Microstructure and Creep Behavior of Fe-27Al-1Nb Alloys with Added Carbon

0448406 - ÚFM 2016 RIV US eng J - Článek v odborném periodiku
Dobeš, Ferdinand - Kratochvíl, P. - Pešička, J. - Vodičková, V.
Microstructure and Creep Behavior of Fe-27Al-1Nb Alloys with Added Carbon.
Metallurgical and Materials Transactions A. Roč. 46, č. 4 (2015), s. 1580-1587. ISSN 1073-5623. E-ISSN 1543-1940
Grant CEP: GA ČR(CZ) GAP108/12/1452
Institucionální podpora: RVO:68081723
Klíčová slova: creep * iron aluminides * threshold stress
Kód oboru RIV: JG - Hutnictví, kovové materiály
Impakt faktor: 1.749, rok: 2015

The effect of Nb and C additions on the phase composition, microstructure, and creep resistance of Fe3Al-type alloys is investigated. Two alloys, which contained (at. pct) (i) 27.6 Al, 1.15 Nb and 0.19 C (Fe balance) and (ii) 27.1 Al, 1.11 Nb, and 0.76 C (Fe balance), were studied in a temperature range from 873 K to 1073 K. The carbide in both alloys was identified as Nb6C5. The creep data can be rationalized by introducing a threshold stress, below which, the creep rate is negligible. The threshold stress and an effective stress exponent were found simultaneously by a numerical method. Using the obtained values of the threshold stress, the activation energy of creep was determined to be 328 kJ/mol. The effective stress exponent varied from 2.0 to 3.1. A breakdown of power-law behavior was observed at higher stresses.
Trvalý link: http://hdl.handle.net/11104/0250168