ISSN:
1573-4889
Schlagwort(e):
eutectic alloys
;
hot corrosion
;
alumina-formers
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
Notizen:
Abstract The hot-corrosion resistance of two γ/γ′-δ eutectic alloys, Ni-23.1 Nb-4.4 Al and Ni-19.7Nb-6Cr-2.5 Al, has been studied using three techniques: (1) a salt-coated test, in which the specimens are coated with a thin layer of Na2SO4 and oxidized; (2) the Dean rig test, in which salt is evaporated into the gas stream and allowed to condense continuously on the specimen; and (3) a sulfidation/oxidation test, in which the specimens were presulfidized for a short time in a H2/H2S mixture and then oxidized. The salt-coated test suggested that these alloys are generally quite resistant to sodium-sulfateinduced corrosion, although localized severe attack was sometimes encountered. The morphology of the corrosion products suggested that the mechanism of the attack was sulfidation/oxidation, and that salt fluxing mechanisms were relatively unimportant. In the Dean rig test it was shown that sodium chloride greatly increased the severity of attack, as has been shown earlier for alumina-forming superalloys.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00616101
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