Document Type : Original Article
Engineering, Mechanical, Neyperse Company (MAPNA Group), Tehran, Iran
Project management, Neyrperse Company, Tehran, Iran
Gas turbines play a fundamental role in the power generation, marine, and aviation industries. Their blades are one of the most valuable and critical parts of this machine. Failure of blades causes serious damage in the next stages of the turbine and compressor. Also, it can cause shut down for a long time. In this paper, the failure of the third-stage blades of a GE-F6 gas turbine unit is studied and investigated using mechanical analysis and metallurgical experiments. The blades were made of
IN-738 alloy and failed during an initial operation during a test to change the fuel from natural gas to liquid fuel and caused severe damage to the turbine and turbine casing. This study includes mechanical and metallurgical experiments, stress analysis by numerical methods, and analysis of recorded data from the control system during the failure time and compared them with standard data. This data is compared to the data contained in the manufacturer's instructions during startup. This research shows that the blade failure occurred because of an interior object in the third stage of the turbine part. And this interior object has been separated from the turbine’s blades because of the poor quality of the blades’ material.