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 - Swaminathan, Srinivasan A1 - Kumar, S. A1 - Kranzmann, Axel A1 - Hesse, Rene A1 - Goldbeck, Hennig A1 - Fantin, Andrea T1 - Corrosion characteristics of 316L stainless steel in oxide-rich molten solar salt at 600◦C N2 - An attempt has been made in this work, to observe the influence on alloy aging by the sodium oxide (Na2O) in solar salt (60 wt% NaNO3 + 40 wt% KNO3). The accelerated aging was established by adding Na2O (0.005, 0.07, 0.135 and 0.2 wt%) to the solar salt and their effect on corrosion of 316L stainless steel (SS) at 600 ◦C in that oxide-rich solar salts for 168 h in synthetic air was investigated. Corrosion is significantly more in oxide-rich solar salt compared to pure solar salt. Strikingly, the oxide scale-base metal interface is wavy in solar salt containing 0.005 % Na2O clearly shows the oxide addition to salt melt influences Cr-rich inner oxide layer formation and its selective dissolution at early stage that leads to non-uniform corrosion. Interestingly, with increase of Na2O to 0.07 %, steel corrosion proceeded uniformly by accelerated disintegration of Cr-rich inner layer and subsequent dissolution. Severe scale spallation and weight loss in nitrate melt containing 0.2 % Na2O fostering more rapid corrosion, alarming that substantial tolerance of oxide content in solar salt is ≥ 0.135 % for an acceptable corrosion of 316L SS. Despite preferential dissolution of Cr and scale degradation/spallation with increased oxide content in solar salt, the corrosion layer in all cases comprised of sodium ferrite, and Cr-rich Cr-Fe mixed oxides with the Ni enrichment at the scale-metal interface. Competing processes between oxide scale growth, degradation and dissolution or even spallation has been discussed with an emphasis of Na2O addition to solar salt. KW - Molten salt corrosion KW - Solar salt KW - Thermal energy storage KW - Stainless steel KW - Concentrating solar power PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610819 DO - https://doi.org/10.1016/j.solmat.2024.113176 VL - 278 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-61081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Borehole integrity of austenitized and annealed pipe steels suitable for carbon capture and storage (CCS) N2 - Properties of pipe steels for CCS (carbon capture and storage) technology require resistance against the corrosive environment of a potential CCS-site (heat, pressure, salinity of the aquifer, CO2-partial pressure). The influence of austenitzing in heat treatment routines of two different injection pipe steels (1.4034, X46Cr13 and 1.4021, X20Cr13) was evaluated. Steel coupons were austenitized at different temperatures (900-1050 °C) for different lengths of time (30-90 min) before quenching and annealing prior to long term corrosion experiments (60°C, 100 bar, artificial brine close to a CCS-site in the Northern German Basin, Germany). In general, fewer pits are found on X46Cr13. Comparing steels with 13% chromium each the higher carbon content of X46Cr13 (0.46% C) results in a lower number of pits compared to X20Cr13 (0.20% C). It is found that neither the carbon content of the steels nor austenitizing temperature has much influence, but local corrosion behaviour is most susceptible towards austenitzing time. T2 - 6th International Conference on Future Environment and Energy (ICFEE 2016) CY - Pattaya, Thailand DA - 23.01.2016 KW - CCS KW - CO2 KW - Corrosion KW - Steel KW - Heat treatment PY - 2016 SP - 9 EP - 14 AN - OPUS4-38980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Wollschläger, Nicole A1 - Mosquera Feijoo, Maria A1 - Kranzmann, Axel T1 - Microstructure, smoothening effect, and local defects of alumina sol-gel coatings on ground steel N2 - Porous alumina films with thicknesses of a few microns were prepared via a dip-coating technique on steel P92. The coating is shown to protect the steel against massive corrosion, which is typical in the hot reactive environment of coal fired power plants. To mimic real conditions ground steel plates were coated with a boehmite-sol. This leads to an overall smoothing of the formerly rough surface. In the following short annealing step the inner porous construction with worm-like particles consisting of nano-crystallites and amorphous alumina is formed. Due to the simultaneous diffusion of chromium and iron ions out of the bulk steel material into the porous alumina coating, a dense interface with satisfactory adhesion is formed. However, the film exhibits few local defects like cracks or dense alumina nodules caused by steep edges in the ground surface or agglomeration of boehmite-sol components, respectively. Cracks especially have to be avoided. This problem can be overcome so far by slight modifications in the sol preparation process and surface treatment of the substrates. Nevertheless the results demonstrate the potential of sol-gel based alumina coatings as a time- and cost-saving protection type for commercial steel P92. KW - Alumina coating KW - Steel protection KW - TEM PY - 2017 DO - https://doi.org/10.1007/s10971-016-4188-8 SN - 0928-0707 VL - 81 IS - 1 SP - 185 EP - 194 PB - Springer CY - New York AN - OPUS4-40044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Costa e Silva, A. A1 - Coelho, D. A1 - Rizzo, F. A1 - Kranzmann, Axel T1 - Simulation of Fe-Cr-X alloy exposed to an oxyfuel combustion atmosphere at 600 °C N2 - In coal-fired power plants using oxyfuel combustion process with carbon capture and sequestration, instead of air, a mixture of oxygen and recirculated flue gas is injected in the boiler. A series of steels were exposed to CO2-SO2-Ar-H2O gas mixtures at 600 °C for 1000 h to compare their high temperature corrosion behavior. During the corrosion process, carburization, decarburization and recrystallization were observed underneath the oxide scale depending on the gas mixture and alloy composition. The conditions that lead to carburization are not yet completely understood, but decarburization can be simulated using thermodynamic and kinetic models. In this work, the results of these simulations are compared with measured values for one of the alloys that displayed a decarburized region. Since the mobility of carbon in the scale is not known, two strategies were adopted: simulation of alloy-atmosphere contact; and estimation of the carbon flux to produce the observed decarburization. The second approach might give an insight on how permeable to carbon the scale is. KW - CALPHAD approach KW - Corrosion KW - Decarburization KW - DICTRA modeling KW - Experimental kinetics KW - Iron alloys KW - Kinetics KW - Multicomponent diffusion KW - Steel PY - 2016 DO - https://doi.org/10.1007/s11669-015-0421-3 SN - 1547-7037 SN - 1863-7345 VL - 37 IS - 1 SP - SI, 19 EP - 24 PB - Springer US AN - OPUS4-40110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, Anja A1 - Schiz, J. A1 - Kranzmann, Axel ED - Jha, A. ED - Wang, C. ED - Neelameggham, N.R. ED - Guillen, D.P. ED - Li, L. ED - Belt, C.K. ED - Kirchain, R. ED - Spangenberger, J.S. ED - Johnson, F. ED - Gomes, A.J. ED - Pandey, A. ED - Hosemann, P. T1 - The role of austenitizing routines of pipe steels during CCS N2 - Properties of pipe steels for CCS technology require resistance against the corrosive environment of a potential CCS-site (heat, pressure, salinity of the aquifer, CO2-partial pressure). The influence of austenitizing in heat treatment routines of two different injection pipe steels (1.4034, X46Cr13 and 1.4021, X20Cr13) was evaluated. Steel coupons were austenitized at different temperatures (900 – 1050 °C) for different lengths of time (30–90 min) before quenching and annealing prior to long term corrosion experiments (60°C, 100 bar, artificial brine close to a CCS-site in the Northern German Basin, Germany). In general, fewer pits are found on X46Cr13. Comparing steels with 13% chromium each the higher carbon content of X46Cr13 (0.46% C) results in a lower number of pits compared to X20Cr13 (0.20% C). It is found that neither the carbon content of the steels nor austenitizing temperature has much influence, but local corrosion behaviour is most susceptible towards austenitizing time KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Austenitizing PY - 2015 SN - 978-1-119-08240-8 DO - https://doi.org/10.1002/9781119093220.ch15 SP - 131 EP - 137 PB - Wiley AN - OPUS4-34924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Einfluss der Wärmebehandlung auf die Korrosionsbeständigkeit von hochlegierten chromhaltigen Stählen unter CCS-Bedingungen N2 - Proben unterschiedlich wärmebehandelter, hochlegierter, rostfreier Stahlqualitäten, die potenziell als Injektionsrohr-Stähle eingesetzt werden können - AISI 420 X46Cr13, AISI 420J X20Cr13 und AISI 630 X5CrNICuNb16-4 - wurden bei 60 °C sowohl bei Normaldruck als auch bei 100 bar für 700 bis 8.000 Stunden in einem C02-gesättigtem, synthetisch hergestellten Laboraquiferwasser ausgelagert. Dieses Laboraquiferwasser entspricht der erwarteten Zusammensetzung des Aquiferwassers des norddeutschen Beckens, in das im CCS- Versuchsfeld von Ketzin (CCS Carbon Capture and Storage) über zwei Jahre hinweg technisch reines C02 injiziert wurde. Die Korrosionsraten und Schichtwachstumsraten auf den Stählen sind am niedrigsten für Stähle, die vor der Langzeitauslagerung gehärtet und anschließend zwischen 600 °C und 670 °C angelassen wurden. Lokale Korrosion (Lochfraß) zeigt sich in Form von kleinsten Löchern auf der Stahloberfläche. Der Durchmesser dieser Löcher nimmt mit steigendem Kohlenstoffgehalt des Stahls ab. Gleichzeitig nimmt die Anzahl der gezählten Löcher auf der Oberfläche zu. Insgesamt wird festgestellt, dass Stähle mit einer martensitischen Gefügestruktur in dieser nachempfundenen CCS-Atmosphäre die beste Korrosionsbeständigkeit gegenüber dem C02-gesättigten, salinen Aquifer bietet. T2 - 47. Kraftwerktechnisches Kolloquium CY - Dresden, Germany DA - 13.10.2015 PY - 2015 SN - 978-3-934409-70-5 SP - 926 EP - 936 PB - SAXONIA CY - Freiberg AN - OPUS4-35008 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, A. A1 - Wolthusen, Helmut A1 - Zastrow, Philip A1 - Kranzmann, Axel ED - Jha, A. ED - Wang, C. ED - Neelameggham, N.R. ED - Guillen, D.P. ED - Li, L. ED - Belt, C.K. ED - Kirchain, R. ED - Spangenberger, J.S. ED - Johnson, F. ED - Gomes, A.J. ED - Pandey, A. ED - Hosemann, P. T1 - Evaluation of heat treatment performance of potential pipe steels in CCS-environment N2 - To resist the corrosive geothermal environment during carbon capture and storage CCS -such as: heat, pressure, salinity of the aquifer, CO2-partial pressure, properties of pipe steels-require certain specification. For evaluation samples of differently heat treated high alloyed stainless injection-pipe steels AISI 420 X46Cr13, AISI 420J X20Cr13 as well as X5CrNiCuNb16–4 AISI 630 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h up to 8000 h in a CO2-saturated synthetic aquifer environment similar to a possible geological situation in the northern German Basin. Corrosion rates and scale growth are lowest after long term exposure for steels hardened and tempered at 600 °C to 670 °C and pits -indicating local corrosion- decrease in diameter but increase in number as a function of carbon content of the steel. Martensitic microstructure is preferred with respect to these particular conditions. KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - High temperature KW - High pressure PY - 2015 SN - 978-1-119-08240-8 DO - https://doi.org/10.1002/9781119093220.ch2 SP - 15 EP - 22 PB - Wiley AN - OPUS4-34717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Kranzmann, Axel A1 - Wolthusen, Helmut T1 - Unusual Corrosion Behavior of 1.4542 Exposed a Laboratory Saline Aquifer Water CCS-Environment N2 - Differently heat treated coupons of 1.4542 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h - 8000 h in an a) water saturated supercritical CO2 and b) CO2-saturated synthetic aquifer environment similar to on-shore CCS-sites in the Northern German Basin. Surface corrosion layers are homogeneous but unusually discontinuously ellipsoidal. After 8000 h at 100 bar maximum corrosion rate in the liquid phase is approximately 0.014 mm/year, with normalizing providing best corrosion resistance and approximately 0.003 mm/year in the supercritical phase where hardening+tempering at 670 °C leads to lowest corrosion rates. KW - CO2-storage KW - Supercritical CO2 KW - Steel KW - Pipeline KW - Corrosion KW - CCS PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-418472 DO - https://doi.org/10.1016/j.egypro.2017.03.1679 VL - 114 SP - 5229 EP - 5240 PB - Elsevier Ltd. AN - OPUS4-41847 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Borehole integrity of austenitized and annealed pipe steels suitable for carbon capture and storage (CCS) N2 - Properties of pipe steels for CCS (carbon capture and storage) technology require resistance against the corrosive environment of a potential CCS-site (heat, pressure, salinity of the aquifer, CO2-partial pressure). The influence of austenitzing in heat treatment routines of two different injection pipe steels (1.4034, X46Cr13 and 1.4021, X20Cr13) was evaluated. Steel coupons were austenitized at different temperatures (900- 1050 °C) for different lengths of time (30-90 min) before quenching and annealing prior to long term corrosion experiments (60°C, 100 bar, artificial brine close to a CCS-site in the Northern German Basin, Germany). In general, fewer pits are found on X46Cr13. Comparing steels with 13% chromium each the higher carbon content of X46Cr13 (0.46% C) results in a lower number of pits compared to X20Cr13 (0.20% C). It is found that neither the carbon content of the steels nor austenitizing temperature has much influence, but local corrosion behaviour is most susceptible towards austenitzing time. T2 - International Conference on Future Environment and Energy CY - Pattaya, Thailand DA - 23.01.2016 KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Austenitizing PY - 2017 SP - Article A0005, 213 EP - 219 AN - OPUS4-41854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Potential of martensitic stainless steel X5CrNiCuNb 16-4 as pipe steel in corrosive CCS environment N2 - Pipe steels suitable for carbon capture and storage technology (CCS) require resistance against the corrosive environment of a potential CCS-site (heat, pressure, salinity of the aquifer, CO2-partial pressure). X5CrNiCuNb16-4 has been proven to be sufficient resistant in corrosive environments, but shows rather unusual corrosion behaviour in CCS environment. Therefore differently heat treated coupons of 1.4542 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h - 8000 h in an a) water saturated supercritical CO2 and b) CO2-saturated synthetic aquifer environment similar to on-shore CCS-sites in the Northern German Basin. Additionally fatigue tests were performed via push-pull tests with a series of 30 specimens was tested at stress amplitudes between 150 MPa and 500 MPa (sinusoidal dynamic test loads, R=-1; resonant frequency ~ 30 Hz). Best corrosion resistance in the liquid phase is achieved via normalizing prior to exposure and hardening+tempering at 670 °C leads to lowest corrosion rates in the supercritical phase. With no regard to atmosphere discontinuously ellipsoidal surface corrosion regions appear after exposure of 4000 h and more. The endurance limit of X5CrNiCuNb16-4 measured in air is reduced by more than 50% when exposed to CCS environment (maximum number of cycles (10 x 106) at a stress amplitude of 150 MPa) The scatter range TN = 1:34 is disproportionately large contributing to an overall unusual corrosion behaviour. KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Heat treatment KW - Fatigue KW - Endurance limit PY - 2017 DO - https://doi.org/10.18178/ijesd.2017.8.7.998 SN - 2010-0264 VL - 8 IS - 7 SP - 466 EP - 473 AN - OPUS4-41863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Influence of CO2 on the corrosion behaviour of 13%Cr martensitic stainless steel AISI 420 and low alloyed steel AISI 4140 exposed to saline aquifer water environment T2 - International Conference on Environment 2008 (ICENV 2008) - Environmental Management and Technologies Towards Sustainable Development CY - Penang, Malaysia DA - 2008-12-15 KW - Steel KW - Pipeline KW - Corrosion KW - Carbonate layer KW - CCS KW - CO2-injection KW - CO2-storage PY - 2008 SN - 978-983-3986-39-2 SP - 1 EP - 9 AN - OPUS4-18669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, Anja A1 - Kranzmann, Axel ED - C.A. Brebbia, ED - V. Popov, T1 - Influence of CO2 on the corrosion behaviour of 13Cr martensitic stainless steel AISI 420 and low-alloyed steel AISI 4140 exposed to saline aquifer water environment T2 - 17th International Conference on Modelling, Monitoring and Management of Air Pollution CY - Tallinn, Estonia DA - 2009-07-20 KW - Steel KW - Pipeline KW - Corrosion KW - CCS KW - Carbon capture KW - CO2-injection PY - 2009 SN - 978-1-84564-195-5 DO - https://doi.org/10.2495/AIR090371 SN - 1746-448X SN - 1746-3541 VL - 123 SP - 409 EP - 418 PB - WIT Press AN - OPUS4-19783 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, A. A1 - Kranzmann, Axel ED - Brebbia, C.A. ED - Longhurst, J.W.S. T1 - The role of pit corrosion in engineering the carbon storage site Ketzing, Germany T2 - Air pollution XVIII CY - Kos, Greece DA - 2010-06-21 KW - CO2-Speicherung KW - Ketzin KW - Korrosion KW - Steel KW - Pipeline KW - Pit corrosion KW - CCS KW - CO2-injection KW - CO2-storage PY - 2010 SN - 978-1-84564-450-5 DO - https://doi.org/10.2495/AIR100101 SN - 1746-448X SN - 1734-3541 SP - 109 EP - 119 PB - WIT Press AN - OPUS4-21683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, A. A1 - Linke, B. A1 - Kranzmann, Axel T1 - Predicting the long term corrosion behaviour of pipe steels used at the CCS-site Ketzing, Germany in laboratory CO2-saturated saline aquifer CCS-environment T2 - First international conference on materials for energy CY - Karlsruhe, Germany DA - 2010-07-04 KW - CCS KW - Corrosion KW - Steels KW - Injection pipe PY - 2010 SN - 978-3-89746-117-8 IS - Paper 1067 SP - 1005 EP - 1007 AN - OPUS4-21684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Oxidation of a single crystal nickel-base superalloy at 950 °C - a kinetic and microstructure study N2 - The nickel-base single crystal alloy investigated is a widely used material for first and second row blades in stationary gas turbines. Nickel-base superalloys are especially designed to resist high temperature oxidation by process gases. To determine this high temperature behaviour oxidation testing was carried out using samples cut perpendicular to (001)-direction. Microstructures were characterized by X-ray diffraction XRD, Light Microscopy LM, Scanning Electron Microscopy SEM, and X-ray energy dispersive spectroscopy (EDS), after a series of heat treatments (950 °C, 0 h - 1000 h). Mass gain and the respective thicknesses of the different oxide layers were measured to determine oxidation kinetics. In general, the isothermal oxidation behaviour at 950 °C, as defined by weight gain, follows a parabolic law with a parabolic rate constant around 1.4 · 10-2 mg2/(cm4 · h). A short incubation time is followed by the constitution of a multi-layered oxide scale. The oxide scale consists of a three layer structure. An outer scale contains a Ti-bearing thin film associated as TiO2 and NiTiO3 but mostly Cr attributed to Cr2O3, (Ni/Co)Cr2O4 beside NiTaO4. This outer scale is connected to a discontinuous layer of inner oxidation consisting mainly of Al2O3, which is followed by an area of γ´-depletion within the base material. PY - 2008 SP - 1 EP - 9 AN - OPUS4-17263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Kranzmann, Axel ED - Roland Span, ED - Ingo Weber, T1 - Corrosion of steels in H2O-CO2 atmospheres at temperatures between 500°C and 700°C N2 - The introduction of carbon capture technology into thermal power plants benefits from combustion of fuel and pure oxygen due to high partial pressures of CO2 in the flue gas. The consumption of energy for carbon capture devices and oxygen production plants has to be compensated by higher efficiencies of the power plant. Consequently IGCC plants with 80 bar reactors and high temperature turbine equipment, boilers with 700 °C steam raising units will be the next generation power plants. All plants have in common locally in the process gas compositions with high CO2 partial pressure and steam. In our test we applied a gas composition with 30% H2O and 70% CO2 an composition in between the water content of coal burned in pure oxygen and Methane-oxygen combustion. Additional gas fractions such as SO2 will be added in coming experiments. In this paper we discuss the attack of our model gas composition on different typical power plant construction steels with chromium contents in the range of 1 to 24%. The test conditions were annealing time up to 1000 h, 80 bar pressure, fast flowing gas and temperatures between 500 and 700°C depending on the maximum working temperature of the individual steel. Dependent on the test parameters and in particular the chromium content the oxide scale growth mechanism, the scale thickness, the scale microstructure and phase sequences differed. In particular we observe the growth of FeO at temperatures lower than 570°C which is the eutectic decomposition temperature in the Oxygen-iron phase diagram. Iron carbides are primarily formed in low alloyed steels near the oxide steel interface. The steels studied containing more then 9% chromium the growth of Fe3O4 and Fe-Cr-Spinel was typical. Co and W influenced the reaction in 9 - 12% Cr-steel. The attrition of Mn and other alloying additions was monitored. In no case a dense and protective Cr2O3 or an other Metal-Cr-oxide layer was observed. The oxide scale thickness increases strongly with temperature and decrease with raising chromium content. Data of oxide scale thickness up to corrosion time of 1000 h will be presented. A model will be presented, which deals with possible reactions paths during the corrosion processes in flowing CO2 and water. The steels can be arranged according the reaction with gas and their alloying elements such as Mn, Co and W. In the test environment the maximum working temperature of the steels decreased 50K compared to working temperature in current power plant environment. T2 - 15th International Conference on the Properties of Water and Steam (ICPWS XV), "Water, Steam, and Aqueous Solutions - Advances in Science and Technology for Power Generation" CY - Berlin, Germany DA - 2008-09-07 KW - High temperature corrosion KW - 9-12% Cr-steels KW - H2O-CO2 PY - 2008 SN - 978-3-931384-64-7 IS - Session 06: Electro-12 SP - 1 EP - 7 AN - OPUS4-19061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kranzmann, Axel A1 - Hünert, Daniela T1 - Technologien für den Klimaschutz und ihre Anforderungen an Werkstoffe N2 - Der Klimaschutz erfordert die Reduzierung des Ausstoßes von Kohlendioxid. Neue Kraftwerke mit Sauerstoffverbrennung und möglicherweise CO2-Abscheidung sollen eine Reduktion des CO2 im Bereich der Energietechnik ermöglichen. Die heute üblichen Hochtemperaturwerkstoffe werden anderen Umgebungsbedingungen ausgesetzt, und es sind andere Korrosionsraten und Korrosionsreaktionen zu erwarten. In diesem Beitrag werden die Kraftwerkstechnologien kurz vorgestellt und an einem Beispiel erläutert, dass die Oxidation an Luft mit der Oxidation in Wasser nicht direkt vergleichbar ist. KW - Klimaschutz KW - CO2-arme Kraftwerke KW - Werkstoffe PY - 2006 DO - https://doi.org/10.1002/cite.200600030 SN - 0009-286X SN - 1522-2640 VL - 78 IS - 12 SP - 1809 EP - 1817 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-19040 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hünert, Daniela A1 - Kranzmann, Axel T1 - Influence of pressure and chromium content on corrosion reactions at 600°C in a CO2-H2O atmosphere T2 - NACE - International Corrosion Conference CY - New Orleans, USA DA - 2008-03-16 KW - High temperature corrosion KW - Corrosive gases KW - Mild steels KW - 9-12% Cr-steels KW - Pressure effect PY - 2008 SN - 0010-9312 SN - 1938-159X IS - Paper No. 08447 SP - 1 EP - 19 PB - National Association of Corrosion Engineers CY - Houston, Tex. AN - OPUS4-19041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, Anja A1 - Linke, Barbara A1 - Kranzmann, Axel T1 - Carbon capture and storage technique (CCS): Reliability of pipe steels used in Ketzin, Germany verified in laboratory saline aquifer corrosion experiments N2 - During the compression emission gasses in deep geological layers (Carbon Capture and Storage, CCS) CO2-corrosion will become a relevant safety issue. The reliability of the steels used at the geological onshore CCS-site at Ketzin, Germany, (heat treated steel 42CrMo4 (1.7225, AISI 4140) used for casing, and the martensitic stainless injection pipe steels X46Cr13 (1.4034, AISI 420 C), X20Cr13 (1.4021, AISI 420 J), X35CrMo17 (1.4122)) is demonstrated in 1 and 2 years laboratory experiments. Samples were kept in a synthetic aquifer environment similar to the geological CCS-site at Ketzin, Germany at T=60 °C. This corrosive environment is then saturated with technical CO2 at a flow rate of 3 l/h. Microstructures were characterized by X-ray diffraction, light microscopy, scanning electron microscopy, and energy dispersive X-ray, after a series of heat treatments (700 h to 2 years). Due to very slow mass loss at extended exposure times to CCS-environment one year is sufficient to predict stable surface corrosion rates from laboratory experiments. The non-linear isothermal surface corrosion behaviour of the steels reveals surface corrosion rates around 0.1 to 0.8 mm/year, when obtained by mass gain. The loss of the base material is higher when calculated from the corrosion layer magnitude due to the unpredictable local corrosion attacks. Severe pit corrosion (pit heights ca. 4.5 mm) are only located on the high chromium steels. Main phases of the continuous scales are siderite FeCO3 and goethite α-FeOOH. The formation of the non-protective layer is likely to form via a transient Fe(OH)2-phase. T2 - MWWD & IEMES 2010 - 6th International conference on marine waste water discharges and coastal environment CY - Langkawi, Malaysia DA - 2010-10-25 KW - Saline aquiver KW - Environmental issues KW - CCS KW - CO2-injection KW - CO2-storage KW - Corrosion KW - Phase formation PY - 2010 SN - 978-9944-5566-4-4 IS - Paper 047_P SP - 1 EP - 17 AN - OPUS4-22333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kranzmann, Axel A1 - Hünert, Daniela A1 - Rooch, Heidemarie A1 - Urban, Ingrid A1 - Schulz, Wencke A1 - Österle, Werner T1 - Reactions at the interface between steel and oxide scale in wet CO2 containing atmospheres N2 - The resistance of structural steels against corrosion in CO2-H2O and CO2-H2O-O2 atmospheres at temperatures above 550°C was observed with high magnification methods. The test atmosphere is the basic composition of an oxyfuel coal combustion atmosphere. The analytical information base was applied to develop reaction schemes for the oxidation of steels. It was demonstrated that the formation of phases and the kinetics of oxidation reactions in this atmospheres is affected by the formation of intermediate iron hydroxide and a high carbon activity. In the temperature regime above 550°C the thermal equilibrium between H2O, CO2 and Fe reacted and formed CO. CO triggers the formation of FeO and carbides and increases the reaction kinetics. Porosity at the interface is established by gaseous phases such as Fe(OH)2 or H2O. H2 formation is not limited to the steel - oxide interface but can occur in the whole oxide scale. Examples of the experimental results were compared with a thermodynamic approach. The objective of the work was to derive qualitative rules of the basic corrosion reactions. T2 - NACE International corrosion conference 2009 CY - Atlanta, Georgia, USA DA - 2009-03-22 KW - High temperature corrosion KW - Corrosion gases KW - Mild steels KW - 9-12% Cr-steels KW - Hydrogen transport KW - Oxyfuel combustion PY - 2009 SP - 1 EP - 10 (Paper 09265) AN - OPUS4-22334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Kranzmann, Axel T1 - Simultaneous oxidation and carburization under oxyfuel conditions N2 - The combustion of coal in CO2-reduced Oxyfuel power plants requires creep resistant and corrosion resistant materials, which can withstand high temperatures up to 600°C and CO2 rich atmospheres. Among the heat resistant materials, the 9-12% chromium steels are proven to resist high wall temperatures in conventional power plants and are suitable as membrane wall, superheaters and steam piping. During Oxyfuel combustion a flue gas is generated, which consists mainly of H2O (30 mol %) and CO2 (70 mol %). The present paper is focused on the corrosion of 9-12% chromium steels under oxyfuel conditions in a temperature range between 550 and 625°C. Depending on Chromium content of the 9-12%chromium steels, carburization of the base material, perlite formation and carbide formation were observed. Alloys with lower chromium content form a non protective oxide scale with perlite at the scale-alloy interface. Steels with 12% chromium have a small growing oxide scale with enlarged M23C6-particles at the scale-alloy interface. The carburization of the base material is found to be increased for the 9% Cr-steel. Higher pressure of the flue gas results in the formation of less resistant scales and cause accelerated carburization of the base materials. However, the carburization has an impact on the mechanical properties at the surface and leads to an embrittlement, which is deleterious during thermal cycling. Oxidation kinetics, phase analysis of the scale (transmission electron microscope) and carburization depths (microprobe) of the base materials are presented. T2 - EUROCORR 2009 CY - Nice, France DA - 2009-09-06 KW - High-temperature corrosion KW - Carburization KW - 9-12 % Cr-steel KW - M23C6-particles KW - Power plant steels PY - 2010 IS - Paper 7805 SP - 1 EP - 11 AN - OPUS4-22500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Kranzmann, Axel T1 - Corrosion behavior of ferritic and martensitic power plant steels under conditions of dual atmospheres N2 - The most efficient construction materials for boiler water walls and superheaters in steam power plants are ferritic and martensitic steels. In practical operation, tubes are exposed simultaneously to combustion gas and air/steam on their opposite surfaces. The corrosion behavior of ferritic-martensitic steels under such dual atmospheres is nondistinctive and has been investigated in a specially designed test equipment between 500°C and 620°C. The power plant conditions were simulated with a flowing and pressurized (80 bar) combustion gas on the inner side of the tube, which contains water (H2O) and carbon dioxide (CO2). On the outer side, tube material was exposed to air. Oxides that formed on the air side under dual atmosphere conditions were significantly different from the oxide scales formed when the alloy was exposed to air only. It is assumed that the anomalous corrosion behavior during the dual atmosphere exposure is due to hydrogen and carbon diffusion through the bulk alloy from the combustion gas side to the air side. Both species are produced when the material reacts with the gas phase. Because of its high diffusivity, hydrogen is thought to affect the corrosion process on the air side from the beginning of the corrosion exposure, whereas carbon reaches the opposite side after a considerably longer time period. KW - Chromium steels KW - Corrosive gases KW - Dual atmosphere KW - High-temperature corrosion KW - Hydrogen transport KW - Mild steel PY - 2010 SN - 0010-9312 SN - 1938-159X VL - 66 IS - 12 SP - 126001-1 - 126001-7 PB - National Association of Corrosion Engineers CY - Houston, Tex. AN - OPUS4-23217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, A. A1 - Linke, B. A1 - Schulz, Sabrina A1 - Kranzmann, Axel T1 - CO2-corrosion of steels exposed to saline water environment N2 - With CO2 being one reason for climate change carbon capture and storage (CCS) is discussed to mitigate climate change. When emission gases are compressed into deep geological layers CO2-corrosion can easily cause failure of injection pipes. Different steels 42CrMo4, X46Cr13 and X20Cr13 were tested as well as X35CrMo17 and X5CrNiCuNb16-4 in a laboratory Environment similar to the conditions of the CCS engineering site at the Northern German Bassin. Samples were exposed to synthetic aquifer water saturated with technical CO2 at a flow rate of 3 NL/h. Corrosion rates obtained via mass loss vary in a wide range (0,005 to 2.5 mm/year). The precipitations within the corrosion scale revealed a complicated multiphase layer containing siderite FeCO3, goethite α-FeOOH, lepidocrocite γ-FeOOH, mackinawite FeS and akaganeite Fe8O8(OH)8Cl1,34 and spinelphases of various compositions. T2 - TMS 2011 - 140th Annual Meeting & Exhibition CY - San Diego, CA, USA DA - 27.02.2011 KW - CCS KW - Steel KW - Corrosion KW - Carbon Capture and Storage PY - 2011 DO - https://doi.org/10.1002/9781118062173.ch102 VL - 3 IS - 0807 SP - 807 EP - 814 AN - OPUS4-23472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -