Society for Metallurgy and Materials (ASMET) , 2015Conference paper (Refereed)
  • 41.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Jönsson, Martin
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Atmospheric corrosion of magnesium alloys: Influence of temperature, relative humidity, and chloride deposition2004In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 60, no 4, p. 356-361Article in journal (Refereed)
    Abstract [en]

    Laboratory tests have been performed to determine how climatic parameters, e.g., relative humidity, temperature, and the amount of sodium chloride (NaCl), influence the corrosion rate of magnesium alloys AZ91D (UNS M 11916) and AM50 (UNS M 10500). The effect of the surface state also has been investigated. The exposures were performed at 75%. 85%. and 95% relative humidity (RH) and at 25°C and 35°C. The amount of NaCl ranged from 14 μg cm-2 to 240 μg cm-2 . The corrosion rate of both materials increased as a function of temperature, RH, and amount of NaCl. A strong influence of the surface state, i.e., as-cast or polished, was observed mainly due to the combined effect of an active surface layer and the roughness of as-cast surfaces. © 2004, NACE International.

  • 42.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Jönsson, Martin
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Atmospheric corrosion of magnesium alloys: Influence of temperature, relative humidity and chloride deposition2003In: NACE - International Corrosion Conference Series, National Association of Corrosion Engineers International , 2003Conference paper (Refereed)
    Abstract [en]

    Laboratory tests have been performed in order to determine how the climatic parameters e.g. relative humidity and temperature, and the amount of NaCl influence the corrosion rate of magnesium alloys AZ91D and AM50. The effect of the surface state has also been investigated. The exposures were performed at 75%, 85% and 95% R.H. and at 25 and 35oC. The amount of sodium chloride ranged from 14 to 240 μg cm-2. The corrosion rate of both materials increased as a function of temperature, relative humidity and NaCl amount. A strong influence of the surface state e.g. as cast or polished was observed mainly due the discontinuity of as cast surfaces.

  • 43.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Nazarov, Andrej
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Assessment of corrosion de-adhesion of thick marine paints applied on steel using scanning Kelvin Probe technique2017In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017, Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers , 2017Conference paper (Refereed)
  • 44.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Application of scanning Kelvin probe, XANES and FTIR microspectroscopy for investigating the mechanisms of filiform corrosion on coated aluminium alloys2004In: EUROCORR 2004 - European Corrosion Conference: Long Term Prediction and Modelling of Corrosion, 2004Conference paper (Refereed)
    Abstract [en]

    Filiform corrosion is an active corrosion cell that moves across the metal surface underneath the coating, leaving a tail filled with corrosion products. Filiform corrosion is a main problem on coated aluminium alloys exposed to a humid atmosphere. The corrosion is generally initiated in defects in the coating and propagates in presence of aggressive ions (chloride, sulphate...), oxygen and sufficient relative humidity. The aim of this investigation is to provide more information on the mechanism of filiform corrosion on coated aluminium alloys using complementary localized techniques: the scanning Kelvin probe (SKP), the Fourier Transformed Infra-Red (FTIR) microspectroscopy and X-ray absorption near-edge structure (XANES) technique. SKP can provide information on the potential distribution during corrosion processes on both bare and coated metals with a spatial resolution of approximately 50 μm. Here, SKP measurements have been performed in order to identify the anodic and cathodic sites on filaments formed on coated aluminium during atmospheric exposure. FTIR microspectroscopy permits the identification of thin surface films of corrosion products both under ex-situ and in-situ conditions. As the spatial resolution is similar to the SKP, this technique has provided information on the composition of corrosion products formed in the head and in the tail of the filaments. The initiation and the propagation of filiform corrosion on coated aluminium alloy were investigated using an experimental set-up for in-situ infrared reflection absorption spectroscopy. It consisted of an in-situ cell, where samples were exposed to controlled humid conditions, and an optical microscope linked with a Fourier Transformed Spectrometer. XANES measurements were performed on coated chromated aluminium alloys in order to study the mechanisms of inhibition of chromate on the filiform corrosion. This was performed using a high resolution beam (e.g. 15-35 μm), making possible the establishment of X-ray maps of Cr(VI) and total chromium over the surface including the filament.

  • 45.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    In situ studies of the initiation and propagation of filiform corrosion on aluminium2003In: Proceedings - Electrochemical Society, 2003, p. 111-122Conference paper (Refereed)
    Abstract [en]

    We have investigated the initiation and propagation of filiform corrosion on coated aluminium surfaces was using in situ FTIR microspectroscopy and the scanning Kelvin probe. During the initiation partially hydrolysed aluminium chloride was formed in a defect on the coated surface. The conditions in the defect resembled the environment that is found in growing pits with low pH and high chloride concentration close to the coating interface. This weakened the adhesion of the organic coating and initiated the formation of a filament. The movement of the active head was followed with in situ FTIR microspectroscopy in humid air using the characteristic IR band around 2500 cm-1 from Al(H2O)6 3+. This band is present in spectra from partially hydrolysed aluminium chloride, which was found in the head during propagation of the filament. The absorption of water in the hygroscopic corrosion products in the head of the filament was followed by measuring the changes in the intensity of the Al(H2O)6 3+ band during variation in the relative humidity.

  • 46.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    In situ studies of the initiation and propagation of filiform corrosion on aluminum2004In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 151, no 7, p. B440-B445Article in journal (Refereed)
    Abstract [en]

    We have investigated the initiation and propagation of filiform corrosion on coated aluminum surfaces using a new experimental set-up for in situ Fourier transform infrared (FTIR) microspectroscopy and the scanning Kelvin probe. During the initiation partially hydrolyzed aluminum chloride was formed in a defect on the coated surface. The conditions in the defect resembled the environment that is found in growing pits with low pH and high chloride concentration close to the coating interface. This weakened the adhesion of the organic coating and initiated the formation of a filament. The movement .of the active head was followed with in situ FTIR microspectroscopy in humid air using the characteristic IR band around 2500 cm-1 from Al(H 2O)6 3+. This band is present in spectra from partially hydrolyzed aluminum chloride, which was found in the head during propagation of the filament. The absorption of water in the hygroscopic corrosion products in the head of the filament was followed by measuring the changes in the intensity of the Al(H2O)6 3+ band during variations in the relative humidity. The hygroscopic properties of the aluminum hydroxy chloride salts formed in the head have important consequences for filiform corrosion, especially concerning the influence of climatic parameters such as the relative humidity and the effect of wet/dry transitions on the propagation of filiform corrosion.

  • 47.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Axelsen, Sten B.
    Statoil ASA, Norway.
    Effect of climatic parameters on filiform corrosion of coated aluminium alloys AA60162003In: NACE - International Corrosion Conference Series, National Association of Corrosion Engineers International , 2003Conference paper (Refereed)
    Abstract [en]

    The effects of temperature, relative humidity and wet dry transition on initiation and propagation of filiform corrosion on coated aluminium alloys AA6016 have been studied. The aluminium surfaces were tested in both milled and grinded conditions with chromium, phosphate and titanium-zirconium based pretreatment. A full paint system used for automotive applications (ED coat + top-coat) and an electrodeposited coat (ED coat) were investigated for the different combinations of mechanical finish, surface pretreatment and coating system. In the temperature range between 5 to 50°C, filiform corrosion, or underfilm corrosion in general, increased significantly. The effect of relative humidity and wet-dry cycling on the other hand, seems to be strongly influenced by parameters like pretreatment, coating system, and also temperature. Filiform corrosion was the highest in the range 75 to 95 % relative humidity and a distinct maximum was observed at 85% R.H. for some coating systems. However, filiform corrosion propagated at humidity down to 40-50% R.H. For specimens with chromate and phosphate based surface pretreatments, filiform corrosion was lower after exposure to tests with wet-dry cycles. The samples with titanium-zirconium based pretreatments, on the other hand, had a very poor filiform corrosion resistance in the cyclic test compared to exposures at constant relative humidity. © 2003 by NACE International.

  • 48.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Axelsen, Sten B.
    Statoil ASA, Norway.
    Effect of climatic parameters on filiform corrosion of coated aluminum alloys2004In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 60, no 6, p. 584-593Article in journal (Refereed)
    Abstract [en]

    The effects of temperature, relative humidity, and wet-dry transition on initiation and propagation of filiform, corrosion on coated aluminum alloy 6016 (AA6016 [UNS A96016]) have been studied. Corrosion products formed in the filament were analyzed using Fourier transform infrared (FTIR)- microspectroscopy. The aluminum surfaces were tested in both milled finish and grinded conditions with chromium, phosphate, and titanium-zirconium-based pretreatment. An electrodeposited coat (ED coat) and a full paint system used for automotive applications (ED coat + topcoat) were investigated for the different combinations of mechanical finish, surface pretreatment, and coating system. In the temperature range between 5°C and 50°C, filiform corrosion, or underfilm corrosion in general, increased significantly. The effect of relative humidity and wet-dry cycling, on the other hand, seems to be strongly influenced by parameters like pretreatment, coating system, and temperature. Filiform corrosion was the highest in the range from 75% to 95% relative humidity (RH), and a distinct maximum was observed at 85% RH for some coating systems. However, filiform. corrosion propagated at humidity down to 40% to 50% RH. For specimens with chromate- and phosphate-based surface pretreatments, filiform, corrosion was lower after exposure to tests with wet-dry cycles. The samples with titanium-zirconium-based pretreatments, on the other hand, had a very poor filiform corrosion resistance in the cyclic test compared to exposures at constant relative humidity. © 2004, NACE International.

  • 49.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Pelissier, Krystel
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    A new accelerated corrosion test for marine paint systems used for ship's topsides and superstructures2018In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 69, no 4, p. 447-459Article in journal (Refereed)
    Abstract [en]

    Several studies sponsored by the French Naval Authorities have been conducted during the last 10 years aiming to develop more reliable testing conditions than the conventional neutral salt spray test that should not be used for prediction of material performance. A satisfying correlation to atmospheric field exposure on a ship in service was observed using a 6 months cyclic test from the automotive industry (e.g., Volvo STD23-0014) with a deviation inferior to 25% and an acceleration factor of 4. The possibility to shorten the test duration with a target of 3 months without losing correlation to field exposures is investigated in the present study. A design of experiment is used to study key parameters such as NaCl concentration, the mode of salt application and its frequency as well as the temperature. Ten different marine paint systems used for shipbuilding have been selected. The results indicate an enhancement of the aggressiveness of the test when doubling the salt concentration from 1 to 2 wt%, increasing the number of salt spray per week (from 2 to 3), and the temperature from 35 to 45 °C. The data are compared to marine field exposures in tropical and temperate climates. The most reliable testing conditions to field exposure in marine sites of severity from low C5M to CX on steel include cyclic corrosion tests using 2 wt% of NaCl.

  • 50.
    LeBozec, Nathalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Persson, Dag
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Riener, Christian K.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Luckeneder, Gerald H.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Influence of microstructure of zinc-aluminium-magnesium alloy coated steel on the corrosion behavior in outdoor marine atmosphere2019In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 374, p. 897-909Article in journal (Refereed)
    Abstract [en]

    Model hot-dip Zn-Al-Mg coatings with various microstructures were produced in a galvanising simulator by changing the cooling rate. Full characterization of the coatings was performed to identify the chemical composition of the different phases, the size of the grains and their distribution. The corrosion properties of the model microstructures were investigated in outdoor marine atmosphere up to 2 years. Weight loss measurements and cross section observations revealed a tendency for fine microstructures enriched in eutectic phases to be the most corrosion resistant. This was connected to a lower size of cathodic areas at the surface (zinc dendrites), the preferential dissolution of Mg-rich phase (eutectic) and the formation of a stable layered double hydroxide on the surface.

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