High-temperature corrosion of Inconel (R) Alloy 718, Haynes (R) 282 (R) Alloy and CoWAlloy1&2 in supercritical ammonia/ammonium chloride solutio

Journal article


Publication Details

Author(s): Kimmel AC, Malkowski TF, Griffiths S, Hertweck B, Steigerwald T, Freund L, Neumeier S, Göken M, Speck JS, Schlücker E
Journal: Journal of Crystal Growth
Publisher: ELSEVIER SCIENCE BV
Publication year: 2018
Volume: 498
Pages range: 289-300
ISSN: 0022-0248


Abstract

Corrosion of process equipment during ammonothermal synthesis at high temperature and pressure is still one of the big limitations of this process because of reduced crystal quality and safety issues. In this paper we present preliminary ammonothermal corrosion experiments with two Ni-base superalloys (Inconel (R) Alloy 718 and Haynes (R) 282 (R) Alloy) and two newly developed Co-base superalloys (CoWAlloy1&2) in a supercritical NH3/NH4Cl-solution (24 h/550 degrees C/105 MPa). After the experiment, the samples were analyzed by their mass change per initial surface area (specific weight change). Additionally, the morphological and elemental changes of the corrosion layers were evaluated. None of the investigated alloys developed a passivation layer and the corrosion layers were very fragile. In agreement with previous studies, the Ni-base alloys showed intergranular attack with severe general corrosive degeneration. Despite their high potential for high-pressure at high-temperature applications and in contrast to a ternary Co-Al-W-alloy, the investigated multinary Co-base alloys were strongly attacked, too. However, CoWAlloy2 presented the lowest specific weight change of the investigated alloys. Thus, it shows the best potential for application in acidic environment of the investigated alloys. Additionally, CoWAlloy2 proved good stability in a supercritical NH3/Na-solution (24 h/550 degrees C/93 MPa).


FAU Authors / FAU Editors

Freund, Lisa
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Göken, Mathias Prof. Dr.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Hertweck, Benjamin
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Kimmel, Anna-Carina
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Neumeier, Steffen Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Schlücker, Eberhard Prof. Dr.-Ing.
Lehrstuhl für Prozessmaschinen und Anlagentechnik
Steigerwald, Thomas
Lehrstuhl für Prozessmaschinen und Anlagentechnik


External institutions
University of California


How to cite

APA:
Kimmel, A.-C., Malkowski, T.F., Griffiths, S., Hertweck, B., Steigerwald, T., Freund, L.,... Schlücker, E. (2018). High-temperature corrosion of Inconel (R) Alloy 718, Haynes (R) 282 (R) Alloy and CoWAlloy1&2 in supercritical ammonia/ammonium chloride solutio. Journal of Crystal Growth, 498, 289-300. https://dx.doi.org/10.1016/j.jcrysgro.2018.06.018

MLA:
Kimmel, Anna-Carina, et al. "High-temperature corrosion of Inconel (R) Alloy 718, Haynes (R) 282 (R) Alloy and CoWAlloy1&2 in supercritical ammonia/ammonium chloride solutio." Journal of Crystal Growth 498 (2018): 289-300.

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Last updated on 2019-06-01 at 12:10

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