Investigating the transport mechanisms governing the oxidation of Hastelloy BC-1 by in situ ToF-SIMS. (October 2019)

• Record Type: Journal Article
• Authors: Henderson, Jeffrey D.; Seyeux, Antoine; Zanna, Sandrine; Biesinger, Mark C.; Shoesmith, David W.; Noël, James J.; Marcus, Philippe
• Is Part Of: Corrosion science. Volume 159(2019)
• Publication Date: 2019-10
• Subjects: Hastelloy BC-1 -- Superalloy -- Oxidation -- Solid-state ion transport -- Isotopic labelling -- In situ -- ToF-SIMS -- XPS; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.108138
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The air-formed oxide on Hastelloy BC-1 contained Cr- and Mo- rich regions in the inner and outer oxide, respectively. Empirical evidence shows O atom incorporation at the outer interfaces of both the Cr- and Mo-rich regions of the oxide. Heating the air-formed oxide to 300 °C did not increase its thickness, but, further heating to 500 °C led to the thickening. In all cases, temperature increases induced structural modification to the oxides which then reverted during oxidation. Abstract: This paper presents insight into the structure and transport mechanisms involved in the surface oxidation of Hastelloy BC-1, gained by means of in situ time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The native, air-formed oxide, comprising Cr-rich (inner) and Mo-rich (outer) layers, was found to be on the order of 1–2 nm thick. Oxide thickness did not change when the temperature was increased to 300 °C in oxygen atmosphere but increased to ˜10 nm after exposure at 500 °C. The mechanisms of oxide growth/maintenance as well as observations on the effect of elevated temperatures on oxide structure are discussed.