Metallurgical factors governing water oxidation-transpassive dissolution interplay and transpassive intergranular corrosion susceptibility of non-sensitized Ni-Fe-Cr alloys

Hariharan K, Kosanam K, Kammermeier E, Zenk C, Virtanen S (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Corrosion Science Elsevier

Book Volume: 268

Article Number: 113950

DOI: 10.1016/j.corsci.2026.113950

Abstract

This study investigates metallurgical factors influencing the interplay between oxygen evolution reaction (OER)/water oxidation and alloy dissolution as well as the intergranular corrosion (IGC) susceptibility of Ni-Cr-Fe corrosion-resistant alloys (Alloy 600, Alloy 800 and model Ni-15Cr-10Fe) in 0.1 M K2SO4 (pH = 5) at transpassive potentials. The total anodic charge passed is fully accounted by the transpassive dissolution in Alloy 600, against only 50% accounting for dissolution in Alloy 800. In fact, Alloy 800 suffered 6 times lower dissolution than Alloy 600 under the same electrochemical conditions. In terms of localized corrosion, Alloy 600 suffers from severe IGC and grain-fallout, while Alloy 800 experiences lower IGC resisting grain-fallout. While the lower overall dissolution in Alloy 800 is explained by secondary passivation due to higher Fe content, IGC seems to be strongly influenced by special grain boundaries (GBs) and their interconnectivity. The fraction of special GBs (Σ ≤ 29) and resistant triple junctions increase between Alloy 600 and Alloy 800, coinciding with decreasing IGC susceptibility. Further analysis on model Ni-15Cr-10Fe alloy under two different heat treatments revealed that the interconnectivity of special GBs had a greater influence in governing the transpassive IGC than the absolute special GB fraction, at a fixed Fe content.

Authors with CRIS profile

Koushik Kosanam Professur für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) Elisabeth Kammermeier Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle) (WTM) Christopher Zenk Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle) (WTM) Sannakaisa Virtanen Professur für Werkstoffwissenschaften (Korrosion und Oberflächentechnik)

Involved external institutions

Indian Institute of Technology Bombay IN India (IN)

How to cite

APA:

Hariharan, K., Kosanam, K., Kammermeier, E., Zenk, C., & Virtanen, S. (2026). Metallurgical factors governing water oxidation-transpassive dissolution interplay and transpassive intergranular corrosion susceptibility of non-sensitized Ni-Fe-Cr alloys. Corrosion Science, 268. https://doi.org/10.1016/j.corsci.2026.113950

MLA:

Hariharan, Karthikeyan, et al. "Metallurgical factors governing water oxidation-transpassive dissolution interplay and transpassive intergranular corrosion susceptibility of non-sensitized Ni-Fe-Cr alloys." Corrosion Science 268 (2026).

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