Filtern
Erscheinungsjahr
- 2018 (1)
Dokumenttyp
Sprache
- Englisch (1)
Referierte Publikation
- ja (1)
Schlagworte
- High temperature corrosion (1)
- In situ diffraction (1)
- Sulfidation (1)
Organisationseinheit der BAM
Insights into early damage mechanisms during high-temperature gas corrosion provide important aspects for the prediction of the long-term stability of hightemperature materials exposed to a hot and corrosive environment. The current work presents a real time study concerning the combined oxidation and sulfidation of ferritic model alloys in a hot SO2 containing atmosphere using energy dispersive X-ray diffraction. The applied high temperature reactor allows the transmittance of high energetic X-rays in order to collect X-ray diffraction pattern of the sample surface in situ during the reaction with the reactive environment. The results revealed that the first phases crystallizing on iron with 2 wt% chromium and with 9 wt% chromium are oxides. The aging experiments at T = 650° C with 0.5% SO2 and 99.5% Ar were followed in situ and caused an external mixed oxide-sulfide layer on top of iron with 2 wt% chromium. On the higher alloyed material the external scale consists of iron oxides and the inner scale of mixed (Fe,Cr)-oxides and chromium-sulfides. The oxide content continuously increases parallel to an increase of the sulfide amount. Thus, the initially formed (Fe,Cr)-oxides do not have a protective character and support the transport of sulfur through the growing oxide scale.