Title of article :
Correlation between Fracture Morphology and MicrostructuralEvolution during Long-Term Aging of EK61 Superalloy
Author/Authors :
Zheng, Lei School of Materials Science and Engineering - University of Science and Technology Beijing - Beijing 100083, China , Huang, Jin School of Materials Science and Engineering - University of Science and Technology Beijing - Beijing 100083, China , Xu, Guohua High-Temperature Materials Department - China Iron & Steel Research Institute Group - Beijing 100081, China , Qin, Heyong High-Temperature Materials Department - China Iron & Steel Research Institute Group - Beijing 100081, China
Abstract :
Microstructural evolutions of EK61 superalloy during long-term aging until 1000 h at 700°C and 750°C, respectively, are studied bycombination of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Impact fracturemorphologies after aging for different time are observed by the SEM. The microstructure is found to be relatively stable duringaging at 700°C, and the fracture morphologies are characterized by transgranular fracture. At 750°C, the coarsening ofγ′phaseleads the reduction of the quantity of dimples, the chainization of carbides on grain boundaries leads to intergranular fracture,and the netting ofηphases within grains leads to the formation of lamellar cleavage steps. It is obvious that the destabilizationof precipitated phases affects fracture morphology significantly. The relationship between fracture morphology and themicrostructure promotes the evaluation of service reliability of EK61 superalloy.
Keywords :
Correlation , Fracture Morphology , Microstructural Evolution , Long-Term Aging , EK61 Superalloy , Microstructural evolutions of EK61
