TY - JOUR A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Corrosion of Carbon Steel in Artificial Geothermal Brine: Influence of Carbon Dioxide at 70 °C and 150 °C N2 - This study focuses on the corrosion mechanism of carbon steel exposed to an artificial geothermal brine influenced by carbon dioxide (CO2) gas. The tested brine simulates a geothermal source in Sibayak, Indonesia, containing 1500 mg/L of Cl-, 20 mg/L of SO4 2-, and 15 mg/L of HCO3-with pH 4. To reveal the temperature effect on the corrosion behavior of carbon steel, exposure and electrochemical tests were carried out at 70 °C and 150 °C. Surface analysis of corroded specimens showed localized corrosion at both temperatures, despite the formation of corrosion products on the surface. After 7 days at 150 °C, SEM images showed the formation of an adherent, dense, and crystalline FeCO3 layer. Whereas at 70 °C, the corrosion products consisted of chukanovite (Fe2(OH)2CO3) and siderite (FeCO3), which are less dense and less protective than that at 150 °C. Control experiments under Ar-environment were used to investigate the corrosive effect of CO2. Free corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) confirm that at both temperatures, the corrosive effect of CO2 was more significant compared to that measured in the Ar-containing solution. In terms of temperature effect, carbon steel remained active at 70 °C, while at 150 °C, it became passive due to the FeCO3 formation. These results suggest that carbon steel is more susceptible to corrosion at the near ground surface of a geothermal well, whereas at a deeper well with a higher temperature, there is a possible risk of scaling (FeCO3 layer). A longer exposure test at 150 °C with a stagnant solution for 28 days, however, showed the unstable FeCO3 layer and therefore a deeper localized corrosion compared to that of seven-day exposed specimens. KW - Carbon steel KW - CO2 KW - Corrosion KW - Electrochemical impedance spectroscopy KW - Geothermal PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498168 DO - https://doi.org/10.3390/ma12223801 SN - 1996-1944 VL - 12 IS - 22 SP - 3801-1 EP - 20 PB - MDPI CY - Basel AN - OPUS4-49816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehri Sofiani, F A1 - Chaudhuri, Somsubhro A1 - Elahi, S.A. A1 - Hectors, K. A1 - De Waele, W. T1 - Quantitative Analysis of the Correlation between Geometric Parameters of Pits and Stress Concentration Factors for a Plate Subject to Uniaxial Tensile Stress N2 - The offshore environment is inherently corrosive. Consequently, pits may nucleate on exposed steel surfaces. Corrosion pits can be a source of crack initiation when the structure is subject to fatigue loading. The criticality of a corrosion pit with respect to the structural integrity depends on its shape and size and can be quantified using a stress concentration factor (𝐾𝑡). In this work, a parametric 3D finite element model is developed to perform stress analysis of a pitted plate subjected to uniaxial tensile stress. The model is used for an extensive parameter study in which 𝐾𝑡 is determined for various pit configurations. It is demonstrated that each one of the geometrical parameters holds a substantial influence on the location of the Most Critical Region (MCR). It is shown that 𝐾𝑡 increases as the pit gets narrower. Pits with an elliptical mouth yield higher 𝐾𝑡 values when the angle between the load direction and the pit mouth major axis increases. Moreover, 𝐾𝑡 increases with the increase in the localized thickness loss which is more pronounced for relatively wider pits. Finally, a regression model is presented for estimating 𝐾𝑡 based on the geometric parameters of a pit. KW - FEM KW - Corrosion KW - SCF KW - Pitting corrosion PY - 2023 DO - https://doi.org/10.1016/j.tafmec.2023.104081 SN - 0167-8442 VL - 127 SP - 1 EP - 27 PB - Elsevier Ltd. AN - OPUS4-58284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - Buggisch, E. A1 - Schiller, Bernadette Nicole A1 - Beck, M. T1 - Corrosion Study on Wellbore Materials for the CO2 Injection Process N2 - For reliability and safety issues of injection wells, corrosion resistance of materials used needs to be determined. Herein, representative low-cost materials, including carbon steel X70/1.8977 and low alloyed steel 1.7225, were embedded in mortar to mimic the realistic casing-mortar interface. Two types of cement were investigated: (1) Dyckerhoff Variodur commercial Portland cement, representing a highly acidic resistant cement and (2) Wollastonite, which can react with CO2 and become stable under a CO2 stream due to the carbonation process. Exposure tests were performed under 10 MPa and at 333 K in artificial aquifer fluid for up to 20 weeks, revealing crevice corrosion and uniform corrosion instead of expected pitting corrosion. To clarify the role of cement, simulated pore water was made by dispersing cement powder in aquifer fluid and used as a solution to expose steels. Surface analysis, accompanied by element mapping on exposed specimens and their crosssections, was carried out to trace the chloride intrusion and corrosion process that followed. KW - Carbon capture storage KW - CCS KW - Carbon dioxide KW - Corrosion KW - Carbon steel KW - Aquifer fluid KW - Cement KW - Casing KW - Pitting PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519774 DO - https://doi.org/10.3390/pr9010115 SN - 2227-9717 VL - 9 IS - 1 SP - 115 PB - MDPI CY - Basel AN - OPUS4-51977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Heide, K. T1 - Roaldite in the iron-meteorite São Julião de Moreira N2 - Roaldite – Fe4N – has been identified in the São Julião de Moreira iron meteorite using electron backscatter diffraction (EBSD) and simultaneously acquired energy-dispersive x-ray spectroscopy (EDS). Mean-periodic-number images derived from raw EBSD patterns confirm this phase by an even higher spatial resolution compared to EDS. Roaldite appears in the form of systematically and repetitively aligned plates. Despite the locally heavy plastic deformation, it is shown that the origin of the oriented precipitation of roaldite is linked to the orientation of the kamacite matrix. Roaldite can be considered to be precipitated from kamacite using an inverse Kurdjumov-Sachs (K-S) or Nishiyama-Wassermann (N-W) orientation relationship. A more accurate discrimination is impossible due to the accumulated shock deformation, which blurs the local reference orientation of kamacite. The habit plane of roaldite is found to be {112}R, which is most likely parallel to {120}K of kamacite. Some of the roaldite plates contain two orientation variants which repeatedly alternate. Their misorientation angle is about 12°. KW - Plastic deformation KW - Iron meteorite KW - Corrosion KW - Nitride KW - Orientation relationship PY - 2019 DO - https://doi.org/10.1016/j.chemer.2019.125538 VL - 79 IS - 4 SP - 125538 PB - Elsevier AN - OPUS4-50338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Wolf, M. A1 - Kranzmann, Axel T1 - Corrosion and Corrosion Fatigue of Steels in Downhole CCS Environment—A Summary N2 - Static immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4, and X5CrNiCuNb16-4 at T = 60°C and ambient pressure, as well as p = 100 bar were performed for 700–8000 h in a CO2-saturated synthetic aquifer environment similar to CCS sites in the Northern German Basin (NGB). Corrosion rates at 100 bar are generally lower than at ambient pressure. The main corrosion products are FeCO3 and FeOOH with surface and local corrosion phenomena directly related to the alloy composition and microstructure. The appropriate heat treatment enhances corrosion resistance. The lifetime reduction of X46Cr13, X5CrNiCuNb16-4, and duplex stainless steel X2CrNiMoN22-5-3 in a CCS environment is demonstrated in the in situ corrosion fatigue CF experiments (axial push-pull and rotation bending load, 60°C , brine: Stuttgart Aquifer and NGB, flowing CO2: 30 L/h, +/- applied potential). Insulating the test setup is necessary to gain reliable data. S-N plots, micrographic-, phase-, fractographic-, and surface analysis prove that the life expectancy of X2CrNiMoN22-5-3 in the axial cyclic load to failure is clearly related to the surface finish, applied stress amplitude, and stress mode. The horizontal grain attack within corrosion pit cavities, multiple fatigue cracks, and preferable deterioration of austenitic phase mainly cause fatigue failure. The CF life range increases significantly when a protective potential is applied. KW - Carbon capture and storage KW - Steel KW - High alloyed steel KW - Corrosion KW - Corrosion fatigue KW - CCS PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523948 DO - https://doi.org/10.3390/pr9040594 VL - 9 IS - 4 SP - 594 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Bettge, Dirk T1 - On the corrosion mechanism of CO2 transport pipeline steel caused by condensate: Synergistic effects of NO2 and SO2 N2 - To study the effects of condensed acid liquid, hereafter referred to as condensate, on the CO2 transport pipeline steels, gas mixtures containing a varying concentration of H2O, O2, NO2, and SO2, were proposed and resulted in the condensate containing H2SO4 and HNO3 with the pH ranging from 0.5 to 2.5. By exposing the pipeline steel to the synthetic condensate with different concentration of acidic components, the corrosion kinetic is significantly changed. Reaction kinetic was studied using electrochemical methods coupled with water analysis and compared with surface analysis (scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffractometry (XRD)) of corroded coupons. The results showed that, although the condensation of NO2 in the form of HNO3 causes faster general corrosion rate, it is the condensation of SO2 in the form of H2SO4 or the combination of SO2 and NO2 that may cause much more severe problems in the form of localized and pitting corrosions. The resulting corrosion forms were depended on the chemical nature of acids and their concentration at the same investigated pH. The effects of changing CO2 flow rate and renewing condensate on pitting corrosion were further studied. KW - Carbon capture, utilization and storage technology KW - CCUS KW - Corrosion KW - Condensate KW - Electrochemical characterisation KW - Pitting corrosion KW - Impurities KW - Carbon steel PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-473685 UR - https://www.mdpi.com/1996-1944/12/3/364 DO - https://doi.org/10.3390/ma12030364 SN - 1996-1944 VL - 12 IS - 3 SP - 364, 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-47368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Local Corrosion of Martensitic Stainless Steels during Exposure to Saline Aquifer Water and CO2 Environment N2 - Carbon Capture and Storage (CCS) is well acknowledged to mitigate climate change. Therefore, pipe Steels suitable for CCS technology require resistance against the corrosive environment of a potential CCS-site, e.g. heat, pressure, salinity of the aquifer, CO2-partial pressure. Samples of different mild and high alloyed stainless injection-pipe Steels partially heat treated: 42CrMo4, X20Cr13, X46Cr13, X35CrMo4 as well as X5CrNiCuNb16-4 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h - 8000 h in a CO2-saturated synthetic aquifer environment similar to possible geological on-shore CCS-sites in the northern German Basin. Main corrosion products analysed on pits are FeCO3 and FeOOH. The carbon content does not show significant influence on the pitting behaviour. Generally, higher chromium Content results in better corrosion resistance. Although X35CrMo17-1 and X5CrNiCuNb16-4 show low surface corrosion rates, their resistance against local corrosion in CCS environment is not significantly better compared to the much less costly Steels X20Cr13 and X46Cr13. KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Heat treatment PY - 2018 DO - https://doi.org/10.18178/ijcea.2018.9.1.694 SN - 2010-0221 VL - 9 SP - 26 EP - 31 PB - International Association of Computer Science and Information Technology Press CY - Singapore AN - OPUS4-46627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blank, Robin A1 - Nitschke, Heike A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Materialographic Preparation of Salt N2 - Molten salt containing systems gain in importance for sustainable energy use and production. For research and development, interactions of molten salts with potential container materials are of major interest. This article introduces preparation procedures to display an intact metal and salt microstructure and their interface using light optical microscopy and scanning electron microscopy. The exemplary material combination is the ternary salt mixture NaCl-KCl-MgCl2 and the low alloyed steel 1.4901 (T92) with a maximum service temperature of 550 °C. These are potential elements/materials for use in latent heat thermal energy storages. KW - Molten salt KW - Corrosion KW - Steel KW - Aging KW - Dry preparation PY - 2021 DO - https://doi.org/10.1515/pm-2022-0058 VL - 59 IS - 10 SP - 628 EP - 640 PB - De Gruyter AN - OPUS4-56048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knauer, S A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Jaeger, P T1 - Contact angle and corrosion of a Water – CO2 system on X70 and S41500 at 278 K and pressures up to 20 MPa N2 - Interfacial properties related to wettability and corrosion in CO2 transport pipelines are experimentally determined by the sessile and the pendant drop methods. The contact angle of a water drop in a compressed CO2 atmosphere is analyzed on an X70 pipeline carbon steel and compared to that on a martensitic steel S41500 to elucidate the effect of corrosion process on active wetting behaviour. The measurements are performed with liquid CO2 at 278 K and pressures ranging from 5 to 20 MPa. The results show that the contact angle (CA) increases with pressure from 132 ° to 143 ° for S41500 and from 117 ° to 137 ° for X70 and decreases with drop age by 20 ° to 24 ° regardless of the pressure and of the fact that corrosion only occurs on X70, which is confirmed by scanning electron microscopy, element mapping and energy dispersive x-ray spectrometry (EDS) analysis. At higher pressure, the contact angles on both materials converge. Further, related properties like density and interfacial tension were determined. CO2 - saturated water has a higher density than pure water: At 5 MPa saturated water reaches a density of 1017 kg⋅m^(-3) and at 20 MPa 1026 kg⋅m^(-3) compared to pure water with a density of 1002 kg⋅m^(-3) and 1009 kg⋅m^(-3), respectively. In this pressure range the IFT drops from 33 mN⋅m^(-1)at 5 MPa to 23 mN⋅m^(-1) at 20 MPa. KW - Carbon capture KW - Utilization, and storage (CCUS) technology KW - Contact angle KW - Wetting KW - Corrosion KW - Condensate KW - Impurities KW - Carbon steel PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S1750583618309472?dgcid=author DO - https://doi.org/10.1016/j.ijggc.2019.06.021 SN - 1750-5836 SN - 1878-0148 VL - 89 SP - 33 EP - 39 PB - Elsevier, ScienceDirect AN - OPUS4-48601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - Bender, R. A1 - Féron, D. A1 - Mills, D. A1 - Ritter, S. A1 - de Graeve, I. A1 - Dugstad, A. A1 - Grassini, S. A1 - Hack, T. A1 - Halama, M. A1 - Han, E.-H. A1 - Harder, T. A1 - Hinds, G. A1 - Kittel, J. A1 - Krieg, R. A1 - Leygraf, C. A1 - Martinelli, L. A1 - Mol, A. A1 - Neff, D. A1 - Nilsson, J.-O. A1 - Odnevall, I. A1 - Paterson, S. A1 - Paul, S. A1 - Prosek, T. A1 - Raupach, M. A1 - Revilla, R. I. A1 - Ropital, F. A1 - Schweigart, H. A1 - Szala, E. A1 - Therryn, H. A1 - Tidblad, J. A1 - Virtanen, S. A1 - Volovitch, P. A1 - Watkinson, D. A1 - Wilms, M. A1 - Winning, G. A1 - Zheludkevich, M. T1 - La corrosion: un défi pour une société durable N2 - Une transition mondiale vers des systèmes énergétiques plus durables, abordables et fiables a été initiée par l’accord de Paris et l’Agenda 2030 des Nations unies pour un développement durable. Il s’agit là d’un défi industriel majeur car les systèmes et infrastructures énergétiques résilients au changement climatique exigent de se positionner pour le long terme. Se pencher sur le comportement dans la durée des matériaux structurels - principalement des métaux et des alliages - s’impose alors comme une nécessité. Dans cette optique, « La corrosion : un défi pour une société durable »présente une série de cas montrant l’importance de la tenue à la corrosion et de la protection anticorrosion des métaux et des alliages pour le développement de systèmes durables, économiques et fiables de production d’énergie. KW - Corrosion KW - Coûts de la corrosion KW - Protection KW - Anticorrosion KW - Stratégies deprévention PY - 2023 DO - https://doi.org/10.51257/a-v1-cor2000 SN - 2555-5383 VL - 2023 IS - Avril SP - 1 EP - 23 CY - Saint-Denis, France AN - OPUS4-57927 LA - fra AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Ricky A1 - Sturm, Patrick A1 - Keßler, S. A1 - Gluth, Gregor T1 - Corrosion of hybrid alkaline cements in saline solution simulating evaporite rock – effect of the Portland clinker content N2 - Two hybrid alkaline cements (HAC) based on Portland clinker, ground granulated blast furnace slag (GGBFS), fly ash and sodium sulfate, as well as an alkali-activated GGBFS/fly ash blend and a Portland cement paste were exposed to a saturated saline solution for 70 days. The combined chemical attack of chloride, magnesium and sulfate ions and the associated changes of the phase assemblage of the materials were studied by X-ray diffraction, thermal analysis and spatially resolved X-ray fluorescence spectroscopy. The experimental results revealed dissolution of ettringite, C-N-A-S-H and calcite, and the formation of gypsum, Kuzel's salt and Friedel's salt; thermodynamic modeling indicated the formation of M-S-H. The resistance of the HAC against attack by the saline solution increased with Portland clinker fraction. The capacity of portlandite to maintain pH at values above 10 is found to be a major factor controlling the resistance of HAC against corrosion in the saline solution. KW - Hybrid cements KW - Alkali-activated materials KW - Magnesium chloride KW - Corrosion KW - Salt attack PY - 2023 DO - https://doi.org/10.1016/j.cemconres.2023.107215 SN - 0008-8846 SN - 1873-3948 VL - 172 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-57638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matamoros-Veloza, A. A1 - Stawski, Tomasz A1 - Vargas, S. A1 - Neville, A. T1 - Study of a Local Structure at the Interface between Corrosion Films and Carbon Steel Surface in Undersaturated CO2 Environments N2 - Industries transporting CO2 gas-saturated fluids have infrastructures made of carbon steel. This is a good material with great mechanical properties but prone to corrosion and potential failure. Corrosion in sweet environments involves the formation of FeCO3 as a corrosion film, which is recognized to play a protective role under certain conditions. This work on the dissolution of corrosion films in sweet environments, under acidic and undersaturated conditions, demonstrates that the effects on the integrity of steel are far more significant than the damage observed on the surface of the corrosion film. Our results prove that dissolution of FeCO3 involved the presence of an amorphous phase, the intermediate formation of FeCl2 or FeCl+, and the presence of a phase with short distance atom–atom correlations. The amorphous phase was identified as a mixture of retained γ-Fe and Fe3C. Partially broken α-Fe and Fe3C structures were identified to prove the damage on the material, confirming the interface zone without evident damage on the corrosion film. Dissolution affected both the α-Fe and FeCO3, with the lattice [102̅] from the FeCO3 crystalline structure being the fastest to dissolve. The damage of steel at the molecular scale was evident at the macroscale with pit depths of up to 250 μm. The impact on the integrity of steel can be, therefore, more drastic than frequently reported in industrial operations of CO2 transport industries that use cleaning procedures (e.g., acid treatment, pigging) as part of their operational activities. KW - Steel KW - Corrosion KW - Siderite KW - Diffraction KW - Pair distribution function KW - Synchrotron PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572156 DO - https://doi.org/10.1021/acsomega.2c07631 SN - 2470-1343 VL - 8 IS - 9 SP - 8497 EP - 8504 PB - ACS AN - OPUS4-57215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Morell, Daniel A1 - von der Au, Marcus A1 - Wittstock, Gunther A1 - Ozcan, Ozlem A1 - Witt, Julia T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung: Auswirkungen auf Legierungsstabilität und Elektrokatalyse N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors. N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen. KW - Transpassive dissolution KW - Corrosion KW - Multi-prinicpal element alloys (MPEAs) KW - Passivation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045 DO - https://doi.org/10.1002/anie.202317058 SP - 1 EP - 8 PB - Wiley VHC-Verlag AN - OPUS4-59704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kingsbery, P. A1 - Manzoni, Anna M. A1 - Suarez Ocaño, Patricia A1 - Többens, D. M. A1 - Stephan‐Scherb, C. T1 - High‐temperature KCl‐induced corrosion of high Cr and Ni alloys investigated by in‐situ diffraction N2 - High‐temperature KCl‐induced corrosion in laboratory air was observed in situ utilizing X‐ray diffraction. High Cr‐containing model alloys (Fe‐13Cr, Fe‐18Cr‐12Ni, and Fe‐25Cr‐20Ni) were coated with KCl and exposed to dry air at 560°C. KCl‐free alloys were studied in the equivalent atmosphere as a reference. After exposure to KCl‐free environments, all alloys showed the formation of very thin oxide layers, indicating good corrosion resistance. In contrast, KCl‐bearing alloys showed distinct damage after exposure. KW - Corrosion KW - In-situ diffraction KW - High-temperature corrosion PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600831 DO - https://doi.org/10.1002/maco.202314224 SN - 0947-5117 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-60083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitenbach, Romy A1 - Silbernagl, Dorothee A1 - Toepel, J. A1 - Sturm, Heinz A1 - Broughton, William J. A1 - Sassaki, G. L. A1 - Gorbushina, Anna T1 - Corrosive extracellular polysaccharides of the rock-inhabiting model fungus Knufia petricola N2 - Melanised cell walls and extracellular polymeric matrices protect rock-inhabiting microcolonial fungi from hostile environmental conditions. How extracellular polymeric substances (EPS) perform this protective role was investigated by following development of the model microcolonial black fungus Knufia petricola A95 grown as a sub-aerial biofilm. Extracellular substances were extracted with NaOH/formaldehyde and the structures of two excreted polymers studied by methylation as well as NMR analyses. The main polysaccharide (~ 80%) was pullulan, also known as α-1,4-; α-1,6-glucan, with different degrees of polymerisation. Αlpha-(1,4)-linked-Glcp and α-(1,6)-linked-Glcp were present in the molar ratios of 2:1. A branched galactofuromannan with an α-(1,2)-linked Manp main chain and a β-(1,6)-linked Galf side chain formed a minor fraction (~ 20%). To further understand the roles of EPS in the weathering of minerals and rocks, viscosity along with corrosive properties were studied using atomic force microscopy (AFM). The kinetic viscosity of extracellular K. petricola A95 polysaccharides (≈ 0.97 × 10-6 m2 s-1) ranged from the equivalent of 2% (w/v) to 5% glycerine, and could thus profoundly affect diffusion-dominated processes. The corrosive nature of rock-inhabiting fungal EPS was also demonstrated by its effects on the aluminium coating of the AFM cantilever and the silicon layer below. KW - Corrosion KW - EPS KW - Melanised microcolonial fungi (MCF) KW - Pullulan KW - Sub-aerial biofilms (SAB) KW - α-1,4- and α-1,6-glucans KW - AFM cantilever vibration KW - Nanoviscosity KW - Nanocorrosion of aluminium and silicon PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-435910 DO - https://doi.org/10.1007/s00792-017-0984-5 SN - 1433-4909 SN - 1431-0651 VL - 22 IS - 2 SP - 165 EP - 175 PB - Springer CY - Berlin AN - OPUS4-43591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ronald A1 - Fischer, J. A1 - Bügler, M. A1 - Nowak, M. A1 - Thöns, S. A1 - Borrmann, A. A1 - Straub, D. T1 - Assessing and updating the reliability of concrete bridges subjected to spatial deterioration - principles and software implementation N2 - Inspection and maintenance of concrete bridges is a major cost factor in transportation infrastructure, and there is significant potential for using information gained during inspection to update predictive models of the performance and reliability of such structures. In this context, this paper presents an approach for assessing and updating the reliability of prestressed concrete bridges subjected to chloride-induced reinforcement corrosion. The system deterioration state is determined based on a Dynamic Bayesian Network (DBN) model that considers the spatial variability of the corrosion process. The overall system reliability is computed by means of a probabilistic structural model coupled with the deterioration model. Inspection data are included in the system reliability calculation through Bayesian updating on the basis of the DBN model. As proof of concept, a software prototype is developed to implement the method presented here. The software prototype is applied to a typical highway bridge and the influence of inspection information on the system deterioration state and the structural reliability is quantified taking into account the spatial correlation of the corrosion process. This work is a step towards developing a software tool that can be used by engineering practitioners to perform reliability assessments of ageing concrete bridges and update their reliability with inspection and monitoring data. KW - Structural reliability KW - Dynamic Bayesian Networks KW - Spatial deterioration KW - Inspection KW - Monitoring general KW - Analysis and design methods KW - Reinforcement KW - Corrosion KW - Prestressed concrete PY - 2015 DO - https://doi.org/10.1002/suco.201500014 SN - 1464-4177 VL - 16 IS - 3 SP - 356 EP - 365 PB - Ernst & Sohn CY - Berlin AN - OPUS4-34336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurzler, Nina A1 - Sobol, Oded A1 - Altmann, Korinna A1 - Radnik, Jörg A1 - Özcan Sandikcioglu, Özlem T1 - Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior N2 - Stainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal‐reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface‐sensitive techniques such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron‐rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox‐active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox‐active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces. KW - Corrosion KW - Stainless steel KW - Surface analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528117 DO - https://doi.org/10.1002/maco.202012191 VL - 72 IS - 6 SP - 974 EP - 982 PB - Wiley AN - OPUS4-52811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - von der Au, Marcus A1 - Dietrich, P. M. A1 - Radnik, Jörg A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - The comparison of the corrosion behavior of the CrCoNi medium entropy alloy and CrMnFeCoNi high entropy alloy N2 - This work presents the determination of the corrosion characteristics of CrCoNi (medium entropy alloy) and CrMnFeCoNi (high entropy alloy) in 0.1 M NaCl and 0.1 M H2SO4. The morphology and chemical composition of the oxide layers formed on CrCoNi and CrMnFeCoNi were comparatively analyzed by scanning Kelvin probe microscopy (SKPFM) and scanning electron microscopy (SEM) and supported with chemical analysis by means of inductively coupled plasma mass spectrometry (ICP-MS) and X-Ray photoelectron spectroscopy (XPS). The analysis of the 3p core level peaks showed that the oxide layer (native and after anodic passivation) on CrCoNi consisted mainly of Cr oxides, while the oxide layer on CrMnFeCoNi was primarily composed of a mixture of Cr and Fe oxides. In addition, XPS was utilized to assess the oxide layer thicknesses. These results were compared to the thicknesses obtained by means of electrochemical impedance spectroscopy (EIS), with both approaches yielding values up to about 4 nm depending on the electrolyte and the alloy. Cyclic polarization measurements indicated superior corrosion resistance of CrCoNi in both aqueous environments compared to CrMnFeCoNi, as well as to AISI 304 stainless steel. KW - Medium entropy alloy KW - High entropy alloy KW - SKPFM KW - XPS KW - Passivation KW - Corrosion PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559902 DO - https://doi.org/10.1016/j.apsusc.2022.154171 SN - 0169-4332 VL - 601 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-55990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Yusenko, Kirill A1 - Stawski, Tomasz A1 - Kulow, Anicó A1 - Cakir, Cafer Tufan A1 - Röder, Bettina A1 - Naese, Christoph A1 - Britzke, Ralf A1 - Sintschuk, Michael A1 - Emmerling, Franziska T1 - BAMline - A real-life sample materials research beamline N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. The BAMline, a real-life sample materials research beamline, provides unique insights into materials’ electronic and chemical structure at different time and length scales. The beamline specializes in x-ray absorption spectroscopy, x-ray fluorescence spectroscopy, and tomography experiments. This enables real-time optimization of material properties and performance for various applications, such as energy transfer, energy storage, catalysis, and corrosion resistance. This paper gives an overview of the analytical methods and sample environments of the BAMline, which cover non-destructive testing experiments in materials science, chemistry, biology, medicine, and cultural heritage. We also present our own synthesis methods, processes, and equipment developed specifically for the BAMline, and we give examples of synthesized materials and their potential applications. Finally, this article discusses the future perspectives of the BAMline and its potential for further advances in sustainable materials research. KW - Extended X-ray absorption fine structure KW - Energy storage KW - Environmental impacts KW - Nondestructive testing techniques KW - X-ray fluorescence spectroscopy KW - Corrosion KW - Near edge X-ray absorption fine structure spectroscopy KW - X-ray absorption spectroscopy PY - 2023 DO - https://doi.org/10.1063/5.0157194 VL - 158 IS - 24 SP - 1 EP - 22 PB - AIP Publishing AN - OPUS4-57824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cakir, Cafer Tufan A1 - Piotrowiak, T. A1 - Reinholz, Uwe A1 - Ludwig, A. A1 - Emmerling, Franziska A1 - Streli, C. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - Exploring the Depths of Corrosion: A Novel GE-XANES Technique for Investigating Compositionally Complex Alloys N2 - In this study, we propose the use of nondestructive, depth-resolved, element-specific characterization using grazing exit X-ray absorption near-edge structure spectroscopy (GE-XANES) to investigate the corrosion process in compositionally complex alloys (CCAs). By combining grazing exit X-ray fluorescence spectroscopy (GE-XRF) geometry and a pnCCD detector, we provide a scanning-free, nondestructive, depth-resolved analysis in a sub-micrometer depth range, which is especially relevant for layered materials, such as corroded CCAs. Our setup allows for spatial and energy-resolved measurements and directly extracts the desired fluorescence line, free from scattering events and other overlapping lines. We demonstrate the potential of our approach on a compositionally complex CrCoNi alloy and a layered reference sample with known composition and specific layer thickness. Our findings indicate that this new GE-XANES approach has exciting opportunities for studying surface catalysis and corrosion processes in real-world materials. KW - Degradation mechanisms KW - Grazin exit XANES KW - Depth resolved XANES KW - Compositional complex alloys KW - Corrosion PY - 2023 DO - https://doi.org/10.1021/acs.analchem.3c00404 VL - 95 SP - 4810 EP - 4818 PB - ACS Publications AN - OPUS4-57823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -