Corrosion of Fe₃Al-4Cr Alloys at 1000°C in N₂-0.1%H₂S Gas

Abstract

Pure Fe3Al and Fe3Al+4%Cr alloys were corroded at 1000 °C for up to 200 h in N2-0.1%H2S-mixed gas in order to study their corrosion behavior in H2S-containing atmosphere. The formed scales consisted primarily of α-Al2O3, FeAl2O4, and Fe2O3. In these oxide scales, hydrogen and sulfur dissolved according to the reaction; H2S→2H+S. Corrosion products of Cr were not identified in the scales from the XRD analysis, indicating that Cr dissolved in the oxide scales. Fe3Al+4%Cr alloy displayed poorer corrosion resistance than Fe3Al alloy, indicating that chromium accelerated the corrosion rates of Fe3Al alloys.

High-Temperature Corrosion Performance of FeAl-Based Alloys Containing Carbon in Molten Salt

“…Transition metal aluminides such as Fe, Ti, Ni, etc. are potentially more suitable alternatives to superalloys at high temperatures with applications in aggressive environmental conditions [1][2][3]. These materials show excellent resistance to corrosion, oxidation, sulfidation, and carburizing atmospheres, even at high temperatures, due to the formation of stable alumina layer [2,4].…”

The Effect of Hot Treatment on Composition and Microstructure of HVOF Iron Aluminide Coatings in Na2SO4 Molten Salts

“…Transition metal aluminides, mainly those based on Ni and Fe, are potentially applicable at high temperatures and provide a sufficient alternative to superalloys (Ref [4][5][6][8][9][10][11][12]. The alumina layer, formed on the surface of materials, is responsible for their excellent resistance to oxidizing, sulfiding and carburizing atmospheres even at temperatures exceeding 1000°C ( Ref 5,10,13).…”

“…Other HVOF and novel cold-spray coatings, such as Cr 3 C 2 -NiCr and WC-Co, are widely studied regarding their wear resistance behavior (Ref 1-3, 7, 25, 76) while great emphasis is placed upon hot corrosion-related applications. Iron aluminide intermetallics appear to provide interesting properties favorable to hot corrosion protection and also manifest wear resistance at high temperatures, providing competition to cobalt binder in WC-Co composites and Nibased superalloys ( Ref 5,6,[10][11][12]60,[77][78][79][80][81].…”