ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Nickel base alloys Haynes 230 and Inconel 617 are of interest for gas cooled reactors. Athigh temperature in impure helium, they generally form surface chromium-rich oxides. Howeverabove a critical temperature called TA, the scales are not stable anymore and the chromiadestruction comes with a production of carbon monoxide. Reactivity tests on model alloys, with andwithout carbon, prove that chromia is reduced by the carbon from the alloy. TA vs P(CO) curveswere also plotted for the two commercial alloys based on the experimental determination of TA invarious atmospheres with increasing partial pressures of carbon monoxide. Unexpectedly, bothmaterials exhibit an almost identical behavior although a basic equilibrium approach suggests thatthe chromia scale would be reduced in different conditions due to the thermodynamic particularityof the interfacial alloy/scale system
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.595-598.439.pdf
Permalink