Microstructure and chemical composition of the oxide scale formed on the sanicro 25 steel tubes after fireside corrosion. (January 2016)

• Record Type: Journal Article
• Authors: Rutkowski, Bogdan; Gil, Aleksander; Czyrska-Filemonowicz, Aleksandra
• Is Part Of: Corrosion science. Volume 102(2016)
• Page Start: 373
• Page End: 383
• Publication Date: 2016-01
• Subjects: A. Steel -- B. TEM -- C. Amorphous structures -- C. Fireside corrosion -- C. Internal oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2015.10.030
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Cr2 O3 scale having tens nanometer sized grains was formed on Sanicro 25 at 650 °C. M23 C6 carbides was thermodynamically unstable in Cr-depleted zone. Beneath the Cr2 O3 a layer with short-range ordering typical for glass was formed. Nanometer sized Cu-rich particles were precipitated from the austenitic matrix. Abstract: The Sanicro 25 austenitic steel is foreseen as a potential material for steam superheaters and reheaters in ultra-supercritical power plants. The aim of investigation was to characterize in detail an oxide scale grown on the Sanicro 25 tube after fireside oxidation at 650 °C. The morphology of the oxide scale and the microstructure of the bulk material were investigated using advanced electron microscopy methods. A multilayered and multicomponent oxide scale containing mainly Cr2 O3 was found on the surface exposed to combustion gases. Directly under the oxide scale, a chromium-depleted zone with no M23 C6 carbides was observed.