TY - JOUR A1 - Wollschläger, Nicole A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Schulz, Wencke A1 - Sojref, Regine A1 - Kranzmann, Axel T1 - Exposition of sol-gel alumina-coated P92 steel to flue gas: Time-resolved microstructure evolution, defect tolerance, and repairing of the coating N2 - Technically relevant P92 steel (9% Cr) was coated with a micron-thick porous alumina layer prepared by sol-gel technique and treated with flue gas (60 CO2-30 H2O-2 O2-1 SO2-7 N2 (mole fraction in %)) at 650 ° to mimic an oxyfuelcombustion process. Local defects in the coating were marked using focused ion beam (FIB) technique and were inspected after exposition to hot flue gas atmosphere at 300, 800, and 1300 h, respectively. Local defects like agglomerated alumina sol particles tend to spall off from the coating uncovering the underlying dense chromia scale. Re-coating was found to restore the protection ability from oxidation when repeatedly treated with hot flue gas. Cracks and voids did not promote the local oxidation due to the formation of crystalline Mn/S/O species within and on top of the coating. The protective character of the steel-coating system is a result of (i) the fast formation of a dense chromia scale at the surface of sol-gel alumina-coated P92 steel bars in combination with (ii) the porous alumina coating acting as diffusion barrier, but also as diffusion partner in addition with (iii) fast Mn outward diffusion capturing the S species from flue gas. KW - Alumina coatings KW - Oxyfuel KW - Steel P92 KW - High temperature corrosion PY - 2018 DO - https://doi.org/10.1002/maco.201709712 SN - 1521-4176 SN - 0947-5117 SN - 0043-2822 VL - 69 IS - 4 SP - 492 EP - 502 PB - Wiley-VCH Verlag GmbH&Co. KGaA CY - Weinheim AN - OPUS4-45300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nützmann, Kathrin A1 - Wollschläger, Nicole A1 - Rockenhäuser, Christian A1 - Kranzmann, Axel A1 - Stephan-Scherb, Christiane T1 - Identification and 3D reconstruction of Cr5S6 precipitates along grain boundaries in Fe13Cr N2 - Metal sulfide grain boundary precipitates of a ferrous model alloy with 13 wt.% chromium formed at 650°C under a gas atmosphere containing 0.5% SO2 and 99.5% Ar were investigated after ageing for 3 h, 6 h, and 12 h. The precipitates formed along grain boundaries were identified as Cr5S6 using energy-dispersive x-ray spectroscopy in transmission electron microscopy and electron backscatter diffraction analysis. Serial focused ion beam slicing was conducted followed by three-dimensional reconstruction to determine the number, size, and penetration depth of the precipitates evolved at the different time steps. There was a linear increase in the number of precipitates with time, while their average size increased only for the initial aging time but became constant after 6 h. Based on these results, a model for grain boundary sulfidation of ferritic alloys is discussed. KW - Internal Sulfidation KW - Grain Boundary Corrosion KW - FIB Tomography PY - 2018 DO - https://doi.org/10.1007/s11837-018-2940-y SN - 1047-4838 SN - 1543-1851 VL - 70 IS - 8 SP - 1478 EP - 1483 PB - Springer Science + Business Media CY - New York, NY AN - OPUS4-45090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kratzig, A. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Menneken, M. A1 - Bäßler, Ralph T1 - Early Stage of Corrosion Formation on Pipeline Steel X70 Under Oxyfuel Atmosphere at Low Temperature N2 - The early stage of corrosion formation on X70 pipeline steel under oxyfuel atmosphere was investigated by applying a simulated gas mixture (CO2 containing 6700 ppmv O2, 100 ppmv NO2, 70 ppmv SO2 and 50 ppmv H2O) for 15 h at 278 K and ambient pressure. Short-term tests (6 h) revealed that the corrosion starts as local spots related to grinding marks progressing by time and moisture until a closed layer was formed. Acid droplets (pH 1.5), generated in the gas atmosphere, containing a mixture of H2SO4 and HNO3, were identified as corrosion starters. After 15 h of exposure, corrosion products were mainly X-ray amorphous and only partially crystalline. In-situ energy-dispersive X-ray diffraction (EDXRD) results showed that the crystalline fractions consist primarily of water-bearing iron sulfates. Applying Raman spectroscopy, water-bearing iron nitrates were detected as subordinated phases. Supplementary long-term tests exhibited a significant increase in the crystalline fraction and formation of additional water-bearing iron sulfates. All phases of the corrosion layer were intergrown in a nanocrystalline network. In addition, numerous globular structures have been detected above the corrosion layer, which were identified as hydrated iron sulphate and hematite. As a type of corrosion, shallow pit formation was identified, and the corrosion rate was about 0.1 mma−1. In addition to in-situ EDXRD, SEM/EDS, TEM, Raman spectroscopy and interferometry were used to chemically and microstructurally analyze the corrosion products. KW - Corrosion KW - CCUS KW - In-situ ED-XRD KW - CO2 pipeline transport KW - Oxyfuel KW - Carbon steel KW - Impurities PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506303 DO - https://doi.org/10.3390/pr8040421 SN - 2227-9717 VL - 8 IS - 4 SP - 421-1 EP - 421-19 PB - MDPI CY - Basel AN - OPUS4-50630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, A. A1 - Kranzmann, Axel T1 - Corrosion and Fatigue of Heat Treated Martensitic Stainless Steel 1.4542 used for Geothermal Applications N2 - During capture and storage technology (CCS) as well as in geothermal energy production Steels need to withstand the corrosive environment such as: heat, pressure, salinity of the aquifer and CO2-partial pressure. 1.4542 shows unusual corrosion phenomena, but is still sufficiently resistant in corrosive environments. To better understand its behaviour differently heat treated coupons of 1.4542 and for comparison X20Cr13 and X46Cr13 were kept in the artificial brine of the Northern German Basin at T=60 °C. Ambient pressure as well as p=100 bar for 700 h - 8000 h in water saturated supercritical CO2 and CO2-saturated synthetic aquifer Environment was applied. Fatigue tests were performed via push-pull tests with a series of 30 specimens from 150 MPa to 500 MPa (sinusoidal dynamic test loads, R=-1; resonant frequency ~ 30 Hz). FeCO3 and FeOOH are corrosion products also after dynamic corrosion tests. Martensitic microstructure offers good corrosion resistance in geothermal environment. The S-N-curve showing no typical fatigue strength and very steep slopes of possible fatigue strength for finite life. Possible influencing artefacts, such as Al-inclusions could not be correlated to early rupture despite specimens containing inclusions at the fracture surface and cross section reached lower number of cycles. Applied potential proofed to enhance fatigue life tremendously. KW - High Alloyed Steel KW - Pitting KW - Corrosion Fatigue KW - Corrosion KW - Endurance Limit PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503765 DO - https://doi.org/10.20319/mijst.2019.51.138158 SN - 2454-5880 VL - 5 IS - 1 SP - 138 EP - 158 PB - Global Research and Development Services Publishing CY - Rajasthan, India AN - OPUS4-50376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, J. A1 - Terrell, J. A1 - Ferris, L. A1 - Tucker, D. A1 - Leonhardt, T. A1 - Goldbeck, Hennig T1 - Low-Cost Fabrication of Tungsten-Rhenium Alloys for Friction Stir Welding Applications N2 - Friction stir welding (FSW) of high-melting temperature alloys, such as steel and Inconel, requires tooling that can survive under the applied loads at the elevated temperatures. Tungsten-Rhenium (W-Re) alloys are a suitable candidate for this application; however, the costs typically associated with achieving the required densities and grain structure for the tooling are high due to the lengthy traditional processing required. Further costs are incurred in machining the starting bar stock to the final FSW tooling configuration. An alternate processing method is used in this study to shorten the fabrication time using direct current sintering which rapidly consolidates the starting powders at lower temperatures than used in traditional powder metallurgy. Although this process enables retention of the fine grain size, the sintering time is too short to form the desired single, solid phase. Therefore, the specimens were subjected to a post-consolidation heat treatment to fully solutionize the W matrix. Once the desired density and solid solution phase was verified in coupons, the final processing parameters were used to consolidate a net shape tool for FSW. KW - Tungsten-Rhenium KW - Friction Stir Welding KW - Fabrication PY - 2019 DO - https://doi.org/10.1007/s11663-019-01726-6 VL - 51 IS - 1 SP - 35 EP - 44 PB - Springer AN - OPUS4-50027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, A. A1 - Wolf, M. A1 - Kranzmann, Axel T1 - The role of surface texture on the corrosion fatigue behavior of high alloyed stainless steel exposed to saline aquifer water environment N2 - Corrosion fatigue specimen with different surfaces (technical surfaces after machining and polished surfaces) of high alloyed martensitic stainless steel X46Cr13 (1.4043) and duplex stai nless steel X2CrNiMoN22 3 2 (1.4462) were compared at load amplitudes from 175 MPa to 325 MPa in the geothermal brine of the N orthern German Basin at 98 °C. Surface corrosion layers and pits reveal carbonate corrosion products on the surface such as FeCO 3 and FeOOH as the main precipitation phases with no dependence on the original surface roughness . At high stress amplitudes above 275 MPa technical surfaces (P50% at σa 300 MPa=5 × 10 5 ) resulted in more cycles to failure than polished (P50% at σa 300 MPa=1.5 × 10 5 ). The greater slope coefficient for technical surfaces k = 19.006 compared to polished surfaces k =8.78 demonstrate s earlier failure at given stress amplitude σa . KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Heat treatment PY - 2019 DO - https://doi.org/10.17706/ijmse SN - 2315-4527 VL - 7 IS - 2 SP - 26 EP - 33 PB - IAP - International Academy Publishing CY - San Bernardino, CA AN - OPUS4-50365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Kranzmann, Axel A1 - Knauer, S. T1 - Droplet corrosion of CO2 transport pipeline steels N2 - In this work, the focus was set on the corrosion process of condensate as drops on the surface of carbon steels (X52, X70), martensitic steel UNS S41500, and superaustenite UNS N08031 in CO2 atmosphere with impurities at 278 K (to simulate the transportation condition in a buried pipeline). Exposure tests were performed at both normal pressure and high pressure where CO2 is supercritical or in dense phase. The drop, 1 ‑ 10 μL in volume, was prepared by dropping CO2 saturated ultra-pure water onto the surface of steel coupons in a one-liter-autoclave. The CO2 gas stream, simulating the oxyfuel flue gas with varying concentration of impurities (SO2 and O2 ), was then pumped into the autoclave to observe the condensation and corrosion impacts of impurities. Comparable exposure tests were carried out with the same gas mixture and the same volume of water as vapor to observe the drop formation and the corrosion process that follows. The wettability and stability of drops on the surface of steel coupons in CO2 supercritical/dense phase environment was evaluated additionally by contact angle measurement. T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - Geothermal KW - Coating KW - SiO2 KW - Polyaniline KW - Corrosion PY - 2018 SP - 10845, 1 EP - 11 PB - Omnipress CY - Houston AN - OPUS4-44917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Effect of CO2 gas on carbon steel corrosion in an acidic-saline based geothermal fluid N2 - Geothermal energy is one of the most promising energy resources to replace fossil fuel. To extract this energy, hot fluids of various salts and gases are pumped up from a geothermal well having a certain depth and location. Geothermal wells in volcanic regions often contain highly corrosive CO2 and H2S gases that can be corrosive to the geothermal power-plants, which are commonly constructed of different steels, such as carbon steel. This research focuses on the corrosion behaviour of carbon steel exposed to an artificial geothermal fluid containing CO2 gas, using an artificial acidic-saline geothermal brine as found in Sibayak, Indonesia. This medium has a pH of 4 and a chloride content of 1,500 mg/L. Exposure tests were conducted for seven days at 70 °C and 150 °C to simulate the operating temperatures for low and medium enthalpy geothermal sources. Surface morphology and cross-section of the specimens from the above experiments were analysed using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Electrochemical tests via open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were performed to understand the corrosion processes of carbon steel in CO2-containing solution both at 70 °C and 150 °C. Localized corrosion was observed to a greater extent at 70 °C due to the less protectiveness of corrosion product layer compared to that at 150 °C, where FeCO3 has a high corrosion resistance. However, a longer exposure test for 28 days revealed the occurrence of localized corrosion with deeper pits compared to the seven-day exposed carbon steel. In addition, corrosion product transformation was observed after 28 days, indicating that more Ca2+ cations incorporate into the FeCO3 structure. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Carbon steel KW - CO2 KW - EIS KW - Geothermal KW - Corrosion PY - 2019 SP - Paper 200245, 1 EP - 5 CY - Madrid, Spain AN - OPUS4-49099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Schiller, B.N. A1 - Beck, M. A1 - Bettge, Dirk T1 - On the corrosion behaviour of co 2 injection pipe steels: role of cement N2 - Carbon Capture and Storage (CCS) is identified as an excellent technology to reach the target of CO2 reduction. However, the safety issue and cost-effectiveness hinder the future of CCS. For the reliability and safety issues of injection wells, the corrosion resistance of the materials used needs to be determined. In this study, representative low-cost materials including carbon steel 1.8977 and low alloyed steel 1.7225 were investigated in simulated pore water at 333 K and under CO2 saturation condition to represent the worst-case scenario: CO2 diffusion and aquifer fluid penetration. These simulated pore waters were made from relevant cement powder to mimic the realistic casing-cement interface. Electrochemical studies were carried out using the pore water made of cement powder dissolved in water in comparison with those dissolved in synthetic aquifer fluid, to reveal the effect of cement as well as formation water on the steel performance. Two commercially available types of cement were investigated: Dyckerhoff Variodur® and Wollastonite. Variodur® is a cement containing high performance binder with ultra-fine blast furnace slag which can be used to produce high acid resistance concrete. On the other hand, Wollastonite is an emerging natural material mainly made of CaSiO3 which can be hardened by converting to CaCO3 during CO2 injection. The results showed the pH-reducing effect of CO2 on the simulated pore water/aquifer (from more than 10 to less than 5) leading to the active corrosion process that happened on both 1.8977 and 1.7225. Electrochemical characterization showed negative free corrosion potential and polarisation curves without passive behaviors. The tested coupons suffered from pitting corrosion, which was confirmed by surface analysis. Interestingly, basing on the pit depth measurements from the tested coupons and the hardness of cement powder, it is suggested that Variodur® performed better than Wollastonite in both aspects. The electrochemical data was compared to that resulted from exposure tests to give a recommendation on material selection for bore-hole construction. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Cement KW - Carbon capture KW - Corrosion and storage (CCUS) technology KW - Utilization KW - Carbon steel KW - Crevice corrosion PY - 2019 SP - Paper 200597, 1 EP - 4 PB - SOCIEMAT CY - Madrid, Spain AN - OPUS4-49109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, A. A1 - Wolf, M. A1 - Kranzmann, Axel T1 - In-situ testing of corrosion and corrosion fatigue behavior of stainless steels in geothermal environment N2 - In CCS environment (carbon capture and storage) pipes are loaded statically and/or cyclically and at the same time exposed constantly to the highly corrosive hot thermal water. Experimental procedures such as ambient pressure immersions tests, in-situ corrosion fatigue experiments using a flexibly designed corrosion chamber at ambient pressure and a specially designed corrosion chamber at high pressure. Experimental set-ups for push/pull and rotation bending load are introduced. The corrosion behavior and lifetime reduction of high alloyed steels (X46Cr13, 1.4043), (X5CrNiCuNb16-4, 1.4542) and (X2CrNiMoN22-5-3, 1.4462) is demonstrated (T=60 °C, geothermal brine: Stuttgart Aquifer flow rate: 9 l/h, CO2 ). T2 - 10th International Conference on Chemical, Biological and Environmental Engineering ICBEE 2018 CY - Berlin, Germany DA - 27.09.2018 KW - Adiabatic calorimeter KW - Thermal energy storage KW - Phase change material KW - Salt eutectics PY - 2018 DO - https://doi.org/10.7763/IPCBEE.2018.V103.5 VL - 103 SP - 13 EP - 20 AN - OPUS4-50364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -