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Showing 1 to 18 of 18 for “"hot corrosion"”.
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Type 1 hot corrosion furnace testing and evaluation.
… systems was conducted to determine if type 1 hot corrosion seen in operating gas turbine engines and burner rigs could be more simply reproduced. Furnace parameters were varied to determine optimum (most aggressive) values for a short term type 1 hot corrosion test. The results of these tests …
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Polymer-derived Si-al-c-n Ceramics:oxidation, Hot-corrosion, And Structural Evolution
… of ceramics. In this dissertation, oxidation/hot-corrosion behavior and the structural evolution of Si-Al-C-N ceramics have been studied. The structural evolution and crystallization behavior of the SiCN and SiAlCN ceramics are investigated using FT-IR, XRD, and NMR. The results revealed that …
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Hot corrosion behaviour of new candidates for thermal barrier coatings application in turbine simulated environments
… barrier coatings (TBCs). In current work, hot corrosion behavior of new candidates including Gd2Zr2O7, ZrO2 stabilized with Ta2O5, zirconia stabilized with both Ta2O5 and Y2O3 and zirconia stabilized with CeO2 and TiO2 is investigated. For YSZ case, the reaction between NaVO3 and Y2O3 …
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Modelling Gas Turbine Degradation
… procedure for the computational simulation of hot corrosion and related phenomenon in gas turbines using Reynolds-averaged Navier Stokes (RANS) computational fluid dynamics (CFD) simulations. Non-uniform distribution of gaseous species as a result of film coolant injection was observed on a …
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High temperature corrosion in gas turbines : thermodynamic modelling and experimental results
… have raised a need for re-evaluation of the hot corrosion risk in industrial gas turbines. In this study, the risk of hot corrosion was determined using thermodynamic modelling for different impurity-contents and combustion parameters. Based on these results, the parameters for the corrosion …
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Rauchgasseitige Korrosion von Nickelbasislegierungen für zukünftige 700C-Dampfkraftwerke
… base alloys are well investigated due to their hot corrosion behaviour. It is known that sodium sulphate may generate hot corrosion on those alloys at temperatures above its melting point of 884°C. On nickel base alloys an eutectic mixture of nickel sulphate and sodium sulphate with a melting …
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The Effect of Superimposed Stress on High Temperature Degradation of Single Crystal Superalloys during Exposure to Various Sulphur and Sea Salt Environments
… the single crystal turbine blades, can initiate hot corrosion. Low temperature Type II corrosion consists of the formation of a fused salt melt, which interacts with the combustion gases and causes other constituents of the alloy to dissolve. The resulting melt prevents the oxide to be …
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Tip leakage flow, heat transfer and blade lifing in a jet engine turbine
… the significant blade life reduction mechanisms, hot corrosion, oxidation, and melting were determined. calculations for typical jet engine conditions, In the present a maximum tip temperature of 1488 K was predicted which would lead to high oxidation rates for present day turbine blade alloys.
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Untersuchungen zur Freisetzung und Einbindung von Alkalimetallen bei der reduzierenden Druckwirbelschichtverbrennung
… Combined Cycle Power Systems require a reliable hot gas cleanup. Especially alkalimetals, such as Sodium and Potassium, can lead to severe damage of the gasturbine blading due to hot corrosion. The investigations described in this thesis were performed to determine the potential of alkalimetal …
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Sodium sulfate corrosion of silicon carbide fiber-reinforced lithium aluminosilicate glass-ceramic matrix composites
Sodium sulfate hot corrosion of a SiC fiber-reinforced lithium aluminosilicate (LAS) glass-ceramic matrix composite was studied using Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). Changes in the microstructural chemical composition of the specimens were investigated. The samples …
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Untersuchungen zur Alkalireinigung von Heißgasen für Anlagen mit Kohlenstaub-Druckfeuerung
… at temperatures above 1600 °C, can cause hot corrosion of gas turbine materials in contact with the hot flue gas. That's why a hot gas cleanup related to alkalis is indispensable. Silicate melts like coal ash slags have a high alkali retention. Thus it was investigated how far the sorption …
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Interdiffusion Analysis For Nicocraly And Nial Vs. Various Superalloys
Hot section components in gas turbines can be NiCoCrAlY-coated to provide the component with an Al reservoir that maintains a protective oxide layer on its surface. Over the service life of the component, the coatings degrade by composition and phase changes due to oxidation/hot-corrosion, and …
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Corrosion resistant chemical vapor deposited coatings for SiC and Si3N4
… turbine engine components are susceptible to hot corrosion by molten sodium sulfate salts which are formed from impurities in the engine's fuel and air intake. Several oxide materials were identified which may be able to protect these components from corrosion and preserve their structural …
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Untersuchungen zum Alkaliverhalten unter Oxycoal-Bedingungen
… partial pressure of CO2 in the flue gas, the hot gas chemistry and ash behaviour of the system change in comparison to conventional air blown systems. The aim of the present work was to examine the effects of these changes concerning the condensation and stability of alkali metal containing …
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Investigation of thermodynamic properties of alkali metals in oxide systems relevant to coal slags
… the formation of sticky deposits in boilers or hot corrosion of turbine blades in combined cycle power systems. Therefore, the information about thermodynamic properties of oxide systems containing silica and alumina as well as alkali and alkaline-earth oxides is important. The knowledge of …
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Non-destructive Microstructural Evaluation Of Yttria Stabilized Zirconia, Nickel Aluminides And Thermal Barrier Coatings Using Electrochemical Impedance Spectroscopy
… gradient, thermal cycling, oxidation and hot-corrosion, TBCs can fail by spallation at the interface between the metal and ceramic. The lack of understanding in failure mechanisms and their prediction warrant a development of non-destructive evaluation technique that can monitor the …
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Einbindung von Alkalimetallen bei der Druckkohlensstaubfeuerung
… of the PPCC is the high alkali content of the hot flue gases. The alkalis released during coal combustion can react with gaseous sulphur to alkali sulphates. These compounds cause high temperature corrosion of the Ni-base alloys of the turbine bladings. For this reason, the present …