0310263 - ÚFM 2009 RIV UA eng J - Journal Article
Dobeš, Ferdinand - Kratochvíl, P. - Milička, Karel
Compressive creep of Fe3Al-type iron alumide with Zr additions.
[Tlakový creep aluminidu železa typu Fe3Al s přídavkem zirkonia.]
Problemy pročnosti (Strength of Materials). -, č. 1 (2008), s. 117-120. ISSN 0556-171X.
[MSMF /5./. Brno, 27.06.2007-29.06.2007]
R&D Projects: GA ČR GA106/05/0409
Institutional research plan: CEZ:AV0Z20410507
Keywords : iron aluminides * creep * threshold stress
Subject RIV: JG - Metallurgy

High-temperature creep of a Fe3Al-type iron aluminide alloyed by zirconium was studied in the temperature range 873–1073 K. The alloy contained (wt.%) 31.5% Al, 3.5% Cr, 0.25% Zr, 0.19% C (Fe balance). It was tested in two states: (i) as received after hot rolling and (ii) heat treated (1423 K/ 2 h/air). Creep tests were performed in compression at constant load with stepwise loading: in each step, the load was changed to a new value after steady state creep rate had been established. Stress exponent and activation energy of the creep rate were determined and possible creep mechanisms were discussed in terms of the threshold stress concept. A rapid fall of the stress exponent and of the threshold stress with the increasing temperature indicates that creep is impeded by the presence of precipitates only at temperature 873 K. The results were compared with the results of long-term creep tests in tension performed recently on the same alloy.

Vysokoteplotní creep aluminidu železa typu Fe3Al legovaného zirkoniem byl studován v teplotním rozsahu 873 až 1073 K. Slitina byla studována ve dvou různých stavech: (i) po válcování za tepla a (ii) po tepelném zpracování (1423 K/2 hodiny/vzduch). Byl určen napěťový exponent a aktivační energie rychlosti creepu a možné mechanismy creepu byly diskutovány pomocí koncepce prahového napětí. Výsledky byly porovnány s výsledky dlouhodobých creepových zkoušek v tahu provedených nedávno na stejné slitině.
Permanent Link: http://hdl.handle.net/11104/0162188