Inhibited aluminization of an ODS FeCr alloy

SURFACE & COATINGS TECHNOLOGY

卷:206

Article

Put, A. Rouaix-Vande¹  Pint, B. A.¹ 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

关键词: Chemical vapor deposition;    Aluminide coatings;    ODS alloys;    Ferritic steels;    Fusion energy;   

DOI  :  10.1016/j.surfcoat.2012.05.041

来源: Elsevier

【 摘 要 】

Aluminide coatings are of interest for fusion energy applications both for compatibility with liquid Pb-Li and to form an alumina layer that acts as a tritium permeation barrier. Oxide dispersion strengthened (ODS) ferritic steels are a structural material candidate for commercial reactor concepts expected to operate above 600 degrees C. Aluminizing was conducted in a laboratory scale chemical vapor deposition reactor using accepted conditions for coating Fe- and Ni-base alloys. However, the measured mass gains on the current batch of ODS Fe-14Cr were extremely low compared to other conventional and ODS alloys. After aluminizing at two different Al activities at 900 degrees C and at 1100 degrees C, characterization showed that the ODS Fe-14Cr specimens formed a dense, primarily AIN layer that prevented Al uptake. This alloy batch contained a higher ( > 5000 ppma) N content than the other alloys coated and this is the most likely reason for the inhibited aluminization. Other factors such as the high O content, small (similar to 140 nm) grain size and Y-Ti oxide nano-clusters in ODS Fe-14Cr also could have contributed to the observed behavior. Examples of typical aluminide coatings formed on conventional and ODS Fe- and Ni-base alloys are shown for comparison. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

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