Search results for "High-temperature corrosion"
showing 4 items of 14 documents
Reactive Element (Y,Ce) Effect on Stresses Determined In-Situ during Iron Oxidation at 800°C
2001
In-situ stress determinations by X-ray diffraction have been performed during pure iron oxidation (p(O 2 ) = 2 x 10 -3 Pa, T = 800°C). On yttrium implanted specimens the stress level is close to zero before oxidation. On CeO 2 coated specimens, the initial compressive stress due to surface polishing is not modified by the coating. During oxidation, the in-situ compressive stress value determined in the Fe (1-x) O scale, is not strongly dependent upon the reactive element nature. Nevertheless, the stress evolution during cooling and residual stresses determined after cooling to room temperature are very different. Blank and CeO 2 coated specimens show relatively high compressive stresses whe…
Influence of Chlorine, Sulphur and Water Vapor on High Temperature Corrosion of Fe, Cr, Ni Alloys for Waste Incinerators
2006
The behavior of three different materials with respect to their Fe, Cr, Ni contents have been studied between 450°C and 700°C, in waste incinerators combustion conditions, where it occurs a main influence of chlorine, sulfur and water vapor. This works analyzes the behavior of these materials which depends on their capability to form melted compounds and on the nature of these melted phases. Also as the corrosion mechanism is influenced by the presence or missing of any corrosive species, the study focalizes on the specific influence of SO2 and alkaline chorine. Effect of additive ashes on the corrosion behavior of tested materials is also studied. The mechanism of corrosion in waste incine…
High Temperature Corrosion of Superheater Tubes in Waste Incinerators and Coal-Fired Plants
2004
Mechanical Stresses: Inhibitor of Catalyst of High Temperature Oxidation?
2001
Oxidation of metals is a complex reaction in which mechanical and chemical phenomena occur. A dynamic and macroscopic model is developed in order to simulate oxidation kinetics of a metal. It includes the stress/diffusion coupling in the bulk and the interfacial phenomena at metal/oxide interface. Its application to the Zr/ZrO 2 system shows the important role of stress field distribution in oxide on kinetic behavior. According to the sign of stress gradient in the oxide scale, the oxidation rate can speed up or slow down. The calculated kinetic curves could he fitted using a k p .t 1/n law where n and kp vary all over the process, like for the experimental kinetic curves.