Sulfur Effect on Corrosion Behavior of Fe-20Cr-(Mn, Si) and Fe-20Ni-20Cr-(Mn, Si) in CO₂-H₂O at 650°C

Abstract

Model alloys, , and these alloys doped with 0.5% Si or 2% Mn, were exposed to Ar-20%CO 2 -20%H 2 O-(0%, 0.1%, 0.5%, 1.0%)SO 2 gas mixtures at 650 • C. The reaction kinetics were analyzed gravimetrically and the reaction products were characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. In sulfurfree gases, thick iron-rich oxide scales and internal carbides formed on alloys of Fe-20Cr-(2Mn) and Fe-20Cr-20Ni-(0.5Si). Additions of SO 2 promoted the maintenance of protective chromia scale on these alloys, but had no benefit for the already highly corrosion resistant Fe-20Cr-0.5Si and Fe-20Cr-20Ni-2Mn alloys. The role of sulfur in retarding carburization is discussed with reference to its strong adsorption on oxide-metal interfaces and oxide grain boundaries.

Effect of pressure and impurities on oxidation in supercritical CO2

“…In these experiments, the addition of H 2 O resulted in much faster oxidation rates, especially for Fe‐base alloys . The addition of O 2 showed both positive and negative effects as has the addition of SO 2 . At high pressure, O 2 additions have shown slightly negative effects or little effect .…”

“…Considerable testing has been conducted at ambient pressure in CO 2 with and without H 2 O, O 2 and SO 2 additions to support a variety of technologies including fuel cells, oxy‐combustion of coal and the direct‐fired sCO 2 cycle . In these experiments, the addition of H 2 O resulted in much faster oxidation rates, especially for Fe‐base alloys .…”

Corrosion by Hot CO2 Gases

“…As a result, carbon penetration via oxide grain boundary is retarded, as is carburization. [38][39][40] It was found 40 that adding only 0.1%SO 2 reduced the carburization kinetics of Fe-9Cr-0.5Si alloy significantly (Fig. 7a).…”

Formation of Nanoscale Al2O3 Protective Layer by Preheating Treatment for Improving Corrosion Resistance of Dilute Fe-Al Alloys

“…Numerous reports on tons of pollutants caused by alloying [9,10], electroplating [11][12][13] and protective painting [14,15] that cause serious damage to the environment are available. Due to the lack of a better alternative (so far), most commonly, the resistance to the oxidation and electrochemical corrosion of Fe is increased by adding high ratios of Cr and Ni [5,6,[16][17][18] which are expensive, and which also have a negative impact on the plasticity of ferroalloys [19].…”