Nickel-base superalloys, strengthened by the ´ phase dispersion, presents the typical precipitation strengthened alloys. In creep testing conditions, particles of secondary phase can be effectively blocks of dislocations movement at high temperatures as well. However, particles must be sufficiently stable with respect to coalescence, it means the average distance between them increases very slowly during creep. The aim of this work is the study of structural changes of the material Inconel 7I3 LC by image analysis. It is focused on short-time creep tests at temperatures 850°C and 950°C.
Po ukončeni provozu oběžných lopatek plynove turbiny z lité superslitiny ŽS6K byly sledovany změny ve struktuře. Degradace struktury byla sledovana pomoci svetelné a elektsonové mikroskopie. Nežádouci faze &sigma vyskytující se v matrici slitiny byla zjištěna EDS a EBDS analýzou.
EN
Blades made of cast Ni base superalloy ZHS6K after service in gas turbine were analyzed with the aim to characterize changes in structure. Structure degradation was analysed by light and electron microscopy. Harmful phase a was detected in matrix by EDS and ESBD analysis.
In the working conditions of the jet engines gas turbines of supersonic plane blades are loaded by the cycles, this process is the function of the time, temperature and stress. The blade are exposed to influence of degradable processes namely of the high-temperature corrosion, fatigue process and creep. As the result of short overloading as it happens for instance during the starts and landing, eventually in some other irregularities of the jet engine function, the increase of stress and temperature leads to the changes of microstructure and properties. The presented work is aimed at the study of structural changes of the material Inconel 7I3 LC subjected to short-time creep tests at s = 180 MPa and temperature 900°C and after air traffic. The thesis is a part of a complex project aimed at study of mechanical-structural characteristics of the polycrystalline nickel-base super alloy.