Thermodynamic modeling of oxidation of Al–Cr–Ni alloys

High Temperature Corrosion Resistance of Pt-Based Superalloys in 0.2% SO2-N2 Gas

“…The Raman peak at 981 cm -1 wavenumber is due to the symmetric stretching mode, whilst the Raman peak at 1051 cm -1 is as a result of the asymmetric stretching mode [30]. A broad peak at approximately 840cm -1 wavenumber is believed to be due to molecular vibrations of SO 4 2-ions. Co 3 O 4 was detected on the surface of the two Co-containing alloys, Alloy P420 and Alloy P421.…”

“…Two prominent peaks that are similar to all the investigated alloys occur within the 1026-1032cm -1 and 1048-1062cm -1 ranges. The peaks were assigned to molecular vibrations of SO 4 2-ions. Sulphates form prints in the 900-1250cm -1 and 570-680 cm -1 range.…”

“…Early age gas turbine engines were designed to operate at 700ºC. Improvements in metallurgical processes, from vacuum casting, through to single crystal casting, advanced cooling and application of coatings, all contributed towards increasing working temperatures [3][4][5][6]. The continued improvements in the aerospace gas turbine industry subsequently also benefited the land based gas turbine industry [7], and currently land based turbines are fast approaching the efficiencies achieved in the aerospace engines.…”

“…Today's gas turbines are operating at 1100ºC. In addition, there is a demand to further increase the working temperatures to 1350°C [4]. Increases in inlet gas turbine temperatures benefit the gas turbine industry by allowing for improved efficiencies, reduction in fuel consumption and a greener environment, because of a reduction in the levels of CO 2 and hydrocarbon emissions [8,9].…”

Combined experiment and first-principles study of the formation of the Al2O3 layer in alumina-forming austenitic stainless steel

“…1 The excellent oxidation stability of the stainless steel is closely related to the formation of the thermodynamically stable oxide layer, restraining the diffusion of the metal atoms from the matrix and slowing the oxidation rate. [2][3][4] As the common oxide layers, the Cr 2 O 3 -based protective scale can prevent stainless steels from oxidizing in hightemperature applications. However, such scale will be destroyed under water-steam environment when the service temperature is higher than 650 C because of the formation of volatile Cr x (OH) y species, thus losing its protective role and causing the failure of the stainless steels.…”