Ändra sökning
Avgränsa sökresultatet
1234567 51 - 100 av 500
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Chen, Jiaxin
    et al.
    Studsvik Nuclear AB, Sweden.
    Jädernäs, Daniel
    Studsvik Nuclear AB, Sweden.
    Lindberg, Fredrik
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Pettersson, Henrik
    Chalmers University of Technology, Sweden.
    Bjurman, Martin
    Studsvik Nuclear AB, Sweden.
    Kese, Kwadwo
    Studsvik Nuclear AB, Sweden.
    Jenssen, Anders
    Studsvik Nuclear AB, Sweden.
    Cocco, Massimo
    Forsmark Kraftgrupp AB, Sweden.
    Johansson, Hanna
    Forsmark Kraftgrupp AB, Sweden.
    Microstructures of oxide films formed in alloy 182 bwr core shroud support leg cracks2019Ingår i: Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors, Springer International Publishing , 2019, s. 1633-1647Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper contributes to a TEM examination on the oxide films formed at three locations along a crack path in Alloy 182 weld from a BWR core shroud support leg, namely, the crack mouth, the midway between the mouth and the crack tip, and the crack tip. In the crack mouth the oxide film was approximately 1.6 μm in thickness and consisted of relatively pure NiO. The midway oxide film was mainly a nickel chromium oxide with a film thickness of 0.3 μm. At the crack tip the oxide film was a nickel chromium iron oxide with a film thickness of 30 nm. In all studied locations the main oxides had the similar rocksalt structure and the cracks were much wider than the thicknesses of the oxide films. It probably suggests that the corroded metal was largely dissolved into the coolant. The different dissolution rates of nickel, chromium and iron cations in the oxide films are clearly displayed with the compositions of the residual oxides. The oxide stability under different redox potentials along the crack path is briefly discussed.

  • 52.
    Chen, Jiaxin
    et al.
    Studsvik Nuclear AB, Sweden.
    Lindberg, Fredrik
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Wells, Daniel
    Electric Power Research Institute, USA.
    Bengtsson, Bernt
    Ringhals AB, Sweden.
    EELS and electron diffraction studies on possible bonaccordite crystals in pressurized water reactor fuel CRUD and in oxide films of alloy 600 material2017Ingår i: Nuclear engineering and technology : an international journal of the Korean Nuclear Society, ISSN 1738-5733, E-ISSN 2234-358X, Vol. 49, nr 4, s. 668-674Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Experimental verification of boron species in fuel CRUD (Chalk River Unidentified Deposit) would provide essential and important information about the root cause of CRUD-induced power shifts (CIPS). To date, only bonaccordite and elemental boron were reported to exist in fuel CRUD in CIPS-troubled pressurized water reactor (PWR) cores and lithium tetraborate to exist in simulated PWR fuel CRUD from some autoclave tests. We have reevaluated previous analysis of similar threadlike crystals along with examining some similar threadlike crystals from CRUD samples collected from a PWR cycle that had no indications of CIPS. These threadlike crystals have a typical [Ni]/[Fe] atomic ratio of ∼2 and similar crystal morphology as the one (bonaccordite) reported previously. In addition to electron diffraction study, we have applied electron energy loss spectroscopy to determine boron content in such a crystal and found a good agreement with that of bonaccordite. Surprisingly, such crystals seem to appear also on corroded surfaces of Alloy 600 that was exposed to simulated PWR primary water with a dissolved hydrogen level of 5 mL H2/kg H2O, but absent when exposed under 75 mL H2/kg H2O condition. It remains to be verified as to what extent and in which chemical environment this phase would be formed in PWR primary systems.

  • 53.
    Christodoulakis, John
    et al.
    National and Kapodistrian University of Athens, Greece.
    Tzanis, Chris G.
    National and Kapodistrian University of Athens, Greece.
    Varotsos, Costas A.
    National and Kapodistrian University of Athens, Greece.
    Ferm, Martin
    IVL Swedish Environmental Research Institute, Sweden.
    Tidblad, Johan
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Impacts of air pollution and climate on materials in Athens, Greece2017Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 17, nr 1, s. 439-448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For more than 10 years now the National and Kapodistrian University of Athens, Greece, has contributed to the UNECE (United Nations Economic Commission for Europe) ICP Materials (International Co-operative Programme on Effects on Materials including Historic and Cultural Monuments) programme for monitoring the corrosion/soiling levels of different kinds of materials due to environmental air-quality parameters. In this paper we present the results obtained from the analysis of observational data that were collected in Athens during the period 2003-2012. According to these results, the corrosion/soiling of the particular exposed materials tends to decrease over the years, except for the case of copper. Based on this long experimental database that is applicable to the multi-pollutant situation in the Athens basin, we present dose-response functions (DRFs) considering that "dose" stands for the air pollutant concentration, "response" for the material mass loss (normally per annum) and "function", the relationship derived by the best statistical fit to the data.

  • 54.
    Cieślik, M.
    et al.
    Jagiellonian University.
    Engvall, Klas
    RISE, Swerea, Swerea KIMAB AB.
    Pan, J.
    Royal Institute of Technology.
    Kotarba, A.
    Jagiellonian University.
    Silane-parylene coating for improving corrosion resistance of stainless steel 316L implant material2011Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 53, nr 1, s. 296-301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The corrosion resistance of a two-layer polymer (silane+parylene) coating, on implant stainless steel was investigated by microscopic observations and electrochemical measurements. Long term exposure tests in Hanks solution revealed that the coating of 2μm can be successfully used for corrosion protection. However, the addition of H2O2, simulating the inflammatory response of human body environment causes a dramatic destruction of the protective coating. Analysis of the experimental data in terms of circuit models enables proposing a deterioration mechanism. OH radicals formed at the metal surface attack the polymer, thus the deterioration starts from the metal/polymer interface and progress towards the outward surface. © 2010 Elsevier Ltd.

  • 55.
    Cieślik, M.
    et al.
    Jagiellonian University, Poland.
    Kot, M.
    AGH University of Science and Technology, Poland.
    Reczyński, W.
    AGH University of Science and Technology, Poland.
    Engvall, Klas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Rakowski, W.
    AGH University of Science and Technology, Poland.
    Kotarba, A.
    Jagiellonian University, Poland.
    Parylene coatings on stainless steel 316L surface for medical applications: Mechanical and protective properties2012Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 32, nr 1, s. 31-35Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mechanical and protective properties of parylene N and C coatings (2-20 μm) on stainless steel 316L implant materials were investigated. The coatings were characterized by scanning electron and confocal microscopes, microindentation and scratch tests, whereas their protective properties were evaluated in terms of quenching metal ion release from stainless steel to simulated body fluid (Hanks solution). The obtained results revealed that for parylene C coatings, the critical load for initial cracks is 3-5 times higher and the total metal ions release is reduced 3 times more efficiently compared to parylene N. It was thus concluded that parylene C exhibits superior mechanical and protective properties for application as a micrometer coating material for stainless steel implants. © 2011 Elsevier B.V. All rights reserved.

  • 56.
    Cieślik, M.
    et al.
    Jagiellonian University.
    Reczyński, W.
    AGH University of Science and Technology.
    Janus, A.M.
    Institute of Metallurgy and Materials Engineering, Poland.
    Engvall, Klas
    RISE, Swerea, Swerea KIMAB AB.
    Socha, R.P.
    Polish Academy of Sciences.
    Kotarba, A.
    Jagiellonian University.
    Metal release and formation of surface precipitate at stainless steel grade 316 and Hanks solution interface: Inflammatory response and surface finishing effects2009Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 51, nr 5, s. 1157-1162Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of surface finishing (polishing and passivation) on the release of Cr, Fe, Ni from the stainless steel 316 implant materials to Hanks solution with or without H2O2 (simulating a body inflammatory response) was investigated. The surfaces were characterized by means of SEM EDXS, XPS and Kelvin Probe measurements before and after exposure to the synthetic body fluids. The total metal ions release rates are more than 10 times higher in the presence of H2O2, independently of the surface finishing. In the absence of H2O2, formation of a surface layer consisting mainly of Ca3(PO4)2 was observed, most likely it was responsible for the observed decrease of the release rates. © 2009 Elsevier Ltd. All rights reserved.

  • 57.
    Comanescu, Iulian
    RISE, Swerea, Swerea KIMAB AB.
    Influence of MIC on corrosion of oil field water injection pipelines2013Ingår i: Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013, Australasian Corrosion Association , 2013, s. 143-152Konferensbidrag (Refereegranskat)
    Abstract [en]

    Water injection or water flooding is widely used as a secondary recovery method to increase the production of oil usually from mature oil wells. It requires the injection of water into the reservoir, typically using carbon steel pipelines. Their corrosion is a major issue for the oil and gas industry, involving high costs of periodic chemical treatment, including biocides, oxygen scavengers, corrosion and scale inhibitors, and pipeline pigging. There is also the high potential cost of premature failure of the pipelines relative to life-time predictions, and the associated potential for unpredicted costs and major environmental implications should the pipeline fail. The present paper presents a review of a pilot study supported by the oil industry and the European Community that aimed to improve understanding of the corrosion behaviour of these pipelines. It draws on data and observations for the long-term corrosion, water quality, intelligent pigging records and microbiological testing to gain a better understanding why some pipelines suffer mild corrosion yet others, apparently similar, are prone to highly aggressive channelling corrosion. Herein the documented experience of several pipelines is reviewed. Observation data taken into consideration include pigging operation information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Also, the distribution of corrosion along the pipeline as well as the localization of corrosion attack is noted. Preliminary correlations between and conclusions about observed corrosion, operational conditions and service history are made. A Joint Industry research project currently is being arranged by the offshore oil industry to extend this work. Copyright © 2013 by the Australasian Corrosion Association.

  • 58.
    Comanescu, Iulian
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Johansson, Eva
    RISE, Swerea, Swerea KIMAB AB.
    Data base and corrosion models for MIC in oil & gas2011Ingår i: European Corrosion Congress 2011, EUROCORR 2011, 2011, Vol. 3, s. 2574-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Systems for handling stabilised oil like equipment for top side oil export systems, oil transport and processing plants are subject to high level of bio-corrosion. Bio-corrosion results in extensive and costly damages for the equipment and additional losses due to the shutting down of the transport and production units for several weeks. The objective of this project is to build a database of bio-corrosion case histories on carbon steel in systems containing produced water, to design a statistical model correlating physical and chemical parameters and to create a basis for modelling the prediction of MIC in produced water, as e.g. extracted from the hydrocarbon stream. The intention is to develop the data base to an expertise tool for MIC that can be used for anticipating and preventing bio-corrosion. The work is following the methodology "From the field, through the lab, to the field". The work starts with an extensive literature study for collection of published MIC failures in relevant environments. Additionally, close interactions will be held with field operators within Statoil, M-I SWACO and other oil & gas related companies for collection of MIC failures from the fields. In order to have statistical data existing field and literature data will be complemented with field and laboratory studies both within and outside the Marie Curie BIOCOR ITN. A schematic view of the procedure for the work is given below.

  • 59.
    Comanescu, Iulian
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Melchers, Robert E.
    University of Newcastle, Australia.
    Taxén, Claes
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Corrosion and durability of offshore steel water injection pipelines2015Ingår i: Ships and Offshore Structures, ISSN 1744-5302, E-ISSN 1754-212X, Vol. 11, nr 4, s. 424-437Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon steel pipelines are widely used for injection of sea and other waters into oil and gas wells so as to increase the rate of recovery, particularly from mature fields. Internal corrosion usually is mild. However, cases of very aggressive channelling corrosion along the bottom of the pipeline have been observed. Practical experience and anecdotal observations have attributed this to microbiologically influenced corrosion even though extensive use is made of preventative measures including biocides, oxygen scavengers, corrosion and scale inhibitors, and pipeline pigging. Interpretation of data and observations for five water injection pipelines, made available by industry, indicate that microbiologically influenced corrosion may play a part in causing channelling corrosion but that the most likely cause is under-deposit corrosion under pipe debris that settles during periods of pipeline shut-downs and low water velocity.

  • 60.
    Comanescu, Iulian
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Taxén, Claes
    RISE, Swerea, Swerea KIMAB AB.
    Assessment of MIC in carbon steel water injection pipelines2012Ingår i: Society of Petroleum Engineers - SPE International Conference and Exhibition on Oilfield Corrosion 2012, 2012, s. 227-234Konferensbidrag (Refereegranskat)
    Abstract [en]

    The present study compares corrosion mass loss and pit depth measurements on carbon steel corrosion coupons exposed under similar operating parameters, but with different biological consortia. One set of data were obtained from standard flush disc corrosion coupons used to monitor corrosion rates in a water injection pipeline on the North Sea continental shelf. The coupons were exposed on average for 6 months over 6 years operational time. These data are compared with published corrosion data of coupons exposed in abiotic district hot water systems from several power plants situated in Europe. The exposure time for these coupons was 9 months. Both systems were anoxic and in the same temperature range and are comparable. Observations regarding relationship between MIC and bacterial consortia, bacterial numbers and type, water quality and corrosion products are also made. The corrosion rate of the water injection pipeline is approximately 10 times higher compared with the corrosion rate in the abiotic district hot water system. It is concluded that the increased corrosion on the carbon steel coupons in the early stage is caused by MIC. This is also supported by the chemical and biological information available for the pipelines. The results reported here constitute the first step of an overall study to improve the level of understanding of the bacterial contribution to the total corrosion rates of carbon steel in water injection flowlines. Such understanding is expected to improve management and operational decision-making for practical control of corrosion in the field, by providing predictions of expected life time as a function of control of biotic consortia (e.g. through pigging, and biocide treatments). Further, it will facilitate decisions concerning choice of pipeline construction materials for future design. Copyright 2012, Society of Petroleum Engineers.

  • 61.
    Comanescu, Iulian
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Taxén, Claes
    RISE, Swerea, Swerea KIMAB AB.
    Life time assessment of offshore water injection pipelines as a function of microbiologically influenced corrosion2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Corrosion of water injection pipelines (WIP) in the oil and gas industry is a major issue involving potential premature life time predictions and unpredicted costs like periodic biocide treatment and pipeline pigging. This paper presents a part of a larger project concerned with improving understanding of the influence of bacterial activity on corrosion, as distinct from abiotic corrosion, in oil and gas transport systems for better management of pipeline systems. Observations are made concerning life time as a function of microbiologically influenced corrosion (MIC) risk and relationships between MIC, bacterial numbers and types, and water quality. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).

  • 62.
    Comanescu, Iulian
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Taxén, Claes
    RISE, Swerea, Swerea KIMAB AB.
    The possible influence of microorganisms on the patterns of corrosion seen in water injection pipelines2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    A major problem for the management of oil and gas pipelines is corrosion influenced by microorganisms particularly, bacteria. The present study focuses on the influence particularly of the sulfate reducing bacteria on the internal corrosion of water injection pipelines. The research is based on reports from long-term observations of several water injections pipelines from the North Sea continental shelf. Observation data taken into consideration are pigging operation information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Observations regarding water quality and mitigation methods are made also. The distribution of corrosion including pitting and 'features' along the pipeline as well as the localization of these in relation to the orientation of the surfaces, is considered. This includes different corrosion patterns along the pipeline and the relative severity of six o'clock corrosion. These observations are used to make correlation estimates between severity and location of corrosion and service history and the local environmental conditions, where this information is available. The correlations are used to develop a clearer view of the proportion of biocorrosion contributing to the total corrosion in water injection pipelines. Additionally, an assessment is made of the efficiency of mitigation procedures such as biocide treatments and pigging operations. The paper provides possible explanations for different rates and spatial patterns of corrosion for water injection pipelines. © 2013 by NACE International.

  • 63.
    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, Material och produktion, KIMAB.
    Prosek, Tomas
    RISE - Research Institutes of Sweden, Material och produktion, 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 coating2017Ingår i: 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 , 2017Konferensbidrag (Refereegranskat)
  • 64.
    Danielsson, Mats
    RISE, Swerea, Swerea KIMAB AB.
    A stress update algorithm for constitutive models of glassy polymers2013Ingår i: International Journal for Computational Methods in Engineering Science and Mechanics, ISSN 1550-2287, E-ISSN 1550-2295, Vol. 14, nr 4, s. 336-342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A semi-implicit stress update algorithm is developed for the elastic-viscoplastic behavior of glassy polymers. The case of near rate-insensitivity is addressed, and the stress update algorithm is designed to handle this case robustly. A consistent tangent stiffness matrix is derived based on a full linearization of the internal virtual work. The stress update algorithm and (a slightly modified) tangent stiffness matrix are implemented in a commercial finite element program. The stress update algorithm is tested on a large boundary value problem for illustrative purposes. © 2013 Copyright Taylor and Francis Group, LLC.

  • 65.
    Danielsson, Mats
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Gårdstam, Johannes
    RISE, Swerea, Swerea KIMAB AB.
    Temperature dependent material properties of MaterialA used for quenching simulations2012Rapport (Refereegranskat)
    Abstract [en]

    This report describes the experimental and computational programs that were used to extract material properties required for finite-element-based quenching simulations. Several metallurgical phases appear prior to, during, and after the quenching operation. The experimental program was designed so as to provide both temperature-dependent thermal and temperature-dependent elastic-plastic material properties for every appearing phase. One thermal property, enthalpy, was calculated using computational thermodynamics. In addition to material properties, metallurgical transformations (diffusion-governed and diffusionless) were quantified experimentally. The obtained data in this work was used to calibrate material models and models for phase transformation kinetics in the finite element software Sysweld.

  • 66.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Larche, Nicolas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Degres, Yves
    NKE, France.
    Biofilm sensor for deep sea2014Ingår i: 2014 IEEE Sensor Systems for a Changing Ocean, SSCO 2014, Institute of Electrical and Electronics Engineers Inc. , 2014Konferensbidrag (Refereegranskat)
    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.

  • 67.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Larché, Nicolas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Carbon steel and stainless-steel cathodic protection design data in Deepsea Water - Influence of the environment on the biofilm cathodic activity2019Ingår i: 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 , 2019Konferensbidrag (Refereegranskat)
    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. 

  • 68.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Ledan, F
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    LeBozec, Nathalie
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Real-time monitoring of the degradation of metallic and organic coatings using electrical resistance sensors2017Ingår i: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 68, nr 12, s. 1365-1376Artikel i tidskrift (Refereegranskat)
    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. 

  • 69.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, 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, Material och produktion, KIMAB.
    Rouvellou, B.
    Universite de Brest, France.
    Initial formation of corrosion products on pure zinc and MgZn2 examinated by XPS2014Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 79, s. 83-88Artikel i tidskrift (Refereegranskat)
    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.

  • 70.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, 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, Material och produktion, KIMAB.
    Rouvellou, B.
    Université de Bretagne Occidentale, France.
    Chemistry of corrosion products of Zn and MgZn pure phases under atmospheric conditions2012Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 65, s. 178-186Artikel i tidskrift (Refereegranskat)
    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.

  • 71.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, 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, Material och produktion, KIMAB.
    Rouvellou, B.
    Laboratoire de Magnétisme de Bretagne, France.
    Stability of ZnMgO oxide in a weak alkaline solution2012Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, nr 7, s. 2819-2823Artikel i tidskrift (Refereegranskat)
    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.

  • 72.
    Diler, Erwan
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, 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, Material och produktion, KIMAB.
    Characterization of corrosion products of Zn and Zn-Mg-Al coated steel in a marine atmosphere2014Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 87, s. 111-117Artikel i tidskrift (Refereegranskat)
    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.

  • 73.
    Doostmohammadi, H.
    et al.
    KTH.
    Jönsson, P.G.
    KTH.
    Komenda, Jacek
    RISE, Swerea, Swerea KIMAB AB.
    Hagman, S.
    Ovako Bar.
    Inclusion characteristics of bearing steel in a runner after ingot casting2010Ingår i: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 81, nr 2, s. 142-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the uphill teaming method of ingot casting molten metal from the ladle goes into the runner system, which feeds one or several ingot moulds. This method is still important for production of bearing steel. In order to make clean steel, which has a controlled amount of inclusions, good understanding of inclusions characteristics is necessary. In this work non-metallic inclusions of steel left in the runner part of an ingot casting system were studied. Inclusion type, size, and morphology were the main focus of this study. A scanning electron microscope (SEM) was used to assess inclusion size and morphology. The chemical composition of inclusions was determined by SEM equipped with EDS. An automated program called 'INCAFeature' was used to collect statistics of inclusion characteristics. Based on the statistical analysis of inclusion composition, four types of inclusions including oxides, sulfides, carbonitrides and complex inclusions were defined. The inclusion characteristics in the runner were also compared to literature data of inclusions found in ladle and mould samples. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 74.
    Drake, Henrik
    et al.
    Linnaeus University, Sweden.
    Tullborg, Eva-Lena
    University of Gothenburg, Sweden.
    Whitehouse, Martin
    Swedish Museum of Natural History, Sweden.
    Sandberg, Bertil
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Blomfeldt, Thomas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Åström, Mats E.
    Linnaeus University, Sweden.
    Extreme fractionation and micro-scale variation of sulphur isotopes during bacterial sulphate reduction in deep groundwater systems2015Ingår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 161, s. 1-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study conducted at the Äspö Hard Rock Laboratory, SE Sweden, determines the extent and mechanisms of sulphur-isotope fractionation in permanently reducing groundwater in fractured crystalline rock. Two boreholes >400m below the ground surface were investigated. In the 17-year-old boreholes, the Al instrumentation pipes had corroded locally (i.e., Al-[oxy]hydroxides had formed) and minerals (i.e., pyrite, iron monosulphide, and calcite) had precipitated on various parts on the equipment. By chemically and isotopically comparing the precipitates on the withdrawn instrumentation and the borehole waters, we gained new insight into the dynamics of sulphate reduction, sulphide precipitation, and sulphur-isotope fractionation in deep-seated crystalline-rock settings. An astonishing feature of the pyrite is its huge variability in δ34S, which can exceed 100‰ in total (i.e., -47.2 to +53.3‰) and 60‰ over 50μm of growth in a single crystal. The values at the low end of the range are up to 71‰ lower than measured in the dissolved sulphate in the water (20-30‰), which is larger than the maximum difference reported between sulphate and sulphide in pure-culture experiments (66‰) but within the range reported from natural sedimentary settings. Although single-step reduction seems likely, further studies are needed to rule out the effects of possible S disproportionation. The values at the high end of the range (i.e., high δ34Spy) are much higher than could be produced from the measured sulphate under any biogeochemical conditions. This strongly suggests the development of closed-system conditions near the growing pyrite, i.e., the rate of sulphate reduction exceeds the rate of sulphate diffusion in the local fluid near the pyrite, causing the local aqueous phase (and thus the forming pyrite) to become successively enriched in heavy S (34S). Consequently, the δ34S values of the forming pyrite become exceptionally high and strongly decoupled from the δ34S values of the sulphate in the bulk fluid. The Al-(oxy)hydroxide and calcite precipitates are explained by a combination of deposit and galvanic corrosion initiated by Al corrosion by H2S produced by sulphate-reducing microorganisms.

  • 75.
    Du, Hongying
    et al.
    KTH Royal Institute of Technology, Sweden.
    Karasev, Andrey
    KTH Royal Institute of Technology, Sweden.
    Stavlid, Nils
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Björk, Thomas
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Lövquist, Simon
    AB Sandvik Coromant, Sweden.
    Jönsson, Pär
    KTH Royal Institute of Technology, Sweden.
    Using chip weight distribution as a method to define chip breakability during machining2018Ingår i: Procedia Manufacturing, E-ISSN 2351-9789, Vol. 25, s. 309-315Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nowadays, the existing evaluation methods of chip breakability in industry are based on subjective visual evaluations of the chip formation during cutting or on a chip chart made after the tests. However, more sensitive methods are needed to provide more in-depth information. Thus, this study proposes a method to better evaluate the chip breakability. Based on a systematically study using the weight distribution measurement method, the results show that a great consistency and reliability to evaluate the chip breakability can be obtained. Overall, it is an objective, available and precise method to be applied in the academic and industrial research.

  • 76.
    Dubus, Michel
    et al.
    Centre de Recherche et de Restauration des Musées de France, France.
    Kouril, Milan
    Institute of Chemical Technology, Prague, Czech Republic.
    Nguyen, Thi Phuong
    Centre Technique de la Bibliothèque Nationale de France, France.
    Prosek, Tomas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Saheb, Mandana
    CEA, France.
    Tate, James
    National Museums Scotland, United Kingdom.
    Monitoring copper and silver corrosion in different museum environments by electrical resistance measurement2010Ingår i: Studies in Conservation, ISSN 0039-3630, E-ISSN 2047-0584, Vol. 55, nr 2, s. 121-133Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The results are reported of a systematic programme of electrical resistance measurement (ERM) of copper and silver corrosion rates within various museum environments, directed towards developing preventive conservation understanding and practice. Electrical resistivity measurements were made using copper and silver probes for one month and one year in 33 locations, and these are interpreted in comparison with two standards. Advantages and drawbacks of different methods available for the evaluation of the corrosion aggressiveness of indoor air are discussed. Practical solutions are proposed for improving the protection of metal objects collections. Improvements are also proposed to maximize the efficiency and suitability of the measuring device to the very specific applications of cultural heritage collections.

  • 77.
    Duret-Thual, Claude
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB. INSA de Lyon, France.
    Pitting and crevice corrosion - Basic mechanistic aspects for the selection and use of stainless steels2011Ingår i: Materiaux et Techniques, ISSN 0032-6895, Vol. 99, nr 1, s. 81-91Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pitting and crevice corrosion are major forms of degradation that affects stainless steel in chloride containing solutions. From a practical point of view, they produce localised corrosion, difficult to detect and, in the case of crevice corrosion, difficult to avoid. The purpose of this paper is not to give a comprehensive review of the pitting and crevice corrosion mechanisms: fundamental work as well as applied research were and are still devoted to this topic and entire books are dedicated to it. However, some basic knowledge of the mechanisms of these corrosion processes may help in the selection, specification and use of stainless steels. In the present paper we will present the main features of the pitting and crevice corrosion processes. We then focus on initiation and propagation mechanisms. The effects of main parameters regarding the material (composition, microstructure (heterogeneities such as non metallic inclusions)), the surface condition (effect of pollutions, biofilm), and the solution (redox potential) are summarised and illustrated using examples coming from the literature or author's experience. The standardised test methods and usual experiments used to characterise pitting and crevice corrosion resistance are given. More specific experimental approaches to predict the long term pitting corrosion resistance of alloys are discussed, such as metastable pitting and repassivation potentials. In the case of crevice corrosion, the geometrical parameters (width and depth) are key factors and more and more refined models are developed in the literature to define critical conditions.

  • 78.
    Duret-Thual, Claude
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Thierry, Dominique
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Mendibide, Christoph
    RISE - Research Institutes of Sweden, Material och produktion, 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 program2019Ingår i: 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 , 2019Konferensbidrag (Refereegranskat)
    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

  • 79.
    Däcker, Carl-Åke
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Sohlgren, T.
    SSAB EMEA.
    The influence of mould powder properties on shell formation in continuous casting of steels2010Ingår i: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 81, nr 10, s. 899-907Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For peritectic steel grades the shell formation is uneven resulting in quality problems such as surface cracks. Production of these steels calls for good control and knowledge of the critical factors for shell formation. By optimisation of process parameters, it is possible to enable production of crack sensitive slabs for heavy plate. This also gives a unique possibility to study the interaction between process parameters and shell formation. The paper presents the results from two large investigations with this ambition covering the total of 27+30 heats of 220 tons of steel at SSAB EMEA-Oxelösund and concludes how surface cracks can be significantly decreased. © 2010 Wiley-VCH Verlag GmbH & Co.

  • 80.
    Eidhagen, J.
    et al.
    Sandvik Materials Technology, Sweden.
    Kivisäkk, U.
    Sandvik Materials Technology, Sweden.
    Le Manchet, S.
    Industeel, France.
    Larché, Nicolas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Marchebois, H.
    Total E and P, France.
    UNS S32707 combinded to UNS s31266; an alternative to titanium for seawater-cooled heat exchangers2017Ingår i: NACE - International Corrosion Conference SeriesVolume 3, 2017, Pages 2005-2018Corrosion Conference and Expo 2017; New Orleans; United States; 26 March 2017 through 30 March 2017, National Assoc. of Corrosion Engineers International , 2017, s. 2005-2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the process industry, seawater is commonly used when available to cool process fluids. However chlorination of the seawater is widely used to limit any microbial activity; that makes the environment quite aggressive. Chlorination oxidizes and increases the corrosion potential to approximately +600mVSCE for stainless steels and leads to higher susceptibility to localized corrosion. Super duplex stainless steels, PRENw >40, in seawater-cooled heat exchangers can be used at limited temperatures otherwise Ti Gr.2 shall be used for equipment integrity over the service life. Recent results with combination of hyper duplex UNS S32707 tubes and super austenite UNS S31266 plate, with PRENw of 49 resp. 53, for seawater-cooled heat exchangers are presented. Testing is performed in seawater cooled scale model heat exchangers with 0.5 ppm residual chlorine during a period of 18 months. Thus, it shows a corrosion resistance of the materials at a heat flux representative to a tube skin temperature up to 95°C inside in the seawater. These new results also show a good correlation with the field service and help to challenge the use of Titanium in seawater-cooled heat exchangers.

  • 81.
    Elger, R.
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Magnusson, H.
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Frisk, K.
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Modelling internal nitridation in an alumina-forming austenitic stainless steel2017Ingår i: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 68, nr 2, s. 143-150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An austenitic alumina forming stainless steel was exposed in a nitriding atmosphere comprising 5 vol% H2/N2 for 100 and 1000 h. After 100 h, the sample displayed aluminium nitrides down to 450 μm and chromium nitrides down to 200 μm. Thermodynamic equilibrium calculations and kinetic modelling of the system to simulate 100 h of exposure time were performed using the software ThermoCalc 4.1 including DICTRA. The order of appearance of nitrides in the sample starting from the surface can be understood from the thermodynamic equilibria as well as from results of kinetic modelling. However, the nitridation depth predicted by the kinetic modelling, was larger than experimentally observed, and the cubic chromium nitride predicted to be present on the surface was not detected in the exposed sample. One difference between model and experiment was a thin oxide layer present on the surface of the sample. As this oxide layer can decrease the inwards flux of nitrogen, attempts were made to describe the effects of this layer in the model. The model was also used for qualitative comparison of varying alloy compositions, temperatures and initial nitrogen contents of the matrix.

  • 82.
    Elger, Ragna
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Lindberg, Fredrik
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Norling, Rikard
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Pettersson, Rachel
    Jernkontoret, Sweden.
    Exposure of 304L and 310S in chlorinating gasification environments2015Ingår i: Materials at High Temperature, ISSN 0960-3409, E-ISSN 1878-6413, Vol. 32, nr 1-2, s. 36-43Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work examines the difference in behaviour between two austenitic steels, 304L and 310S, in a simulated environment with carbon and oxygen activities typical of the syngas cooler of a steam blown gasifier. The cyclic exposures were performed with and without addition of 500 ppm HCl for a total duration of 960 h. The oxide layers (200-600 nm) were studied using TEM, a focused ion beam microscope with EDX (FIB-EDX), electron back scattered diffraction (EBSD), SEM and X-ray diffraction (XRD). For 304L, a Cr and Ni depleted zone with a ferritic structure was observed below the oxide layer and a thin, manganese rich layer at the metal/oxide interface. For 310S, circular oxide patches were observed on the surface after exposure with HCl. These displayed elevated concentration of Al, Ca and Si, typical of inclusions. Results indicate that the addition of HCl results in a difference in oxide quality and structure but that HCl at the level of this study has little impact on the sound metal thickness.

  • 83.
    Elger, Ragna
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Pettersson, R.
    Jernkontoret.
    Effect of Addition of 4 % Al on the High Temperature Oxidation and Nitridation of a 20Cr–25Ni Austenitic Stainless Steel2014Ingår i: Oxidation of Metals, ISSN 0030-770X, E-ISSN 1573-4889, Vol. 82, s. 469-490Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In high temperature applications, the alumina forming austenites (AFA) have recently gained more focus. These utilise the advantageous effect of Al on oxidation resistance, and also have good mechanical properties. Two experimental alloys [20Cr–25Ni–1Mn–0.5Si–Fe (wt.%)] were prepared. To one of the alloys 3.77 wt.% Al was added. The alloys were studied in air and air/water at 700 °C and 1,000 °C, in a sulphidising/chlorinating environment at 700 °C and in a nitriding atmosphere at 1,000 °C. The time of exposure was 100 h, except for one 1,000 h exposure in air/water. At 700 °C in air and air/water, the AFA displayed lower mass gain than the reference material. After exposure in the sulphidising-chlorinating environment, the material displayed a surface alumina layer with some spallation. In air or air/water at 1,000 °C, internal aluminium nitride and alumina formation occurred, appreciably reducing the sound metal thickness. The nitridation was enhanced in the nitriding environment. © 2014, Springer Science+Business Media New York.

  • 84.
    Eliasson, Johan
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Siwecki, Tadeusz
    RISE, Swerea, Swerea KIMAB AB.
    Luo, Chunhui
    RISE, Swerea, Swerea KIMAB AB.
    Hardenability and tempering modelling of high strength steels in matlab2008Ingår i: 3rd International Conference on Thermomechanical Processing of Steels, TMP 2008, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of the present work is to develop the hardenability and tempering models for various quenching and tempering treatments of high strength/martensitic steels. The hardenability model is divided in three sub-models: 1. Dissolution of particles during reheating. 2. Kinetic calculation of hardenability with respect to dissolution of particles. 3. Grain size and grain growth is considered in relation to particles and their dissolution. The hardenability model can be used specifically for steels containing less than 0.4% C. For C-contents below 0.2%, Cr and Mo has less influence on hardenability, while there is a positive interaction effect between Mo and Ni. This is considered in the modelling. The semi-empirical tempering model is combined with the hardenability model for prediction of hardness and ultimate tensile strength at room temperature after tempering. The final properties are dependent on dissolution of alloying elements during reheating. Predicted properties for different steel grades by hardening and tempering models were compared with hardness and tensile strength results determined experimentally. The models are verified with examples of experimental data of hardened and tempered high strength steels. The tempering model generally works well in comparison with experimental data. The pre-history treatment of steel before quench affects the level of hardness and strength after tempering which is considered in the modelling.

  • 85.
    Eman, Jesper
    et al.
    RISE, Swerea, Swerea SICOMP AB.
    Mannberg, Peter
    RISE, Swerea, Swerea SICOMP AB.
    Andersson, Peter
    RISE, Swerea, Swerea KIMAB AB.
    Thermal conductivity of thermosetting composite materials2012Ingår i: ECCM 2012 - Composites at Venice, Proceedings of the 15th European Conference on Composite MaterialsKonferensbidrag (Refereegranskat)
    Abstract [en]

    In this work the thermal conductivity, λ, of composite materials is investigated. The experimental results are from the experimental transient hot wire method and the experimental transient plate source method. The measurements are carried out on pure RTM6 epoxy resin and glass fibre and carbon fibre composites. The material is investigated both in its fully cured, pristine shape as well as during curing, consolidation and degradation. The λ-values for pure epoxy, glass fibre composite and material during degradation has been determined.

  • 86.
    Engman, Martin
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Falkenström, Magnus
    RISE, Swerea, Swerea KIMAB AB.
    Yield strength correlated to directional dependent wave velocities in hot rolled steel using laser ultrasonics2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Yield strength has been shown to correlate well with ultrasonic longitudinal bulk wave velocities in hot rolled steel. With a laser ultrasonic's technique developed at the institute, velocities in different directions along the plate can be measured and correlated to the yield strength in the corresponding direction. © 2010 American Institute of Physics.

  • 87.
    Fahlkrans, Johan
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Melander, A.
    RISE, Swerea, Swerea KIMAB AB.
    Gårdstam, Johannes
    RISE, Swerea, Swerea KIMAB AB.
    Haglund, Sven
    RISE, Swerea, Swerea KIMAB AB.
    Straightening of induction hardened shats-inluence on fatigue strength and residual stress2012Ingår i: HTM - Haerterei-Technische Mitteilungen, ISSN 0341101X, Vol. 67, nr 3, s. 179-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Straightening of distorted components ater heat treatment is oten a necessary operation. he straightening operation leads to local plastic deformation, which is afecting the residual stress state, the hardness, and ultimately the fatigue strength of the component. he present study evaluates the inluence of a straightening operation on fatigue strength and on the residual stress state of induction hardened shats of steel EN 42CrMo4. A simpliied FEM model was formulated. he model showed that the residual stress state was asymmetric along the circumference of a straightened shat. Fatigue testing was performed in a three point bending and showed that the fatigue strength was reduced by up to some 20 % by heavy straightening. A fracture mechanics model for fatigue crack growth and arrest was developed. he model could be used to predict the fatigue strength of a straightened shat provided that the residual stress state was known. © 2012 Carl Hanser Verlag, München.

  • 88.
    Fahlkrans, Johan
    et al.
    Scania CV.
    Melander, Arne
    RISE, Swerea, Swerea KIMAB AB.
    Haglund, Sven
    RISE, Swerea, Swerea KIMAB AB.
    Gas quench rate ater low pressure carburizing and its inluence on fatigue properties of gears2013Ingår i: HTM - Journal of Heat Treatment and Materials, ISSN 18672493, Vol. 68, nr 6, s. 239-245Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Process modifications of the gas quench sequence for low pressure carburized gears can increase the performance of up to 22 %, compared to direct gas quenching. Several test series were made with diferent interruptions of the gas quenching sequence, near the martensite start temperature Ms. The quench interruption resulted in an increase in magnitude of compressive residual stress which was attributed to temperature homogenization and rearrangement of local stresses. The increased fatigue strength was a result of the combination of enhancement of the compressive residual stress state, and of mechanical stabilization of austenite.

  • 89.
    Fahlkrans, Johan
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Melander, Arne
    RISE, Swerea, Swerea KIMAB AB.
    Johansson, K.
    Scania.
    Haglund, Sven
    RISE, Swerea, Swerea KIMAB AB.
    Hosseini, S.B.
    SKF Group.
    Influence of tempering on contact fatigue2011Ingår i: International Journal of Microstructure and Materials Properties, ISSN 1741-8410, E-ISSN 1741-8429, Vol. 6, nr 6, s. 465-478Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Most components are tempered after heat treatment operations such as case hardening or induction hardening. The common opinion is that the martensitic structure after heat treatment is too brittle and tempering is necessary to increase toughness. Tempering is an additional operation which leads to increased costs by energy, handling, and investments. Eliminating tempering from the heat treatment process leads to increased productivity, energy savings, and lowered environmental impact. Two carburised steels, Ovako 253A (~EN 22NiCrMo12-5F mod. A) and EN 20NiCrMo2 (SAE 8620, SS2506), were tested for contact fatigue resistance in a roller to roller rig. The tested samples were characterised with respect to amount of fatigue damage, residual stress, amount of retained austenite and hardness. The objective was to determine if tempering is always necessary after a heat treatment operation. The contact fatigue tests show that tempering results in lower contact fatigue resistance. Further, fatigue cracks were found to have initiated in different ways between tempered and untempered steel. Copyright © 2011 Inderscience Enterprises Ltd.

  • 90.
    Fahlström, Karl
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB. University West, Sweden.
    Andersson, O.
    Volvo Cars, Sweden; KTH Royal Institute of Technology, Sweden.
    Melander, A.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Karlsson, L.
    University West, Sweden.
    Svensson, L. -E
    University West, Sweden.
    Correlation between laser welding sequence and distortions for thin sheet structures2017Ingår i: Science and technology of welding and joining, ISSN 1362-1718, E-ISSN 1743-2936, Vol. 22, nr 2, s. 150-156Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thin ultra-high strength steel shaped as 700 mm long U-beams have been laser welded in overlap configuration to study the influence of welding sequence on distortions. Three different welding directions, three different energy inputs as well as stitch welding have been evaluated, using resistance spot welding (RSW) as a reference. Transverse widening at the ends and narrowing at the centre of the beam were measured. A clear correlation was found between the weld metal volume and distortion. For continuous welds there was also a nearly linear relationship between the energy input and distortion. However, the amount of distortion was not affected by a change in welding direction. Stitching and RSW reduced distortion significantly compared to continuous laser welding.

  • 91.
    Fahlström, Karl
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea KIMAB AB.
    Andersson, Oscar
    Volvo Cars, Sweden.
    Karlsson, Leif
    University West, Sweden.
    Svensson, Lars-Erik
    University West, Sweden.
    Metallurgical effects and distortions in laser welding of thin sheet steels with variations in strength2017Ingår i: Science and technology of welding and joining, ISSN 1362-1718, E-ISSN 1743-2936, Vol. 22, nr 7, s. 573-579Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Geometrical distortions occur while welding, but the understanding of how and why they occur and how to control them is limited. The relation between the weld width, weld metal volume, total energy input, width of hard zone and distortions when laser welding three different thin sheet steels with varying strength has therefore been studied. Weld metal volume and total energy input show a good correlation with distortion for one steel at a time. The best correlation with the when including all three steel grades was the width of the hard zone composed of weld metal and the martensitic area in the heat affected zone. © 2017 Institute of Materials, Minerals and Mining.

  • 92.
    Falkenström, Magnus
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Engman, Martin
    RISE, Swerea, Swerea KIMAB AB.
    Lindh-Ulmgren, Eva
    RISE, Swerea, Swerea KIMAB AB.
    Laser ultrasonics for process control in the metal industry2011Ingår i: Nondestructive Testing and Evaluation, ISSN 1058-9759, E-ISSN 1477-2671, Vol. 26, s. 237-252Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Laser ultrasonic (LUS) techniques show great promise for online measurement of material structures and properties during the processing of steels and other metals due to their high information content combined with their ability to operate in difficult environments. Laboratory-scale experiments are presented together with theoretical background showing how LUS can provide insight into the phenomena of recrystallisation, grain growth and phase transformation based on the measurements of velocities for different wave types and on their attenuation. This technique is unique in allowing dynamic observations of such phenomena at elevated temperatures. As microstructure is the most important factor governing the strength of metals, it follows that LUS signals are closely correlated with strength properties in many cases. The LUS equipment has been applied in several industrial trials to successfully evaluate mechanical properties of the product materials. It is also shown how absolute measurements of dimensions such as plate thickness can be made without physical contact and without the need for any calibration factors. © 2011 Taylor & Francis.

  • 93.
    Festy, Dominique
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Leroy, Etienne
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Lautrou, Nicolas
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Trovel, Y.
    NKE, France.
    Cathodic protection current demand measurement: Sensor "CADIP"2013Ingår i: Materiaux et Techniques, ISSN 0032-6895, Vol. 101, nr 5-6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The CADIP sensor is going to complete potential measurements of harbor structures cathodically protected with protecting current density measurements. The sensor is based on the measurement of potential gradients generated by the current which is channeled by an isolating tube. The laboratory tests and numerical models of which results are presented enabled the sensor principle to be more deeply understood. They demonstrated that it is interesting to select the tube section as a function of the measured current density level and thus to select the amplification factor while cathodic potential perturbation are limited. These results demonstrated the necessity to control the sensor/structure interface quality to be able to well delimit the measurement area and to prevent underestimated current value. These results enabled the industrial development work of the sensor to be oriented on sensor calibration and on sensor/structure interface quality control.

  • 94.
    Flyg, Jesper
    RISE, Swerea, Swerea KIMAB AB.
    Corrosion of austenitic and duplex stainless steels in flue gas cleaning systems for waste combustion processes2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Condensing flue gases are highly corrosive and present severe challenges in terms of materials selection. The sulphuric acid condensation which occurs in coal-fired power plants has been long recognised as a cause of corrosion in flue gas desulphurisation (FGD) units, but the more complex conditions which can arise with increasing combustion or co-combustion of biomass and waste have been less thoroughly investigated. In this paper results are presented from laboratory tests designed to simulate the corrosive conditions in flue gas cleaning systems and based on analysis of actual condensate. The major focus is on waste combustion, where the main condensate component is hydrochloric acid but varying amounts of H2SO4, HBr, HNO3, HF and metal ions may also be present. These data are correlated to field tests of creviced and welded coupons in power plants. The range of steels investigated spans from UNS S31726 to the superaustenitic grades S34565, S31254 and S32654 and the superduplex S32750. Results are presented in terms of the measured uniform corrosion rates, and the contributions from crevice corrosion are considered. Comparisons are made to earlier data from coal fired plants. © 2013 by NACE International.

  • 95.
    Flyg, Jesper
    RISE, Swerea, Swerea KIMAB AB.
    Localised corrosion in stainless steels-An integrated approach to identify risk conditions2011Ingår i: 7th European Stainless Steel Conference: Science and Market, Proceedings, Associazione Italiana di Metallurgia , 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Stainless steels have superb corrosion resistance compared with the vast majority of engineering materials and can withstand a wide range of aggressive conditions. However, there is a risk of localised corrosion, in the form of pitting, crevice corrosion or stress corrosion cracking, in some chloride-containing environments. Work within a recently-concluded European project has focussed on using relatively rapid laboratory testing in an integrated approach to map the risk areas for all three of these types of localised corrosion. In this paper measurements of critical temperatures for pitting and crevice corrosion are evaluated and compared for two very different stainless steels grades: the standard austenitic EN 1.4404 (316L) and the superduplex EN 1.4410 (2507). Stress corrosion cracking is also evaluated using constant load and slow strain rate testing. Two different chloride environments have been employed: sodium chloride and magnesium chloride. Similarities and differences between the two environments are highlighted and a series of screening test for evaluation of new materials is proposed and applied to EN 1.4462 (2205) as an example.

  • 96.
    Flyg, Jesper
    RISE, Swerea, Swerea KIMAB AB.
    Materials performance in plant exposures and laboratory simulation of a cement kiln environment2008Ingår i: 17th International Corrosion Congress 2008: Corrosion Control in the Service of Society, 2008, Vol. 4, s. 2148-2158Konferensbidrag (Refereegranskat)
    Abstract [en]

    The performance of high temperature steels, nickel-base overlay welds and carbon steel has been evaluated. Field exposures for 7000 hours at 615°C or 1450 hours at 805°C were conducted in a cement kiln fired principally with coke. The environment had a high ash content, a significant sulphur content, but only low levels of chloride. Laboratory simulation of the environment was carried out at 700°C for 960 hours with application of a 99% CaSO 4-1%KCl deposit every 160 hours. The gaseous atmosphere was N 2-30%CO 2-5%H 2O-1%O 2-0.03%SO 2. The steels investigated were Fe-25Cr-20Ni (UNS S31008, EN 1.4845), Fe-21Cr-11Ni-Si-N-Ce (UNS S30815, EN 1.4835) and Fe-15Cr-10Ni 6Mn-1Mo (UNS S21500, EN 1.4982) These were also compared with overlay weld metals of Ni-21Cr-9Mo-Nb (UNS N06625, EN 2.4856) and Ni-16Cr-16Mo-W (UNS N10276, EN 2.4819). Metal loss was evaluated from metrology and generally gave similar ranking of alloy performance from field and laboratory tests. The corrosion rate could be decreased by 50% to 99% by replacing carbon steel by higher alloyed materials. Detailed metallography has been used to elucidate the corrosion attack and the occurrence of oxidation and sulphidation at the reaction front. © 2009 by NACE International.

  • 97.
    Flyg, Jesper
    et al.
    RISE, Swerea, Swerea KIMAB AB.
    Viklund, Peter
    RISE, Swerea, Swerea KIMAB AB.
    High temperature corrosion under simulated biomass deposit conditions2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Biomass is gaining increasing importance as a renewable energy source for the production of heat, electricity and transport fuels. However, corrosion issues are numerous and include accelerated wastage under ash and alkali salt deposits, erosion, and metal dusting in conjunction with gasification. This work focuses on deposit issues and is based on laboratory exposures for a total of 960 hours at 550°C (1022°F) and 700°C (1292°F) under deposits of 52.4 wt% KCl + 47.6 wt% K2SO4 in a nitrogen- based gaseous atmosphere containing 15% H2O, 5%O2, 13%CO 2 and 0.02%HCl. The materials tested include carbon steel, low alloyed steels with 2%Cr or 9%Cr, the austenitic AISI 304 and the high temperature grade 253MA (21%Cr, 11 %Ni, 1.6%Si, Ce). Metal loss data obtained from metallographic evaluation show the corrosion rate to decrease in this order and illustrate how materials substitution can permit an increase in process temperature. Examination of the reaction interface underlines the importance of both chlorination and oxidation in the materials corrosion process. © 2009 by NACE International.

  • 98.
    Frisk, Karin
    RISE, Swerea, Swerea KIMAB AB.
    Analysis of oxide reduction during sintering of Cr-alloyed steel powder through photoacoustic spectroscopy measurements2009Ingår i: Proceedings of the Euro International Powder Metallurgy Congress and Exhibition, Euro PM 2009, European Powder Metallurgy Association (EPMA) , 2009, Vol. 3Konferensbidrag (Refereegranskat)
    Abstract [en]

    The usage of steel powders prealloyed with chromium in PM components for high performance applications is steadily increasing. Excellent mechanical properties are achieved with these powder grades, provided that the processing into components is accurately done. Photoacoustic spectroscopy (PAS) technique has been used here to study oxide reduction during sintering in 90N2/10H2 atmosphere of test specimens based on 3%Cr-0.5%Mo prealloyed powders with 0.5% C added. Results from performed reduction trials show that Fe oxides on the powder surfaces are removed by H2 reduction early in the heating stage of the process. Carbothermal reduction is the main mechanism for reduction of stable Cr-containing oxides from 900°C and above. Efficient Cr oxide reduction requires a sintering temperature of at least around 1200°C. Therefore, small oxide particles remain in the material after sintering at 1120°C for 30 minutes. However, such oxides have earlier been shown to have no significant influence on mechanical properties.

  • 99.
    Frisk, Karin
    RISE, Swerea, Swerea KIMAB AB.
    Investigation of Cu distribution and porosity in Fe-2Cu and Fe-2Cu-0.5C compacts2013Ingår i: International Powder Metallurgy Congress and Exhibition, Euro PM 2013, European Powder Metallurgy Association (EPMA) , 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    The distribution of the alloying element Cu in steel compacts is important in determining the properties of the sintered products. In this work, mixtures of Fe-2Cu and Fe-2Cu-0.5C were compacted at 600 MPa and sintered at 1120oC for the holding times of ts= 3, 13, 23, and 33 min. Dilatometry and light optical microscopy is used to investigate porosity, Cu distribution and its effect on the dimensional changes during sintering. The result shows that the molten Cu penetrates into the Fe interparticle and grain boundaries in less then 3 min holding time at 1120°C, however C addition hinders the liquid penetration of Cu. Furthermore, it is found that the C-added compact has lower volume expansion and porosity compared to the C-free system, after 33 min of holding time at 1120°C.

  • 100.
    Frisk, Karin
    RISE, Swerea, Swerea KIMAB AB.
    Simulation of precipitation of secondary carbides in hot work tool steels2012Ingår i: Materials Science and Technology, ISSN 0267-0836, E-ISSN 1743-2847, Vol. 28, nr 3, s. 288-294Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Precipitation of secondary carbides in hot work tool steels during tempering heat treatments has been investigated using simulations based on a thermodynamic description coupled with kinetic parameters through multicomponent nucleation and growth models. The simulations reproduce the measured effects of steel composition on the precipitation of secondary carbides. Both Si and V increase the volume fraction of fine secondary carbides precipitated during tempering provided that the austenitising temperature is adjusted to give the same fraction of retained primary carbides. The most important effect of Si in 5%Cr steels is its influence on the primary carbide stability at austenitisation temperatures, but increasing the V contents has a strong effect on the fraction of secondary carbides, without increasing the size, and can thus improve the yield strength. The most critical input to the calculations is the thermodynamic description of the individual phases. © 2012 Institute of Materials, Minerals and Mining.

1234567 51 - 100 av 500
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.8