Comparison of the high-temperature chloride-induced corrosion between duplex steel and Ni based alloy in presence of H2S. (15th July 2018)

• Record Type: Journal Article
• Authors: Schmid, Alexander; Mori, Gregor; Hönig, Stefan; Weil, Matthias; Strobl, Susanne; Haubner, Roland
• Is Part Of: Corrosion science. Volume 139(2018)
• Page Start: 76
• Page End: 82
• Publication Date: 2018-07-15
• Subjects: High temperature corrosion -- Steel -- Ni based alloy -- Hydrogen sulphide -- Hydrogen chloride; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.04.042
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: High temperature corrosion of Duplex steel and nickel based alloy in HCl and H2 S atmosphere. Testing gas atmosphere without HCl is hardly corrosive at 680 °C. Layered structure of the corrosion products was observed. Nickel is a beneficial alloying element in this gas atmosphere, iron is detrimental. Abstract: Duplex steel 1.4462 and Ni-based alloy Centralloy ET45 micro were tested in HCl- and H2 S-containing atmospheres at 680 °C for 24, 72 and 240 h. Corroded samples were investigated by metallography, SEM/EDX and XRD. Corrosion products on the surface consisted of Cr2 O3 and chromium sulfides. Beneath this surface layer, iron and chromium chloride were found. A depletion of iron was observed due to formation of volatile iron chloride. Both materials displayed a selective attack of the existing phases. The ferrite phase of the Duplex steel was attacked, while the Ni-based alloy showed the selective attack of chromium carbides.