Role of Cr-rich carbide precipitates in the intergranular oxidation of Ni-Cr alloys

SCRIPTA MATERIALIA

卷:156

Article

Sushko, Maria L.¹  Schreiber, Daniel K.¹  Rosso, Kevin M.¹  Bruemmer, Stephen M.¹ 

[1] Pacific Northwest Natl Lab, 902 Battelle Blvd, Richland, WA 99354 USA

关键词: Corrosion;    Oxidation;    Alloy;    Atom probe tomography;    First-principle calculation;   

DOI  :  10.1016/j.scriptamat.2018.07.016

来源: Elsevier

【 摘 要 】

The influence of grain boundary Cr carbides on the intergranular oxidation behavior of a Ni-16Cr alloy is considered using atomistic-to-mesoscale model and atom probe tomography. Cr carbide strongly perturbs the collective reactive dynamics of oxidizing species and alloy elements in the intergranular region. Strong attractive interactions between oxygen and carbide create a driving force for Cr and Ni accumulation in the grain boundary adjacent to the carbide, and for the depletion of Cr and Ni ahead of the oxidation front beyond the carbide. The results shed light on the mechanism of carbide-assisted protection of the alloy against grain boundary corrosion/oxidation. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All tights reserved.

【 授权许可】

Free