Investigation on Grain Size Changes in Gamma Prime Precipitate on Varying Surface Location of IN738 Engine Turbine Blade

A used nickel based gas turbine blade was received and it has been previously operated for more than 52000 hours and exposed to temperature approximately 720°C. The main purpose of this project is to investigate the grain size changes in gamma prime precipitate and to identify other different phases that occurred due to the high heat exposure. A few different locations of the turbine blade have undergone SEM to obtain the SEM images for grain size measurement and also EDX the to obtain the elemental analysis. It is found that the grain size of gamma prime precipitate varies throughout the surface of the turbine blade and there is a significant difference between the leading edge and the trailing edge. There are also different types of phases present at the microstructure of the blade due to extreme exposure to the turbine blade