Remelting of Nickael Based Superalloy (IN738LC) and its Effect on the Physical Metallurgy and Microstructure

Please enable javascript in your browser.

Rezaee Ardani, Mohammad Reza | 2010

724 Viewed

Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 41017 (07)
University: Sharif University of Technology
Department: Materials Science and Engineering
Advisor(s): Yoozbashizadeh, Hossein
Abstract:
Well worn gas turbine blade made of Nickel based superalloy, IN738LC was remelted due to remove inclusion and use it in casting process of new blade after microstrucrure investigation in neutral atmosphere and vacuum. The composition of slags for removing inclusions used for this practice were 70CaF2-20CaO-10Al2O3 and 55CaO-45Al2O3. The microstructural characterization involved use both optical as well as electron microscope including application of EDS technique for denoted the type of carbides and inclusion investigation. Chemical composition was determined by despersive spectroscopy method. The changing in main elements were reported too low. Number of inclusions were decreased in the remelted samples in vacuum and after that in the neutral atmosphere. the increasing in hardness caused by formation of a continuous films of M23C6 and M6C carbides in grain boundaries due to transformation of MC carbides in high temperatures
Keywords:
Gas Turbine Blades ; Nickel-Base Superalloy ; Electroslag Refining ; Inclusion Removal

No TOC