Fracture Resistance of 14Cr ODS Steel Exposed to a High Temperature Gas

0506817 - ÚFM 2020 RIV CH eng J - Journal Article
Hojná, A. - Michalička, J. - Hadraba, Hynek - Di Gabriele, F. - Duchon, J. - Rozumová, L. - Husák, Roman
Fracture Resistance of 14Cr ODS Steel Exposed to a High Temperature Gas.
Metals. Roč. 7, č. 12 (2017), č. článku 560. E-ISSN 2075-4701
R&D Projects: GA ČR(CZ) GA14-25246S; GA MŠMT(CZ) LQ1601
Institutional support: RVO:68081723
Keywords : ferritic alloys * behavior * microstructure * mechanisms * stability * cr * nanostructured steel * thermal aging * impact fracture * microanalysis * oxidation
OECD category: Materials engineering
Impact factor: 1.704, year: 2017
Method of publishing: Open access
https://www.mdpi.com/2075-4701/7/12/560/htm

This paper studies the impact fracture behavior of the 14%Cr Oxide Dispersion Strengthened (ODS) steel (ODM401) after high temperature exposures in helium and air in comparison to the as-received state. A steel bar was produced by mechanical alloying and hot-extrusion at 1150 degrees C. Further, it was cut into small specimens, which were consequently exposed to air or 99.9% helium in a furnace at 720 degrees C for 500 h. Impact energy transition curves are shifted towards higher temperatures after the gas exposures. The transition temperatures of the exposed states significantly increase in comparison to the as-received steel by about 40 degrees C in He and 60 degrees C in the air. Differences are discussed in terms of microstructure, surface and subsurface Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) observations. The embrittlement was explained as temperature and environmental effects resulting in a decrease of dislocation level, slight change of the particle composition and interface/grain boundary segregations, which consequently affected the nucleation of voids leading to the ductile fracture.
Permanent Link: http://hdl.handle.net/11104/0300090