TY - JOUR A1 - Bäßler, Ralph A1 - Keserovic, Amela A1 - Sobetzki, Joana A1 - Sarmiento Klapper, Helmuth T1 - Materials evaluation for geothermal applications N2 - In order to provide basic information on corrosion resistance to the designers and users of geothermal plants different metallic materials including duplex and austenitic stainless steels as well as a nickel alloy have been evaluated in artificial geothermal fluids simulating the conditions in some locations with geothermal potential in Germany as well as two sites in Indonesia. By electrochemical and long-term exposure tests at 100 °C and 150 °C the suitability of low alloyed steel UNS G41300, stainless steels UNS S31603 UNS S31803, UNS S32760, super austenitic steel UNS N08031 and nickel based alloy UNS N06059 was investigated in these geothermal fluids, using critical potentials and corrosion rates. In high-saline environments the crevice corrosion turned out to be the determining mechanism. The nickel based alloy shows excellent corrosion resistance against pitting corrosion. Excluding its high cost, it is very good to be used in the construction of geothermal facilities having highly saline brines. Stainless and duplex steels exhibit a limited corrosion resistance concerning pitting and crevice corrosion. Therefore they are not suitable for highly saline brines. The super austenite UNS N08031 showed a temperature depending behavior. In non-saline environments the low-alloyed steel UNS G41300 (beside of the higher alloyed materials) could be employed as a constructional material for the geothermal power plant, as long as a sufficient wall thickness of the material is considered. KW - Geothermal KW - Corrosion KW - Crevice corrosion KW - Suitability PY - 2015 UR - http://www.jurnalteknologi.utm.my/index.php/jurnalteknologi/article/view/5164 SN - 2180-3722 VL - 75 IS - 7 SP - 7 EP - 14 PB - Penerbit UTM Press CY - Johor Bahru AN - OPUS4-34747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Keserovic, Amela T1 - Geothermal systems in Indonesia - Influence on the corrosion resistance of stainless steel materials N2 - The growth in a global demand for energy, as well as the awareness of a significant climate change, have evolved a very strong incentive for utilizing and expanding the use of clean and renewable energy resources. Geothermal energy is considered as one of a few alternatives ideal for replacing conventional sources due to its consistency and reliability, and is receiving ever more attention. However, geothermal Systems are found to be the most aggressive natural environments in terms of corrosion. High temperature and pressure conditions, as well as the existence of almost an entire periodic System of elements in form of corrosive salts, present a major threat to the integrity of the construction material. Therefore, in order to achieve a safer and continuous energy production, and increase the competitiveness of geothermal energy on the world scene, a comprehensive assessment of the materials suitability is of high importance for operators and vendors. Finally, thäs would lead to an inoreased lifespan of the power plant, as well as its economic profit, due to the reduced maintenance costs. KW - Geothermal energy KW - Indonesia KW - Carbon steel KW - Stainless steel KW - Corrosion PY - 2014 SP - 1-130, A1-A34 CY - Berlin AN - OPUS4-31033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Keserovic, Amela A1 - Bäßler, Ralph T1 - Geothermal systems of Indonesia - Influence of different factors on the corrosion performance of carbon steel API Q125 N2 - Among all of the existing electric power generation facilities, corrosion is considered to be the most severe on geothermal power plants. The focus of this research was set to evaluate the suitability of carbon steel API Q125 as a construction material on the geothermal sites Sibayak and Lahendong, Indonesia. The investigations were performed in the artificial geothermal brines under stagnant conditions by means of short-term electrochemical methods (Tafel extrapolation) and long-term exposure tests (up to 6 months). Furthermore, the influence of different parameters on the steels performance (temperature 70 °C, 100 °C and 175 °C, salinity 20 mg/L and 1,500 mg/L chlorides, pH 2 and 4) was assessed as well to ensure a “safer operating window” of a power plant. The results showed carbon steel API Q125 could be suitable for application in stagnant geothermal brines up to temperatures of 175 °C and a chloride concentration of 1,500 mg/L. Its applicability is limited in highly acidic environments (pH 2). T2 - World Geothermal Congress 2015 CY - Melbourne, Australia DA - 19.04.2015 KW - Corrosion KW - Carbon steel KW - Electrochemistry KW - Exposure KW - Sibayak KW - Lahendong PY - 2015 SN - 978-1-877040-02-3 SP - paper 27025, S. 1 EP - 8 AN - OPUS4-34751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Keserovic, Amela A1 - Sobetzki, Joana A1 - Sarmiento Klapper, Helmuth A1 - Dimper, Matthias T1 - Laboratory evaluation of metallic materials for geothermal applications N2 - In the last years, geothermal power has become a reliable and significant energy source. Because service conditions in geothermal facilities from deeply located aquifers are usually critical in terms of corrosion, materials selection is a very important issue. Preliminary evaluation of the material's suitability represents therefore a valuable strategy to ensure a secure and reliable operation of the facilities. In geothermal applications, the use of high-alloyed materials such as superaustenitic stainless steels, duplex stainless steels, and nickel-based alloys has been considered as a good alternative because of their remarkable corrosion resistance and appropriate mechanical properties. Nevertheless, the corrosion behavior of those metallic materials in geothermal fluids at service conditions has not been determined in many cases. In this work, laboratory tests including electrochemical investigations and exposure tests at 100 degrees C and 150 degrees C (1,500 kPa) showed the limits of suitability concerning localized corrosion of three different, corrosion-resistant alloys in the highly saline fluid of the North German Basin. T2 - EPRI International Conference on Corrosion in Power Plants CY - San Diego, CA, USA DA - 12.10.2015 KW - Geothermal KW - Corrosion KW - Crevice corrosion KW - Suitability PY - 2015 DO - https://doi.org/10.5006/1.3676631 SP - paper 6 AN - OPUS4-34754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keserovic, Amela A1 - Bäßler, Ralph T1 - Suitability of UNS S31603 steel for geothermal brines in volcanic areas - Influence of different physiochemical conditions on its corrosion behavior N2 - Geothermal sources are found to be the most aggressive natural environments for construction materials in terms of corrosion. This study was focused on investigating the suitability of stainless steel UNS S31603 in volcanic areas of geothermal sites Sibayak and Lahendong (Indonesia). Influence of different factors (temperatures up to 175 °C, chloride content up to 1500 mg/L and pH down to 2) was assessed to determine a 'safe operating window' of a power plant and assure the system integrity. Investigations were performed by means of electrochemical methods and long-term exposure tests. KW - Corrosion KW - Stainless steel KW - Sibayak KW - Lahendong KW - Geothermal energy PY - 2015 DO - https://doi.org/10.1016/j.geothermics.2014.09.001 SN - 0375-6505 VL - 53 SP - 479 EP - 487 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-32742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -