Hot corrosion failure in the first stage nozzle of a gas turbine engine

Salehnasab, B.; Poursaeidi, Esmaeil; Mortazavi, S. A.; Farokhian, G.H.

doi:10.1016/j.engfailanal.2015.11.057

Cited by 72 publications

(30 citation statements)

References 18 publications

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“…To validate the results of the five-phase model, data are obtained from prior models, FEA models and experimental results for comparison with the five-phase model [4,7,37,45,50,51,58,80,[82][83][84]. Comparison of results obtained from the five-phase model with results obtained from other models is drawn and the graphical representation of this comparison can be seen in Figure 19.…”

Section: Validation Of the Calculated Resultsmentioning

confidence: 99%

“…The progression in engineering alloys led to the design and development of the present era turbine engines [1]. The components of a turbine engine are exposed to elevated temperatures as well as to oxidative and corrosive gaseous environments [2][3][4]. These conditions lead to an early degradation of components due to high wear and tear at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

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Modelling Thermal Conductivity of Porous Thermal Barrier Coatings

2019

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Thermal conductivity of porous thermal barrier coatings was evaluated using a newly developed five-phase model. It was demonstrated that porosities distributed in coating strongly affect thermal conductivity. The decisive reason for this change in thermal conductivity can be traced back to defect morphology and its orientation, depending on the coating deposition technique and process parameters used during deposition. In this paper, the Bruggeman’s two-phase model was used as a reference, and a five-phase model was developed to evaluate the thermal conductivity of porous coatings. This approach uses microstructural details of the shape, size, orientation and volumetric fraction of defects of coatings as input parameters. The proposed model can predict thermal conductivity values better than the previous two-phase model.

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Section: Validation Of the Calculated Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling Thermal Conductivity of Porous Thermal Barrier Coatings

2019

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“…Nevertheless, the separation of substrate curves is higher in comparison with the other ones studied, reporting highest corrosion rates. On the other hand, the corrosion rate is very low for both systems (Three-layer Painting System and Thermal Spray System), generating a protection of zinc and aluminum pigments respectively; although there is a little consumption increase of current density in 2250 hours, for both systems, fact that raises zinc and aluminum consumption, forming oxides: The above phenomena are corroborated on the SEM images, leading to lose of paint adherence and an increment of rate corrosion [27][28][29][30][31][32][33].…”

Section: Figurementioning

confidence: 93%

Corrosion protection in saline environment of a carbon steel coated (aluminum & three-layer painting system) by eats

Pérez-Muñoz¹,

Marulanda-Arévalo²,

Téllez³

2018

Rev.Fac.Ing.Univ.Antioquia

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This paper presents a comparative study on corrosion protection of low-carbon steel coated with two different painting systems. The first set of samples was coated with an aluminum layer of primer deposited by Electric Arc Thermal Spray (EATS), after which two additional layers of paint were applied, thereby creating an aluminum-painting system; while the second set of samples was coated with the traditional three-layer painting system (zinc-rich layer of primer). Afterwards, all the samples were exposed to the salt spray chamber. The samples were monitored to record their reactions in the corrosive saline environment. Scanning Electron Microscopy (SEM), adhesion and electrochemical corrosion tests were performed to characterize the coatings and report changes in their properties (adhesion, topography and homogeneity), which are related to exposure time. The three-layer painting system barely complied with manufacturer claims on protection time under corrosive conditions; on the other hand, the aluminum-painting system yielded better results by prolonging protection time. RESUMEN: Este artículo presenta un estudio comparativo de protección contra la corrosión de aceros de bajo carbono recubiertos con dos sistemas diferentes de pintura. El primer grupo de muestras fue recubierto con una capa de aluminio depositada por Rociado Térmico por Arco Eléctrico (EATS por sus siglas en inglés), subsecuentemente dos capas adicionales de pintura fueron aplicadas, creando así un sistema aluminio/pintura. Mientras que, un sistema tradicional de tres capas de pintura (primera capa de pintura rica en zinc) fue depositado en el segundo grupo de muestras. Finalmente, todas las muestras fueron expuestas en la cámara de niebla salina. Las muestras fueron monitoreadas para obtener su comportamiento en el corrosivo ambiente salino. Microscopia Electrónica de Barrido (SEM por sus siglas en inglés), ensayos de adhesión y corrosión electroquímica fueron realizadas para caracterizar los recubrimientos y reportar los cambios en sus propiedades (adhesión, topografía y homogeneidad), las cuales están relacionadas con el tiempo de exposición. El sistema de tres capas escasamente cumplió con la garantía dada por su fabricante en lo referente al tiempo de protección bajo condiciones corrosivas; por otro lado, el sistema de aluminio/pintura entregó mejores resultados al prolongar el tiempo de protección.

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“…Such issues include accelerated thermal creep, material degradation due to oxidation, and cycle fatigue [4]. Thermalrelated corrosion issues arise at various temperature levels anywhere in the range of 650-1700 °C [2,[5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Computational Evaluation of Thermal Barrier Coatings: Two-Phase Thermal Transport Analysis

Irick

Fathi

2019

ASME 2019 Verification and Validation Symposium

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In the power plant industry, the turbine inlet temperature (TIT) plays a key role in the efficiency of the gas turbine and, therefore, the overall — in most cases combined — thermal power cycle efficiency. Gas turbine efficiency increases by increasing TIT. However, an increase of TIT would increase the turbine component temperature which can be critical (e.g., hot gas attack). Thermal barrier coatings (TBCs) — porous media coatings — can avoid this case and protect the surface of the turbine blade. This combination of TBC and film cooling produces a better cooling performance than conventional cooling processes. The effective thermal conductivity of this composite is highly important in design and other thermal/structural assessments. In this article, the effective thermal conductivity of a simplified model of TBC is evaluated. This work details a numerical study on the steady-state thermal response of two-phase porous media in two dimensions using personal finite element analysis (FEA) code. Specifically, the system response quantity (SRQ) under investigation is the dimensionless effective thermal conductivity of the domain. A thermally conductive matrix domain is modeled with a thermally conductive circular pore arranged in a uniform packing configuration. Both the pore size and the pore thermal conductivity are varied over a range of values to investigate the relative effects on the SRQ. In this investigation, an emphasis is placed on using code and solution verification techniques to evaluate the obtained results. The method of manufactured solutions (MMS) was used to perform code verification for the study, showing the FEA code to be second-order accurate. Solution verification was performed using the grid convergence index (GCI) approach with the global deviation uncertainty estimator on a series of five systematically refined meshes for each porosity and thermal conductivity model configuration. A comparison of the SRQs across all domain configurations is made, including uncertainty derived through the GCI analysis.

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Hot corrosion failure in the first stage nozzle of a gas turbine engine

Cited by 72 publications

References 18 publications

Modelling Thermal Conductivity of Porous Thermal Barrier Coatings

Modelling Thermal Conductivity of Porous Thermal Barrier Coatings

Corrosion protection in saline environment of a carbon steel coated (aluminum & three-layer painting system) by eats

Computational Evaluation of Thermal Barrier Coatings: Two-Phase Thermal Transport Analysis

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