International Journal of Hydrogen Energy, Vol.36, No.7, 4580-4587, 2011
High-temperature oxidation performance of a new alumina-forming Ni-Fe-Cr-Al alloy in flowing air
A new type of alumina-forming Ni-Fe-Cr Al-based alloy (HAYNES (R) HR-224 (TM) alloy) has been recently developed for aggressive oxidizing environments. This paper evaluates cyclic oxidation resistance of newly developed HR-224 alloy and its comparative performance to selected alumina- and chromia-forming heat-resistant alloys in flowing air at 982 degrees C and 871 C. The HR-224 alloy outperformed several chromia-forming alloys owing to its ability to form and maintain a continuous, slow-growing, and adherent alumina scale. In fact, results indicated that HR-224 alloy exhibits comparable oxidation resistance to one of the most oxidation resistant alumina-forming Ni-Cr-Al-based 214 (R) alloy. Moreover, in this paper, growth kinetics of alumina scale in these two alumina-forming alloys is discussed in detail. Among chromia-formers, Ni-Cr based alloys with low Fe contents exhibited excellent oxidation resistance. Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Heat-resistant alloys;Alumina- and chromia-forming alloys;Oxidation resistance;Flowing air;HR-224 alloy