(Aeronáutica) Comunicación de Congresos
URI permanente para esta colecciónhttps://digitalpro.inta.es/handle/20.500.12666/49
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Examinando (Aeronáutica) Comunicación de Congresos por Autor "Agüero, Alina"
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Ítem Acceso Abierto A direct comparative study of the corrosion behaviour of Si-free and Si-rich slurry aluminide coatings in molten carbonate melts(LNEG Laboratorio Nacional de Energia e Geologia, 2022-11-24) Audigié, Pauline; Sergio, Rodríguez Catela; Agüero, Alina; Pedrosa, Fátima; Paiva, Teresa; Diamantino, TeresaThis study is focused on the evaluation of the hot corrosion behaviour of two low-cost slurry aluminide coatings with and without Si addition deposited on ferritic-martensitic steels, comparing them with uncoated steel, after 1000-h of exposure to Li, K, Na molten carbonates at 650ºC, under static and dynamic conditions with a high linear velocity (1.3 m/s). Both coatings evidenced a high performance increase in comparison with uncoated substrates after exposure in both conditions. Both coatings behaved in a similar way according to the gravimetric results. However, after dynamic exposure, the Si-free aluminide maintained its morphology and composition after 1000 h with α-LiAlO2 as the only corrosion product while the Si-rich coating showed a higher attack extent in the outer part and developed a large quantity of voids at the coating/substrate interface, leading to substrate corrosion.Ítem Acceso Abierto A slurry coating for Cd replacement for aircraft components(Mondragon Unibertsitatea, 2008-07-25) Agüero, Alina; Blanco, C; Gutiérrez del Olmo, Marcos; García Martínez, MaríaÍtem Acceso Abierto Behaviour of coated and uncoated ferritic steels under isothermal and cyclic steam oxidation conditions(VTT, 2007-06-14) Agüero, Alina; González, Vanessa; Gutiérrez, M.Next generation steam turbines are expected to operate at 600-650°C and at these temperatures, currently available high strength ferritic-martensitic steels need to be coated to prevent oxidation. Slurry deposited aluminide coatings have shown excellent performance up to 650°C under isothermal conditions. The behaviour of these coatings as well as that of uncoated P92 under thermal cycling conditions has been studied both in steam and in air at 650°C. The tested specimens were characterized by field emission scanning electron microscopy. A comparison with isothermal steam oxidation has been established. In cyclic oxidation, evidence of scale spallation from uncoated substrates was observed at shorter exposure times than for specimens tested under isothermal conditions. In the coated specimens, cracks originally present in the "as deposited" coating did not propagate or become sites of preferential oxidation during isothermal steam testing. However, the cracks widened and propagated causing substrate oxidation when the specimens were tested by thermal cycling in steam or in air.Ítem Acceso Abierto Co-ordination of European Research in Structural Materials for Power Generation Equipment(University of Liège, 2014-09-17) Sommitsch, Chrisof; Vanstone, Rod; Kern, Torsten Ulf; Barnard, Peter; Mayr, Peter; Thompson, Rachel; Agüero, AlinaSommitsch, C., Vanstone, R., Kern, T.-U., Barnard, P., Mayr, P., Thomson, R., & Agüero, A. (2014). Co-ordination of European Research in Structural Materials for Power Generation Equipment. In Liège Conference on Materials for Advanced Power Engineering (Vol. Band / Volume 234, pp. 3-18). (Schriften des Forschungszentrums Jülich, Reihe Energie & Umwelt / Energy & Environment). ..Ítem Acceso Abierto Coatings for Oxycombustion - Supercritical Steam Boilers Components(University of Hakodate, 2014-01-21) Agüero, Alina; Baraibar, Ignacio; González, Vanessa; Gutiérrez del Olmo, Marcos; Muelas Gamo, Raúl; Plana, DanielÍtem Acceso Abierto Development and Validation of Advanced Oxidation Protective Coatings for Super Critical Steam Power Generation Plants(Grafische Medien, 2006-07-06) Scheefer, M.; Bernard Henderson, Michael; Agüero, Alina; Allcock, B.; Norton, B.; Tsipas, D. N.; Durham, R.; European Commission (EC)Increasing the efficiency of coal-fired power plant by increasing steam temperatures and pressures brings benefits in terms of cheaper electricity and reduced emissions, particularly CO 2 . In recent years the development of advanced 9%Cr ferritic steels with improved creep strength has enabled power plant operation at temperatures up to 600 -620ºC such that these materials are currently being exploited to construct a new generation of advanced coal-fired plant. However, the move to higher temperatures and pressures creates an extremely hostile oxidising and errosive environment. To enable the full potential of the advanced 9%Cr steels to be achieved, it is vital that protective coatings are developed, validated under high pressure steam environments and applied successfully to candidate components from the high pressure steam path. This paper reviews recent work conducted within the Framework V Brite EuRam project "Coatings for Supercritical Steam Cycles" (SUPERCOAT) to develop and demonstrate advanced slurry and thermal spray coating technologies capable of providing steam oxidation protection at temperatures in excess of 620°C and up to 300 bar pressure. The programe of work described has demonstrated the feasibility of applying a number of candidate coatings to steam turbine power plant components and has generated long-term steam oxidation rate and failure data that underpin the design and application processing work packages needed to develop and establish this technology for future and retrofit plant.Ítem Acceso Abierto Experience with 9Cr3W3CoVNbBN base material and crosswelds at 650°C for implementation in USC power plants(National Institute for Materials Science, Tsukuba , Japan, 2009-06-14) Mayr, Peter; Mendez Martín, Francisca; Holzer, Iván; Agüero, Alina; González, Vanessa; Baumgartner, Susanne; Cerjak, Horst HannesThis manuscript gives an overview on recent developments of a martensitic steel grade based on 9Cr3W3CoVNb with controlled additions of boron and nitrogen. Alloy design by thermodynamic equilibrium calculations and calculation of boron-nitrogen solubility is discussed. Two melts of a 9Cr3W3CoVNb steel were produced. The oxidation resistance was examined at 650°C in steam atmosphere. The alloy exhibited high resistance to steam oxidation at 650°C for at least 5.000 hours of exposure. Microstructural evolution during welding within the heat-affected zone was investigated by physical weld simulation, thermo-dilatometry and in situ X-ray diffraction using high energy synchrotron radiation. The heat-affected zone microstructure is characterized by optical microscopy. Two multilayer welds, one with a nickel based filler and one with a newly developed flux cored filler of matching chemical composition, were fabricated. All weldability experiments showed that within the heat-affected zone the initial base material microstructure is retained to a large extent. The formation of a uniform fine-grained heat-affected zone region is suppressed. Uniaxial creep tests of base material, weld metal and crossweld specimens were started at different levels of stress at 650°C. Up to the established maximum testing time of 20.000 hours, the base material shows significant improvement compared to standard 9 wt. % Cr grades P91 and P92. Crossweld specimens show an improved strength level, higher than that of grade P92 base material. Preliminary results of an extensive testing program on a 9Cr3W3CoVNbBN steel show significant improvement compared to the state-of-the-art 9 wt. % Cr martensitic steel grades.Publicación Acceso Abierto Experience with 9Cr3W3CoVNbBN Steel in Terms of Welding, Creep and Oxidation(Electric Power Research Institute (EPRI), 2016-10-11) Abstoss, K. G.; Nitsche, A.; Mayr, P.; Schlacher, C.; González, V.; Agüero, AlinaThe presented work summarizes the results of more than 10 years of research at TU Graz and TU Chemnitz and partners on a martensitic boron and nitrogen stabilized 9Cr3W3Co (MARBN) steel grade. The design philosophy of MARBN steels is presented and critical issues regarding boron and nitrogen balance are discussed. Microstructural characterization of two different laboratory heats, is presented and efforts in European projects towards an upscaling of melts are presented. Base material creep testing data at 650 °C up to 50.000 hours is presented and assessed to commercial alloys such as ASTM grades P91 and P92. An increase of creep rupture stress of more than +20% was recorded. Oxidation tests in steam at 650°C revealed an anomalous response of the material. Several specimens exhibited excellent oxidation resistance commonly only seen for grades of higher chromium content. The anomalous oxidation behaviour is identified and discussed, although the causes remain yet unclear. Results of manufacturing, characterization and testing of different MARBN welds, including gas-tungsten-arc-, gas-metal-arc-, friction stir and electron beam welds reveal a microstructure memory effect in the heat affected zone, so that no uniform fine-grained zone is present. The behaviour of crosswelds during long-term creep testing at 650 °C up to more than 32.000 hours is assessed and the susceptibility to Type IV cracking is discussed. The manuscript summarizes research of more than 10 years, presents current research activities on MARBN and describes open questions for an alloy identified as a promising martensitic steel grade for elevated temperature components.Ítem Acceso Abierto Fe-Al Intermetallic Phases Present in Fe Aluminide Coatings(Universidad de Las Palmas de Gran Canaria, 2011-09-09) Agüero, Alina; González, Vanessa; Gutiérrez del Olmo, Marcos; Muelas Gamo, RaúlIron aluminide coatings are known to protect steels at elevated temperatures in diverse industrial environments. Depending on the Al content of the Fe-Al phase, a protective Al2O3 scale can be formed and maintained and the coatings are relatively stable up to approximately 900º C. At higher temperatures, Al inwards diffusion causes impoverishment of Al at the surface until it reaches a critical concentration below which the protective oxide will not form. Depending on the coating composition an Al content of 4 to 8 wt. % seems to be sufficient to maintain the protective scale [1-3]. Among the diverse coating deposition techniques, the application of slurries is one of the most economical, practical and versatile. Aluminide coatings have been generated by applying an Al slurry followed by heat treatment which depends on the substrate. For instance, it has been shown that on ferritic steels, deposition of an Al slurry followed by heat treatment at 700º C for 10 h generates a complex aluminide coatings composed of several intermetalllic phases including FeAl3, Fe2Al5 and FeAl (see figure 1). Under the coating, AlN acicular precipitates can form within the substrate, if the substrate contains sufficient N (≥ 0.01 wt. %) [4-6]. The coatings exhibit thickness-through cracks probably due to brittleness of the Fe2Al5 phase and to thermal expansion mismatch between the different phases. Figure 1: SEM cross sections of an "as deposited" Al slurry coating on P92 followed by heat treatment for 10 h at 700º CÍtem Acceso Abierto Hot Corrosion and Mechanical Performance of Aluminide Coated Austenitic Steel(Thermal Energy Storage Materials, Media, and Systems, 2025-11-18) Oger, Loïc; Agüero, Alina; Audigié, PaulineThe present study aims at improving coatings to allow higher operating temperatures – up to 700 °C – while resisting hot corrosion in future heat transfer fluids and storage systems for CSP technology. An aluminide coating was produced onto a 347H austenitic alloy to resist Li-Na-K molten carbonate corrosion at 700 °C. Multiple surface preparations were investigated and, after optimization, a new diffusion heat treatment was selected. A homogeneous 3-layer coating was formed with Al content reaching up to 69 at.% at the top surface. Corrosion was significantly decreased by the coating compared to the uncoated material. After 500h-exposure, a 100 µm-thick multi-layered and non-adhesive alkali elements rich oxide formed at the surface of uncoated 347H alloy. On the contrary, the coated material preserved its morphology and a mix of α-LiAlO2 and γ-LiAlO2 formed on the top coating. From the mechanical perspective, local hardness measurements highlighted a broad variation along the different layers of the coating. 3-point bending tests showed that deformation in the plastic domain was required to cause crack formation. Cracks remained in the two outermost layers of the coating and did not reach the underneath substrate.Ítem Acceso Abierto Improved Creep and Oxidation Behavior of a Martensitic 9Cr Steel by the Controlled Addition of Boron and Nitrogen(University of Liege, 2010-09-27) Mayr, Peter; Holzer, Iván; Mendez Martín, Francisca; Albu, Mihaela; Mitsche, Stefan; González, Vanessa; Agüero, AlinaÍtem Acceso Abierto Oxidation performance of high temperature steels and coatings for future supercritical power plants(University of Liege, 2010-09-22) Auerkari, Pertti; Salonen, Jorma; Toivonen, Aki; Penttilä, Sami; Juha, Häkkilä; Agüero, Alina; Gutiérrez del Olmo, Marcos; Muelas Gamo, RaúlThe operating efficiency of current and future thermal power plants is largely dependent on the applied temperature and pressure, which are in part limited by the internal oxidation resistance of the structural materials in the steam systems. Alternative and reference materials for such systems have been tested within the COST 536 (ACCEPT) project, including bulk reference materials (ferritic P92 and austenitic 316 LN steels) and several types of coatings under supercritical combined (oxygen) water chemistry (150 ppb DO) at 650ºC/300 bar. The testing results from a circulating USC autoclave showed that under such conditions the reference bulk steels performed poorly, with extensive oxidation already after relatively short term exposure to the supercritical medium. Better protection was attained by suitable coatings, although there were clear differences in the protective capabilities between different coating types, and some challenges remain in applying (and repairing) coatings for the internal surfaces of welded structures. The materials performance seems to be worse in supercritical than in subcritical conditions, and this appears not to be only due to the effect of temperature. The implications are considered from the point of view of the operating conditions and materials selection for future power plants.Ítem Acceso Abierto Steam oxidation behavior of high strength newly developed ferritic/martensitic steels at 650º C(2010-05-24) Agüero, Alina; González, Vanessa; Mayr, Peter; Spiradek, Krystina
