Original title:
The effect of σ-phase formation on long-term durability of SUPER 304H steel
Authors:
Horváth, J. ; Král, Petr ; Janovec, J. ; Sklenička, Václav Document type: Papers Conference/Event: METAL 2015 - International Conference on Metallurgy and Materials /24./, Brno (CZ), 20160603
Year:
2015
Language:
eng Abstract:
This work presents results of the analysis of phases formed in a SUPER 304H steel during a medium-term static isothermal ageing (675 degrees C/15000 h). The investigations of the precipitates were especially focused on the occurrence of sigma-phase because its formation leads to the serious embrittlement. \nThe evaluation and distribution of brittle sigma-phase were determined on macroscopic level by using light microscopy/colour etching. The microstructure was also investigated on microscopic level by scanning electron microscopes Tescan Lyra 3 and JEOL JSM 5410 equipped by electron backscatter diffraction unit and by transmission electron microscope Jeol 2100F. This work also investigates the effect of sigma-phase formation on the impact strength of an aged state of SUPER 304H steel. For comparison reasons the microstructure and the mechanical properties of the initial as-received) state were also investigated. It was found that the formation of brittle sigma-phase in the aged and therefore degraded microstructure led to the significant decrease of the impact strength. The influence of brittle sigma-phase on long-term durability of the degraded steel regarding its insufficient impact strength is discussed.
Keywords:
austenitic steel; impact strength; medium-term ageing; sigma-phase; SUPER 304H Host item entry: METAL 2015: 24th International Conference on Metallurgy and Materials, Conference Proceedings, ISBN 978-80-87294-62-8
Institution: Institute of Physics of Materials AS ČR
(web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences. Original record: http://hdl.handle.net/11104/0270132