Analysis of a Directionally Solidified (DS) GTD-111 Turbine Blade Failure

Sabri, Khier; Gaceb, Mohamed; Si-Chaib, Mohamed Ouali

doi:10.1007/s11668-020-00920-y

Cited by 7 publications

(2 citation statements)

References 33 publications

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“…It is well known that GTD-111 undergoes a microstructural degradation caused mainly by γ'-phase coarsening and coalescence. Several authors have found a gradual increase in γ' particle size, depending on the temperature and thermal exposure time [15,33,34]. Therefore, the size of γ' particles can be used to evaluate the in-service temperature at different blade locations.…”

Section: First-stage Turbine Bladementioning

confidence: 99%

Computational and Experimental Study on Failure Mechanism of a GTD-111 First-Stage Blade of an Industrial Gas Turbine

Bayro-Lazcano,

Piedra-Gonzalez,

García-Moreno

et al. 2023

Metals

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This paper investigates the root cause of a recurring failure observed in the first-stage blades of an industrial gas turbine. The failure involves the loss of the trailing edge tip of the blades. The study employs a combination of metallographic analysis and computational simulations utilizing the finite element method and computational fluid dynamics. The metallographic analysis reveals significant degradation in the GTD-111 nickel-based superalloy within the region where the failure occurs. This degradation is characterized by the coarsening and coalescence of the gamma prime phase, which can be attributed to localized overheating. Additionally, the computational study enables the calculation of the trajectory, pressure, and temperature profiles of the hot gases, as well as the distribution of temperatures within the blade. These findings demonstrate that the cooling airflow is influenced by the hot gas flow, particularly in the vicinity of the fault location, owing to the orientation of the cooling ducts, which results in overheating in this area. Ultimately, the temperatures derived from the microstructural analysis using the Ostwald-ripening theory align remarkably well with the results obtained from the simulation, validating the accuracy of the computational model. By combining metallographic analysis and computational simulations, this study provides crucial insights into the failure mechanism of the first-stage blades.

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Section: First-stage Turbine Bladementioning

confidence: 99%

Computational and Experimental Study on Failure Mechanism of a GTD-111 First-Stage Blade of an Industrial Gas Turbine

Bayro-Lazcano,

Piedra-Gonzalez,

García-Moreno

et al. 2023

Metals

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“…In actual gas turbine operation, the internal surface of cooling holes is not protected with any coating system. A study conducted by Sabri et al found that the cooling holes with oval shape, which have relatively wider hole openings, have suffered severe pitting and oxidation [52]. Wider hole openings have allowed for the ingestion of debris and for contaminant particles to enter the cooling holes internal surface.…”

Section: Tbc-assisted Cooling Air In Advanced Gas Turbinementioning

confidence: 99%

Test-Rig Simulation on Hybrid Thermal Barrier Coating Assisted with Cooling Air System for Advanced Gas Turbine under Prolonged Exposures—A Review

et al. 2021

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Thermal barrier coating (TBC) and cooling air systems are among the technologies that have been introduced and applied in pursuing the extensive development of advanced gas turbine. TBC is used to protect the gas turbine components from the higher operating temperature of advanced gas turbine, whereas cooling air systems are applied to assist TBC in lowering the temperature exposure of protected surfaces. Generally, a gas turbine operates in three main operational modes, which are base load, peak load, and part peak load. TBC performance under these three operational modes has become essential to be studied, as it will provide the gas turbine owners not only with the behaviors and damage mechanism of TBC but also a TBC life prediction in a particular operating condition. For TBC under base load or so called steady-state condition, a number of studies have been reviewed and discussed. However, it has been found that most of the studies have been conducted without the assistance of a cooling air system, which does not simulate the TBC in advanced gas turbine completely. From this review, the studies on TBC-assisted cooling air system to simulate the advanced gas turbine operating conditions have also been summarized, which are limited to test rig simulations under thermal cyclic mode where thermal cyclic represents peak and part peak load conditions. The equipment used to simulate the gas turbine operating condition, test temperatures, and durations are parameters that have been taken into consideration under this review. Finally, a test rig that is capable of simulating both TBC and cooling air effects at a high operating temperature of advanced gas turbines for prolonged exposure under steady-state condition has been proposed to be developed.

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