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2. Master Thesis / Tesis Master
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Title:	Analyses and wear characteristics of gas turbine combustor components
Authors:	Ahmad Afiq Pauzi (P75020)
Supervisor:	Mariyam Jameelah Ghazali, Prof. Madya Dr.
Keywords:	Wear Fuel nozzle Combustion liner Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	20-Nov-2017
Description:	Combustor components are the most valuable components in gas turbines. The fuel nozzle, combustion liner and transition piece are the vital components in the combustion section. Wear is one of the main problems found in the combustor components of gas turbines during inspection. Wear occurs at each contacting surface of the components. The first set of contacting surfaces is between the fuel nozzle and the combustion liner, while the other set is between the combustion liner and the transition piece. These vital components are exposed to high temperatures of up to 1100 °C and pressure (~ 25 bar) while in operation. In this study, the mechanical and microstructural properties of vital combustor components in a gas turbine were analysed to characterise their wear behaviour and to determine the dominant wear mechanisms, thus develop the wear maps. Several mechanical test and microstructural analysis were performed to meet these deliverables, including visual observations, XRay Fluorescent (XRF) tests to determine the chemical composition, macrostructural examinations, hardness tests, surface roughness tests, pin-on-disc wear tests, Scanning Electron Microscope (SEM) analyses, and optical microscopic analyses. The results were further divided into tests on the actual components as well as other tests on the materials of the gas turbine combustor components that were conducted on a laboratory scale using a pin-on-disc configuration. The visual inspection results confirmed that wear in the form of material loss occurred on the contacting surfaces of the vital components. Macrograph images captured during on-site tests confirmed that adhesive and fretting wear were observed on these contacting surfaces. The pin-ondisc wear test results confirmed that the volume loss increased with an increase in the contact temperature and time for both contacting surfaces. At contact temperatures of between 25 °C to 200 °C, the disc material (grade 304 stainless steel) presented a higher wear coefficient of up to 1.9 x 10-4 mm3/Nm compared to the pin material (Hastelloy X) for grade 304 stainless steel-Hastelloy X tribo-pair. At the same temperature range, the disc material (Nimonic 263) presented a higher wear coefficient of up to 2.57 x 10-5 mm3/Nm compared to the pin material for the Nimonic 263-Hastelloy X tribo-pair. The hardness was also found to have decreased to 18 % with increasing contact temperature, while the surface roughness had increased up to 19 % with an increase in time. Due to the work hardening effect, the pin material showed an increase in hardness as the contact temperature increased. Through diagnostic matching identification, the microstructural analysis of the worn samples as well as the analysis of the wear debris, it was concluded that adhesive and abrasive wear were the dominant mechanisms for the grade 304 stainless Steel-Hastelloy X tribo-pair, while abrasive and fretting wear were the dominant wear mechanisms for the Nimonic 263-Hastelloy X tribo-pair.,Master of Science
Pages:	314
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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