Metallurgical Failure Investigation of Combustion Chamber Leakage in a Heavy-duty Gas Turbine Engine

In this contribution, a case study is presented describing the failure of a combustion chamber assembly in a non-OEM (Original Equipment Manufacturer) gas turbine engine used for power generation. It showed how even advanced fabrication methods, such as Electron Beam (EB) welding, could trigger fatigue fracture, even if there are no material defects, no weld imperfections, no fabrication flaws, and even if everything is within specified limits. As is so often the case in component failures, the fact that failures occur anyway, despite the absence of out-of-spec material properties, and even though there were no fabrication flaws, is attributable to the design; which is often not sturdy enough to withstand unexpected dynamic loading.