Creep Behavior of Novel Oxide Dispersion Strengthened Chromium based alloys

摘要

Novel oxide dispersion strengthened chromium-based alloys (Cr > 50 wt percent, named Ducrolloy, tradenameof Plansee AG, A-6600 Reutte, Austria) for structural parts inoxidising or aggressive atmospheres at high temperatures havebeen investigated. There are two groups of chromium-basedalloys that differ by the type of oxide layers formed: Aluminiumfree alloys like Cr-5Fe-1Y_2O_3 with chromium oxide layersand aluminium containing alloys like Cr-5Fe-5Al-0,3Ti-0,5Y_2O_3 with alumina layers. While the former alloys showan excellent oxidation resistance up to 1100 deg C, the latter canwithstand temperatures of up to 1400 deg C. The combination ofa high melting point between 1500 and 1900 deg C, a protectiveoxide layer and the particle strengthening with oxide dispersoidsof typically 20 nm diameter leads to an unique combination ofhigh strength and oxidation resistance at temperatures above theoperation range of conventional superalloys. This is shown byan assessement of the potential of these alloys with tensile andcompressive creep tests under constant strain rate conditions attwo different temperatures, namely 920 deg C for a comparisonwith the conventional superalloys and 1327 deg C revealing theperspective for high temperature applications.