TY - JOUR A1 - Munasir, A1 - Triwikantoro, A1 - Zainuri, M. A1 - Bäßler, Ralph A1 - Darminto, T1 - Mechanical Strength and Corrosion Rate of Aluminium Composites (Al/SiO2): Nanoparticle Silica (NPS) as Reinforcement N2 - The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO2 (NPS) powder from Indonesian silica sands. Two different active solutions,namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO2 nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO2(Al/SiO2(B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO2(T)). From the microstructural analysis, we found that the SiO2 particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO2. The corrosion rate of Al/SiO2(T) was lower than that of Al/SiO2(B) composites. KW - Aluminium KW - Silica KW - Al/SiO2 composite KW - Mechanical strength KW - Corrosion rate PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-487185 DO - https://doi.org/10.21315/jps2019.30.1.7 SN - 1675-3402 SN - 2180-4230 VL - 30 IS - 1 SP - 81 EP - 97 PB - USM Press CY - Pulau Pinang, Malaysia AN - OPUS4-48718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munasir, A1 - Triwikantoro, A1 - Zainuri, M. A1 - Bäßler, Ralph A1 - Darminto, T1 - Corrosion Polarization Behavior of Al-SiO2 Composites in 1M NaCl and Related Microstructural Analysis N2 - The composites combining aluminum and silica nanoparticles with the addition of tetramethylammonium hydroxide (Al-SiO2(T)) and butanol (Al-SiO2(B)) as mixing media have been successfully fabricated. Corrosion behavior of Al-SiO2 composites before and after exposure in 1M NaCl solution was examined using potentiodynamic polarization (Tafel curve analysis). The study was also equipped with scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) investigations. Before exposure, Al-SiO2(T) exhibited the best corrosion resistance. Performance improvement was indicated by Al-SiO2(B) up to 10 times better than Al-SiO2(T) after exposure. The increased SiO2 content did not significantly enhance the corrosion resistance of the composites. The Al-SiO2 composites with 5% SiO2 content showed very high corrosion resistance (as the optimum composition). Furthermore, pitting corrosion was observed in the Al-SiO2 composites, indicated by the formation of corrosion products at grain boundaries. The product was affected by the presence of SiO2 in the Al matrix and the NaCl environment at 90 °C (approach to synthetic geothermal media: Na+, Cl, H+, OH-). Our study revealed the presence of γ-Al2O3, γ-Al(OH)3, and Al(OH)2Cl as the dominant corrosion products. KW - Al-Composite KW - Corrosion KW - Corrosion rate KW - SiO2 Nanoparticle KW - Tafel Plot PY - 2019 DO - https://doi.org/10.5829/ije.2019.32.07a.11 SN - 1025-2495 SN - 1735-9244 VL - 7 IS - 32 SP - 982 EP - 990 PB - Materials and Energy Research Center AN - OPUS4-48742 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 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - Kratzig, Andreas A1 - Knauer, S. T1 - Factors Influencing Droplet Corrosion in Dense Phase CO2 N2 - Recent studies have shown that even at a very low concentration of impurities (less than 100 ppmv of SO2, NO2, O2 and H2O) the droplet formation and condensation of sulfuric and nitric acids in dense phase CO2 are possible and observable. To reveal the mechanism of droplet corrosion in dense phase CO2 at high pressure and low temperature, further studies on factors that affect wettability and resulting corrosion behaviors of transport pipeline steels are needed. In this study, effects of surface morphology were investigated by varying surface roughness of carbon steel coupons exposed to CO2 stream containing impurities to measure the wettability by contact angle and to observe the condensation as well as possible droplet corrosion that followed. Other considered factors were: pH of the droplet, temperature, droplet volume, and exposure time. T2 - NACE International Corrosion Conference 2019 CY - Nashville, TN, USA DA - 24.03.2019 KW - CCUS KW - Dense phase KW - CO2 KW - Droplet KW - Corrosion KW - Condensation KW - Carbon steel PY - 2019 SP - 13017-1 EP - 13017-13 PB - NACE International CY - Houston AN - OPUS4-47915 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 - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Schiller, B.N A1 - Beck, M. A1 - Bettge, Dirk T1 - On the corrosion behaviour of CO2 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 - Carbon capture KW - Utilization, and storage (CCUS) technology KW - Corrosion KW - Carbon steel KW - Mortel KW - Crevice corrosion PY - 2019 AN - OPUS4-49105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Langklotz, U. A1 - Babutzka, Martin A1 - Schneider, M. A1 - Burkert, Andreas T1 - The combination of minimally invasive electrochemical investigations and FTIR‐spectroscopy to analyze atmospheric corrosion product layers on zinc N2 - The present work describes the combination of electrochemical investigations by using a gel‐type electrolyte with Fourier‐transformed infrared spectroscopy to investigate partially extremely thin corrosion product films on titanium‐zinc. The gel pad method enables the determination of corrosion relevant parameters such as the potential and the linear polarization resistance without altering the corrosion product layers, which are extremely prone to re‐dissolution when freshly formed. Complementary infrared spectroscopy enables the determination of main compounds of even very thin surface layers of few tenth of nanometers with a certain lateral resolution. It was found that zinc forms mostly zinc carboxy‐hydroxides such as hydrozincite, under various exposure conditions. The protective properties of these hydrozincite layers depend on the structure of the corrosion product film rather than on its thickness. In mid‐term exposure tests, shallow corrosion pits were found even in the absence of corrosive agents such as chloride. KW - Gel-type electrolytes KW - Gelartige Elektolyte KW - Zinc coatings KW - Zinkdeckschichten KW - Korrosionsprüfung KW - Corrosion testing KW - FT-IR PY - 2019 DO - https://doi.org/10.1002/maco.201810696 SN - 0947-5117 SN - 1521-4176 VL - 70 IS - 7 SP - 1314 EP - 1325 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-47728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Langklotz, U. A1 - Babutzka, Martin A1 - Burkert, Andreas A1 - Schneider, M. T1 - FT-IR spectroscopy of corrosion products formed on zinc under atmospheric conditions N2 - Zinc materials are of high importance in the field of corrosion protection. For example, almost half of the annual production of zinc is used as anti-corrosive layer for steel components, particularly under atmospheric conditions. The corrosion protection is frequently ascribed to zinc carbonate species with low solubility which form on the metal surface under atmospheric conditions. Due to the technological importance and wide use of zinc materials, its corrosion behavior and the formation of reaction products has been intensively investigated over decades. Assuming atmospheric corrosion conditions, an initial native passive film of few nanometers thickness forms spontaneously. It consists of zinc oxide and hydroxide, transforming into various species in dependence of the surrounding atmospheric conditions. This study focusses on the investigation of corrosion product layers on massive titanium-zinc sheets, formed during short- and mid-term exposure experiments by Fourier-transformed infrared spectroscopy. This method enables the investigation of extremely thin native passive films which form during the initial hours of exposure. Furthermore, aged surface layers are analyzed which were formed by transformation of initial passive layers over the time of several weeks. The spectroscopic investigations are complemented by scanning electron microscopy (SEM/EDX) in order to obtain information on the chemical composition and morphology of the corrosion products. The combination of both methods offers a comprehensive view on the processes occurring in the early stages of zinc corrosion. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Zinc coatings KW - FT-IR KW - Layer formation PY - 2019 AN - OPUS4-49132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Kranzmann, Axel T1 - Interaction of Oxidizing and Reductive Components in CO2 Streams with Transport Pipeline Steel X70 at High Pressure and Low Temperature N2 - Specific amounts of oxidizing and reductive impurities as well as some moisture were added to dense phase CO2 to replicate CO2 streams from sources in a CCS pipeline network. Due to the moisture content being only 50 ppmV no visible acid condensation took place. To simulate stress conditions at the inside pipeline surface due to fluid pressure (10 MPa) specimens were preloaded using a load frame. Experiments conducted at 278 K and at 313 K revealed the highest corrosion rate at lower temperature. Corrosive effect of impurities was strongest applying mixed atmosphere, containing oxidizing and reductive components, closely followed by CO2 streams with pure oxidizing character. By far, the lowest corrosion rate (10x lower) resulted from reductive atmosphere. In general, at constant temperature and pressure the CO2 stream composition strongly influences the morphology, thickness and composition of the corrosion products. Applying oxidizing or mixed impurities, iron hydroxides or oxides (e.g. goethite, hematite) occur as dominating corrosion products, capable to incorporate different amounts of sulfur. In contrast, using reductive atmosphere very thin corrosion layers with low crystallinity were developed, and phase identification by XRD was unfeasible. SEM/EDX analysis revealed the formation of Fe-O compounds, most likely attributed to the oxygen partial pressure in the system induced by CO2 (≥0.985 volume fraction) and volatile H2O. In addition to the surface covering corrosion layer, secondary phases had grown locally distributed on top of the layer. These compounds are characteristic for the applied atmosphere and vary in number, shape and chemical composition. T2 - 14th Greenhouse Gas Control Technologies Conference (GHGT-14) CY - Melbourne, Australia DA - 21.10.2018 KW - CCS KW - CO2 Corrosion KW - Pipelines PY - 2019 UR - https://ssrn.com/abstract=3365756 VL - 2019 SP - 1 EP - 15 AN - OPUS4-49711 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 - Kauss, Norman A1 - Heyn, A. A1 - Halle, T. A1 - Rosemann, Paul T1 - Detection of sensitisation on aged lean duplex stainless steel with different electrochemical methods N2 - Ageing at 600 °C (from 0.1 h up to 20 h) leads to the formation of precipitations at the ferrite-ferrite (α/α) and ferrite-austenite (α/γ) grain boundaries of the lean duplex stainless steel (LDSS) X2CrNiN22-2. This leads to sensitisation due to chromium depletion and decreased pitting corrosion resistance proven by the results of various electrochemical methods (DL-EPR and determination of CPT, Epit). These results were compared with the KorroPad method, which uses an agar-based gel-electrolyte for the detection of stainless steel surfaces prone to pitting corrosion. However, the standard configuration of the KorroPad showed no differentiation for the various ageing conditions. Therefore, modified versions of the KorroPad with two, five and ten times higher NaCl and potassium ferrocyanide III (K3[Fe(CN)6]) concentrations were successfully used to visualise the behaviour detected by DL-EPR, Epit and CPT. Therefore, the KorroPad method can also detect a microstructure related reduction of pitting corrosion resistance, which can drastically reduce the experimental effort to generate sensitisation diagrams for stainless steels. KW - Lean duplex KW - Stainless steel KW - Sensitisation KW - Polarisation KW - Critical pitting temperature KW - Pitting corrosion KW - KorroPad KW - Ageing treatment PY - 2019 DO - https://doi.org/10.1016/j.electacta.2019.05.081 SN - 0013-4686 SN - 1873-3859 VL - 317 SP - 17 EP - 24 PB - Elsevier AN - OPUS4-48374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kamaraj, Abinaya A1 - Erning, Johann Wilhelm A1 - Reimann, S. A1 - Ahrens, A. T1 - Susceptibility of 304 stainless steel to crevice corrosion in electrochemically active fluids N2 - The susceptibility of AISI 304 stainless steel to crevice corrosion on the effect of contact with electrochemically active fluids was investigated using exposure and stepwise potentiostatic polarisation. Crevice materials made up of 304 SS and Polyether ether ketone (PEEK) forming two kinds of crevices including 304 SS-to-PEEK and 304 SS-to-304 SS were tested. T2 - NACE International Corrosion Conference 2019 CY - Nashville, TN, USA DA - 24.03.2019 KW - Steel KW - Crevice KW - Corrosion KW - ECA KW - Stainless PY - 2019 SP - Paper 12868 PB - NACE International CY - Houston AN - OPUS4-49286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kamaraj, Abinaya A1 - Erning, Johann Wilhelm A1 - Reimann, S. A1 - Ahrens, A. T1 - Susceptibility of 304 stainless steel to crevice corrosion in electrochemically active fluids N2 - The susceptibility of AISI 304 stainless steel to crevice corrosion on the effect of contact with electrochemically active fluids was investigated using exposure and stepwise potentiostatic polarisation. Crevice materials made up of 304 SS and Polyether ether ketone (PEEK) forming two kinds of crevices including 304 SS-to-PEEK and 304 SS-to-304 SS were tested. T2 - Corrosion 2019 NACE CY - Nashville, TN, USA DA - 24.03.2019 KW - Desinfection KW - Crevice corrosion KW - ECA PY - 2019 AN - OPUS4-49284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hlavacek, Petr A1 - Reinemann, Steffi A1 - Gluth, Gregor A1 - Ebell, Gino A1 - Mietz, Jürgen ED - Serdar, M. ED - Stirmer, N. ED - Provis, J. T1 - Behaviour of reinforced alkali-activated fly ash mortars under leaching conditions N2 - Corrosion of steel reinforcement in concrete is one of the major deterioration mechanisms limiting the service life of reinforced concrete structures. While for conventional (Portland cement-based) concretes a great amount of experience exists in this regard, the factors that determine the onset of reinforcement corrosion in alkali-activated materials are incompletely understood yet. One aspect of corrosion protection is leaching and the accompanying changes of the concrete pore solution. In the present study, alkali-activated fly ash mortars with embedded carbon steel rebars were exposed to de-ionised water for periods up to 330 days, and the electrochemical response of the steel (free corrosion potential, polarisation resistance), the alteration of the mortar (ohmic resistance, mechanical strength, pore size distribution) as well as the pore solution composition were monitored. Although substantial alkali leaching was observed, the pH of the pore solution remained at values sufficient to protect the embedded steel from depassivation. The mortar did not exhibit indications of significant deterioration. Thus, the present results suggest that leaching is not critical for protection of steel reinforcement in alkali-activated fly ash mortars and concretes. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Alkali-activated materials KW - Steel corrosion KW - Leaching PY - 2019 SN - 978-2-35158-223-7 VL - 1 SP - 118 EP - 124 PB - RILEM Publications CY - Paris AN - OPUS4-47585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hlavacek, Petr A1 - Reinemann, Steffi A1 - Gluth, Gregor A1 - Ebell, Gino A1 - Mietz, Jürgen T1 - Behaviour of reinforced alkali-activated fly ash mortars under leaching conditions N2 - Corrosion of steel reinforcement in concrete is one of the major deterioration mechanisms limiting the service life of reinforced concrete structures. While for conventional (Portland cement-based) concretes a great amount of experience exists in this regard, the factors that determine the onset of reinforcement corrosion in alkali-activated materials are incompletely understood yet. One aspect of corrosion protection is leaching and the accompanying changes of the concrete pore solution. In the present study, alkali-activated fly ash mortars with embedded carbon steel rebars were exposed to de-ionised water for periods up to 330 days, and the electrochemical response of the steel (free corrosion potential, polarisation resistance), the alteration of the mortar (ohmic resistance, mechanical strength, pore size distribution) as well as the pore solu¬tion composition were monitored. Although substantial alkali leaching was observed, the pH of the pore solution remained at values sufficient to protect the embedded steel from depassivation. The mortar did not exhibit indications of significant deterioration. Thus, the present results suggest that leaching is not critical for pro¬tec¬tion of steel reinforcement in alkali-activated fly ash mortars and concretes. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Alkali-activated materials KW - Leaching KW - Steel corrosion PY - 2019 AN - OPUS4-47621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Harnisch, J. A1 - Dauberschmidt, C. A1 - Ebell, Gino A1 - Mayer, T. T1 - The new DGZfP Specification B12 "Corrosion Monitoring of Reinforced Concrete Structures" N2 - The corrosion of steel in reinforced concrete structures is one of the main threats to their durability. Based on the scientific achievements of the past decades the knowledge about the deterioration mechanisms and possible repair strategies for corrosion induced damages have found their way into practice. It is common sense, that a detailed assessment of the structure is the foundation for a successful repair measure. In addition to the “traditional” singular on-site-procedures such as measurement of concrete cover, carbonation depth, half-cell potentials and chloride contents the monitoring of corrosion related parameters has gained in importance over the past few years. The advantages of a corrosion monitoring are obvious. In new buildings, structural elements which cannot be assessed after completion (e.g. tunnel segments), or members with electrically isolating coatings can be monitored by means of integrated sensors providing an insight into the development of crucial parameters such as electrochemical potentials, corrosion currents and the electrical resistivity of the concrete. A less known but very beneficial field of application is the use of corrosion monitoring as an integral part of a repair measure based on principles such as the cathodic protection of steel in concrete (CP) or increasing the electrical resistivity of the concrete (IR). By implementing a corrosion monitoring system, it is possible to survey the time dependent effect of the repair measure on the corrosion process which may lead to a confirmation of successful repair measure or to a modification of the repair strategy. As the principle of cathodic protection for steel in concrete is a recognized repair measure today, the number of applications increases steadily and thus increasing the relevance for corrosion monitoring. Nevertheless, no standards or guidelines concerning the corrosion monitoring are available in Germany today, making it difficult to implement corrosion monitoring in common practice. With this in mind an international task group formed to develop the specification B12 “Corrosion Monitoring of Reinforced and Prestressed Concrete Structures” published by the German Society for Non-Destructive Testing, DGZfP, spring 2018. This paper will present the new specification B12 by highlighting the basic measurement principles and illustrating the potentials of corrosion monitoring for new and existing concrete structures by means of case studies. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Monitoring KW - Corrosion KW - Concrete structures PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-487980 SP - We.4.A.1, 1 PB - SMAR 2019 AN - OPUS4-48798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Harnisch, J. A1 - Dauberschmidt, C. A1 - Ebell, Gino A1 - Meyer, T. T1 - The new DGZfP Specification B12 N2 - The corrosion of steel in reinforced concrete structures is one of the main threats to their durability. Based on the scientific achievements of the past decades the knowledge about the deterioration mechanisms and possible repair strategies for corrosion induced damages have found their way into practice. It is common sense, that a detailed assessment of the structure is the foundation for a successful repair measure. In addition to the “traditional” singular on-site-procedures such as measurement of concrete cover, carbonation depth, half-cell potentials and chloride contents the monitoring of corrosion related parameters has gained in importance over the past few years. The advantages of a corrosion monitoring are obvious. In new buildings, structural elements which cannot be assessed after completion (e.g. tunnel segments), or members with electrically isolating coatings can be monitored by means of integrated sensors providing an insight into the development of crucial parameters such as electrochemical potentials, corrosion currents and the electrical resistivity of the concrete. A less known but very beneficial field of application is the use of corrosion monitoring as an integral part of a repair measure based on principles such as the cathodic protection of steel in concrete (CP) or increasing the electrical resistivity of the concrete (IR). By implementing a corrosion monitoring system, it is possible to survey the time dependent effect of the repair measure on the corrosion process which may lead to a confirmation of successful repair measure or to a modification of the repair strategy. As the principle of cathodic protection for steel in concrete is a recognized repair measure today, the number of applications increases steadily and thus increasing the relevance for corrosion monitoring. Nevertheless, no standards or guidelines concerning the corrosion monitoring are available in Germany today, making it difficult to implement corrosion monitoring in common practice. With this in mind an international task group formed to develop the specification B12 “Corrosion Monitoring of Reinforced and Prestressed Concrete Structures” published by the German Society for Non-Destructive Testing, DGZfP, spring 2018. This paper will present the new specification B12 by highlighting the basic measurement principles and illustrating the potentials of corrosion monitoring for new and existing concrete structures by means of case studies. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Corrosion KW - Monitoring PY - 2019 AN - OPUS4-48805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Faes, W. A1 - Lecompte, S. A1 - van Bael, J. A1 - Salenbien, R. A1 - Bäßler, Ralph A1 - Bellemans, I. A1 - Cools, P. A1 - de Geyter, N. A1 - Morent, R. A1 - Verbeken, K. A1 - de Paepe, M. T1 - Corrosion behaviour of different steel types in artificial geothermal fluids N2 - Geothermal energy is an interesting alternative to polluting fossil energy sources. Therefore, in Belgium, two wells have been drilled for a deep geothermal power plant. However, the environment to which the installations are exposed is challenging. The geothermal brine has 165 g/l total dissolved solids (of which 90% are sodium and chlorine) and the production temperature can be up to 130 °C. To assess their suitability to be used in a geothermal power plant, the corrosivity of the artificial brine to three common construction materials was investigated with exposure and electrochemical tests. The metals under consideration are a low-alloyed carbon steel (S235JR), an austenitic stainless steel (UNS S31603) and a duplex stainless steel (UNS S31803). The carbon steel, that was found to corrode uniformly, could be considered as a constructional material if a sufficient wall thickness is chosen. The austenitic stainless steel and the duplex stainless steel demonstrate very low uniform corrosion rates. They are however susceptible to pitting and crevice corrosion. To guarantee safe operation of the geothermal power plant, the susceptibility of the alloys to stress corrosion cracking should be tested and in situ experiments should be performed. KW - Geothermal energy KW - Corrosion KW - Carbon dioxide KW - Carbon steel KW - Stainless steel PY - 2019 DO - https://doi.org/10.1016/j.geothermics.2019.05.018 SN - 0375-6505 VL - 82 IS - 11 SP - 182 EP - 189 PB - Elsevier Ltd. AN - OPUS4-48759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erning, Johann Wilhelm A1 - Kamaraj, Abinaya T1 - Susceptibility of 304 stainless steel to crevice corrosion in electrochemically active fluids N2 - The crevice corrosion behaviour of stainless steel 304 L n ECA fluids is investigated. Results are described, rules for operation are suggested T2 - Ceocor-Tagung 2019 CY - Copenhagen, Denmark DA - 21.05.2019 KW - Desinfection KW - Crevice corrosion KW - ECA PY - 2019 AN - OPUS4-49280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erning, Johann Wilhelm T1 - Observations of copper pitting corrosion in german tap waters N2 - In recent years, a new type of pitting corrosion is observed on half-had copper pipes. examples are given and possible reasons are discussed T2 - Eurocorr 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Water KW - Pitting KW - Corrosion KW - Copper KW - Drinking PY - 2019 AN - OPUS4-49281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -