Oxidation of mild and low-alloy steels in CO2 based atmospheres

Corrosion of 9Cr Steel in CO2 at Intermediate Temperature II: Mechanism of Carburization

“…Its traceability through the steel surface could indicate if it is in good agreement with the proposed void-induced oxidation mechanism [1]. Moreover, it has been shown in the past, that carburization could be at the origin of a catastrophic phenomenon occurring on mild steel and 9-12 Cr steel called ''breakaway oxidation'' [2][3][4][5]. For this reason, the following of the carbon transfer into the steel as a function of time and as a function of experimental conditions such as the total pressure of CO 2 is of interest.…”

“…This phenomenon could occur either by slow desorption of CO after oxidation or by a build-up of CO(g) in open pores. Antill et al [3] have demonstrated that, with pure iron and Fe 3 O 4 at 500°C, among reactions (4) and (5), this is the Boudouard reaction (5) which is kinetically predominant. Even if chromium in our alloy could influence the first reaction in delaying the CO desorption, the scenario of a CO build-up in pores at the oxide/metal interface followed by the Boudouard reaction is in perfect agreement with the void-induced duplex oxide formation exposed in [1].…”

The challenge in understanding the corrosion mechanisms under oxyfuel combustion conditions

“…Achievement of the Boudouard equilibrium in a flawy and porous scale formed on steel in an oxyfuel power plant is not probable because of high water and oxygen concentrations. Anthill et al (1968) described the corrosion of pure Fe and low alloyed steels in dry CO 2 and with 2.2 vol% water at temperatures below 500 • C and total pressures between 1 and 20 atm. In dry CO 2 at 1 atm all materials formed a protective magnetite layer according to Surman (1973).…”

The Oxidation of Ferritic Stainless Steels in Simulated Solid-Oxide Fuel-Cell Atmospheres

“…Outer layers containing Fe and Mn have been known to form on stainless steels for many years. 25 This is somewhat remarkable since the steel usually only contain about 1% Mn. The high mobility of Mn ions in chromia is also in agreement with theoretical studies.…”