High temperature oxidation of steels in CO2 containing impurities. (March 2020)

• Record Type: Journal Article
• Authors: Oleksak, Richard P.; Tylczak, Joseph H.; Holcomb, Gordon R.; Doğan, Ömer N.
• Is Part Of: Corrosion science. Volume 164(2020)
• Publication Date: 2020-03
• Subjects: A. Stainless steel -- C. High temperature corrosion -- C. Oxidation -- C. Carburization -- C. Sulfidation -- Supercritical CO2 power cycle -- Oxyfuel combustion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.108316
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Several steels were exposed to 95 % CO2, 4 % H2 O, 1 % O2 with/without 0.1 % SO2 at 550 °C and 1 atm. Low-Cr steels formed thick Fe-rich oxide scales regardless of SO2 . High-Cr steels formed thin Cr-rich oxide scales in the absence of SO2 . SO2 caused breakdown in Cr-rich oxide growth due to S in the scale. The evolving microstructure of the alloy sub-surface influenced the oxidation reaction. Abstract: Future power systems require steels that resist corrosion in high temperature CO2 containing combustion products/impurities. Here we evaluate the corrosion behavior of several commercial steels exposed to 95% CO2 -4 % H2 O-1 % O2, with/without 0.1 % SO2, at 550 °C and 1 atm. High-Cr steels formed thin Cr-rich oxides and low-Cr steels thick Fe-rich oxides during SO2 -free exposures. Additions of SO2 had little effect on low-Cr steels but enhanced corrosion of high-Cr steels, where S within the chromia scale led to its failure and subsequent Fe-rich oxide nodule growth. The results are rationalized by considering the thermodynamic and kinetic factors controlling the reaction.