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Effect of thermal exposure on microstructure and nano-hardness of broached Inconel 718

Chen, Zhe; Peng, Ru Lin; Avdovic, Pajazit; Zhou, Jinming LU ; Moverare, Johan; Karlsson, Fredrik and Johansson, Sten (2014) 2nd European Symposium on Superalloys and their Applications In Eurosuperalloys 2014 - 2nd European Symposium on Superalloys and their Applications 14. p.08002-08002
Abstract
Inconel 718 is a high strength, heat resistant superalloy that is used extensively for components in hot sections of gas turbine engines. This paper presents an experimental study on the thermal stability of broached Inconel 718 in terms of microstructure and nano-hardness. The broaching process used in this study is similar to that used in gas turbine industries for machining fir-tree root fixings on turbine discs. Severe plastic deformation was found under the broached surface. The plastic deformation induces a work-hardened layer in the subsurface region with a thickness of similar to 50 mu m. Thermal exposure was conducted at two temperatures, 550 degrees C and 650 degrees C respectively, for 300 h. Recrystallization occurs in the... (More)
Inconel 718 is a high strength, heat resistant superalloy that is used extensively for components in hot sections of gas turbine engines. This paper presents an experimental study on the thermal stability of broached Inconel 718 in terms of microstructure and nano-hardness. The broaching process used in this study is similar to that used in gas turbine industries for machining fir-tree root fixings on turbine discs. Severe plastic deformation was found under the broached surface. The plastic deformation induces a work-hardened layer in the subsurface region with a thickness of similar to 50 mu m. Thermal exposure was conducted at two temperatures, 550 degrees C and 650 degrees C respectively, for 300 h. Recrystallization occurs in the surface layer during thermal exposure at 550 degrees C and alpha-Cr precipitates as a consequence of the growth of recrystallized delta phases. More recrystallized grains with a larger size form in the surface layer and the alpha-Cr not only precipitates in the surface layer, but also in the sub-surface region when the thermal exposure temperature goes up to 650 degrees C. The thermal exposure leads to an increase in nano-hardness both in the work-hardened layer and in the bulk material due to the coarsening of the main strengthening phase gamma ''. (Less)
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author
organization
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Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Eurosuperalloys 2014 - 2nd European Symposium on Superalloys and their Applications
volume
14
pages
08002 - 08002
publisher
EDP Sciences
conference name
2nd European Symposium on Superalloys and their Applications
external identifiers
  • wos:000351930400024
  • scopus:84906910411
ISSN
2261-236X
DOI
10.1051/matecconf/20141408002
language
English
LU publication?
yes
id
bb125ed9-45a8-4a6b-8cfc-4911e0d74d80 (old id 5281706)
date added to LUP
2015-04-24 11:56:11
date last changed
2017-11-05 04:09:42
@inproceedings{bb125ed9-45a8-4a6b-8cfc-4911e0d74d80,
  abstract     = {Inconel 718 is a high strength, heat resistant superalloy that is used extensively for components in hot sections of gas turbine engines. This paper presents an experimental study on the thermal stability of broached Inconel 718 in terms of microstructure and nano-hardness. The broaching process used in this study is similar to that used in gas turbine industries for machining fir-tree root fixings on turbine discs. Severe plastic deformation was found under the broached surface. The plastic deformation induces a work-hardened layer in the subsurface region with a thickness of similar to 50 mu m. Thermal exposure was conducted at two temperatures, 550 degrees C and 650 degrees C respectively, for 300 h. Recrystallization occurs in the surface layer during thermal exposure at 550 degrees C and alpha-Cr precipitates as a consequence of the growth of recrystallized delta phases. More recrystallized grains with a larger size form in the surface layer and the alpha-Cr not only precipitates in the surface layer, but also in the sub-surface region when the thermal exposure temperature goes up to 650 degrees C. The thermal exposure leads to an increase in nano-hardness both in the work-hardened layer and in the bulk material due to the coarsening of the main strengthening phase gamma ''.},
  author       = {Chen, Zhe and Peng, Ru Lin and Avdovic, Pajazit and Zhou, Jinming and Moverare, Johan and Karlsson, Fredrik and Johansson, Sten},
  booktitle    = {Eurosuperalloys 2014 - 2nd European Symposium on Superalloys and their Applications},
  issn         = {2261-236X},
  language     = {eng},
  pages        = {08002--08002},
  publisher    = {EDP Sciences},
  title        = {Effect of thermal exposure on microstructure and nano-hardness of broached Inconel 718},
  url          = {http://dx.doi.org/10.1051/matecconf/20141408002},
  volume       = {14},
  year         = {2014},
}