STUDIES ON TRANSIENT-STAGE-SCALE GROWTH ON Fe-22wt.% Cr ALLOYS CONTAINING 120 PPM La + 270 PPM Ce
نویسندگان
چکیده
Reactive elements (RE), such as Ce, La or Y, are known to improve oxidation resistance of Fe based alloys that form Cr2O3 scales. The current investigation aims to characterize the oxide scale in a Fe-22 wt.% Cr alloy containing 120 ppm La and 270 ppm Ce (added during melt-stage processing) as a function of oxidation times (at 800°C in dry air) during the transient stage of scale formation. The surface oxidation processes were imaged in-situ through a Confocal Scanning Laser Microscope (CSLM). The results are correlated with post-experiment characterization through FEG-SEM and dual beam FIB-SEM. The evolution of the reactiveelements-containing scale, its morphology and composition are determined.
منابع مشابه
An Electron Microscopy Investigation of the Transient Stage Oxidation Products in an Fe-22Cr Alloy with Ce and La Additions Exposed to Dry Air at 1073 K (800 C)
In this study, the effects of Ce (270 ppm) and La (120 ppm) mischmetal additions on the transient oxidation of an Fe-22Cr alloy were investigated. The oxidation process was imaged in situ using a confocal scanning laser microscope. The oxidation microstructures were studied by scanning electron microscopy, energy dispersive X-ray analysis, and transmission electron microscopy with the help of f...
متن کاملEffect of surface-applied reactive elements on the early stage oxidation of Fe- 18Cr-5Al and Fe-18Cr-5Al-1Hf alloys
The effect of lanthanum implantation on the early stage oxidation of Fe-18wt%Cr5wt%Al and Fe-l8wt%Cr-5wt%Al-Iwt%Hf alloys at 1100 OC has been investigated. I t was found that the reactive element enriched surfaces oxidized almost two times faster initially, and the scale that formed had a higher iron content. An extremely wavy scale/alloy interface developed in the early stage due to the accele...
متن کاملCorrosion of chromium containing alloys in non-steady state environments containing oxygen, carbon, and chlorine
Internal attack of chromium containing alloys in mixed oxygen-chlorine environments occurs by the formation of pores which penetrate down grain boundaries of the alloys. No internal attack was detected in a binary Fe-20 %Cr alloy at 1200 K in environments containing 2500 ppm C12. The rate of internal attack of alloy 800H in such environments was increased by replacing the O2 in the gas by C02 ....
متن کاملNew Creep-Resistant Cast Alloys with Improved Oxidation Resistance in Water Vapor at 650–800°C
Cast stainless steel CF8C-Plus (19wt%Cr/12%Ni) has excellent creep properties, but limited oxidation resistance above 700°C in environments containing H2O. One strategy to improve the alloy oxidation performance is to increase the Cr and Ni concentration. Two new alloys, with, respectively, 21wt%Cr–15wt%Ni and 22wt%Cr–17.5wt%Ni were therefore developed and their long-term oxidation behaviors in...
متن کاملThe Effect of the Third Element Cr on Oxidation Behavior of Fe - x Cr - 10 Al ( at . % ) Alloys at 900 o C
Alloys Fe-(0, 5, 10)Cr-10Al (all in at.%) were oxidized at 900 o C in 1 atm oxygen to study the effect of Cr additions on the oxidation behavior. The oxidation kinetics was recorded with a thermal microbalance. The morphologies and microstructures of the oxide scales were examined using SEM, EDS, and XRD. Fe-10Al developed an Al2O3-rich scale during the initial stage of oxidation, and a non-pro...
متن کامل