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This content will become publicly available on May 9, 2019

Title: Temperature-dependent selective oxidation processes for Ni-5Cr and Ni-4Al

The selective oxidation of Ni-5Cr and Ni-4 Al alloys is evaluated during high (800 °C) and low (420 °C) temperature exposures with the oxygen partial pressure moderated by a Ni/NiO powder buffer. Internal oxidation of Cr and Al is observed throughout the matrix and at grain boundaries at 800 °C accompanied by the ejection of Ni onto the surface for both. At 420 °C, matrix internal oxidation was eliminated and only Ni-4 Al exhibited intergranular (IG) oxidation. Surprisingly, a protective surface oxide rapidly formed for Ni-5Cr blocking IG oxidation. Finally, this is contradictory to results in 330–360 °C hydrogenated water environments where both alloys show IG oxidation.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Energy and Environment Directorate
Publication Date:
Report Number(s):
PNNL-SA-129585
Journal ID: ISSN 0010-938X; PII: S0010938X17318577
Grant/Contract Number:
AC05-76RL01830
Type:
Accepted Manuscript
Journal Name:
Corrosion Science
Additional Journal Information:
Journal Name: Corrosion Science; Journal ID: ISSN 0010-938X
Publisher:
Elsevier
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1437016